Fullscreen HTML5Med Res (??MB)HTML4

SILICON CHIP JANUARY 2010 ISSN 1030-2662 1030-2662 ISSN 11 01 9 771030 771030 266001 266001 9 PRINT POST APPROVED - PP255003/01272 8 METEOROLOGY’s NEW DOPPLER RADAR: $ 95* NZ $ 11 00 INC GST INC GST YOU can BE the weatherman! PLUS: ScreenScope: bargain digital scope Temperature logger and controller AND . . . GPS CAR COMPUTER siliconchip.com.au Us e it on its own . . . or with a laptop and mapping software! January 2010  1 SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.jaycar.com.au Contents Vol.23, No.1; January 2010 SILICON CHIP www.siliconchip.com.au Features 12 The Automatic Identification System (AIS) In The Pilbara We counted over 200 ships off the Pilbara using AIS from several thousand kilometres away – by Stan Swan 16 Review: ScreenScope SSC-A531 Digital Scope Just add a USB mouse and a monitor and you’ve got a full-featured 50MHz 2-channel digital scope (and it costs just $539) – by Mauro Grassi 21 The Bureau Of Meteorology’s New Doppler Weather Radar It’s the latest in the Bureau of Meteorology’s weather radar upgrades and you can view its images via the ’net – by Ross Tester Pro jects To Build ScreenScope SSC-A531: A FullFeatured Digital Oscilloscope For Less Than $540.00! – Page 16. 28 A Multi-Function GPS Car Computer, Pt.1 Compact unit boasts a digital speedometer, over-speed alarm, fuel economy meter and a GPS clock. It also indicates the time & distance to destination, altitude, current latitude & longitude and more – by Geoff Graham 42 A Balanced Output Board For The Stereo DAC Simple add-on board adds a pair of balanced outputs with XLR connectors to the High-Quality Stereo DAC – by Nicholas Vinen 62 Precision Temperature Logger & Controller, Pt.1 New design provides precise temperature logging for up to 12 hours & can control a 230V heater at up to 10A. The accuracy is 0.1% (excluding probe error) & it interfaces to a PC for control & programming – by Leonid Lerner Multi-Function GPS Car Computer – Page 28. 78 Voltage Interceptor For Cars With ECUs, Pt.2 Pt.2 this month has the full assembly details for both the main unit & the Pushbutton Controller which is used for programming. There are also full details on installing & using the device – by John Clarke 85 WIB: Web Server In A Box, Pt.3 Final article looks at customising the WIB to meet your own requirements, describes how dynamic content is achieved and gives an example FTP session – by Mauro Grassi Special Columns 58 Serviceman’s Log Ever a sucker for punishment – by the Serviceman 68 Circuit Notebook (1) PICAXE-Controlled Slow-Down For DCC Model Trains; (2) Simple Battery Tester; (3) Bathroom Fan Timer Has Single Switch Operation; (4) Using An Old Mobile Phone Battery To Power A LED Torch; (5) PICAXE Digital Clock Balanced Output Board For The Stereo DAC – Page 42. 88 Vintage Radio The impressive STC Capehart A8551 radiogram – by Rodney Champness Departments   2   4 57 67 Publisher’s Letter Mailbag Product Showcase Order Form siliconchip.com.au 94 98 101 102 Back Issues Ask Silicon Chip Notes & Errata Market Centre Precision Temperature Logger & Controller – Page 62. January 2010  1 SILICON SILIC CHIP www.siliconchip.com.au Publisher & Editor-in-Chief Leo Simpson, B.Bus., FAICD Production Manager Greg Swain, B.Sc. (Hons.) Technical Editor John Clarke, B.E.(Elec.) Technical Staff Ross Tester Jim Rowe, B.A., B.Sc Mauro Grassi, B.Sc. (Hons), Ph.D Photography Ross Tester Reader Services Ann Morris Advertising Enquiries Glyn Smith Phone (02) 9939 3295 Mobile 0431 792 293 glyn<at>siliconchip.com.au Regular Contributors Brendan Akhurst Rodney Champness, VK3UG Mike Sheriff, B.Sc, VK2YFK Stan Swan SILICON CHIP is published 12 times a year by Silicon Chip Publications Pty Ltd. ACN 003 205 490. ABN 49 003 205 490. All material is copyright ©. No part of this publication may be reproduced without the written consent of the publisher. Printing: Hannanprint, Noble Park, Victoria. Distribution: Network Distribution Company. Subscription rates: $94.50 per year in Australia. For overseas rates, see the order form in this issue. Editorial office: Unit 1, 234 Harbord Rd, Brookvale, NSW 2100. Postal address: PO Box 139, Collaroy Beach, NSW 2097. Phone (02) 9939 3295. Fax (02) 9939 2648. E-mail: silicon<at>siliconchip.com.au ISSN 1030-2662 * Recommended and maximum price only. 2  Silicon Chip Publisher’s Letter Wind power is no substitute for base-load generators Back in the July 2009 issue we featured a story on Sydney’s water desalination plant together with a panel entitled “Where does the electricity come from?” As explained in the panel, the state government has decided to build wind farms to generate the power which would otherwise come from coal-fired base load power stations, albeit at a higher price. But in the this month’s Mailbag pages, reader Paul Miskelly points to the fallacy in this arrangement. Desalination plants must run continuously and therefore must draw their substantial electricity requirement from the grid all the time. Paul Miskelly has taken the trouble to analyse the figures for wind farm output and has produced graphs which clearly indicate that wind power is a very variable source – hardly suitable for running a desalination plant. It is stating the blindingly obvious to say that the wind does not blow all the time. But it doesn’t and for the politicians and public servants to try and pass off wind power as a “green solution” is just a lie. When the wind stops blowing, all the electricity required by the desalination plant must come from the coal-fired power stations. There are no ifs, buts or maybes. And one can envisage a situation where, if there was a major overload on the grid and the wind wasn’t blowing, the desalination plant would be one of the last to be subject to “load shedding”. In other words, normal commercial and domestic consumers will be blacked out long before the desalination plant. I remember some years ago having lunch with one of the magazine’s advertisers and the subject of the mooted Sydney desalination plant came up. I wondered out loud where the power for the plant should come from. Nuclear power was the instant and only practical answer. “Where should we put it?” was the next question. The immediate answer was “Right next to the desalination plant at Kurnell!” Then “How big should it be?” and the answer was “A bloody big one!” And while the answers to the questions may have been glib, they were absolutely correct and practical. Desalination plants need lots of power and nuclear plants can provide that power on a relatively small site with no air pollution at all. None. Since such a large amount of power is required, it makes sense to site the power plant right next to the desal plant, to minimise transmission losses. And since Sydney requires more base load power in any case, having the nuclear power station adjacent to the city also makes sense, to minimise transmission losses. That’s how they do it in many other parts of the world. Sadly, while everything we discussed was and is correct and practical, nothing like that is ever likely to eventuate even in the far future, given that State and Federal governments appear to be so inimical to the concept. But those people who say that we can rely more on renewable energy sources must face the fact that when those source are not available, such as when the wind is not blowing, then the base-load power stations must be able to take up all the slack. Unfortunately though, all of the interconnected electricity grid for the eastern states of Australia is running very close to capacity, especially in the summer months. Finally, those people who point to European countries which apparently have a much higher component of their electricity coming from wind power should realise that those same countries buy their electricity from nuclear-powered France when the wind doesn’t blow. Furthermore, those countries that have invested heavily in renewable energy, such as Spain with its government-mandated solar energy, are paying much more for their energy. That is now recognised as a gross misallocation of resources. Leo Simpson siliconchip.com.au This is NOT a USB Oscilloscope! It is a 50MHz, 3-channel full-featured ’scope you can hold in the palm of your hand! Just add a monitor and mouse (no PC needed)! Se Screene the review Scope i SILICONn Jan 2010 CHIP! THE A-351 SCREENSCOPE IS A GENUINE STAND-ALONE, REAL-TIME OSCILLOSCOPE: DO NOT CONFUSE WITH INFERIOR USB SCOPES! Here’s what you get:            A genuine digital scope that is ready in seconds! 50MHz 240MSPS real-time sampling 3 channels - 2x 8-bit and 1x 1-bit input FFT in dBVrms, dBm (50, 75, 100, 300 600 Ohm termination) with selectable window +, --, x and. -- math functions and memories . Auto and manual measurements using markers USB host - save waveforms as .txt or .csv Save screen shots as .bmp Easy fast uploads of new firmware revisions Perfect with widescreen monitors (but fine with just about any old computer monitor!) Very easy operation - just single mouse clicks for controls and you can easily move waveforms and objects directly And  so much more (see our website for full specs) NEW:  XY MODE! Introducing ScreenScope - the new type of scope you are going to love to take anywhere and use anywhere. All you need is a mouse and virtually any computer monitor. You don’t need a PC and it’s fun to use! And just look at the low, low price: ONLY $539 (inc GST) with a money-back guarantee! CALL NOW: (03) 9714 8269 www.screenscopetraces.com MAILBAG Letters and emails should contain complete name, address and daytime phone number. Letters to the Editor are submitted on the condition that Silicon Chip Publications Pty Ltd may edit and has the right to reproduce in electronic form and communicate these letters. This also applies to submissions to “Ask SILICON CHIP” and “Circuit Notebook”. National broadband network will waste power I agree with your observations and concerns regarding the government’s proposed NBN FTTH network (Publisher’s Letter, November 2009). Like you, I am convinced that the government is committed to separating Telstra in order to gain access to the underground duct infrastructure without proper and fair compensation. While it may be valid to deplore the crippling of upload speed on the FTTH network, my major question is whether it is absolutely necessary for the average home to have access to 100MBit/s download speed. A homeowner might think it is cute to be able to view a full length movie in real time on a networked TV set but this is a very poor justification for piping such a wide bandwidth into every home. My contention is that FTTH for 99% of the population is well and truly overkill and the expense of $43 billion can not be justified. I contend that all that is required by the average home is a minimum 15MBit/s which can be adequately provided by a much less expensive network using FTTN. While it would be possible to allow existing exchange switches to Great service on faulty kit I recently purchased a Digital Audio Generator (SILICON CHIP, June 2009) kit from Altronics and on completion found I had a display problem in that it just showed a series of dark squares on the LCD, although some of the tones appeared to be working. Contact via email was made with Daniel from the Altronics mail order department in Perth and after a bright cheery conversation he said he would pop upstairs and if there was a programmed PIC there, he would send it to me. That was 4  Silicon Chip provide standard POTS over the old copper cables while transferring the high-speed services to the fibre, this is unlikely to be considered economically justifiable. After all, why run a fibre to every home just to provide a high-speed internet service? So it is probable that fixed-line telephone services would operate using VoIP over the fibre connection. But this service will only be reliable if the home fibre terminal is powered by a UPS. It would also mean that the existing exchange infrastructure would be redundant despite it being capable of providing reliable telephony service for many years yet. Another point which I have wondered about is the comparison between energy costs associated with a FTTH network as compared to a FTTN network. As I understand it, a FTTH network requires every home to have a fibre terminal which must be powered from the domestic mains supply and if the customer wants to have an uninterrupted service the terminal must also have a UPS. These terminals will be the responsibility of the home owner to maintain and to pay for the power which runs them. If my maths are correct, each ter- Friday morning, Perth time and on the following Monday afternoon a parcel arrived on my doorstep in Dunedin, New Zealand. Now that’s what I call service! Unfortunately, the replacement PIC did not fix the fault and after one more email, another PIC and an LCD module were sent with similar speed, along with some discount vouchers for my troubles. This time the problem was fixed and I can say I am very pleased with the kit and the after-sales service I received from Altronics. Peter Hamlyn, Dunedin, NZ. minal consumes around 15W. So if there are eight million households, the standing power requirement will be 120 megawatts just to keep the FTTH terminals operational – even when they aren’t actually doing anything for the major period of each day. This isn’t very green in my opinion. In contrast, I would estimate that a FTTH network would consume far less power because only the fibre nodes would have to be powered and this would be performed by the telco (eg, Telstra) via their underground cables in much the same way as the Foxtel cable is now powered. Since the exchange power is batterybacked and the exchange possibly has a diesel generator to cater for long outages, the customer would still have a reliable network and telephone connection, exactly the same as is now provided over copper. Only the high speed internet connection using DSL would be transferred to the fibre nodes which serve up to 1000 customers while the existing fixed-line telephone service would continue to be provided over the existing copper cables. The customer would only have to maintain responsibility for his own network modem etc as he currently does and fixed line telephones would not need to be upgraded to VoIP telephones or to be powered using a UPS. All in all, a FTTN NBN makes more sense in the short to mid term and it also provides a logical phased integration platform for a fully blown FTTH network when it is economically viable. Ross Herbert, Carine, WA. Flinders University pioneered EV development in Australia David Richardson’s letter in the September 2009 issue, which was in response to your Editorial comment siliconchip.com.au regarding a 3-phase powered electric vehicle, suggests that the Flinders University of SA may have constructed a 3-phase powered electric vehicle during the 1990s. I believe that a DC to 3-phase control system for an electric vehicle was developed at a Tasmanian University in the late 1970s or early 1980s. I recollect seeing a photograph of this system and an ASEA motor fitted into a passenger vehicle. The Flinders University electric vehicles were constructed in the late 1970s, early 1980s – not 10 years ago. We were 30 years ahead of the current enthusiasts! The first FUEVG (Flinders University of SA Electric Vehicle Group) vehicle was a space frame with a wheel at each corner. It was not constructed on a Mini Moke chassis but it did bear a passing resemblance to that iconic vehicle. The DC motor ran at constant speed, powering an hydraulic variable-speed transmission. The batteries, as in all FUEVG vehicles, were lead-acid cells. The second FUEVG vehicle was a small Fiat which on completion only had two seats. The battery pack was variable voltage feeding a DC printed circuit permanent magnet modular motor. This used the manual gearbox and clutch to drive the wheels. Regenerative braking was used. The third FUEVG vehicle com- Dodgy rechargeable torches again Following the letter on dodgy torches in the Mailbag pages of the December 2009 issue, my experience with dodgy rechargeable torches is a brand which I found at a camping goods store. It is a key-ring type torch with a fold-away crank handle on the side. The generator does actually charge the batteries, however the rechargeable battery stack is held together with a shrunken plastic sleeve. However the resulting tension is not adequate and so the battery stack forms a bad connection and so can not deliver the charge to the LEDs. menced was a Laser sedan which on completion had four seats. The battery pack was variable voltage feeding a DC printed circuit permanent magnet four module motor. This used the standard clutch and the manual gearbox to drive the wheels. Regenerative braking was used and the motors were modular, with the number of modules being varied to provide for differing power requirements. The Laser, despite being commenced before the fourth and fifth vehicles, was not completed until after the vans (see below). The fourth and fifth FUEVG vehicles commenced were Bedford vans. I found that a short length of tape wrapped tightly around the battery stack cured the problem, however most people would simply throw it away resulting in more metals and plastics going to landfill and wasting of the energy used in manufacturing and transportation. Maybe it’s time that there was legislation mandating a minimum life for products that fail such tests. It might cost a few more cents for something made that bit better but the additional cost would be quickly recouped by not having to buy another one in a few days/weeks. John Evans, Macgregor, ACT. The variable-voltage battery pack was interchangeable to enable “refuelling” at a battery exchange facility in less than three and a half minutes; about the same as a quick petrol refill. The battery pack, which weighed approximately one tonne, fed the DC printed circuit permanent magnet 6-module motor connected through the clutch and the manual gearbox driving the rear wheels. Regenerative braking was used. The number of modules chosen for the motor was based on the required power. Two battery exchange facilities were built and developed by the FUEVG, with one at the Flinders University Australia’s Best Value Scopes! Shop On-Line at emona.com.au GW GDS-1022 25MHz RIGOL DS-1052E 50MHz RIGOL DS-1102E 100MHz 25MHz Bandwidth, 2 Ch 250MS/s Real Time Sampling USB Device & SD Card Slot 50MHz Bandwidth, 2 Ch 1GS/s Real Time Sampling USB Device, USB Host & PictBridge 100MHz Bandwidth, 2 Ch 1GS/s Real Time Sampling USB Device, USB Host & PictBridge Sydney Brisbane Perth ONLY $599 inc GST Melbourne Tel 02 9519 3933 Tel 03 9889 0427 Fax 02 9550 1378 Fax 03 9889 0715 email testinst<at>emona.com.au siliconchip.com.au ONLY $879 inc GST Tel 07 3275 2183 Fax 07 3275 2196 Adelaide Tel 08 8363 5733 Fax 08 8363 5799 ONLY $1,169 inc GST Tel 08 9361 4200 Fax 08 9361 4300 web www.emona.com.au EMONA January 2010  5 Mailbag: continued Helping to put you in Control Control Equipment Ethernet Switches Industrial Ethernet Switch with 8 10/100BaseT(X) ports that provide an economical solution for your industrial Ethernet connections. Also available with Fibre Port. From $299.00+GST XMP-32R/T PLC Integrates a PLC and 7" color touch screen into one unit. 16 Digital In 16 Digital Outputs Supports high-speed counter, high-speed pulse & external interrupts. $995+GST XC1 series of PLC An inexpensive PLC with 8 Digital In and 8 relays supports basic logic control and data operation. Free ladder logic software. $149.95+GST MP3 Trigger Play MP3’s from a microSD card. Pre-selected MP3 tracks can be triggered by 7 pins or by the full duplex serial port. $54.95+GST IMU 6DOF Razor - Ultra-Thin IMU The 6DOF Razor makes use of ST's LPR530AL (pitch and roll) and LY530ALH (yaw) gyros, as well as the popular ADXL335 triple-axis accelerometer, to give you six degrees of measurement on a single, flat board. $99.00+GST Polymer Lithium Ion Batteries 20mAh to 6Ah These are very slim, extremely light weight batteries based on the new Polymer Lithium Ion chemistry. From $6.50+GST RS232/485/422 to optic fiber converter The Model277 Series converter is equipped with a multiple interface circuit that can handle RS-232, or RS-422/485 serial interfaces and multi-mode or single-mode fiber. Pair from $289.00+GST Contact Ocean Controls Ph: 03 9782 5882 www.oceancontrols.com.au 6  Silicon Chip Compact fluorescents are not the solution to energy conservation This CFL issue is an ugly monster. Who in government knows anything about science or engineering? Household incandescent lamps were banned from import last year without an effective replacement. It seems halogen lamps may be more suitable than compact fluorescent lamps although they use more power. People are now forced to buy and install CFLs in place of incandescents, not knowing that if they have too many on the one circuit that switching them on together can keep tripping your breaker (or fuse). The free CFL handout campaign didn’t warn of using too many on one circuit or that you may have to change your circuit breaker to a “D” curve type to overcome the surge. How much will that cost? So much for free lamps. CFLs use a miniature switchmode supply of say 8W, 18W etc. So they have a switch-on surge from the input capacitor charging, leading to problems in some cases. They also have a turn-on delay, some flicker and some have an awful and the other in the City of Adelaide. Other work by the FUEVG was on the development of the lead-acid batteries which constituted the “roadworthy” state of the art 30 years ago. This resulted in significant improvements in energy capacity, increased the number of cycles achieved during a battery’s life, greater mechanical robustness and longer service life in an EV. (The resulting improved performance and lower production costs enabled the co-operating factory in Adelaide to export batteries to their parent company in UK). Parallel work on battery chargers resulted in higher efficiencies, improved power factors, lower line currents, reduced line and radiated interference and faster charging to full capacity. This resulted in lower stresses on the battery structure, in turn leading to longer battery life. Considerable data was gathered on colour and very few can be dimmed. They have no soft-start and no power factor correction. I have actually measured some and they operate at about PF = 0.5. This means that an 18W CFL is actually 36VA. This means that the supply authority always has to struggle to “correct” or “balance” the power factor, leading to higher maintenance costs and who pays for that? How much energy will I save if I changed my toilet lamp which only switches on four or five times at night for about three minutes each time? I doubt if I would ever notice. CFLs are OK for constant lighting which stay on for long periods but not for short, frequent switching and are no good for automatic timers or dimming. By the way, I have two CFLs and standard 2-foot fluoros in my garage where I work for extended periods. I also have four automatic timers so CFLs are excluded there. I believe LED lighting is the real technology that will eventually prevail. Sal Sidoti, Lilyfield, NSW. the operating costs and experiences with the vehicles, both on-road and on the FUEVG-developed computer controlled dynamometer (normal wheel-coupled dynamometers cannot simulate regenerative braking!). The battery improvements were proven by the data from the computer-controlled battery test facility and these improvements incorporated into the 1-tonne packs for operational on-road testing. As a result of the FUEVG achievements with the vans, the variable voltage batteries, modular motors and battery exchange facilities, the SA Government decided to support a pilot manufacturing project to produce, I believe, 10 or more vans. A commercial developer was contracted and I believe the SA Government diverted all EV funding to the commercial manufacturing project. Due to lack of financial support by the State, the Federal Government fisiliconchip.com.au nancial support also disappeared, with the resultant demise of the FUEVG. Roger Pullem, Adelaide, SA. Secret world of oscilloscope probes a revelation My congratulations to Doug Ford for a marvellous and illuminating article on oscilloscope probes in the October 2009 issue. My long-time puzzlement over the reason for distributed resistance in the cable is cured. Well done. John Macleod, Gymea, NSW. High atmosphere CO2 doesn’t cause global warming I note your editorial comment about the flood of emails but I am afraid that Cliff Hignett’s letter cannot go unanswered. He suggests we look into the IPCC reports. Following the release of the emails from the University of East Anglia, does he honestly expect people to believe anything the IPCC says? The emails imply scores of university researchers, some of whom are associated with the IPCC, engaged in fraudulent reporting of data to favour their own climate change agenda. You published Mr Hignett’s graph of atmospheric CO2 over the last 650,000 years and it is interesting. However Professor Plimer’s graph of the past 600 million years (page 242) with both CO2 and temperature integrated is more so, as it shows the hypothesis that high atmospheric CO2 produces global warming is invalid. John Brown, Bibra Lake, WA. Query on wiring standards The company I work for is often engaged in mounting and wiring instruments and components inside various size cabinets or enclosures. Recently, one of our technicians was taken to task over the way in which he had wired up a project. According to our electrical supervisor, it is not permitted to use black & red as plus/minus low voltage wiring if the same enclosure has mains voltage connected internally. Although the mains cable is brown, blue and yellow/ green, we are told that the SAA regards red & black wiring as mains wiring as well. In fact the blue/brown should be connected to the circuit breaker on the input side and the output side is supposed to be red and black which is terminated to the transformer or any other device requiring mains voltage as its primary input. Some of your projects show the internal wiring with black & red as low voltage wiring. I wonder if you could clarify the situation as I assume Issues Getting Dog-Eared? REAL VALUE AT $14.95 PLUS P & P Are your SILICON CHIP copies getting damaged or dogeared just lying around in a cupboard or on a shelf? Can you quickly find a particular issue that you need to refer to? Keep your copies of SILICON CHIP safe, secure and always available with these handy binders Available Aust, only. Price: $A14.95 plus $10.00 p&p per order (includes GST). Just fill in and mail the handy order form in this issue; or fax (02) 9939 2648; or call (02) 9939 3295 and quote your credit card number.                ReNew’s                                          siliconchip.com.au January 2010  7 Mailbag: continued Wind farms & desalination Firstly, congratulations to Leo Simpson for his July 2009 Publisher’s Letter for his easy-to-understand explanation of the complex topic exploring both the relative impacts of the use of coal versus gas for electricity generation, and the relative thermodynamic efficiencies of the respective power plants. Thanks to Geoff Graham for the excellent article in the same issue, explaining the mysteries of water desalination. The article makes it clear that, given the special requirements to protect and maintain the reverse osmosis membranes at the heart of the system, the plant is best operated continuously at full capacity. Therefore, from day one of operation, the desalination plant has not only a base load requirement on the grid but as well, this requirement must be sourced from a rock-solid, secure supply of electricity. With this requirement firmly in mind then, I would like to comment on the content of the sidebar to the article entitled: “Where does the electricity come from?” This sidebar article claims that the principal source of the required electricity will be a wind farm As illustrated in the graph shown in Fig.1, wind farms produce a highly variable, highly erratic and totally unpredictable electricity that your projects must come under the scrutiny of your local regulatory authorities? John Hoskins, Swispec Pty Ltd, Bunbury, WA. Comment: according to the Australian wiring standards, AS/NZS 3000:2007 clause 3.8.1, Earths must be green/ yellow, Neutral black or light blue and Active is any colour other than green, yellow, green/yellow, black or light blue. Recommended Active wire colours are red or brown for single phase and red, white or dark blue for multi-phase. For low-voltage wiring via a transformer (clauses 7.5 and following) 8  Silicon Chip output. In addition, wind farms often produce zero output for long periods of time. Indeed, they draw significant amounts of electricity from the grid during those periods. Wind farm owners always quote the average annual output, never publicising the degree of variability in that output. It may be instructive to consider the output to date of the Capital Wind Farm near Bungendore, one of those identified by the NSW Premier as being the source of the 100% renewable electricity supply for the Kurnell desalination plant. The attached graph (Fig.1), compiled from AEMO-published data, shows the output for the period 30th June 2009 - 24th October 2009. (The Australian Energy Market Operator [AEMO] is responsible for the secure and reliable operation of the eastern Australian electricity grid). It is noteworthy that there are very long periods of zero output and where there is generation, the pattern is extremely spiky. The kindest thing that one can say about this performance is that it is totally unmatched to the requirements of a desalination plant. While it may seem acceptable for their owners to quote wind farm operation in terms of averages, a desalination plant cannot be run on averages or indeed any other statistic. The reality is that while there does not appear to be any mention of specific colours of wires that should or should not be used. Since mains transformers use red and black secondary wires and do comply with AS/NZS 61558.2.6 and AS3108, it would seem that red and black can be used for low-voltage wiring. We agree that the green/yellow earth wire should only be used for earth wiring only, as inferred in AS/NZS 3000:2007 clause 3.8.1. Climate change debate too divisive I look forward to the SILICON CHIP editorial where Leo outlines his views the desalination plant is operational, electricity has to be supplied to it from a reliable, constant source. Therefore, to propose that there is some sort of link between wind farm-generated electricity and the requirements of the desalination plant is tenuous at best. In my view, it is a grossly misleading claim. This claim – that wind farms might be used to fully supply the electricity requirements of a desalination plant – is but one of the many unsustainable claims concerning wind farms. Should readers wish to access the operational data of the Capital Wind Farm or indeed that of any of the other major wind farms connected to the eastern Australian grid, to check the operational data for themselves, instructions as to which links to access, etc can be supplied. Alternatively, readers might like to access the website http://www.landscapeguardians.org.au/data/aemo to download operational data from an updated-daily database holding AEMO-sourced information. Professional electrical engineers in particular and other readers of SILICON CHIP who choose to perform even a preliminary analysis of this data will very quickly realise the futility of connecting wind farms to the electricity grid. Not only is the output from any single wind farm highly erratic but the sum of the outputs, far from being smoothed by wide geographic dispersion (a claim stated as mantra by wind on abortion. NOT! Climate change sceptics are like drinkers about to leave a party and drive home. Arguing with them is pointless. They have done this a thousand times before, have never had a problem, getting a taxi is too hard and returning for the vehicle too inconvenient. Whether their actions are safe or not is not the issue – it is the risk and the increased probability of injury. Speeding and drink-driving will not guarantee injury, any more than pumping carbon dioxide into the atmosphere will guarantee global warming. However, most people accept that the consequences of drink driving siliconchip.com.au energy’s proponents), is even more spiky and destabilising to the grid’s continued operation. Why it has been left to privateers such as myself to perform such an analysis and to highlight the inherent problems in grid-connected wind generation beggars belief. To better show the extent of the detail available, Fig.2 is a graph of the output of the same Capital Wind Farm using the final month of the data shown above. The data points used to generate both graphs are at intervals of five minutes. To supply the requirements of the desalination plant, the troughs and gaps in this output would have to be smoothed by an open-cycle gas turbine plant (OCGT) operating in a very inefficient manner. OCGT’s have much lower thermal efficiencies than the CCGT’s described in Mr Simpson’s July 2009 editorial. Dare one suggest that the CCGT plant described in Mr Simpson’s editorial would make a more suitable source of electricity for the desalination plant? Indeed, one could. Such a plant could be built nearby as the dedicated, sole, continuous source of supply to the desalination plant. With its thermal conditions optimised to operate at maximum efficiency, this CCGT generator would provide the most environmentally friendly of generation technologies currently available in Australia to deliver the electricity requirements for this controversial plant. Whatever one’s view in the cli- mate-change debate, this data shows that grid-connected wind farms can never make any useful contribution to reducing CO2 emissions. Paul Miskelly, Mittagong, NSW. far outweigh the conveniences. Similarly, the costs and inconveniences of reducing greenhouse gases, even if unnecessary, are small compared to the potential consequences. Giving Steve Fielding credence because he is an engineer is going too far. For over 20 years, I have been presenting my fellow engineers and other technical people with the Monty Hall Problem (see Google). They invariably make the wrong choice and refuse to acknowledge their error, no matter what. It often takes weeks to wear them down to the point where they siliconchip.com.au January 2010  9 Mailbag: continued Criticism on inclusion of letter from Ian Plimer I have grown tired of Leo Simpson using this magazine month after month to push his views on the topic of anthropogenic (man made) climate change, which in my opinion has reached the point where it is seriously harming the magazine’s reputation. In his latest instalment (October 2009), Mr Simpson states in his Publisher’s Letter that he is “very pleased to publish a long letter” from Ian Plimer, which like his book “Heaven and Earth”, continues to promote falsehoods. For example, Plimer states in his letter that (global average) temperature has decreased since 1998, which I consider to be a very significant statement. His book does likewise on p391 which states: “The Hadley Centre in the UK has shown that warming stopped in 1998”. It is perhaps not surprising that Prof. Plimer does not cite a reference for that claim, as in fact the Hadley Centre is on record as saying the complete opposite (http://www. metoffice.gov.uk/corporate/pressoffice/2008/warming_goes_on.pdf), commencing with the headline “Anyone who thinks global warming has stopped has their head in the sand”. They further state: “The evidence is clear – the long-term trend is that global temperatures are rising, and humans are largely responsible for this rise. Global warming does not mean that each year will be warmer than the last. Natural phenomena will mean that some years will be much warmer and others cooler. You only need to look at 1998 to see a recordbreaking warm year caused by a very strong El Niño. In the last couple of years, the underlying warming is partially masked, caused by a strong La Niña. Despite this, 11 of the last 13 years were the warmest ever recorded. […] Over the last 10 years, global temperatures have warmed more slowly than the long-term trend. But this does not mean that global warming 10  Silicon Chip has slowed down or even stopped. It is entirely consistent with our understanding of natural fluctuations of the climate within a trend of continued long-term warming.” I find it difficult to believe that Prof. Plimer was not aware of the Hadley Centre’s true position when he wrote his recent letter to SILICON CHIP. There is a wealth of information readily available that refutes many of Plimer’s other arguments in sufficient detail to permit independent verification of the facts by true sceptics. For example, the one compiled by Ian Enting of the University of Melbourne runs to 46 pages alone – http://www.complex.org.au/tikidownload_file.php?fileId=91 A true sceptic would take into consideration the many documented problems with Mr Plimer’s book, which, as far as I am aware, Prof. Plimer has never seen fit to refute and as evidenced by his letter, he perpetuates. Perhaps he has not refuted them because he simply can not do so on scientific grounds. Or perhaps he has not done so because the controversy generates increased book sales. Either way, it does him no credit to remain silent in the face of such overwhelming criticism. It also does the magazine no credit for Mr Simpson to publish a letter containing material errors of fact such as the one I cited above. From his past writings I very much doubt that Mr Simpson falls into the category of a genuine sceptic of anthropogenic climate change, for if he did, he would likely have been well aware of the problems associated with Prof. Plimer’s claims and questioned the merit of publishing them without first verifying their validity. Although I do not expect anything I have written to alter Mr Simpson’s viewpoint on the topic, I do hope he finally sees fit to move on to one more appropriate to the purpose of this magazine. L. Pickersgill, Mt. Lawley, WA. will accept the correct method. The more technical the person, the more stubborn they are in sticking to their original incorrect assumption. I believe that there are more important political issues that are relevant to SILICON CHIP readers than nuclear energy or climate change, which are divisive. These issues include nannystate electrical laws, incandescent globes, digital radio and television, NBN and minimum efficiency standards etc. I know that these have been addressed before but there is still much to be discussed and these are more resolvable and less divisive than the hot potatoes of nuclear energy or climate change. Mark Baker, South Perth, WA. Comment: while you may think that climate sceptics are ratbags, perhaps you should look at some other information which indicates that in fact, the Earth may be cooling. If you don’t accept that, the fact that the Sun is going through a period of record low activity cannot be denied. We do not resile from discussing climate change and the economic and technical ramifications of attempting to fix it with such ill-conceived measures as ETS, CPRS and CCS. SILICON CHIP is one of the few magazines where criticism of these measures has been raised. In fact, until the Publisher’s Letter entitled “Let’s have no more of this carbon pollution nonsense” in the June 2009 issue, virtually no writer in the general media had even seen the silliness of the term “carbon pollution”. Praise for Class-A amplifier I would just like to let you know that I have just completed construction of your class-A 20W/channel amplifier from an Altronics kit. I have it connected to a high-end Yamaha CD player and a pair of VAF Research DCX Gen IV speakers. In my opinion, the quality of sound is as good as you will ever hear from any system, regardless of price or manufacturer. Congratulations and well done for what is undoubtedly a world-class amplifier. Ron Barnes, Otago Bay, Tas. siliconchip.com.au CHINA PCB Supplier Call blocking wanted for telemarketers calls or divert them to voice mail (by my choice). Calls to the carrier I despise telemarketing callers. If on this subject are met with some there was something I needed that disdain. Now that I have had my say on they were selling, I’d have gone looking for it already. The “do not call” this issue, I wonder if you might be register is a solution that is no solu- able to develop a project, perhaps tion because you are simply adding using a PICAXE solution, that can your details to yet another database. sit on my landline before the handThe problem is that the tele­ set, examine the CLID and divert or 1-layer up to 30-layer communications carriers provide reject (by user setting) numberless Cost and telemarketing companies withquality the calls. I understand that there may means to invade my space. My On time deliverybe issues with telecommunications phone services (landline, mobile, equipment regulation compliance Dedicated service VoIP) all have a call blocking facility but this should not be insurmount& Order able given the gamut of devices that but you actually needInstant to have aOnline num- Quote meet theNight regulations from foreign ber to block. CLID for telemarketers ...........Day and and do the oddest of things. are generally “Unavailable” One piecore “Priorders arsources e wGary elcomBroughton, e! vate Number”. More recently, they C h e c k o u r l o w p r i c e a n d s a v e b i g $ Renmark$$SA. have started using 028 numbers. You can’t block those numberless calls Comment: your use of the word “despise” is very appropriate. One with call blocking. I decided that since my telecom- partial way of stopping nuisance munications carrier gave the tele- calls is to listen to all incoming calls marketers the means to invade my via an answering machine. That way space, the telecommunications car- you can elect whether or not to pick rier is legally obligedweb: to provide me up the phone, if you happen to be at www.pcbcore.com with the means to block numberless home at the time. . . . . . prototype thru production email: sales<at>pcbcore.com phone: 86(571)86795686 Crystal clocks with sweep second hands may not last I was not impressed by the lifespan of a tick-less wall clock that I purchased recently. It has a 27cm dia­ meter dial but only worked for some 51 weeks before stopping. If I rotate the clock through 180° so that the 6 o’clock position is topmost, the clock will run again, albeit very noisily. My guess is that because the single coil stepper motor rotor has to rotate 16 times each second, the rotor bearing areas wear out much quicker than the traditional one tick per second rotor. My previous crystal clocks have CHINA PCB Supplier prototype thru production . 1-layer up to 30-layer . Cost and quality . On time delivery . Dedicated service . Instant Online Quote & Order ...........Day and Night One piece orders are welcome! Check our low price and save big $$$ web: www.pcbcore.com email: sales<at>pcbcore.com phone: 86(571)86795686 lasted over five years. I replaced the worn-out clock mechanism (but kept the original hands) with the Jaycar XC-0100 kit, which was cheaper than buying a new clock. Anthony Farrell, SC Chinderah, NSW. JOIN the teChNOLOgy age NOW WIth PICaXe Developed as a teaching tool, the PICAXE is a low-cost “brain” for almost any project. Easy to use and understand, professionals & hobbyists can be productive within minutes. Free software development system and low-cost in-circuit programming. Variety of hardware, project boards and kits to suit your application. Digital, analog, RS232, 1-Wire™, SPI and I2C.PC connectivity. Applications include: Distributed in Australia by 1[Datalogging 1[Robotics 1[Measurement & instruments 1[Motor & lighting control 1[Farming & agriculture 1[Internet server 1[Wireless links 1[Colour sensing 1[Fun games Microzed Computers Pty Ltd Phone 1300 735 420 Fax 1300 735 421 www.microzed.com.au www.siliconchip.com.au siliconchip.com.au NEW X2 HIPS now in sC tock! November 2009  67 January 2010  11 Going “tropo” in the tropics . . . AIS in the Pilbara by Stan Swan Regular SILICON CHIP readers will recall Stan Swan’s AIS article in August 2009. It’s not stretching the truth to say it has stirred an enormous amount of interest. But we bemoaned the fact that there appeared to be very little coverage in Australia’s north west. S o it’s been pleasing to note the welcome establishment of fresh 162MHz marine monitoring stations on both the NZ and the vast Australian coastlines. Perhaps the most notable recent installation has been that near Dampier on the north west coast of WA, as its associated marine traffic web feed has dramatically served to show the scale and intensity of ore and gas shipments from the Pilbara region. “Like bees ’round a honeypot” was one comment arising after viewing the associated AIS activity. 12  Silicon Chip Shore-based observers would only see a handful of ships at a time and hence may never be conscious of the virtual armada lurking over the h d horizon! At the time of writing (early November 2009) around 100 vessels were often detected, with many in shipping lanes stretching clear to In- EARTH’S HORIZON D ONSHORE RECEIVER H Distance to visual horizon: D = 13 H (where H = height in metres, D = distance in km) How far can you see (or LOS radio waves travel? Simply use this formula – don’t forget that both your height and the height of the ship’s AIS transmitter make a considerable difference. siliconchip.com.au The Dampier AIS receiving station is hidden amongst the giant communications antenna farm. It was originally set up to house the local amateur radio repeater. The AIS antenna is that tiny 1/4-wave whip (highlighted) on the roof of the building in the foreground. Normally only line-of-sight, under seasonal “tropo ducting” this often receives VHF marine radio signals out to 1000km away! donesia, almost 1000km away. Coastal viewers have a visual horizon at distance D (in km), related to the observer’s altitude H (in m), by the formula D = √(13 x H). Although downward refraction (“bending”) gives modest VHF coverage a little beyond this range, such signals essentially propagate line of sight (LOS), meaning a radio horizon of perhaps just 20km or so for most ship-mounted AIS antennas. Going tropo So how then can these numerous Dampier vessels, many “hidden” well below the earth’s curvature, be so readily detected in this region using such simple technology? The answer relates to seasonal tropospheric propagation enhancement, well known to arise about now in that region. The troposphere forms the earth’s Tropospheric propagation allows reception many, many times that suggested by the diagram at left. In fact, signals have travelled 1000km and more, sometimes resulting in confusion with VHF radio networks! siliconchip.com.au January 2010  13 Web-sourced maps showing Hepburn Tropospheric propagation possibilities give invaluable insights into tropo enhancement. It’s indeed fortunate that the Pilbara region experiences both intense seasonal tropo ducting and massive off shore AIS activity, as productive “data mining” insights (technical and commercial) may result. lowest atmospheric layer and under suitable conditions higher frequency electromagnetic waves can become trapped near ground level. Such “tropo” propagation typically occurs during periods of stable, anticyclonic weather and usually relates to a thin layer of warm dry air blanketing cooler surface air. Temperature inversions of this type are often encountered when hot summer air (perhaps from deserts) overlays cooler ocean water – fogs are often a visible sign. Unlike near-space ionospheric reflections (greatly influencing medium and short wave reception), it’s the very-much-higher frequencies (VHF, UHF and microwaves) that are usually more favourably tropo propagated. Diverse tropo enhancement effects are known but wave-guide style refractive ducting is the most pronounced. Ducted signals may travel more than 1000 km, leading to unexpectedly long distance reception (under these conditions Australian eastern state FM radio stations may become audible across the Tasman in NZ. Such ducted propagation is usually blocked by mountains. Ground 14  Silicon Chip level receivers may be below a tropoenhanced layer, yet signals could be readily received when on perhaps a 300m hilltop. Long distance (“DX”) tropo reception is often associated with powerful FM and TV broadcasters. In some parts of the world, notably the Mediterranean Sea, Carribean and Persian Gulf, tropospheric ducting conditions can become so established during summer months that viewers regularly receive good quality VHF/ UHF terrestrial TV signals over great distances. Prior to satellite TV, such “tropo season” reception greatly annoyed totalitarian authorities in countries (such as Cuba) attempting to restrict external information! Radio amateurs have long strived for long-distance (DX) contacts via weak VHF/UHF signals. Thanks to the global tropo forecasts of Canadian (and professional meteorologist) William Hepburn – hosted at www. dxinfocentre.com/tropo–aus.html – anticipating suitable conditions is now much easier. Hepburn’s maps graphically indi- If you thought the AIS plot on page 14 was impressive, what about this one! Over 200 vessels have been identified stretching all the way up to and through the Indonesian Archipelago. Comparison of the Hepburn map with the Pilbara’s AIS reception coverage shows HTI propagation predictions well confirmed. As vessel movements naturally tend to follow defined routes, the region’s shipping lanes and movement intensity can be clearly established. siliconchip.com.au As we explained in the article in our August issue, you don’t need a lot of equipment to receive AIS signals. FM RADIO & NOW DIGITAL TV TRANSMITTERS from cate the likely strength of a region’s tropospheric ducting on a ten-point HTI (Hepburn Tropo Index) scale – zero being negligible while ten becomes near “armchair quality”. Dampier’s intense late Octoberearly November 10+ HTI predictions indeed correlated closely with the region’s noted AIS enhancement. Given the well-defined tropo AIS coverage, considerable scope for marine-sourced investigations (both commercial and technical) may now arise. As tropo propagation of higher frequency microwaves can occur, it’s even tempting to consider a crack at the 2.4GHz WiFi record – presently a “mere” 382km! Although FSPL (Free Space Path Losses) increase significantly at such microwave frequencies, it’s feasible tropo-enhanced WiFi links could be made using high gain 2.4GHz dishes to give decent EIRP (Effective Isotropic Radiated Power). After all, AIS signals (originating from ~12W shipboard VHF transmitters) were received over 1000 km away in Dampier with just a simple ¼-wave whip! POWER References: Hosted at: www.manuka.orcon.net. SC nz/ais.htm Looking out over the port of Dampier belies the enormous amount of shipping just over the horizon. It also says nothing about the huge economic benefit to the region, the state and to Australia. Here’s a new record just set (30 November) by the Dampier AIS station: the “Limousin Express” was detected near Christmas Island, nearly 1500km out in the Indian Ocean. It’s just another example of AIS tropo reception. siliconchip.com.au January 2010  15 ScreenScope SSC-A531 . . . a 50MHz real-time standalone oscilloscope with a difference Review by MAURO GRASSI 16  Silicon Chip siliconchip.com.au Fig.1: this screen grab shows the two vertical channels displaying a square wave and a sinusoidal wave. In this case, the square wave is the 1.22kHz signal from channel 3. The sinusoidal wave is the output of an external signal generator at 400Hz. Triggering is set on a rising edge of the sinusoidal wave. Note that the trigger point is to the left of the main vertical axis. Fig.2: a pulse width modulated signal at a frequency of around 520Hz is shown in this screen shot. The duty cycle of the waveform is around 37% (average), as indicated by the text at the top of the display. Automatic measurements can be enabled on a per channel basis and you can display up to three automatic measurements simultaneously. The ScreenScope SSC-A531 is a digital dual-channel oscilloscope with a bandwidth of 50MHz and a wide range of features including FFT but it has no controls, no knobs and no screen. Instead, you connect your own LCD or CRT colour monitor to provide as big a screen as you want. Add a USB wheel mouse and you can control all scope functions as well as drag and move waveforms on the screen. A T SILICON CHIP, we are fortunate to have a number of highperformance digital sampling oscilloscopes and one of them, the Agilent MSO7034A, has a large screen which is great for easy viewing. It and other modern digital scopes also have a VGA or XGA output so you can have a much larger display if you want. Realistically though, many technicians simply cannot afford a modern digital scope and they certainly cannot afford one which has a big screen. But LCD monitors are now quite cheap. You can buy a high-performance LCD 22inch or 24-inch monitor for a few hundred dollars. What if you could get a cheap scope gadget which fed signals to a cheap large-screen monitor? Wouldn’t that be great? No squinting at a tiny screen, trying to glean signal details etc, etc. The people at Diamond Systems must have had a similar thought siliconchip.com.au process. They have developed and produced the ScreenScope SSC-A531, a 50MHz digital scope in a compact box with only three BNC sockets on the front panel but no knobs. On the back panel it has a 9-pin socket for connection to that nice big monitor. All the smarts are in that compact box – no laptop and scope software are required. What a great concept! XGA video signal The SSC-A531 outputs an XGA (1024 x 768 pixels) colour video signal The ScreenScope is built into a rugged aluminium case with three BNC sockets on the front panel. January 2010  17 Fig.3: the Fast Fourier Transform shows the frequency components of the square wave applied to channel 1. You can see the peaks corresponding to the odd harmonics of the fundamental frequency (1.22kHz). The square wave measures 3.2V peak-to-peak, as shown in the top area of the display. Note that the display refresh will slow down when the FFT option is selected. as shown in the accompanying screen grabs. Most LCD or CRT monitors would be suitable although the best display would normally be obtained with a native resolution which is precisely XGA. Monitors with higher resolution may possibly stretch the display and this pixel stretching could lead to slightly less than an optimum picture. We tested the ScreenScope with a widescreen 24-inch BENQ LCD monitor which has a native resolution of 1900 x 1200 pixels and in our case, the display was centred with black stripes on either side (ie, not stretched). The resulting screen display is bright and very easy to read. As already mentioned, the ScreenScope has no controls on the front panel, although it does have a membrane switch which is the On/Off button. Two of the BNC sockets are the channel 1 and channel 2 vertical scope inputs while the third BNC connector is reserved for an external Fig.5: in this screen grab, channel 2 shows a sinusoidal wave at around 400Hz while the blue trace is a previously stored waveform. Each of the four reference waveforms can store a trace in non-volatile memory. Each of the four waveforms can also be measured using the on screen markers or used as an input to the MATHs functions. In this case, the red trace shows the result of multiplying the two traces. 18  Silicon Chip Fig.4: channel 1 shows a square wave at 1.22kHz while channel 2 shows a sinewave at around 400Hz. The result of multiplying the two traces is shown as the MATH trace in red. The MATH trace can also be averaged to reduce noise and automatic measurements displayed at the same time. Both the measurement selected and its running average are superimposed on the display. trigger source or for other functions which we will mention later. Both 1x and 10x probes can be used and the ScreenScope is supplied with two 100MHz 10x passive probes. The rear panel has a DC power socket and two USB sockets, one for connecting a 2-button mouse (with click wheel) and the other for connecting a USB flash drive. And there is also the 9-pin port for connecting a video monitor. A USB flash drive can be used to Fig.6: measuring the period of a sinewave. The values of the two markers are shown in the top left corner of the window. The two markers are also shown as vertical red dashed lines and can be positioned using the mouse. Here we position them so that the delta value measures the period of the waveform. The delta value is shown as 2.4875ms, which agrees with the automatic measurement shown. siliconchip.com.au Fig.7: this screen grab shows a PAL video signal with the timebase set to 2µs/div. The line sync pulse occurs about 6µs from the start of the trace. store waveforms – more on this later. When the ScreenScope is turned on, a red LED glows next to the power button. It takes about seven seconds from initially being turned on to display a waveform, which is a shorter boot up time than many standalone oscilloscopes. From this point on, you control all functions via the mouse. For example, the timebase can be changed by moving the mouse pointer to the panel located in the upper right corner of the display, as seen in Fig.2 where it is shown set to 2ms/div. You can vary the setting using the mouse’s click wheel or the left and right buttons. Pressing the left button decreases the value, while pressing the right button increases the value. This works with most of the other controls too. The timebase can be varied from 3.3ns per division (3.3ns/div) down to an extremely low 1 hour per division. That is much slower than most conventional digital scopes but we should note that timebase settings from 100ms to 1hr/div use the so-called “chart recorder” mode that resembles a data logging mode rather than a standard oscilloscope sweep display. This means that the samples are displayed as soon as they are acquired rather than after a complete sweep. This is a considerable advantage on very slow timebase settings, as you do not need to wait for the entire sweep to see the waveform, which could otherwise be a long time indeed. At 1hr/div, it would take 10 hours for the trace to make one sweep! Vertical resolution is fixed at eight bits while the vertical input sensitivsiliconchip.com.au Fig.8: the line sync pulse (which is around 4.7µs long) is followed by the colour burst signal, shown here using a timebase of 1µs/div for greater detail. ity can be varied from 50mV/div up to 10V/div (on a 1x probe). Display modes For each of the two channels, the ScreenScope allows you to select whether the trace is shown in “full” or “half” mode. In full mode, the waveform is shown at the full vertical 8-bit resolution, spread over the entire 600 pixels of the display window. However, because the viewable display is so large, in some cases, depending on the vertical scale setting, this resolution may be too coarse to achieve a good display. In this case, you should use the “half” mode, which effectively doubles the resolution by using the full vertical resolution to occupy only half of the viewable resolution (that is, eight bits for 300 pixels). Trigger options The ScreenScope can store more samples than are displayed on the screen at any time. This allows the waveform to be panned and zoomed using the mouse. This is very useful for investigating a waveform around its trigger point. All the usual triggering options, except video, are available. You can select to trigger on a rising or falling edge or on a positive or negative pulse width from any of the three channels. There is a configurable filter that can be applied to the trigger source to reduce noise and avoid unwanted triggering. This can be configured both as a low-pass filter to reject high frequency noise or as a differentiating filter that computes the gradient of the signal before applying it to the trigger circuit. The latter is useful for triggering from sharply rising waveforms (which exhibit high gradients) while ignoring low-frequency components. As with most oscilloscopes, the sweep mode can be automatic, triggered or single shot. MATHs features While the ability to add or subtract the input channels is more or less Features At A Glance Bandwidth: 50MHz real-time sampling Channels: 2 analog + 1 digital Sample rate: 240 megasamples (MS) per second Memory Depth: 4 kilosamples (KS) per channel Vertical Resolution: 8-bit ADC Video Output: 1024 x 768 pixels (XGA), 256 colours Size: 160 (W) x 227 (L) x 42mm (H) Weight: 0.95kg January 2010  19 The rear panel of the ScreenScope carries the USB sockets, a power socket and the video output socket. standard on all scopes these days, we did not expect to find the FFT (Fast Fourier Transform) facility which can be applied to channel 1 or channel 2. The FFT resultant trace is shown in red (see Fig.3). The scale can be set to dbV (for an unterminated waveform), dBm 50R (for a 50-ohm termination) or dBm 75R (for a 75-ohm impedance) – note that other impedances are also accounted for. This is simply a timesaving feature with the most common impedance settings. You can also enable averaging on the FFT channel to smooth out noise in the signal. Other MATHs features allow you to multiply and divide the amplitudes of two traces (see Fig.4 and Fig.5). The two traces can be chosen from among the two analog channel inputs, as well as from any one of four previously stored reference waveforms (see below). Note that when you enable any of the MATHs features, the display update frequency will decrease. Saving screen grabs & waveforms ScreenScope allows you to save up to four waveforms in internal non-volatile memory – these are the so-called reference waveforms (see Fig.5). These can be acquired from any of the two analog channels or from the result of the FFT or the arithmetic operations. You can even load a reference waveform from an external USB flash drive. For extra storage, an external USB flash drive allows you to save many more samples where it can function 20  Silicon Chip as a data-logging tool. Note that the data logging to USB may lose samples at very high sampling rates – this is a limitation of the packet size implemented for the USB transfer. Measurements & markers ScreenScope can make measurements of the waveforms that are displayed in the upper area of the screen. Measurements include the peak-to-peak voltage, amplitude, RMS voltage, rise time, fall time, duty cycle, frequency, period and positive and negative pulse width. Up to three measurements from three different groups can be displayed at any one time for both input channels. When selected, the measurements are displayed superimposed on the waveform window in red and white. Both the current reading and its running average are displayed. The units are auto scaling, meaning they change between mV and V or between µs and ms, say, depending on the measurement. Two screen markers can be moved around the waveform window using the mouse (see Fig.6). Actually ScreenScope refer to them as markers but they are displayed as red vertical cursors. The X or Y coordinates corresponding to the markers are then shown in the top-left corner of the waveform window, as well as the delta value (the difference between the two markers). This allows you to measure details of a captured waveform. The markers can be applied to any trace, including both of the input channels and any of the four reference waveforms. Calibration & probe compensation The output on channel 3 can be used for probe compensation as well as for calibration. It provides a 1.22kHz square wave for probe compensation. Calibration is also performed using channel 3. You simply connect the output of channel 3 to the analog channel you wish to calibrate using a short BNC cable. The oscilloscope does the rest. Note that you should run the calibration procedure at least 20 minutes after a cold start to allow for temperature drift. The calibration procedure takes around 10 minutes per channel. Firmware upgrades to incorporate new features or fix bugs can be down­ loaded from the manufacturer’s website and copied to a USB flash drive. The flash drive is then inserted in the host USB socket in the back of the oscilloscope. Conclusion ScreenScope offers a good range of user features with a good bandwidth at low cost – much lower than a standalone scope of the same specifications. The ScreenScope SSC-A531 is available from Diamond Systems and costs $A539 (including GST). For further information, contact: Diamond Systems, PO Box 105, Hurstbridge, Vic 3099. Phone (03) 9714 8269 or visit their website at www. SC screenscopetraces.com siliconchip.com.au Australia gets new advanced weather radar, courtesy of the Bureau of Meteorology . . . Bringing you much more than pretty pictures! I first noticed this giant “golf ball” last year, sitting high on its “tee”, right next to the Terrey Hills golf driving range in Sydney’s north. “Surely,” I thought, “that’s not just an advert for the driving range . . .” No it’s not (although I bet they are very grateful!) – it’s much more interesting than that – it’s the latest in the Bureau of Meteorology weather radar upgrades! And the best part: you can view its images via the ’net. by Ross Tester www.siliconchip.com.au www.siliconchip.com.au siliconchip.com.au JJanuary anuary 2010  21 2010  21 A typical PC “radar” screen showing approaching rainfall. You can add a lot more map features if you wish. W eather forecasting around Australia has become even more accurate and precise with the opening of several new highresolution Doppler weather radar installations. With the newest at Laverton (Vic), Mt Stapylton (Brisbane, Qld) and now at Terrey Hills in Sydney’s north, each has already proved their $4 million price tags money well spent. You can become your own weather forecaster by following the weather radar images on the Bureau of Meteorology’s website. The images from the newest technology weather radars cover the last half hour with screens six minutes apart. Older radars have images 10 minutes apart. There’s always a lag of up to about eight minutes – you can look out the window and see that it’s raining where you are when the screen tells you that the rain is still approaching (and vice versa). That’s mainly because of the incredible amount of computer “number crunching” then the upload times to the net. You can also show the whole of Australia with clouds and rain interpolated from all other radar sites. You get the choice of 64, 128 and 256km range, plus a 512km “composite” interpolated from other radars. You can also enable or disable a variety of map features, such as locations, roads, topography, etc. Rainfall is colour-coded by intensity – my experience is that anything yellow or above is getting rather heavy! You can log on to the Bureau’s website (www.bom.gov.au) and follow the prompts – the Terrey Hills radar images, for example, are at www.bom.gov. au/products/IDR714.loop.shtml#skip. But there’s a lot more than just radar images to look at. The Bureau has a vast array of tools to help the average person understand what the images represent and how to use them. The Terrey Hills radar Completed in April last year and commissioned after extensive testing on September 9, it is the fifth of six new high resolution weather radars to come online around the country thanks to the Federal Government’s $62.2 million radar upgrade project. In fact, the Government has extended the program with another four high resolution weather radars to be installed as part of the upgrade program. As far as Sydney is concerned, the Terrey Hills installation effectively replaces the Appin (south of Sydney) weather radar which has been operating since 1992. As well has having double the resolution of the Appin radar, Terrey Hills also has Doppler capability, which allows the display of wind flows associated with weather systems as well as rainfall intensity. Another problem for the Appin radar was/is that is considered too high above sea level to properly detect lowlevel rainfall over the Sydney area (as you can see by comparing the images from Appin and Terrey Hills at the same time). The Appin Radar will continue to operate in the short term. The Bureau is currently examining sites to the south of Sydney for a planned new Wollongong radar. On-going operational benefits of the Terrey Hills weather radar will include: • Improved short-term forecasts and The Moving Storm: Monday, November 30 2009 22  Silicon Chip www.siliconchip.com.au siliconchip.com.au Left: it’s not rain – how those on the ground wished it was – these radar images from Melbourne (Laverton) at 09.00 UTC (8pm EDT) on 7 February last year, at the height of the Victorian bushfires, where smoke was dense enough to show up. Right: the colour-code located underneath each map/image refers to the rainfall intensite. Here’s the key – and while it’s not absolutely accurate, it’s not too bad, either. I’ve only seen dark brown once – and that was a day that Sydney would rather forget! warnings of severe weather, including hail, damaging winds and tornadoes • Improved radar-derived rainfall rates for use in flood warning applications • Improved short-term forecasts of rainfall • Enhanced tracking of the movement and strength of wind changes such as southerly busters, cold fronts and sea breezes. Because the newest weather radars are Doppler, they can be used to measure speed – of wind, of storm fronts, and so on. Weather radars don’t reflect off clouds (the droplets are too small) but they reflect off the raindrops those clouds produce. Unfortunately, they also sometimes reflect off birds and insects, aircraft and even bats taking to they sky at dusk! Radar close to the coast may also reflect off shipping. The newest site The radar site at Terrey Hills (33.701°S, 151.210°E) is 195m above sea level and is approximately 18km north of the Sydney CBD. The radar covers more than a quarter of Australia’s population. Based on detecting echoes at a height of 3000m, the radar has an unobstructed view to the north, south and east. However, the rough topography of the Great Dividing Range slightly compromises the radar’s view to the west. Even so, high-level (ie upper-atmosphere storm) range extends west to Mudgee and Bathurst, as far north as Bulahdelah and Scone (in the Hunter Valley), and south to Goulburn and Ulladulla (NSW south coast). An examination of the coverage map will show that these limits overlap the coverage area of other weather radars in the system – which of course is part of the overall Bureau of Meteorology design. The heart of the installation at Terrey Hills is a Meteor 1500S dedicated S-Band Doppler weather radar, manufactured by AMS-Gematronik. It operates in the 2.8GHz band with a peak power of 750kW. The 8.5m linear horizontallypolarised dish has a gain of 45dB, 1° half- power beam width and 26dB side lobe suppression. It can scan between 0.2 and 6rpm but normally, the Terrey Hills scan rate is set at 3rpm. It is accurate to 0.1° and is mounted inside the protective fibreglass “radome”. The radar transmitter features a fully solid-state modulator which drives the VKS 8387 klystron tube. The klystron system, together with a coherent receiver, offers up to 20dB improvement in stability and clutter suppression compared to older, coaxial magnetrons. Other advantages of the klystron transmitter included high average and peak power, high gain, high efficiency, longer pulse duration and sufficient control of the waveform and frequency. The “Golf Tee” tower The 20m tower, which weighs in at about 60 tonnes, is made up of a bolt cage foundation, base, column, conical sections, a radar “floor” and topped by a 11m diameter fibreglass radome. The tower itself is 3.8m in diameter and the conical section at the top is 7.2m in diameter. It was manufactured by Melbourne- As a storm, it was only a tiddler. The colours show the rain rate – only a few patches of red, mostly greens, blues and greys. This half-hour “loop” from 04:18 to 04:48 UTC (3:18 to 3:48pm Sydney time) tracks the path of rain across the city. This one is also slow-moving: storms often move right through the area and out to sea in that 30-minute timeframe. www.siliconchip.com.au siliconchip.com.au January 2010  23 Remember Tropical Cyclone Larry, which brought so much devestation to North Queensland in March, 2006 (who could forget the price of bananas). Here Larry is being tracked by the Townsville weather radar (265km away) as it develops out in the Coral Sea and then finally comes ashore right over Innisfail. One surprising aspect of these radar images is the lack of rain intensity – not much above moderate. But if you’ve ever been caught in a cyclone, you’ll know it’s a tad more! based Eliot Engineering, who also manufactured the towers at Melbourne and Brisbane. How it works Contrary to what you might expect (having seen radar at airports, etc), as well as spinning in the horizontal direction weather radar antennas also move in the vertical direction. From a minimum of 0.5° above the horizontal, each rotation of the “dish” increases by 0.5° to build up a “3D” image. If this wasn’t done, the radar image would effectively be at one particular elevation. And as we all know, rain clouds/storms don’t scud along at a single convenient height. Depending on the type of cloud or storm it could be anywhere from virtual ground level right up to tens of thousands of metres. Hence the dish moves to capture the various heights. The hardware and software to control this is quite low level – in fact, a standard 512MB 2GHz PC is used running proprietary “Ravis 1500” software. Radar images are first processed on site by “Aspen DRX” signal processor software. There is an enormous amount of information contained in the reflected radar images. For example, there’s always clutter and false images which need to be analysed and if possible eliminated (although that’s not always practical). And of course, there is the integration of the various radar sweeps to form a single, coherent image. All this requires significant computer grunt, not to mention some pretty smart software. As a standard tool for the meteorological user, AMS - Gematronik has developed a powerful and versatile software package, fittingly enough Joining the two sections involved lining up the bolt holes. November 2008: The first 5m tower section in place 24  Silicon Chip Lowering the 5m pedestal that allows the radar dish to rotate. siliconchip.com.au It’s important that the radar site has an unobstructed view. This semi-fisheye shot is looking towards the west. called “Rainbow”. This offers the integration, processing and distribution of any kind of meteorological data and for remote control of weather radars within a meteorological network. Warnings While duty forecasters will always be monitoring their screens at the various meteorological offices (each capital city), much of the information coming in can trigger warnings which the duty forecasters can then act upon – for example, issue warnings to the media regarding approaching storms, prepare for possible floods, and so on. The duty forecasters’ screens will contain a lot more information than radar images but radar is a very important tool in getting the message out to the public about short-term weather. The highly-skilled operators can identify a lot of varied information February 2009: Installing the 8.5m radar dish onto the pedestal. siliconchip.com.au from weather radar that the untrained person would probably miss completely – for instance, southerly busters (very common in Sydney in summer), differences in thunderstorm types, hail, rotational super-cells. While the various BOM weather radar websites are very popular at the best of times, during storms or other weather events usage shoots up virtually exponentially. Thunderstorm warnings, for example, not only use the information from the weather radars (and other measuring equipment, some at the weather radar site but also located right across the country) and are automatically plotted on maps on the BOM website, with expected direction and intensity. The software tracks the thunderstorm on radar for a couple of cycles then projects its likely track. Even the place names are automati- cally generated and displayed so there can be no doubt in viewer’s minds as to location. Again, all this information can be circulated to the mass media for public warnings. Lightning One thing that radar does not detect is lightning, basically because there is nothing to reflect the beam back. However, there are quite precise methods of measuring lightning strike location and intensity but these are not functions the bureau performs. Instead, private organisations provide this service either in real time or as a delayed report. Lightning strike measurement is a fascinating subject in itself – SILICON CHIP has featured a couple of articles on the subject, the latest being in the November 1996 issue (“LPATS – StrikSC ing a Blow Against Lightning”). March 2009: Placing the last of the radome panels. January 2010  25 SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: dicksmith.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: dicksmith.com.au GPS Pt.1: By Geoff Graham Car Computer This project was inspired by requests from a number of readers. Essentially they said that the GPS module was great for obtaining a precise time . . . but could we produce a project that used its full capabilities for use in a vehicle? T his is the result. It is small enough to sit on the dash also use graphic symbols. The display uses a green LED backlight, with the brightor mount in the radio-sized (DIN) blank panels that ness automatically changed between day and night settings, many vehicles have. It is also relatively simple to construct and uses just a which can be easily configured. An USB interface allows you to plug the device into a few active components on a single PC board with no other wiring. There is no setup or calibration required – just plug laptop for a complete navigation experience with your position accurately pinpointed on a map. The USB interface also it in and away you go! allows you upload new firmware It is designed for use in a and re-program the device withmoving vehicle, where your atout any special hardware. tention should not be distracted GRAPHIC LCD from the road for any longer Block Diagram than is necessary. Therefore Fig.1 shows a block diagram data, such as your speed, is disof the unit. The central item is played in easily-readable 14mm GPS USB TO MICROCONTROLLER a 40-pin microcontroller which high digits, while a button press MODULE LAPTOP does most of the work, includwill show other data as needed. ing receiving data from the GPS You can also set it to autoLDR OR module, driving the LCD and matically step through the data FUEL INJECTOR HEADLIGHTS communicating via USB. screens for complete hands-off THREE PUSHBUTTONS The GPS module used is the operation. EM-408 which we have used in A key component is the Fig.1: conceptually, the GPS Car Computer is quite a number of previous projects. graphic LCD which allowed a simple. The microcontroller takes data from the Once every second this transmits great deal of design flexibility. GPS module, monitors a number of external signals, your current speed, position, Three fonts are used ranging formats the data for display and sends it to the LCD. from a jumbo font to a small While doing this it can also manage communications etc as a serial data stream to the microcontroller. detailed font, while some areas with your laptop via USB. 28  Silicon Chip siliconchip.com.au FEATURES: When a complete set of data has image is reversed in firmware and been collected the microcontrolthe data lines are reversed (D0 on • Digital speedometer ler will calculate parameters such the microcontroller connects to • Over-speed alarm as the fuel economy and format D7 on the LCD, etc). the data for display. This data is An additional output (pin 17 • Fuel economy meter then sent at high speed to the LCD or RC2) is used to control the • Distance and time to destination so that the display updates very backlight of the LCD. The mi• Digital clock with GPS accuracy quickly – in the blink of an eye! crocontroller generates a square The microcontroller also moniwave on this pin which, via Q1, • Altitude in metres tors a number of inputs, the three rapidly switches the backlight • Heading and compass pushbutton switches, a light LEDs off and on. By varying the • Current latitude and longitude dependent resistor (or the car’s duty cycle of this waveform the headlights) for night/day detecmicrocontroller can smoothly • A USB 2.0 interface so that you can tion and a signal from the fuel control the backlight brightness use it with your laptop for navigation injector system used in measuring from off to full on. or uploading firmware changes... fuel economy. It also controls the The firmware allows you to set backlight brightness of the LCD separate levels of the backlight and communicates over USB to brightness for day and night, a laptop. determined by a light sensor or The only other items of note are two voltage regulators the vehicle headlights. When the microcontroller detects a which supply 5V for the microcontroller and 3.3V for the transition between day and night it will change the brightness GPS module. The device can be powered from the vehicle gradually over a period of about a minute. This is done so that 12V battery or from a computer’s USB interface. the driver is not distracted by a sudden change in brightness. The main PC board is very small at 123 x 43mm and The crystal (X1) on pins 13 and 14 provides the main clock. piggybacks onto the LCD readout – the complete display/ Within the microcontroller the 20MHz crystal frequency is PC board stack is about 25mm high. The dimensions were divided by 5 to give 4MHz and then multiplied by 12 in a deliberately kept small so that the complete unit could be phase locked loop (PLL) to generate the processor clock of mounted in many places in addition to sitting on top of the 48MHz. This is further divided by 4 to drive the USB 2.0 dashboard. interface and also divided by 4096 to generate an interrupt to the CPU every 85µS. Circuit Details Continuing in a clockwise direction around the circuit Fig.3 shows the full circuit diagram of the GPS Car Com- diagram, the three pushbuttons go straight to inputs on the puter. As discussed before, it is not very complex and is microcontroller which are pulled high by internal resistors. dominated by the microcontroller, a Microchip PIC18F4550. As a result a button press causes the input to be pulled low. This is mostly concerned with driving the graphic LCD via The firmware switches the pullup resistors off and on as an 8-bit bus (D0 to D7) and seven control lines. needed, so if you use an oscilloscope on these inputs you The LCD is mounted upside down so that the data lines will not see a simple DC voltage. are physically on the bottom of the PC board (viewed from Pin 18 (VUSB) of the microcontroller connects to an the front) and do not short against the GPS module which internal 3.3V regulator which is used to power the USB must be mounted on top. To accommodate this, the display interface within the chip. The 220nF capacitor on that pin External Antenna Connector MMCX type for external GPS antenna (on back of box) USB 2.0 Interface For navigation software on a laptop or loading new firmware. (On end of box). Light Detector LDR (on end of box) for day/night control (vehicle light power can be used instead). Power and Signals 6-pin mini-DIN socket (on end of box) for power and external signal input. GPS CAR COMPUTER SET SILICON CHIP SET Button Switches to an option screen associated with the currently displayed screen. Using the UP/DOWN buttons allow you to change the value of the chosen option. Pressing SET again will save the option and return to the original display screen. siliconchip.com.au GRAPHIC DISPLAY 120 x 32 pixel LCD readout UP Button Will switch to the previous display. When setting an option will increase the value. DOWN Button Will switch to the next display. When setting an option will decrease the value. Fig.2: there are only three push-button controls on the GPS Car Computer – just as you would want to minimise the time your eyes are distracted from the road. Having said that, it’s delightfully easy to use. January 2010  29 helps suppress ripple and noise in the regulator. The data lines (D+ and D-) from the USB socket connect directly to pins 24 and 23 respectively of the microcontroller. This is one of the great features of the Microchip microcontrollers; you do not need external resistors, transceivers or any sort of supporting components. Everything to do with the USB connection is taken care of within the chip. Jumper JP1 is used to prevent a conflict with the USB power source when the GPS Car Computer is permanently powered from a 12V supply. The need for this is explained in the section on assembly options. GPS Module The interface to the EM-408 GPS module has some tricks D1 1N5819 REG2 LP2950CZ-3.3 OUT +5.3V IN GND 10 F 16V 11 +5.3V 4 2 +3.3V Vdd CVref EM-408 GPS MODULE 1 4 Tx 3 Rx 2 GND 3.3k RC1 RE0 5 RA3 25 Tx 6 26 JP1 CON2 1 4 23 2 24 3 18 USB TYPE B RC0 RA1 RB0 C1out RB1 RB2 Rx RD0 RD1 D– RD2 D+ RD3 Vusb RD4 220nF RD5 RD6 SET RD7 36 S1 DOWN UP 37 S2 38 S3 13 X1 20MHz 22pF 22pF 14 10 100 F 16V REG1 LM2940CT-5 OUT RB3 RC2 16 7 8 6 15 5 3 4 A 470nF D2 1N4004 K 19 Vdd CLK CS2 CS1 A0 33 +12V IN GND 2x 100nF 22k 2 6.8k +5.3V 1 +5.6V 220nF IC1 PIC18F4550 -I/P 5 EN MCLR A K 100k 32 Vdd RA0 10k V+ to it that need a little explanation. The signal line from the microcontroller’s pin 25 to the module’s receive data input (Rx) is simple enough. The microcontroller runs at over 5V while the GPS module runs at 3.3V, so the two resistors are necessary to drop the microcontroller’s output voltage to a safe level for the module. The transmit data from the module to the microcontroller is where the problems occur. The voltage level on the EM408’s transmit line is a little lower than the standard TTL threshold for a high logic level. This, coupled with noise and temperature variations will cause intermittent errors in the data stream as read by the microcontroller. If you refer to Fig.4 you can see that we overcome this LED+ Vcon LCD CONT 3 SG12232A LCD MODULE RES E R/W 18 8 9 LED– VR1 10k CON1 100nF 6-PIN MINI DIN 20 6 D7 D6 D5 D4 D3 D2 D1 D0 GND 17 16 15 14 13 12 11 10 1 5 3 4 2 34 1 35 19 20 21 82k* 22 27 28 29 30 3.3k 17 C B Q1 BC338 E RB4 RB6 RB5 RE1 RE2 OSC1 RB7 OSC2 RA5 Vss 12 82k 39 9 10 40 +5.3V 7 + Vss 31 8.2k* 47k PIEZO BUZZER RESISTORS IN RED ARE NOT INSTALLED AT PRESENT (RESERVED FOR FUTURE EXPANSION) LDR1*  * OPTIONAL 1 2 3 4 5 PC BOARD EM-408 CONNECTIONS SC 2010 GPS CAR COMPUTER 1N5819 1N4004 A A K LM2940, LP2950 BC338 K GND B E C IN GND OUT Fig.3: the full schematic for the GPS Display. It is dominated by the microcontroller which is mostly concerned with receiving data from the GPS module and driving the LCD. The only other items of note are two regulators which provide 5.3V and 3.3V. 30  Silicon Chip siliconchip.com.au SERIAL DATA (NOT TTL COMPATIBLE) 4 2 EM-408 GPS MODULE Tx 4 TTL COMPATIBLE SERIAL DATA +12V PIC 18F4550 1.35V REFERENCE COMPARATOR 5 ENGINE MANAGEMENT SYSTEM TO GPS DISPLAY (CON1 PIN 5) +12V 6 26 Rx FUEL INJECTOR SOLENOID 0V UART Fig.4: because the EM-408 GPS module does not deliver standard TTL voltage levels we must convert the signal. This is done by a comparator which compares the signal to a 1.35V reference, both of which are integrated in the microcontroller. The output of the comparator is a TTL compatible signal which is fed to the UART, also within the microcontroller. issue by feeding the transmit data to the non-inverting input of an analog comparator circuit within the microcontroller (pin 5 or RA3). The microcontroller is also set up to generate a 1.35V reference voltage which is available on pin 4 (CVREF). This in turn is connected to the inverting input of the comparator on pin 2 (RA0). The result is that the transmit data signal from the EM408 is compared to 1.35V and the clean, TTL-compatible, output is available on pin 6 (C1OUT), which is connected to the input to the serial data receiver (UART) at pin 26 (Rx). Power Supply The main power is derived from the vehicle’s 12V battery present at pin 4 of the DIN input/output connector. REG1 is a 5V linear regulator designed for automotive use so it can withstand large voltage spikes, momentay reversal of the input voltage and other abuses that are common in the auto environment. Fig.5: a simplified diagram of the fuel injector control in a standard petrol engine. The positive lead of the injector is at 12V and the engine management pulls the negative lead to zero potential to open the solenoid and inject fuel into the inlet manifold. It is this signal that you should feed to the GPS Car Computer. With the backlight turned on full, the regulator will dissipate almost 1W so it is mounted on a small heatsink. Silicon diode D2 in the common leg of the regulator serves to raise its output to 5.6V, then the 1N5819 Schottky diode in series with the output (D1) will drop about 0.3V resulting in an output of about 5.3V for the LCD and microcontroller. This is done for a number of reasons. First, diode D1 serves to isolate the main power supply if the GPS Car Computer Display is plugged into a USB port. If D1 was not present, the 5V supply from the USB port would also try to drive the output pin of the voltage regulator, resulting in an excessive current from the USB source. The second feature of this circuit is that it provides a 5.3V supply to the LCD. This is needed because the contrast of the LCD is controlled by the voltage on pin 3 (Vo) with reference to the voltage on pin 2 (Vdd). For normal contrast the voltage on pin 3 should be about -4.9V to -5.1V compared to pin 2 - although this varies with temperature and manufacturing tolerances. Without going into the subtle details, this means that either the supply voltage on pin 2 of the LCD must be noticeably higher than 5.1V or we must be prepared to The GPS Car Computer mounts on the Jiffy Box lid, which becomes the base . . . with the LCD readout showing through a cutout in the base . . . which becomes the front panel. siliconchip.com.au January 2010  31 47k CON1 82k 220nF 10 3.3k 22k 82k* S1 470nF 100k LDR* 8.2k* CON2 CON5 1 10 F 10k LP2950 X1 20MHz IC1 PIC18F4550 Q1 BC338 CON4 3.3k 100nF External connections All external connections are made through CON1, a 6 pin mini DIN connector. Ground and 12V are on pins 3 and 4 (respectively) of the connector. An external input from the vehicle’s headlight’s circuit can be wired to pin 1 to control the day/night backlight brightness (more on this in the section on assembly options). Pin 5 of the connector can be wired to a fuel injector solenoid if you want to implement the fuel economy meter function. The 82K and 47K resistors serve to drop the vehicle voltage levels to 5V for the microcontroller. There are also two spare connections (pins 6 and 2) which can be connected to pins 9 and 10 of the microcontroller. These are unused and available for future use. They can be set by the firmware to be digital inputs, digital outputs or analog inputs. TO-220 M3 x 10mm Fig.7: the 5V regulator REGULATOR SCREW HEATSINK can dissipate up to SILICONE 1W so it must be GREASE mounted on a heatsink. A smear of heat transfer M3 STAR LOCKWASHER & NUT compound must be PC BOARD applied between the regulator and the heatsink. Before tightening the bolt check that the heatsink clears the nearby solder pads. Only after you have tightened the nut and bolt should you solder the regulator’s leads to the PC board. 32  Silicon Chip REG1 LM2940 100nF VR1 6.8k 10k S3 (TO LCD MODULE) 1 supply a negative voltage to pin 3 to get a proper level of contrast. Our approach of using D1 and D2 to give 5.3V is much simpler than generating a negative voltage. The final benefit of this power supply design is that we can use the 5.6V (via a 10 current limiting resistor) for driving the backlight LEDs. Given the various voltage drops involved (about 3.6V across the LEDs and 0.7V across Q1) it is much easier to get full brightness from a supply that is a bit higher than 5V. This arrangement also means that the backlight is automatically disabled when a USB power source is used – handy because the USB interface on your computer would be overloaded if the backlight was enabled. The second voltage regulator, REG2, is a 3.3V device that supplies the GPS module. It has a low dropout voltage, so it is happy with the 2V voltage differential between its input and output and it comes in a TO92 package, which is convenient as there is not much space on our PC board. 100 F S2 REG2 D1 5819 PIEZO BUZZER 1 Future firmware updates could use these to measure voltages (eg, battery voltage or sensor outputs), detect digital inputs (eg, switch closure or tachometer output) or set them to be an output to control something. PC board The GPS Car Computer is built on a single PC board coded 05101101. The PC board is double sided and uses plated-through holes thereby allowing us to keep the size small. This type of PC board is actually easier to assemble than the single sided version commonly used. This is because the board is coated in a varnish (called solder resist) which protects tracks and areas that should not be soldered. It also has the position and values of the components printed on the top side of the board which means that assembly is mostly an exercise in following the diagrams. When soldering this type of board you should observe normal good soldering practice. Use a temperature controlled iron set to about 360°C with a fine tip (0.8mm chisel is good). Use fine resin-cored solder (0.8mm or less) and don’t hold the iron on a joint for more than three or four seconds. The use of plated-through holes means that you don’t need to install links but it does mean that it is difficult to remove a component after it has been soldered in. So, take care before you apply the soldering iron – check that the component is the right value and orientated correctly. The best way to remove a component from a board with plated through holes is to cut its leads close to the body, then pull the leads out with pliers while applying heat to the solder pad. You can then use de-soldering braid or a solder sucker to remove the excess solder from the pad and hole. 5.3V + – Fig.8: before you solder in the microcontroller and connect the GPS module you should check that these voltages are present. Both have a tolerance of ±150mV. If you cannot measure the IC1 PIC18F4550 correct voltages you should check D1, D2, IC2, IC3 and the power connection. – 1 3.3V + CON5 LP2950 D2 1N4004 1 220nF D2 1N4004 4 JP1 100nF 2 22pF 3 CON3 Fig.6: component overlay for the main PC board. Components marked with an asterisk (*) are optional – their use is explained in the text. The GPS module “plugs into” the header socket, CON5, while the LCD readout module similarly plugs into the longer socket, CON4. 22pF TO GPS MODULE siliconchip.com.au Here’s a photo of the GPS Car Computer to match the overlay at left. In this case, the LDR option is used to control the day/ night function. This an early prototype and the silk screen legend will be slightly different in the final board. If you want to make your own PC board, PDF and (zipped) EPS files can be downloaded from the SILICON CHIP website. However, given the fact that it is a double-sided board AND has plated-through holes, home fabrication is a lot more difficult than standard (single-sided) boards. Gerber format design files for the board, (used by most PCB fabricators) have been uploaded to BatchPCB and you can order it from them by following this link: http://tinyurl. com/ybulgcy. Many other PCB fabricators will also make the board for you and http://opencircuits.com/PCB_Manufacturers lists a large number of these companies. Of course, kit suppliers will include the board as part of the kit. Assembly options Before you start soldering there are a few of assembly options that you need to consider. The first is the control of the backlight brightness. The microcontroller determines if it is day or night by the voltage on pin 40 (RB7). When it is above about 1.4V it is night; less than that it is daytime. By rearranging the components on this input you can use a light dependent resistor (LDR) or the car’s headlight circuit to switch between the night and day brightness levels. The following table lists the components used: LDR Control LDR Install LDR R1 8.2k resistor R2 Leave Empty Headlight Control 47k resistor Leave Empty 82k resistor Note that for headlight control the 47k resistor is installed vertically in the position marked for the LDR. You also need to decide how you will wire up the power and other leads going to the mini DIN plug. If you are in- stalling the GPS Car Computer permanently you should connect the negative to the chassis and the positive power lead to a spare position in the fuse panel (if there is one) with a 500mA fuse. It may be easier to connect to a permanent 12V source and wire via an inline 3AG fuseholder with fuse. Refer to the Features Panel later in this article for the connection of power and other signals to the DIN connector. If you have decided on headlight brightness control you should wire pin 1 of the DIN connector to the vehicle wiring so that the voltage is at 12V when the headlights are turned on. A connection between pin 5 and a fuel injector is also necessary if you want to use the fuel economy feature. Fig.6 shows a typical circuit used in a modern car. You need to locate a negative solenoid lead and connect to that. The crude method would be to pierce the insulation of the wiring at the solenoid in the engine bay. This would expose the wire to corrosion and other dangers. A more elegant and reliable method would be to locate the engine management unit, normally behind the firewall in the passenger compartment and connect to the appropriate lead there. If you need to move the GPS Car Computer around, the best approach would be to wire the power leads to a cigarette lighter style plug with the positive power lead connected to the tip and the negative lead to the side wings. Most of LONG PINS PLASTIC SPACER SHORT PINS SOLDER PINS ON TOP (TOP) LONG PINS ON TOP (BOTTOM) Fig.9: the tactile TACTILE PUSHBUTTON switches must sit SWITCH GAP APPROX 1mm above the PC 1mm board so that the actuating rod will PINS PROTRUDE protrude far enough THROUGH PC BOARD through the front FOR SOLDERING panel. This spacing is achieved by making sure that the switch leads only protrude by a fraction of a millimetre on the underside of the PC board. siliconchip.com.au TRIM OFF PINS LCD MODULE PC BOARD (TOP) (BOTTOM) REMOVE PLASTIC SPACER Fig.10: the LCD has 20 pins which plug into the socket on the main PC board. Insert the long pins of the pin header from the underside of the display so that the plastic spacer is flush with the underside. Solder the pins on the top, lever off the plastic spacer and trim the pins on the top of the LCD board. January 2010  33 This photo shows how to remove the plastic spacer on the underside of the display board using a small screwdriver. You must remove the spacer so that the LCD can snugly mate with the main PC board. The pins on top of the board have already been trimmed. (Refer also to Fig.10). Here’s the partially assembled connector on the LCD. Note that the plastic spacer is on the underside with the long pins running up through the LCD board. The pins have been soldered on top. these connectors have a fuse in the body of the connector but if not, you should insert an in-line fuse holder fitted with a 500mA fuse. Another option for you to consider is jumper JP1, which is used to isolate the USB 5V supply. Normally this is left in place so that you can power the unit from either USB or 12V sources. You cannot use both simultaneously as this would place 5.3V from the GPS Car Computer on the USB 5V line from your computer, possibly causing damage. However, in some cases you might want to permanently wire the unit to 12V but still need to connect it to a comLEFT-HAND END puter via USB. To cover this eventuality JP1 is provided. When the jumper is removed, the USB cannot power the device, thereby removing any possible conflict. Construction Start assembly by soldering the 20-pin socket for the LCD to the PC board. Ensure that it sits fully flush with the PC board before you start soldering. The reason for starting with this socket is that it allows you to temporarily place the LCD display on top of this socket while positioning the other components. RIGHT-HAND END FRONT PANEL (BOTTOM OF BOX) 14 19 C 16 18 29 71 13 B A 32 LCD CUTOUT 71 x 29mm 13 B 16 A 13 B 32 29 15 16 B A D 114 13 17 74 8 15 E A 25 A A HOLE DRILLING DETAILS HOLES A: 3.0mm DIAM. HOLES B: 5.0mm DIAM. HOLE C: 10mm DIAM. HOLE D: 16mm DIAM. HOLE E: 6.0mm DIAM. 36 77 ALL DIMENSIONS IN MILLIMETRES (FOR EXT GPS ANTENNA) NOTE: HOLE B IN LH END IS ONLY NEEDED IF THE LDR IS INSTALLED A REAR PANEL (LID OF BOX) Fig.12: the drill holes and cutout required for the front panel, left and right ends and the box lid (which becomes the base). This diagram is reproduced at 80% – photocopy at 125% so that it can be used as a template. The centre hole in the lefthand end is only necessary if the LDR is installed. The holes in the right-hand end provide ventilation for the 5V regulator – accuracy is not so important in positioning these holes. 34  Silicon Chip siliconchip.com.au PUSHBUTTON CAP Fig.11: this shows how the main PC board and LCD are joined together and mounted in the UB3 jiffy box. It is important that the actuators of the tactile switches protrude far enough that the caps will fit without touching the front panel. It is also important that the LCD bezel is flush with the outside surface of the front panel. LABEL OVERLAPS LCD BEZEL BY 3mm 20mm M3 SCREWS WITH STAR LOCKWASHERS TOP OF LCD BEZEL LEVEL WITH TOP OF FRONT PANEL PUSHBUTTON CAP LCD MODULE BEZEL LCD MODULE PC BOARD 20-WAY SIL SOCKET MAIN PC BOARD 9mm LONG UNTAPPED SPACERS 15mm M3 TAPPED SPACERS M3 NUTS, STAR LOCKWASHERS & FLAT WASHERS BACK PANEL (LID OF UB3 BOX) 10mm M3 MACHINE SCREWS This is important as there is limited clearance (6 to 8mm) between the main PC board and the underside of the LCD display and you need to be sure that the components on the main PC board do not foul the LCD board before you solder them in. This particularly applies to the buzzer and trimpot, both of which tend to have extra plastic on their underside. You should cut this away with a sharp knife and make sure that the body of the component sits flush on the PC board and the top clears the LCD above. Other components that you need to watch out for include the transistor (Q1), the 3.3V regulator (REG2) and the 10F capacitor. For now, continue with the low profile components such as resistors and diodes and then move on to the taller components. At this stage, do not solder in the microcontroller or the push button switches. Note that resistors R3, R4, R5 and R6 are marked on the PC board but not installed as they are reserved for future expansion. Be careful with D1 and D2 as they look alike. The same applies to Q1 (the transistor) and REG1 (the regulator), both are in TO-92 packages and can easily be confused. When soldering in the crystal (X1) ensure that it sits a millimetre or two above the PC board so that there is no danger of the metal case shorting the connecting pads underneath. The LM2940 regulator (REG1) sits on top of a small heatsink as shown in Fig 7. Refer to this diagram for assembly instructions. Before screwing down the regulator check that the heatsink does not touch the solder pads on either side of the heatsink. The spacing is very close here but the heatsink can be slid around to ensure that it has adequate clearance. Once this is correct you can tighten the nut and bolt. Finally solder the regulator’s leads – this is left to last so that the solder joint is not stressed. The PC board has provision for an extra connector (CON3) which also can be seen in photographs of the prototype. Ignore this as it is intended for use with an In Circuit Debugger used only during software development. Quick Test With all components in place (except the microcontroller, switches, GPS and LCD) we can make a quick test to ensure that the voltages are correct. With the power/signal cable plugged into the mini DIN socket and the power turned on you should be able to measure about 5.3V between pins 11 and 12 of the microcontroller. Between pins 2 and 5 of the GPS connector (CON5) you should be able to measure 3.3V. Both could vary by plus or minus 150mV. Refer to Fig.8 for the measurement points. If you cannot measure the correct voltages you should check D1, D2, REG1, Loading New Firmware The GPS Display includes the facility to reprogram itself over the USB, this is sometimes called “flashing”. You don’t need any programming hardware and it uses free software. Full instructions will be included with any updates but the following will give you the flavour of how it works. To place the device into programming mode you hold down the Set button while you plug it into a USB port on your computer. This causes the GPS Display to masquerade as a Microchip PICDEM FS USB board and, as far as your computer is concerned, this is exactly what it is. This small deception allows us to use software developed by Microchip to upload new firmware to their own products – much easier than developing our own. Your computer will then ask for a device driver for the siliconchip.com.au PICDEM board. This is different from the virtual serial port driver used to receive GPS data from the GPS Display and will be included with any updates or can be downloaded from the Microchip web site. When the device driver has finished loading you can run the programming software provided by Microchip for their PICDEM FS USB board. This allows you to load the HEX file and reprogram the device, which takes only 20 seconds or so. You then unplug the USB cable and when you restart your GPS Display it will be running the new firmware. You don’t have to worry about a power failure or accidently unplugging something while it is programming. The programming code will not be affected if something does goes wrong, so you can always restart and try again or reload your original firmware. January 2010  35 REG2 and the power connection. Final PC board assembly Next you should install the microcontroller. This must be first programmed with the file 0510110A. hex (available for download from the SILICON CHIP website) using a normal PIC programmer. When handling the microcontroller and LCD you should take the standard precautions against electro static discharge (ESD) which could zap these devices. This means making sure that your work surface, your soldering iron and you are all grounded. As there is not enough clearance between the PC board and the LCD for an IC socket, the microcontroller must be directly soldered to the PC board. Normally you would need to remove it for reprogramming but as you can upload new firmware by USB, this is not a concern. However, once you have soldered the microcontroller you will not be able to remove it without destroying it. So, please read the next two paragraphs carefully. Pin 1 of the microcontroller is clearly marked on the PC board and is the top right hand pin when the PC board is viewed from the front. This must be matched to the dimple marking pin 1 on the IC’s body. This means that the microcontroller is installed upside down compared to the other components and the silk screen printing on the board. Before you apply the soldering iron, make sure that the part number printed on the chip is inverted compared to the printing on the PC board. We understand that Altronics will be producing a kit with a machine cut front panel which will make construction much easier. This will also allow each button cap to sit within a hole in the front panel and consequently there will be more space between the LCD and PC board. The main advantage of this is that an IC socket (supplied with the kit) can be used for IC1 and you do not need to panic over permanently soldering it in. When you have finished with the microcontroller you can install the three push button switches. These have been left to last because they can be easily damaged if the actuating rod is accidently forced too far to the side during assembly of the board. As illustrated in Fig.9 the body of 36  Silicon Chip GPS Car Computer - Features Summary Automatic Scan Simultaneously pressing both the Up and Down buttons will set auto scan. In this mode the unit will step to the next screen every three seconds. Pressing either Up or Down will terminate auto scan. The data displayed can be configured as described below. Show/Hide Display Screens Holding down the Up button while applying power will enter a special mode to configure what screens will be displayed or hidden. Repeatedly pressing Set will select: • Show (ie, the screen will always be displayed). • Hidden when Auto Scan is operating, otherwise shown. • Hidden Always. This is useful if, for example, the Fuel Economy Meter is not being used – it can then be hidden to reduce the visual clutter. Press Up or Down to move to the next screen to be configured. Remove power to exit this mode. USB 2.0 Interface The GPS Display creates a virtual serial port over USB and you can use this to connect to your laptop to show the GPS output, plot your location on moving maps and other functions using free and paid software. You must load the SILICON CHIP Serial Device Driver on to your PC. Firmware Updates By holding down the Set button when plugging into a USB port the GPS Display will accept firmware updates delivered via USB. Programming hardware is not required. Low Signal In a low signal situation or when first turned on the GPS Display will display a message and a count of the number of satellites found at that time. Pressing the Set button will show the Current Signal Levels screen described on the next page. Full Reset Pressing the Down button for a couple of seconds while applying power will reset the GPS module and all configurable parameters to the factory/design defaults. Automatic Brightness Control The brightness of the LCD backlight can be configured separately for day and night. Control of day/night can be from the vehicle headlights or from a light dependent resistor (LDR). When switching from day and night the brightness is slowly changed over a minute or so to avoid distracting the driver. Power and Signal Connector Pin 3 is ground Pin 4 is +12V power input PIN 5: PIN 6: Pin 5 is the fuel injector input. Connect HEADLIGHTS SPARE to the negative wire of a fuel injector (this PIN 4: is pulled to ground when the injector PIN 3: +12V POWER GROUND solenoid is activated). Pin 1 is the vehicle headlights input. PIN 1: PIN 2: It will control the day/night brightness of FUEL INJECTOR SPARE the backlight. This input is optional and is disabled if a light dependent resistor is used. Pins 2 and 6 are spare input/output lines for future enhancement. In this version they are left unconnected. siliconchip.com.au GPS Car Computer – Readout Summary Digital Clock All data is updated once a second. The currently displayed screen and all settings are saved in non-volatile memory and recalled on power up. Shows the current time in 12 hour (AM/PM) format. The seconds are shown in the bottom right. The time is derived from the GPS signal and is accurate to within 100mS (ie, any error is undetectable to a human observer). Pressing the Set button will allow adjustment of the time in steps of half an hour (ie, this sets the time zone – the exact time is always derived from the GPS satellites). Digital Speedometer with Over-Speed Alarm The digital speedometer will display your speed up to 250km/h. The current setting of the over speed alarm is shown in the bottom right. An audible alarm (two beeps) will sound when this speed is exceeded and the speedo display will switch to reverse video. Built in hysteresis prevents it from continuously beeping if you stay near this speed. The Set button will change the threshold or completely turn it off when set to zero. Fuel Economy Meter The length of the black bar shows the relative fuel consumption for the distance travelled (equivalent to litres per 100km). The longer the bar, the higher the fuel consumption so you would normally adjust your driving to keep the bar as short as possible. The graph is not calibrated but the sensitivity (ie, full scale) can be adjusted by pressing the Set button. This allows you to adjust it to suit different vehicles. Distance and Time to a Destination This display will count down the distance and time (in hours and minutes) to a destination. The time is based on your average speed over the last ten minutes, so if you get onto a slow road the time to your destination will increase accordingly. This display is reasonably accurate; the error is about one kilometre in 100. Press the Set button to setup the initial distance to the destination. Heading, Compass and Altitude The number on the left is the current heading (direction of the vehicle) in degrees. The needle can show either the heading or point to the north – this is configured by pressing the Set button. The numeric reading will always show the heading. Your current altitude in metres is shown on the right of the screen. Latitude and Longitude Your current latitude and longitude. This is shown as degrees, minutes and fraction of a minute and updates continuously as you drive. This is accurate to within a few metres depending on the number of satellites that can be found in the sky. This information (and much more) can be sent to your laptop via USB for use by navigation and mapping software. Current Signal Levels Shows how many satellites should be in the sky and the number that is currently being used by the GPS module. The bar graph shows the signal level of every satellite that can be detected. The module will not use a satellite if its signal level is below a threshold. By pressing the Set button you can adjust the backlight brightness for day and night conditions. Day/Night is determined by a light sensor or your car’s headlights. siliconchip.com.au January 2010  37 the switches must sit 1mm above the PC board. This is necessary so that the actuating rod will protrude far enough through the front panel. This spacing is easily achieved by making sure that the switch leads only protrude by a fraction of a millimetre on the underside of the PC board before soldering. The next assembly step is the connecting pins on the Parts List – GPS Car Computer 1 PC board, code 05101101, 140mm x 57mm 1 EM-408 GPS module manufactured by GlobalSat Technology (available from www.altronics.com.au) 1 SG12232A 122 x 32 dot matrix LCD (Altronics Z7052) 1   20MHz low profile crystal (X1) 1 buzzer – sealed mini PC board type, high output (Altronics S6105) 1   light dependent resistor, 10k to 1M (Altronics Z1621) * 3   tactile switches with 22mm actuating shaft (Altronics S1119) 3 button caps 7.5mm diameter (Altronics S1482) 1 mini DIN socket, 6 pin, PC board mounting 1 mini DIN plug, 6-pin 1   B-type USB socket, PC board mounting 1   2-pin header 1   20-pin header 1   20-way header socket, single row (8mm high socket base) 1   U-style micro heatsink for TO-220 (19 x 19 x 9.5mm) 1   UB3 jiffy box (130 x 67 x 43 mm) 4   15mm metal M3 tapped spacer 4   9mm metal M3 untapped spacer 4   20mm M3 bolt 5   10mm M3 bolt 9   M3 Star washer 4   M3 flat washer 5   M3 nut Semiconductors 1  PIC18F4550-I/P microcontroller (IC1) programmed with 0510110A.hex 1  LM2940CT-5 or LM2938ET-5.0 TO-220 5V voltage regulator (REG1) 1   LP2950CZ-3.3 TO-92 3.3V voltage regulator (REG2) 1   BC338 transistor (Q1) 1   1N4004 diode (D1) 1 1N5819 Schottky diode (D2) Capacitors 1   100F 16V electrolytic (105°C rating) 1   10F 16V tantalum 1   470nF MKT (code 470n or 0.47F) 2  220nF MKT (code 220n or 0.22F) 3   100nF monolithic (code 100n or 0.1F) 2   22pF ceramic (code 22p) Resistors (0.25W 5%) 1 100k 2 82k* 2 47k* 1 22k 1 10k 1 8.2k* 1 6.8k 2 3.3k 1 10 1 10k trimpot, vertical mount front adjust * = Optional – see text 38  Silicon Chip LCD. Start by inserting the long pins of the 20 way pin header strip through the matching holes on the LCD from the bottom. The plastic spacer should be flush on the underside of the display’s PC board and the shorter pins underneath. See Fig 10. Solder the pins on the top of the board while ensuring that the spacer underneath remains flush with the board. Then remove the plastic spacer leaving just the pins. This is best done with a fine screwdriver – lever down one end of the spacer by a few millimetres, then the other end followed by the middle. After repeating this a few times the plastic spacer will slide off the pins. The GPS module is supplied with a cable with identical connectors on each end. Cut off one of the connectors, bare the wires and solder to the pads marked CON5. The grey wire goes to pad 1 which is marked accordingly (the left hand pad when viewing the board from the top). The other wires should be soldered in the same sequence as they emerge from the connector. As a final check, closely inspect the board with a high power magnifying glass. Carefully check every solder joint for blobs, shorts or poor joints. You can now plug the LCD and GPS into the PC board. When you apply 12V power your GPS Car Computer should immediately start by showing the firmware version followed by a message indicating that it is searching for satellites. You will probably have to adjust the 10k trimpot to get an image on the display and then continue adjusting it for a good contrast. Consult the troubleshooting section if you run into problems. The housing The combined PC board and LCD is 123mm wide, 44mm high and about 25mm deep when viewed from the front. This means that it can be mounted in a standard car radio sized cut out in the dashboard. Many vehicles have this and are intended for holding small items. The PC board and LCD will even fit in the smaller radio slot found in newer vehicles. When mounted in this way and with a suitable front panel the GPS Car Computer appears to be part of the vehicle’s instrumentation. In this type of installation you will probably have to either extend the leads to the GPS module so that it can be moved to a more sensitive position in the vehicle or purchase and attach an external antenna. The antenna connector on the GPS module is an MMCX type and you should easily find a suitable antenna on the Internet (just google for “GPS antenna MMCX”). Getting a good signal level is very much dependent on the design of the vehicle and the position of the GPS Car Computer, so experimentation will be the order of the day. We decided to mount our prototype in a standard UB3 “jiffy box” so that it could be portable. The stacked PC board and LCD are mounted on the lid of the box, which becomes the back panel as shown in Fig.11. When the complete assembly is slid into the box the LCD bezel and the shafts of the push buttons will protrude through the base of the box (which becomes the front) as also shown in this diagram, the result is a neat appearance without visible screws. The LCD bezel should protrude through the front panel so that its front face is flush with the box’s outer surface. This means that there will be no need for a window or front glass for the LCD and the front panel label will cover any siliconchip.com.au Fig.13: front panel artwork for the GPS Car Computer, reproduced same size, ready for photocopying as described in the text. This can also be downloaded from siliconchip.com.au GPS CAR COMPUTER SET SILICON CHIP roughness in the cut out. To get this flush appearance you should use the spacers, washers and nuts as illustrated in Fig.11. If your result is not flush (due to tolerances in the hardware) you may need to add or remove some washers. To prepare the box you should drill and cut holes as illustrated in Fig.12. These diagrams are reproduced at 80% so if you photocopy them at 125% they can be used as direct templates for positioning the holes and cutout. If you have purchased the Altronics kit you should follow their instructions as their box will be already prepared and will use a slightly differentRDG_SiliconChip_0110_egx350.pdf sequence of spacers and mounting hardware for 1 1/12/2009 2:58:02 PM the PC board/LCD. To finish the assembly you should copy the front panel design in Fig.13 onto heavy-duty adhesive-backed paper (Avery 936067 is a good choice) and then either hot laminate it or cover the printed surface with adhesive backed clear plastic of the type used to cover books. Then razor cut this paper/plastic sandwich around the edges. When you cut out the centre of the label for the LCD you will notice that it is a little smaller than the LCD bezel. This is deliberate, as shown in Fig.11 the label is designed to overlap the LCD display bezel by a few millimetres. This hides any roughness in the cutout in the front panel and gives a clean, professional finish. Finally, peel off the backing paper from the label and attach to the front panel. C M Y CM MY CY CMY K siliconchip.com.au January 2010  39 The GPS module sits horizontally on top of the PC board and LCD boards with its antenna (the brown/silver assembly on the top) pointing to the sky. This is its most sensitive orientation. To make space for the module you need to use a sharp knife to remove the centre two plastic ribs on the top inside of the box. The module should then sit with its external antenna connector (the gold coloured connector) poking through the hole in the back panel and held in place by the surrounding box and PC board/LCD. If the module rattles around inside the enclosure you will have to attach padding of some type to keep it still. Troubleshooting With only a few active components in this project it should be easy to track down any faults. Firstly, check the two supply voltages as described earlier as nothing much will happen if they are not correct. Next, check the microcontroller. This is best done by measuring the voltage on pin 4 which should be between 1.2V and 1.5V. This voltage is created by the internal voltage reference and implies that the firmware is running, has enabled the reference and configured it for the correct voltage. In other words, it means that the microcontroller is perfectly OK and running its program. In the absence of this voltage, use an oscilloscope to check for a 20MHz sinewave at pins 13 and 14, indicating that the main clock is present. Also check the soldering around the microcontroller for bridges, non soldered joints, etc. If the microcontroller is working the next thing to check is that the pushbuttons are OK. Use a multimeter to check that the switches are open when not pressed and near zero ohms when pressed. If a button is stuck down it will cause the unit to go into one of several special modes when power is applied and that may trick you into thinking that the whole unit is not working. If the actuating arm of a switch is pushed too far to the side this can also cause the switch to close. This can happen if your drilling of the front panel is not accurate. Next is the LCD. First check the voltage on pin 3 of the LCD (Vo), it should be under 0.5V. This voltage is controlled by the 10k trimpot (contrast) and if not correctly adjusted the display will appear blank. The microcontroller only sends data to the LCD and does not expect any response. So, even with the LCD removed or faulty, you should still see signals on the data lines to Choosing a Microcontroller Readers might be interested in the background of why we chose a PIC18F4550 microcontroller for this project. Originally the design started with the Microchip PIC16F877A. This has been around in variou s incarnations for at least 10 yea rs (a long time in semiconductor circles) and has long been the chip of choice when large pin cou nts have been required. How ever, during development we ran into a problem with its limited RAM . Searching through the Mic rochip catalog we found the PIC18F4550. This is a much mo re modern chip which has 204 8 bytes of RAM – plenty for our requirements. As a bonus it also had four times the program me mory, ran four times faster tha n the venerable PIC16F877A and , if that was not enough, it include d a USB 2.0 interface to boot. It had also been used in previou s SILICON CHIP projects so it was not a total stranger. The clincher was when we che cked the Microchip price list. The PIC18F4550 with all its fan cy features was 20% cheaper tha n the plain old PIC16F877A! As an American would say… the decision was a “no brainer ”. the LCD. If the LCD is blank or showing rubbish the only things that you can do is check that it is plugged in correctly and that there are no solder bridges on the connector. With the microcontroller running and the LCD showing the startup message the only other fault would be with the GPS module. The microcontroller will display an error message if the module is not connected or running, so that type of fault should be obvious. The GPS Car Computer could also sit for a long time with the LCD showing a message indicating that it is searching for satellites. This indicates that the GPS module cannot get a signal and moving the unit outside or near a window should correct that. While it is searching you can press the Set button to get the Signal Levels display – this will show you how many satellites can be seen and their signal levels. Assuming all is well, we’re ready to move into some of the more esoteric aspects of operating the GPS Car Computer but alas, space has beaten us so that will have to wait until next month. However, as we said earlier, it really is very simple and quite intuitive to operate, so between now and February you’ll have a good opportunity to play with it yourself and find out many of the good things it can do. We’ve even given you a head start with the various LCD SC readout screens shown earlier! Resistor Colour Codes o o o o o o o o o      No. Value 1 100k 2* 82k 2* 47k 1 22k 1 10k 1* 8.2k 1 6.8k 2 3.3k 1 10 * - Optional, see text 40  Silicon Chip 4-Band Code (1%) brown black yellow brown grey red orange brown yellow violet orange brown red red orange brown brown black orange brown grey red brown blue grey red brown orange orange red brown brown blackblack brown 5-Band Code (1%) brown black black orange brown grey red black red brown yellow violet black red brown red red black red brown brown black black red brown grey red black brown brown blue grey black brown brown orange orange black brown brown brown black black gold brown siliconchip.com.au N CON CO CON ILICONSILIP SILIP S SILIIPCONSIHLIIP IP HI HI DIGITAL I/O 1 +3.3V 100nF CHIP 12 Ya0 Zb 3 5 Yb1 1 Yb0 6 100nF 14 IC1e 10 E S1 S0 9 Vss 8 Vee 7 33pF BFrame EMPH 6 5 3 4 12 DGnd 6 IC5: 74HC14 1F 22k 22k 9 14 5   K 1 2 2 K A 22k 7 9 11 TO - A N A L O G C O N V 1F 1 K 22k 3 K 20 9 AVcc 14 2 8 $ 95* 16 PC4 PC5 9 28 11 26 PC2 13 25 PC1 PC0 RST PB6 7 27 PC3 12 PD6 IC5a 10 2 24 (TO DAC BOARD) all about? What’s it fun with a We have ared camera r FLIR i5 inf 23 1 IC1a IC4 ATMEGA48/V IC1b IC1c 2 5 IC1d 4 9 9 6 11 8 4 7 K Using a ARD . . . and it’s 10 HM GOHM EGO ME AL M GITAL DIGIT DI TION ATIO LA UL SU NS AN AND IIN TER METE AGE ME AKAG LEAK LE D14: 1N4004 K A Try out AREF LM3940T-3.3 OLEDS BC327 100nF GND K A K A 21 GND 22 8 Now affordable for the hobbyist! B E GND IN C GND 8 INC GST r Needed: No Compute WIB n a Box! Webserver I 00 INC GST INC GST tage ECU Volp tor Interce ceptt,, nterrcep IInte gram ogra epro nd rrepr and fy a odiify m mod cle ehiicle veh ny v any utt a bou abo ust a jjust ge! age olta volt or v sor ens sen CU s E ECU nd an ort a for omf com n:: or c For F ion tio sat imiisa nim miin on m atiion rat ibr vib v JANUARY 2010 C 62 1030-2662 ISSN 1030-26 ISSN 11 12 8 $ 95* INC GST NZ$ 11 00 INC GST 11 01 266001 771030 266001 9 771030 9 APPROVED PRINT POST - PP255003/01272 APPROVED PRINT POST - PP255003/01272 $ $ 95* NZ 11 NZ$ 1100 8 $ 95* GY’s METEOROLOER RADAR: NEW DOPPL INC GST NZ$ 11 00 INC GST gear More test to build: Digital or Capacit Leakage Meter man! an Meter weather OUS LEsDtrePeatnsealway! YOU can BE the GINORrM can ead from Look at this - absolutely you nge atch Global Green Challe SpeedM Records tumble in : ple Simple ad Sim ead De D Spec High Spe Hig FM TV/FM HF TV/ F-UHF VHF-U VH mp Am A d ea sthea Masth Ma USB ILE US ATILE RSAT VERS VE ACE RFAC TERF INTE I/O I/O IN D L I ILD BU TO BU TO FREE! at Boat ined Bo Engine on in-Eng atiion TwinTw sat lis ali qua Equ dE ed pee Spe or S tor ot Mo M OUT S PLU BLE: PEB new graphics A fun program to help oards lay out protob 8 IC5e 1030-26622 ISSN 1030-266 ISSN cope PLUS: argain digital s ScreenScope: b ger and controller g Temperature lo AND . . . 1 2 3 4 5 3x 2.2k T & CONTROL BO IC5d LED5 LED4 5 PD3 6 D4 P 2 PD0 3 D1 P 4 PD2 11 INPU you in 8 D9–D13: 1N414 PB7 A IC5b INC GST DECEMBER 2009 266001 99 771030 771030 266001 2 ISSN 1030-266 266001 9 771030 APPROVED PRINT POST - PP255003/01272 12 NOVEMBER 2009 11 266001 9 771030 APPROVED PRINT POST - PP255003/01272 CH C OCTOBER 2009 10 2 ISSN 1030-266 15 FLIR PB2 12 Wideband 02 serncsaor r ERTER 7 C 16 100nF 1 2x 330 13 13 47k INC GST INC 23GST 6 IC5f 1F D12 14 14 B 11 PD5 D13 8 1 8 E 47k 3 22k A 8 A 4.7nF 1nF 13 10 10 LED5 A 16 IC5c +5V A K LED4 Q2 BC327 6.8k 17 47k B C d NZ$ 116008nF $ AGn95* 19 PB5 18 PB4 17 B3 P 15 PB1 13 PD7 14 PB0 1M 22k 47k D11 E 18 Uout 100nF 100nF 22F 4 22 15 APPROVED PRINT POST 01272 Cout - PP255003/ 8 XTI 33pF Q1 BC327 19 FILT 7 12 28 RSV +5V +5V 3 CH CKSEL 5 +3.3V 21 SEPTEMBER 2009 Vcc +3.3V 5 4 RST for outst uality DVD Sound Q +5V D14 6 SCKO ity High Qual AC StereoaD nding K A 4 9 CLKST 7 TO X X1 24.576MHz 10 +5V 7 100 6 10 LRCKO IC3 DIR9001 10 11 BCKO 27 ERROR 3 SOUT1 F 2 OUT0 FS 1 AUDIO IC2 74HC4052 4 Yb3 2 Yb2 DOUT s: lus: Plu P as g:ear I gea MI DM HD ingsH tin tm Test Tes errds sa ds Boa ao CcB PC ri P ing o Millling Mil afxes caxe Pig ” Pic “Xo2w er New “X2 New npde h ck ate Tokai Challeng ate U ck Cloo kiUpd r ster . . . GPS Clo GPS Tesla Road ift IVy Lo iffe a d and Sunsw id 6... GPS a nt r ? 3 Za 13 14 Ya1 12 e 15 Ya2 8 Vcc S Ch 11 Ya3 U04 11 14 PSCK1 13 PSCK0 26 MT1 F 25 FMT0 20 RXIN 3 24 5 Vdd 16 Vdd 22F 100nF 100nF g if t CAR UTER a COMitP . . or with ! n s own . Use it o oftware mapping s laptop and NOW AVAILABLE: SIX MONTH SUBSCRIPTIONS & AUTO RENEWALS In these tough economic times, we understand that taking out a one or two-year subscription may be difficult. Or perhaps you’d like a trial before committing yourself to a full sub. Either way, we’ve made it easy with our new six-month subscriptions. It’s the easy way to make sure you don’t miss an issue . . . and a six month subscription is STILL CHEAPER than the over-the-counter price AND we pick up the postage tab. Have SILICON CHIP delivered to your door every month, normally a few days BEFORE it goes on sale in newsagents (grab some of the advertised bargains early!). We also offer the convenience of auto-renewal if you wish: we’ll renew your subscription for the same period automatically when the time comes. It’s simple and easy – you don’t have to do a thing! Don’t forget: printed edition subscribers* automatically qualify for 10% discount on other SILICON CHIP merchandise. IF ELECTRONICS IS YOUR BUSINESS OR TRADE, A SILICON CHIP SUBSCRIPTION IS NORMALLY 100% TAX DEDUCTIBLE! To Place Your Order: eMAIL (24/7) silicon<at>siliconchip.com.au with order & credit card details OR FAX (24/7) This form (or a photocopy) to (02) 9939 2648 with all details OR PAYPAL (24/7) OR Use PayPal to pay silicon<at>siliconchip.com.au PHONE – (9-5, Mon-Fri) MAIL Call (02) 9939 3295 with your credit card details This form to PO Box 139 Collaroy NSW 2097 OR SUBSCRIPTION LENGTH AND TYPE: q AUSTRALIA 6 MONTHS (INC. GST) (NEW!).............................. $49.50 (PLEASE PRINT) q AUSTRALIA 12 MONTHS (INC. GST)......................................... $94.50 Address______________________________­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­___________________­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­_____________ q AUSTRALIA 12 MONTHS WITH BINDER (INC. GST) .............. $111.00 q AUSTRALIA 24 MONTHS (INC. GST)....................................... $182.00 q AUSTRALIA 24 MONTHS WITH BINDER (INC. GST) .............. $215.00 _____________________________________­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­_______Postcode_________________ q NEW ZEALAND 6 MONTHS (AIR MAIL) (NEW!)....................$AU55.00 q NEW ZEALAND 12 MONTHS (AIR MAIL)...............................$AU99.00 Phone ( )_____________ Email address __________________________________ q NEW ZEALAND 24 MONTHS (AIR MAIL) ...........................$AU196.00 (Daytime number, please) q OVERSEAS (EXCEPT NZ) 6 MONTHS (AIR MAIL) (NEW!).....$AU75.00 Method of Payment: q EFT (ring or email for details) q Cheque/Money Order q PayPal q OVERSEAS (EXCEPT NZ) 12 MONTHS (AIR MAIL)..............$AU135.00 q OVERSEAS (EXCEPT NZ) 24 MONTHS (AIR MAIL) ............$AU260.00 q Visa NEW! CONVENIENT AUTOMATIC q MasterCard SUBSCRIPTION RENEWAL: Your Name____________________________________________________________ q Tick here if you’d like us to automatically renew your subscription Card Expiry: Signature______________________________    as it elapses (ie, 6 month, 12 month or 24 month).    We’ll renew until you tell us to stop! siliconchip.com.au January 2010  41 THIS PAGE MAY BE PHOTOCOPIED WITHOUT INFRINGING COPYRIGHT siliconchip.com.au January 2010  41 *10% DISCOUNT OFFER ONLY APPLIES TO PRINTED EDITION SUBSCRIBERS AND DOES NOT APPLY TO WEBSITE ORDERS. A balanced output board for the Stereo DAC By NICHOLAS VINEN This add-on board is designed to provide a pair of balanced audio outputs for the High-Quality Stereo DAC (Sept-Nov 2009). Two 3-pin male XLR connectors are used for the new outputs and they can either replace or augment the existing unbalanced outputs without affecting their performance. B ALANCED AUDIO is used in recording studios and on stage because of its improved noise immunity. This is due to the fact that the signal is sent differentially (ie, as two signals 180° out of phase) and then converted to a single-ended voltage signal at the far end. If any noise is picked up in the cable, it affects the two out-of-phase signals equally so that when the signals are subsequently subtracted, most of the noise is eliminated. In addition, the DAC’s performance at the balanced outputs generally exceeds that of the unbalanced outputs, although only by a small margin. The signal-to-noise ratio, frequency Table 1: Balanced/Unbalanced Output Performance Comparison Measurement THD+N, 1kHz SNR (unweighted) SNR (A-weighted) Frequency Response, 20Hz-20kHz Channel Separation <at> 1kHz Channel Separation <at> 20kHz 42  Silicon Chip Unbalanced 0.00090% -108dB -114dB +0,-0.15dB -105dB -73dB Balanced 0.00095% -112dB -116dB +0.02,-0.05dB -115dB -111dB response and channel separation are all better, although we measured a tiny bit more distortion from the balanced outputs. However, both levels are so low as to be almost negligible. Performance At this point, it is worth mentioning that during the development of this board, we used a new source of digital sinewave data for distortion measurements. This revealed that the DAC is capable of lower distortion than originally quoted. With a 44.1kHz 16bit computer-generated sinewave, the THD+N at 1kHz is 0.0012% and with a 48kHz 20-bit sinewave the THD+N is 0.0009%. These measurements are only slightly higher than the distortion siliconchip.com.au V+ 10nF 22pF 1 F 560 910 820 3 BP 2 100k 5.6nF 7 8 IC1 1nF 100nF 5 100 6 4 2.2nF LEFT IN 0 L+ V– LEFT OUT CON1 XLR 1 3 L- 2 V+ 10nF 22pF 1 F 560 910 820 3 BP 2 100k 5.6nF 7 8 IC2 1nF 100nF 5 100 6 4 2.2nF V+ 0 V– IC1–IC4: NE5534 OR OPA134 V+ 910 820 3 BP 2 100k 5.6nF 7 8 IC3 1nF 1 V– 100nF 5 100 6 4 2.2nF RIGHT IN 0 R+ POWER IN GND – 100 F 22pF 560 + 2 10nF 1 F 3 100 F V– 1 3 R- 2 RIGHT OUT CON2 XLR V+ 10nF 22pF 1 F 560 910 820 BP 3 2 100k 5.6nF 1nF 7 8 IC4 100nF 5 6 4 V– SC 2010 100 2.2nF 0 BALANCED OUTPUTS FOR THE STEREO DAC Fig.1: the incoming differential signals from the the DAC Board are fed to separate passive high-pass filter stages and then to four active low-pass filter stages based on op amps IC1-IC4. These op amps then drive pins 2 & 3 of the XLR output sockets via passive low-pass filters based on 100Ω resistors and 2.2nF capacitors. measured directly from the Audio Precision System One’s internal sinewave generator (0.0006%) so it’s hard to say exactly what the actual level of siliconchip.com.au distortion is. However, we can safely say it is very low indeed. Table 1 shows a performance comparison between the balanced and unbalanced outputs, measured with the new 48kHz 20-bit sinewave source. Note that while the channel separation from the balanced outputs is January 2010  43 BALANCED RIGHT OUTPUT 100 F CON2 RLX XLR – CON1 XLR 0 TFEL - 2.2nF 820 910 NE5534 OPA134 100nF 1nF RIGHT IN L L– L+ IC4 100k 560 1nF IC3 R 1 F BP 10nF 22pF 5.6nF 100nF 5.6nF 5.6nF 1nF LEFT IN 10nF 22pF NE5534 OPA134 IC2 1nF 100nF IC1 100k 560 100nF NE5534 OPA134 100k 560 NE5534 OPA134 2.2nF 10nF 100 100k 560 2.2nF 22pF 10nF 820 910 22pF 2.2nF 100 100 820 910 100 5.6nF T H GIR RLX r e w oP POWER + + 00000000 100 F 820 910 BALANCED LEFT OUTPUT 1 F BP 1 F BP R– R+ 1 F BP TO POWER SUPPLY BOARD SHIELDED STEREO CABLES FROM DAC BOARD (CONNECT SHIELDS AT THIS END ONLY) Fig.2: follow this parts layout diagram to assemble the Balanced Output Board. The L+, L-, R+ and R- inputs are derived from the DAC Board (see below). STEREO AUDIO OUT RIGHT (RED) LEFT (WHITE) 22pF L R TUO 100nF 8.2nF 100nF 180 180 200 27nF 220 220 22pF 200 R+ 100nF IC11 OPA134 NE5534 820 2.7nF 100nF 820 100 8.2nF 27nF 220 L+ 220 22pF 22pF IC10 OPA134 NE5534 8.2nF 180 180 200 8.2nF R- 2.2nF 200 100 22pF IC9 OPA134 NE5534 IC12 OPA134 NE5534 2.2nF 100nF 100nF IC7 OPA134 NE5534 IC8 OPA134 NE5534 820 820 2.7nF 2.7nF L22pF 2.7nF Fig.3: the L+, L-, R+ and R- points on the DAC Board are marked here in red and drive the inputs of the Balanced Output Board. Note that the parts on the 47 Foutput socket and vice versa. righthandside of this board drive the left channel 47 F 10k 47 F + 44  Silicon Chip – + D15 100nF 100nF much better than from the unbalanced balanced outputs. These are converted REG5 IC6 LM7805T outputs, in practice 73dB is more than (UNDER) to single-ended signals on the DAC 10 F adequate. In29fact, board via 47 Fa pair of differential ampli09011it’s 0 very unlikely that 100F F Fig.3, anybody can hear the difference under 100nF fiers (IC9 & IC12100on September +15V 0V -15V normal circumstances. 2009). This means that the simplest 16 2 1 way to15provide balanced outputs is to Deriving balanced TPOWER UPNsignal I V5IN 1-/+ going to these tap the O/I outputs LATIGID DIGITALdirectly I/O In practice, providing balanced differential amplifiers. outputs from the DAC is relatively Theoretically, the outputs from the straightforward since the DAC chip current-to-voltage (I/V) converter stagwe used – the DSD1796 – itself has es (ICs7, 8, 10 & 11) could be connected directly to the XLR socket outputs via 100Ω isolating resistors. However, we have come up with a more complicated design for a couple of reasons. First, making a direct connection from the existing DAC board to the XLR sockets would bypass some of the low-pass filtering. This filtering is important because it’s designed to remove high-frequency switching artefacts. Second, a direct connection would load the I/V converter stages even more than they already are. In view of this, asking the op amps to drive an additional, unknown amount of cable capacitance seems unwise. As a result, we feed the signal at the outputs of the I/V converter stages to an interface board to provide the balanced outputs. This board also includes four active low-pass filter stages based on NE5534 op amps. Note that because the DAC’s outputs are asymmetric (they only sink current), the outputs of the I/V converters (ICs 7, 8, 10 & 11) are always above 0V. As a result, these outputs are AC-coupled to the op amps in the balanced output stages to remove the DC component of the signal, so that it is centred around 0V. Circuit details Refer now to Fig.1 for the circuit details. It consists of two identical sections, one for each channel. As mentioned, the incoming differential signals are AC-coupled via 1µF bipolar capacitors. These capacitors and the following RC components also form 6dB/octave high-pass filters. We have set the corner frequency of this filter low enough (1.6Hz) so that it has minimal effect on the 20Hz-20kHz frequency response (-0.046dB). The remainder of the circuit consists mainly of the four active low-pass filter (LPF) stages and these are based on op amps IC1-IC4. Each filter is an active third-order LPF with a -3dB point (corner frequency) of 52kHz and a slope of -18dB per octave. These are then followed by passive first-order 720kHz low-pass filters, each based on a 100Ω current-limiting resistor and a 2.2nF capacitor. These are identical to those used at the outputs of IC9 & IC12 on the DAC board and attenuate the 60MHz (approx.) switching spikes that the DAC generates. In addition, since these are passive siliconchip.com.au from the ±15V outputs of the Power Supply Board. The supply rails are fed in via another 3-way screw terminal block on the Balanced Output Board, with two 100µF capacitors providing additional filtering. Construction Refer now to Fig.2 for the parts layout on the PC board. As can be seen, the assembly is straightforward. Begin by checking the PC board for defects, then start the assembly by installing the resistors and wire links. You can either use 0.71mm tinned copper wire for the links or you can use 0Ω resistors (as in the prototype). Next, install the IC sockets, ensuring they are correctly oriented. Follow these with the terminal blocks, ensuring that the openings point towards the edge of the board in all cases. Be sure to seat them properly on the PC board before soldering their pins. The capacitors can go in next. The two 100µF filter capacitors are polarised, so watch their orientation. Follow them with the XLR connectors, then install the four ICs (again, make sure they are correctly oriented). Finally, complete the board assembly by fitting M3 x 6mm tapped Nylon spacers to the mounting points. You will need at least four of these (one in each corner) and they should be secured using M3 x 4mm screws. It’s also a good idea to fit an extra spacer between the two XLR sockets, to ensure extra rigidity when plugging in external leads. An extra mounting This view shows the fully assembled PC board. Be careful with the orientation of the ICs. filters, they are effective at filtering any high-frequency noise which the active filter stages may allow through. The third order active LPFs only require a single op amp each (ICs14). However, unlike the DAC board, there is no performance advantage to be gained by using OPA134 op amps over NE5534s. Instead, testing has revealed that it is the I/V converter stages on the DAC board that benefit from the improved performance of the OPA134s. By contrast, on the Balanced Output Board, the op amps only act as unity gain voltage buffers and the NE5534 performs admirably in this role. However, you can use OPA134s if you wish. For example, if you are not going to be installing the unbalanced outputs, you will have two spare OPA134s from the DAC board, so you only need to buy two more for the Balanced Output Board. Note that the board has pads for the 22pF compensation capacitors required for the NE5534s and if you are purchasing op amps specifically for this board, NE5534s are recommended. Alternatively, if you decide to use OPA134s, you can leave out the 22pF capacitors (although installing them does not hurt). The output of each op amp appears at pin 6. IC1 & IC2 provide the differential output signals for the left channel and these respectively drive pins 2 & 3 of the left-channel XLR socket via the low-pass passive filter stages. Similarly, IC3 & IC4 drive the right-channel XLR socket. The XLR outputs are mounted directly on the PC board, while the input signals from the DAC board are fed in via 3-way screw terminal blocks. The latter provide a 0V connection for shielding purposes but the shield should only be connected at one end. Power for the Balanced Output Board circuitry is derived directly Table 3: Capacitor Codes Value 100nF 10nF 5.6nF 2.2nF 1nF 22pF µF Value 0.1µF 0.01µF .0056µF .0022µF .001µF N/A IEC Code 100n   10n   5n6   2n2   1n0   22p EIA Code    104    103   562   222   102   221 Table 2: Resistor Colour Codes o o o o o o siliconchip.com.au No.   4   4   4   4   4 Value 100kΩ 910Ω 820Ω 560Ω 100Ω 4-Band Code (1%) brown black yellow brown white brown brown brown grey red brown brown green blue brown brown brown black brown brown 5-Band Code (1%) brown black black orange brown white brown black black brown grey red black black brown green blue black black brown brown black black black brown January 2010  45 Here’s one way of installing the Balanced Output Board in the chassis. In this case, the new board has been mounted in the rear righthand corner of the chassis, while the DAC Board has been moved to a new position in the front righthand corner. The left & right channel outputs from the DAC Board are then connected via shielded figure-8 cable to RCA sockets mounted on the rear panel. Be sure to mount the DAC Board far enough to the left to leave room for the RCA plugs. NOTE: THE SUPPLY LEADS TO THE FINAL VERSION OF THE INPUT BOARD ARE REVERSED AT THE TERMINAL BLOCK COMPARED TO THOSE SHOWN HERE. point is also provided along the opposite edge of the board but its use is optional. Installation There are a couple of options when it comes to installing the Balanced Output Board into a case. First, if you are starting from scratch and drilling your own case, then the board can be mounted with its XLR connectors protruding through the front panel, on the righthand side. This would mean moving the Switch Board further towards the centre of the front panel than in the prototype, to allow room for the Balanced Output Board. Alternatively, if you are installing the new board into an Altronics kit 46  Silicon Chip chassis, it will have to be mounted in the rear righthand corner of the chassis, in place of the DAC board – see photo. The DAC board is moved to the location shown in the photo and installed with its RCA output connectors facing towards the righthand side panel. The RCA outputs are then connected via figure-8 shielded cable to a pair of RCA sockets mounted on the rear panel between the Input Board and the Balanced Output Board. Which ever method you choose, you will have to drill the necessary mounting holes for the boards and cut holes in the front or rear panel to match the XLR sockets. The XLR socket holes are the first on the list. These are holes best made by initially drilling two pilot holes 35.5mm apart at the correct height. They are then reamed out to 22mm to allow the socket centre sections to protrude through. That done, mark out and drill the four 2.5mm holes around the outside edge of each cutout. The XLR connectors can then be firmly secured to the panel using the supplied self-tapping screws. Having secured the assembly in this manner, the next step is to remove the Nylon spacers so that you can mark out the mounting holes for the Balanced Output Board in the base of the chassis. The PC board is then removed so that the holes can be drilled (to 3mm). Once these holes have been drilled, siliconchip.com.au place. This step is vital because they are subject to quite a bit of force during cable insertion and removal. Wiring mark out and drill the two holes for the panel-mount RCA sockets. Again, use a pilot drill to start the holes, then carefully ream them to size (9.5mm) using a tapered reamer. If you are modifying an Altronics kit, then the DAC Board can be installed in the location shown in the photo. Once again, you will have to mark out and drill a new set of mounting holes. Note that the edge of the board should be at least 55mm from the righthand chassis panel, to ensure sufficient clearance for the RCA plugs. Next, deburr all the mounting holes using an oversize drill before installing the boards in the chassis. Don’t forget to refit the four screws through the panel to hold the XLR connectors in siliconchip.com.au It’s now just a matter of completing the wiring as shown in Figs.2 & 3 and the photo. First, you will need to run three power supply leads (+15V 0V -15V) to the Balanced Output Board. These supply rails are derived from the output terminal block on the Power Supply Board. Unfortunately, it can be difficult to fit two wires into the terminal block entries (due to the leads already running to the DAC board) but there is a way around this – splice the wires into a “Y” shape with heatshrink insulation applied to the join. You can then connect one end to the power supply, the middle to the DAC board and the remaining end to the Balanced Output Board. Make sure you don’t get any of these +15V 0V -15V connections mixed up. It’s a good idea to twist the supply leads together as shown in the photo. This not only minimises noise pickup but also ensures that a lead cannot wander if it comes adrift. You should also use cable ties to additionally secure the supply leads at the terminal blocks. The connections between the DAC Board and the rear-panel RCA sockets are run using figure-8 shielded cable (ie, two cores with separate shields – do not use 2-core cable with a common shield for these connections). As shown, the leads are directly soldered to the rear-panel RCA sockets at one end and are terminated in RCA plugs at the DAC Board end. Alternatively, if you don’t intend ever using the unbalanced outputs, then this wiring can be left out. Two lengths of twin-core shielded cable are used for the signal connections between the DAC Board and the Balanced Output Board. Begin by stripping back 20mm of the outer insulation from one end of each cable and about 40mm from each of the other ends. Then, at the 40mm ends, trim the shield wires back completely so that they do not project out of the outer insulation. Now, at the 20mm end of each cable, twist the shield wires together tightly and tin them with solder. That done, remove 10mm of insulation from the Parts List 1 PC board, code 01101101, 110 x 67mm 2 PC-mount male 3-pin XLR connectors plus self-tapping screws (Altronics P-0874) 3 3-way screw terminal block (5.08mm pitch) 4 8-pin machined IC socket 6 10mm tapped Nylon spacers 6 M3 x 6mm machine screws 1 500mm length twin-core shielded cable Semiconductors 4 NE5534 op amps (IC1-IC4) Capacitors 2 100µF 25V electrolytic 4 1µF bipolar electrolytic 4 100nF MKT 4 10nF MKT 4 5.6nF MKT 4 2.2nF MKT 4 1nF MKT 4 22pF ceramic Resistors 4 100kΩ 4 910Ω 4 820Ω 4 560Ω 4 100Ω Miscellaneous The following parts are necessary to complete the chassis wiring: 2 RCA plugs, 1 red, 1 black 2 panel-mount RCA sockets 1 500mm length figure-8 shielded cable 8 cable ties 1 600mm-length heavy-duty red hook-up wire 1 600mm-length heavy-duty blue hook-up wire 1 600mm-length heavy-duty black hook-up wire inner wires at both ends, then double the exposed wires back and tin them. Finally, trim the shield wires back to about 10mm and attach the signal cables to the input terminal blocks on the Balanced Output Board - see Fig.2. As shown, the shield wire goes to the centre terminal of each block, the red wire to the “+” terminal and the white wire to the “-” terminal. The red & white wires at the other end of each cable are connected to the pin 6 outputs of ICs 7, 8, 10 & 11 January 2010  47 ning to the 3-terminal input blocks. That way, the lefthand XLR socket (when looking at the front panel) will really be the left channel, while the righthand socket will be the right channel. Testing Another view of the completed Balanced Output Board, this time looking at the XLR connectors. The latter are secured to the rear panel using the self-tapping screws supplied. This ensures that the solder joints on the board don’t crack due to stress as cables are plugged in and removed. on the DAC Board. The best place to make these connections is at the 220Ω resistors that connect to these pins, as shown in Fig.3. You can either make the connections to the top of the DAC Board or you can solder the wires to the pads on the underside of the board (as in the prototype). If you are attaching the wires to the top of the board, simply melt a little solder onto the exposed resistor legs, then solder each wire in turn. Alternatively, if you are not installing the unbalanced outputs, you can leave out the 220Ω resistors and simply feed the wires down through the board holes before soldering them to the pads. Either way, you must protect the board so that the trimmed shield wires can’t short against anything. That can be done either by using heatshrink sleeving or a blob of hot melt glue, or even insulating tape. Once all the wiring has been completed, secure it in place using cable ties as shown in the chassis photo. This not only helps prevent leads from flexing and coming adrift but also ensures that a wire cannot move and contact other parts of the circuit (including the mains terminals on the back of the IEC socket) if its connection is broken. Don’t get the channels mixed Be sure to connect the leads exactly as shown in Figs.2 & 3, so as not to transpose the left and right channels. In particular, note that the components on the righthand side of the DAC Board are actually for the left channel, ie, they drive the left audio output socket. Similarly, the parts on the lefthand side of the board drive the right channel audio output socket. This was done to simplify the layout of the PC tracks running from the DAC chip (IC6). All you have to do is run the signal leads as shown in Figs.2 & 3 and all will be correct. There’s just one wrinkle here – if you mount the Balanced Output Board on the front panel, then you should swap the signal leads run- Once the power supply and signal wiring are complete, power the Stereo DAC up and check that the +15V and -15V inputs to the Balanced Output Board are correct. If these are OK, uou are then ready to connect the balanced outputs to your external equipment and check that they are functioning correctly. If there is a problem, switch off immediately and use a multimeter to confirm that all power and signal connections are correct. If that checks out but it still doesn’t work properly, you will need to remove the Balanced Output Board and check it for short circuits, missed solder joints and incorrect parts placement. If you have not tested the rest of the DAC yet, then it’s a good idea to temporarily disconnect the Balanced Output Board while you make the necessary checks. That way, you’ll at least know that the rest of the DAC works correctly before looking for problems on the Balanced Output Board. That’s it – once wired up, the balanced outputs should provide a very clean output signal from the DAC, even with long cable runs. Phantom power Finally, note that phantom power should not be applied to the XLR sockets on the Balanced Output Board (ie, phantom power should be switched off). Alternatively, cut the tracks between the 100Ω resistors and the XLR sockets and install 10µF bipolar (BP) electrolytic capacitors across the gaps (ie, in series with the pin 2 & pin SC 3 outputs). Issues Getting Dog-Eared? Keep your copies of SILICON CHIP safe with these handy binders REAL VALUE AT $14.95 PLUS P & P Available Aust, only. Price: $A14.95 plus $10.00 p&p per order (includes GST). Just fill in and mail the handy order form in this issue; or fax (02) 9939 2648; or call (02) 9939 3295 and quote your credit card number. 48  Silicon Chip siliconchip.com.au HAPPY NEW YEAR JAYCAR FROM ALL OF US AT TO CELEBRATE THE NEW YEAR WE HAVE SOME GREAT NEW PRODUCTS ARRIVING AND FANTASTIC SAVINGS ON A SELECTED RANGE OF CLEARANCE ITEMS - UP TO 70% OFF*. s in-store * selected item New Helicopters 3 Channel RC Apache Attack Chopper Ideal entry-level DSO for the advanced hobby user or technician and is particularly suited to audio work. Full data storage capabilities and USB interface so you can store traces on a flash drive. With a built-in gyroscope, this chopper is very stable in flight and easy to control. 25 minute charge gives about 10 minutes flying time. Finished in olive drab, complete with chain gun and rocket pods. Remote requires 6 x AA batteries. 699 • 27MHz • 310mm long • Recommended for ages 10+ • Spare parts are available $ 89 95 Cat: GT-3382 Mini 2.4GHz 4 Channel RC Helicopter Very stable and easy to fly, probably the best chopper we've had so far. Four channels gives you complete control for complex and accurate maneuvering, takeoff and landings. The body is made from Lexan so is very flexible and strong. Operating on 2.4GHz frequency this unit is super stable and has little to no interference. Absolutely our most stable easy to fly chopper! 149 Cat: GT-3384 • Fixed leads • Shockproof • Case included • Auto power-off • Display: 5000 count • Category: Cat II 600V / Cat III 300V $ • Basic DCV accuracy: 0.500% Was $59.95 Limited Stock Autoranging Pocket DMM $20 Cat: QM-1544 Plug & Play MPEG-4 IP Cameras Keep a watch on your home with easy access to these cameras via the web service; all you need to do is plug it in! So Simple! These MPEG-4 IP Cameras feature a built-in microphone and resolution of 640 x 480 pixels. Control up to 16 cameras through the included software. FROM $249 $349 $ 249 Wireless USB Trackball Remote Control for PC The trackball works as a mouse and you can type numbers or text in the same way you do with a mobile phone. It also has quick-launch keys, plus controls for multimedia use - play, pause, record etc. You can also program macros or single commands into any key. No software or drivers are needed - just plug in the USB receiver and off you go. Requires 2 x AA batteries. • 2.4GHz 10 metre range • 19mm optical trackball & mouse keys • USB dongle receiver • Microsoft Windows XP MCE/ Vista compatible • MCE hotkeys • Dimensions: 180(L) x 50(W) x 30(H)mm $ In addition to telling you the cost of electricity consumption of an appliance plugged into it and the amount of power used in kilowatt hours, it will tell you how many cumulative kg of CO2 the appliance is putting into the atmosphere. • Battery included. $ 95 • Dimensions: 120(L) x 58(W) x 40(H)mm Cat: MS-6118 39 Voltage Modifier Kit Refer: Silicon Chip Magazine December 2009 This kit intercepts and alters the signal from engine sensors that supply a voltage signal to the engine control unit (ECU). Restore correct air/fuel ratios after engine modifications, prevent engine boost cuts; or alter sensor signals for improved drivability. Requires hand controller for programming, RS232 cable and a suitable input signal. Kit includes PCB, case and electronic components. 39 95 Two models available: QC-3397 Wired IP Camera Wireless IP Camera QC-3399 $ • Channels: 2 • Input impedance: 1Mohm Cat: QC-1932 • Bandwidth: 25MHz • Sampling rate: 500MSa/S • Max input voltage: 400V P-P, Cat II • Dimensions: 310(W) x 150(H) x 130(D)mm • Accessories included : 2 x 10:1 probes, EasyScope software, USB cable Also available 100MHz Dual Trace Digital Storage Oscilloscope Cat. QC-1933 $1,499 Greenhouse Gas (CO2) Meter • 18 minute charge gives about 10 minutes flying time. • Remote requires 4 x AA batteries. $ • 185mm long • Recommended for ages 10+ DMMs are proper test instruments worthy of serious consideration for any tradesman or handyman. This unit has an easy one finger dial selector on the front leaving your other hand free. 25MHz Dual Trace Digital Storage Oscilloscope Recommended with this kit: Hand Controller Cat. KC-5386 $67.95 RS232 Cable Cat. WC-7502 $13.95 $ 79 95 Cat: KC-5490 Touchscreen Car CD/DVD Player With a CD player, AM/FM radio, DVD player, built-in four channel amp plus an input for a reversing camera, it really is the complete package. Compatible with all modern audio and video formats and will accept inputs from just about any source including SD/MMC card, USB or an external audio source like an iPod ® or other media player. The unit is controlled by a touch screen. • 2-DIN 7" motorised widescreen with touch panel controls • DVD/VCD/CD/MP3/WMA/JPEG playback • DVD/R/DVD/RW/CDR/RW playback $ • ESP and antishock mechanism • 4 channels x 20W RMS power output Cat: QM-3784 • 2 x video output • Rear AV input • Rear camera input • Remote control • ISO connector Was $599 Limited Stock 89 Cat: XC-4940 *Savings off original RRP Free Call: 1800 022 888 for orders! 399 $200 IT & Comms USB Desktop Station 19" Rack Mount Cabinets Free yourself from clutter and avoid the stress of losing things. This neat & stylish USB desktop station charges multiple items at once such as your mobile phone, iPod®, PDA and other USB devices. It keeps your workspace free from messy USB leads as well as providing a handy refuge for your wallet, keys, watch, pen, sunglasses etc. It comes with 8 connectors compatible with major brand mobile phones. • 2m USB DC-DC power cord supplied • 4 outlets: 2 x USB outputs and 2 x docking cable outputs • 8 x adaptors compatible with most Nokia, Sony Ericsson, Motorola, Samsung and LG mobile phones Ideal for studios, PA, sound reinforcement, IT, or phone systems installations, with a size and configuration to suit any application. Coupled with our wide range of accessories and options, this 19" rack cabinet offers outstanding features. See website for full details. 6U Rack Mount Enclosure Cat. HB-5170 $199 Dimensions: 530(W) x 360(H) x 450(D)mm 9U Rack Mount Enclosure Cat. HB-5172 $249 $ 29 95 Cat: MB-3640 2U Open Wall Mount Rack Enclosure Cat. HB-5190 $64.95 Dimensions: 485(W) x 95(H) x 380(D)mm $ 4U Open Wall Mount Rack Enclosure 99 Cat. HB-5192 $79.95 Dimensions: 485(W) x 190(H) x 380(D)mm Cat: XC-4941 90W Universal Laptop Mains Adaptor This versatile unit has an output voltage LED display and automatically adjusts output voltage according to which connector is fitted. It also has a USB outlet to charge or power one of your USB devices. Compatible with all major brands. Check our website for compatibility with your laptop. $ Bluetooth to RS-232 Converter Add short range Bluetooth wireless connectivity to RS-232 based devices. It features one 9-pin female RS-232 socket and an 11mm long SMA screw on antenna. A great way to reduce serial cable mess. Perfect for serial printers, scanners, custom built RS232 products and a host of other devices. $ Specifications: • Antenna: 11(H)mm - SMA plug • Led Indicator : SYS (Power) , Pairing • Dimensions: 72(L) x 30(W) x 14(H)mm • Class 1 (up to 100M range) 1U Sliding Rack Shelf Ideal for mounting computer keyboards or other equipment that needs to be accessed easily. The slides have ball bearing runners for smooth operation and will take a load of 20kg. • Dimensions: 483(W) x 52(H) x 350(D)mm $ 79 95 • Max output: 90W Cat: MP-3475 • Voltage range: 15-24V • Current range: 2.04-6A • Dimensions: 154(L) x 58(W) x 37(H)mm 169 99 Cat: HB-5450 Fixed 19" Rack Shelves Ideal for tuners, CD players, amplifiers or any other equipment that you want to include in your rack but doesn't have rack-mounting ears. Each shelf is punched with ample slots for ventilation and a folded return front and rear to take loads of up to 20kg. Solid steel construction, black powder coated finish. 1U Fixed Rack Shelf Cat. HB-5452 $49 Dimensions: 483(W) x 45(H) x 268(D)mm 2U Fixed Rack Shelf Cat. HB-5454 $69 Dimensions: 483(W) x 89(H) x 268(D)mm Cat: XC-4130 Rack Cable Support Takes the pain out of wiring and fault-finding rack cabinets. Your cables are kept organised and neat, with the support also providing strain relief. USB to RS-485/422 Converter Wire up an RS-485/422 device to the 4 socket terminal block to give your hardware USB connectivity. It features surge protection to guard against unpredictable voltage spikes. Suitable for industrial, military, marine, science and custom built applications. One USB A male to male cable is supplied. • Dimensions: 55(L) x 42(W) x 24(H)mm • Includes a 610mm USB A Male to Male cable 1U Rack Cable Supports HB-5430 $34.95 2U Rack Cable Supports HB-5432 $39.95 1U Patch Lead Management Panel HB-5434 $39.95 $ 99 Cat: XC-4132 Serial to Ethernet Converter With this converter, computers can connect to serial devices over Ethernet. It’s an ideal solution for people who need to monitor or access RS-232 based equipment remotely or to share them over a network. There is one 9-pin male RS-232 plug, an RJ-45 socket and a terminal block to wire up RS-485 or RS-422 connections. The device can be accessed remotely through a simple web interface. 2 Dimensions: 530(W) x 626(H) x 450(D)mm Ideal for mounting in other enclosures, such as road cases, but can also be mounted stand-alone. One side is hinged so that patch panels can be easily accessed at the rear for reconfiguring patch sets. Simply plug in the USB receiver to your PC and this stylish and ergonomic wireless keyboard is good to go. So portable you can easily take it with you to and from your home, office or school workstations. Great for cramped workspaces and much easier to use than a laptop touchpad! A complete PC control interface in one neat package. Specifications: • Supports 10/100M • Converts RS-232 , RS-485 and RS-422 • Dimensions: 88(L) x 68(W) x 27(H) 12U Rack Mount Enclosure Cat. HB-5174 $299 Open Wall Mount Rack Enclosures Wireless Trackball Keyboard • 2.4GHz with 8 channels - 10 metre range • Windows NT, 2000, XP & Vista compatible • 12 internet/multimedia hot keys • Requires 4 x AA batteries Dimensions: 530(W) x 493(H) x 450(D)mm $ 169 Cat: XC-4134 19" Rack Blank Panels Blank panels for filling in unused space or configuring panels to your own requirements. Black powder coated steel, 1 or 2 unit, vented or plain. The vented panels are also useful at the back of rack enclosures for attaching wiring looms to. 1U Rack Mount Blank Panel 2U Rack Mount Blank Panel 1U Rack Mount Blank Panel - Vented 2U Rack Mount Blank Panel - Vented Cat. HB-5420 $10.50 Cat. HB-5422 $12.95 Cat. HB-5424 $18.95 Cat. HB-5426 $27.95 Keyring Micro SD USB Card Reader Microscopic would be the best way to describe this card reader at only 19 x 15mm, and that includes the USB plug. Ideal for the travelling shutterbug. • USB 2.0 Micro SD compliant • Keyring lanyard included $ 9 95 Cat: XC-4759 All savings are based on original recommended retail prices. Car Audio & Accessories 9" In-Car LCD Colour Monitor Crisp high resolution, connect this 9" widescreen LCD to your source devices to entertain passengers with DVD movies or keep the kids amused with Xbox ® or Playstation® gameplay. Featuring multisource inputs and reverse image function, it also doubles as a reversing camera monitor. The tilting bracket gives you several in-car options, including dash, ceiling and $ headrest mounting. 199 Cat: QM-3761 • NTSC/PAL system • 9" widescreen - 4:3 & 16:9 switchable format • 800 x 480 display resolution • 12VDC power input, 12W power consumption • Includes mounting bracket and remote control GPS Sunshades to Reduce Screen Glare Simply clip to the top of your GPS unit. Different types to fit popular in-car GPS models: Garmin Nuvi, TomTom Go, Magellan Maestro, Navman etc. Universal Sunshade 3.5" Sunshade for TomTom 4.3" Sunshade for Garmin 4.3" Cat. HS-9005 $14.95 Cat. HS-9006 $19.95 Cat. HS-9007 $19.95 HID Dual Lamp Conversion Kits - 35 Watt Used in the latest model luxury and high performance cars, High Intensity Discharge (HID) vehicle headlights are far brighter, whiter and more efficient than their quartz halogen predecessors. • 35W HID Xenon lamps - H4 base • 6000K colour temperature comparable to sunlight • Extra bright 3200 lumens Available in two easy-installation models: HID Dual Lamp H4 Conversion Kit - low beam Cat. SL-3416 $99 HID Dual Lamp H4 Conversion Kit - high/low beam Cat. SL-3417 $149 Warning: State roads & traffic authorities prohibit the retrofitting of these products to cars with normal headlights. Advised to be used only for off-road and showroom vehicles when replacing quartz halogen bulbs, or as headlight replacements for HID factory-fitted new model vehicles. Due mid January Twisted Pair RCA Stereo Audio Cables Featuring RFI and EMI noise reduction to keep your car's audio sounding wholesome. This twisted pair RCA cable is made from double aluminium foil and quality copper braid shielding for that accurate sound transfer. Sound Dampening Pads These pads are installed inside the door skins opposite the back of the speaker drivers. They absorb standing waves and resonances so you get maximum performance. Each pack includes cyanoacrylate glue for installation. Suitable for 5 - 7" drivers Cat. AX-3665 Sound Dampening Pad 12" - Single Suitable for subs 10 - 15" Cat. AX-3666 • Front USB port, SD/MMC card slot and aux-in • PLL tuner with 18 x FM and 12 x AM presets • DVD±R/RW, CD-R/RW playback • Supports MP3, JPEG and WMA files • 4 channels x 20WRMS output (40WRMS max) • 4-band equaliser (classic, pop, rock, flat) $ 249 Cat: QM-3788 Touchscreen Car Multimedia Player Comprehensive in-car connectivity - this impressive unit plays all the popular AV formats from just about any portable media or mass storage device. Plus it's Bluetooth-ready for handsfree communication when paired with a Bluetooth enabled mobile phone. It's user-friendly touchscreen menu enables you to easily select and control several input play options. Mounting hardware, Bluetooth bus and remote control included. • Motorised 7" touchscreen LCD (480 x 234 pixels) • 22WRMS x 4 channels (45W max each) • Front panel USB, SD & aux-in • 1 x rear camera input, 1 x video output $ 499 Cat: QM-3789 Car Amplifier Wiring Kits Complete wiring kits for installing a car amplifier everything you need down to the cable ties and screws. Save $$ on the individual parts. 4G and 8G kits available, see our website for kit contents: 8G Wiring Kit 4G Wiring Kit Cat. AA-0442 $59.95 Cat. AA-0444 $99.00 HID Single Beam Bulbs Drop-in replacements for cars that have separate HID bulbs for high and low beam. With 3000 hour lifespan, these can be used in single bulb housings but high beams will not function. • 35W 70-100V • 3,000 - 30,000K colour temperature • 2500-3500 lumens H3, H4 and H7 types available: 12V H3 HID Bulb Single Beam Cat. SL-3411 $24.95 12V H4 HID Bulb Single Beam Cat. SL-3412 $24.95 12V H7 HID Bulb Single Beam Cat. SL-3413 $24.95 Due mid January Vifa coaxials will add true high fidelity to your car audio. All feature the legendary Vifa silk dome tweeters, strontium magnets and composite diaphragms. Available in 2 or 4-way configuration. Sold as a pair. $14.95 $14.95 $19.95 $24.95 $29.95 Due mid January Sound Dampening Pad 7" - Pair A solid all-round performer, this in-car entertainment system plays all the popular multimedia formats and devices. It is Bluetooth handsfree ready and comes complete with detachable anti-theft panel with colour LCD display and slimline remote control. Vifa Coaxial Car Speakers • Plug to Plug • Split centre pin connectors • Frosted jacket design • Platinum-plated ends 5 Lengths: 0.3m Cat. WA-1079 0.5m Cat. WA-1071 1.5m Cat. WA-1073 2.5m Cat. WA-1075 5.0m Cat. WA-1077 In-Dash Multimedia Player with USB and Bluetooth $ 39 95 Cat: AX-3665 $ 39 95 Cat: AX-3666 Vifa 5" 2 Way Car Speakers Cat. CS-2393 • Power handling: 60WRMS • Nominal impedance: 4 ohms • Frequency response: 50Hz - 20kHz $ • Sensitivity: 87.9 dB SPL <at>1W, 1m Vifa 6.5" 2 Way Car Speakers Cat. CS-2395 • Power handling: 80WRMS • Nominal impedance: 4 ohms • Frequency response: 45Hz - 20kHz $ • Sensitivity: 86.3dB SPL <at>1W, 1m 119 pr Cat: CS-2393 169 pr Cat: CS-2395 Vifa 6 x 9" 4 Way Car Speakers Cat. CS-2397 • Power handling: 150WRMS • Nominal impedance: 4 ohms • Frequency response: 35Hz - 20kHz • Sensitivity: 90 dB SPL <at>1W, 1m Free Call: 1800 022 888 for orders! www.jaycar.com.au $ 229 pr Cat: CS-2397 3 Massive Savings on Clearance Lines * selected items Listed below are a number of discontinued (but still good) items that we can no longer afford to hold in stock. We need more space in our stores! You can get most of these items from your local store but we cannot guarantee this. Please ring your local store to check stock. At these prices we won't be able to ship from store to store. Items will sell fast and stock is LIMITED - ACT now to avoid disappointment Sorry - NO Rainchecks Stereo Valve Hybrid Amplifier 2 x 18WRMS The circuitry is hybrid valve/solid state. This gives it better power output with lower hum and distortion. If you like the sound of valves but can't bring yourself to part with two grand for an amp, this could be for you. Two sets of stereo inputs plus separate bass and treble controls. • Valves: 2 x 6N1, 2 x 6P15 • Power output: 18WRMS per channel • Input sensitivity: 300mV • Dimensions: 270(W) x 290(D) x 140()mm Was $299 Limited Stock $ $200 99 Cat: AA-0474 25mm Dome Tweeter A compact dome tweeter for bookshelf or satellite speaker applications magnetically shielded, ferrofluid cooled. • Nominal impedance: 5 ohms • Power handling: 15WRMS • Sensitivity: 92dB 2.83V at 1m • Crossover frequency: 2500Hz Was $39.95 Limited Stock $30 $ 9 95 Cat: CT-2009 Digital TV Set Top Boxes Standard Definition If you have an older TV that does not have a digital tuner, you will need a Digital TV set top box that will receive and decode the signals so they can be displayed. With these set top boxes you can enjoy more channels, extra features and clearer reception on your old analogue TV at an excellent price. $20 Two standard definition DTV set top box models available: Economy SD DTV Set Top Box With composite Video and audio left and right outputs. • Size: 120(W) x 35(H) x 100(D)mm $ 95 Was $49.95 Not available in New Zealand Cat: XC-4914 29 SD DTV Set Top Box with Recording Output $15 Features a USB port for AV recording as well as playback. With composite AV and S-video plus digital audio and analogue left and right audio outputs. • Size: 189(W) x 40(H) x 117(D)mm $ 95 Was $64.95 Cat: XC-4912 Not available in New Zealand 49 Digital and HD ready. Digital and high definition TV is already with us, so now is the time to get with the program. Receives all Australian digital TV broadcasts from a standard PAL RF antenna input. Outputs are HDMI, component video, composite video, and optical audio. Great for mobile use such as caravans, camping, 4WD's etc. • Remote requires 2 x AAA batteries. • On-screen menus • Selectable aspect ratio 4:3/16:9 • DVB-T & MPEG-2 HD & SD compliant • Supports up to 1080p resolution • 12VDC Plugpack included $ • Dimensions: 220(W) x 140(D) x 42(H)mm Not available in New Zealand Cat: XC-4916 119 GIFTS & GADGETS CLEARANCE Cat No. GH-1814 GE-4080 GH-1069 GH-1075 GH-1070 GH-1316 GH-1910 GH-1085 GH-1150 GE-4084 WAS $149.00 $54.95 $79.95 $349.00 $54.95 $59.95 $99.95 $79.95 $1.75 $5.95 $1.35 $1.35 $2.30 $69.95 $17.95 $499.00 $199.00 $39.95 $19.95 $69.95 $29.95 $34.95 $34.95 $34.95 $29.95 $49.95 $199.00 $39.95 $99.95 $109.00 $49.95 $69.95 $179.00 $199.00 $54.95 $47.95 $89.95 $169.00 $99.95 $159.00 $69.95 $6.95 $59.95 $54.95 $69.95 $149.00 $79.95 $99.95 $99.95 $24.95 CAR AUDIO & ACCESSORIES CLEARANCE High Definition Description Colour Changing Cube with Timer & PSU Desktop Drum Kit with Record Option Fan with LED Message - Battery operated Fan with Mini LED Light Show - Battery operated Fan with Water Jet Spray - Small Novelty Swear Box Pre-natal Listening Device Remote Control Giggle Machine with 6 Sounds Shot Glass with Flashing LED USB Missile Launcher with Webcam AUDIO VIDEO ACCESSORIES CLEARANCE Description Cat No. AV HDMI Cable Tester with Carry Bag AA-0406 AV HDMI Repeater/Extender Ver 1.3 AC-1697 AV HDMI Repeater/Extender with PSU AC-1698 AV HDMI/RGB/SVID Computer Switch AC-1687 AV Sender Spare Receiver to suit (AR-1838) AR-1839 AV Sender Spare Receiver to suit (AR-1844) AR-1845 AV Sender Wireless 2.4GHz Dual Input with IR Remote AR-1838 AV Sender Wireless 2.4GHz TX/RX Requires 4AA AR-1852 Cable Coax 75R RG6 Belden - Sold per metre WB-2008 Cable Speaker Twisted 2 Core OFC - Sold per metre WB-1723 Cable Speaker Twisted 2 Core Red/Blue - Sold per metre WB-1750 Cable Speaker Twisted 2 Core Red/White - Sold per metre WB-1751 Cable Speaker Twisted 4 Core - Sold per metre WB-1760 Car MP3/Cassette Adaptor with SD Card Slot AR-1764 Computer Headphones with Microphone AA-2028 DJ Dual MP3 Player Controller -Rack mountable AA-0492 Dock 2.1 Speaker - Black for iPod ® CS-2467 FM Stereo Transmitter for iPod® AR-3112 iNano Earphones & Lanyard for iPod® Nano AR-2069 ® Rechargeable Transmitter for iPod AR-1859 Lead AV Game PS3 - 3 RCA Leads 1.8m WV-7430 Lead AV RCA 2 Plugs - 1 S-Video Plug Scart 1.5m WQ-7246 Lead AV RCA 2 Scart Plugs - 1 S-Video Plug Scart 1.5m WQ-7247 Lead AV Scart Plug - Socket Concord 1.5m WQ-7249 Lead Game Nintendo & Wii - S/Video & Audio 1.8m WV-7436 Lead VID RCA 6 Plugs - RGB Plug Scart 1.5m WQ-7243 Multimedia Cable Tester - Tests Voice, Data & Video Cables QP-2290 Noise Cancelling Earphones with Adaptors AA-2057 Noise Cancelling Headphones H/D AA-2058 Remote Control Car Media Player AR-1867 Remote Control IR Extender AR-1810 Single DJ Headphone with Handle AA-2059 Speaker 10" Kevlar/Paper Cone Woofer CW-2158 Speaker 2.1 Suround Sound System with Amp CS-2466 Speaker 25WRMS 2 way for Marine use CS-2392 Speaker 4" High-End Woofer/Mid Range Driver CW-2151 Speaker 5" High-end Woofer/Mid Range Driver CW-2152 Speaker 50WRMS 3 way Stereo Amp AR-1897 Speaker 6.5" Kevlar/Paper Cone Woofer CW-2154 Speaker 8" Kevlar/Paper Cone Woofer CW-2156 Speaker Black Stand 280mm (H) - Sold as a pair CW-2843 Speaker Piezo Horn HD-02 CT-1933 Speaker Ribbon Tweeter - 20WRMS CT-2032 Speaker Tweeter Horn 400WRMS KSN1141A CT-1912 Stereo Bluetooth Adaptor AR-1854 Travel Case - 19" Rack Mount DJ Road Case HB-6347 Travel Case for LPs - Aluminium HB-6345 Wireless 2.4GHz Digital Headphone and Transmitter AA-2035 Wireless 2.4GHz Digital Stereo Headphones AA-2072 AR-3119 Wireless Remote Control for iPod® WAS $49.95 $29.95 $14.95 $6.95 $6.95 $19.95 $49.95 $14.95 $3.95 $109.00 NOW $19.95 $19.95 $7.50 $3.95 $3.95 $9.95 $24.95 $9.95 $0.65 $49.95 SAVE $30.00 $10.00 $7.45 $3.00 $3.00 $10.00 $25.00 $5.00 $3.30 $59.05 Description Cat No. 1 Farad Capacitor with Coloured LED Display RU-6752 2 Farad Capacitor with Coloured LED Display RU-6751 Cable Auto 15A Figure 8 Red & Black - Sold per metre WH-3078 Cable Auto 25A Black - Sold per metre WH-3083 Cable Auto 25A Red - Sold per metre WH-3081 Cable Microphone 2 Core Screened Black - Sold per metre WB-1532 Car Alarm 2 Way Paging System + Rechargeable Remote LA-9018 Car DVD/CD Player with 3" LCD Monitor QM-3787 Car DVD/CD Player with Bluetooth QM-3786 Car Speaker 10" Venom Sub Woofer CS-2356 Car Speaker 12" Response Sub Woofer CS-2354 Car Speaker 12" Venom Sub Woofer CS-2358 Car Speaker 5" Kevlar/Dome Tweeter 2 Way Coax CS-2372 Car Speaker 6" 60WRMS Kevlar Splits CS-2327 Car Speaker 6" Venom Splits with Silk Tweeter CS-2389 Car Speaker 6.5" 60WRMS Kevlar Splits CS-2329 Car Speaker 6.5" Component Car Splits + Ribbon Tweeter CS-2338 Car Speaker 6.5" Kevlar/Dome Tweeter 2 Way Coax CS-2374 Car Speaker 6x9" 4 Way Venom Speaker with Silk Tweeter CS-2388 Car Speaker 6x9" Kevlar/Dome Tweeter 2 Way Coaxial CS-2378 LCD Monitor TFT 7" In Car TV with Remote QM-3782 LCD Monitor with 7" Bluetooth Rear Vision Mirror QM-3763 OBD II LCD Scan Tool QP-2294 Lead AV Car RCA 2 Plugs - 2 Plugs OFC 2.5m WA-1072 Power Window Closer 2 Door LR-8851 Power Window Closer 4 Door LR-8853 Tester Battery/ Charger/ Alternator 24VDC QP-2259 Wireless Relay Immobiliser Slave LA-8976 Car Ribbon Tweeter with Crossover & Mounts CS-2339 Car Lead RCA Car Audio - 2 Plugs 0.5m WA-1068 WAS $119.00 $169.00 $2.50 $1.50 $1.50 $5.50 $329.00 $385.00 $269.00 $99.00 $249.00 $119.00 $99.00 $159.00 $89.95 $169.00 $299.00 $119.00 $69.95 $149.00 $269.00 $299.00 $139.00 $17.95 $59.95 $69.95 $12.95 $99.00 $89.95 $12.95 NOW $99.00 $29.95 $44.95 $199.00 $37.95 $39.95 $69.95 $44.95 $0.35 $1.90 $0.55 $0.55 $1.20 $39.95 $6.95 $349.00 $118.00 $12.95 $8.95 $34.95 $9.95 $9.95 $9.95 $9.95 $9.95 $24.95 $99.00 $22.95 $59.95 $69.00 $29.95 $34.95 $124.00 $99.00 $34.95 $14.95 $49.95 $109.00 $59.95 $99.00 $45.95 $2.45 $34.95 $24.95 $34.95 $99.00 $54.95 $69.95 $59.95 $12.95 SAVE $50.00 $25.00 $35.00 $150.00 $17.00 $20.00 $30.00 $35.00 $1.40 $4.05 $0.80 $0.80 $1.10 $30.00 $11.00 $150.00 $81.00 $27.00 $11.00 $35.00 $20.00 $25.00 $25.00 $25.00 $20.00 $25.00 $100.00 $17.00 $40.00 $40.00 $20.00 $35.00 $55.00 $100.00 $20.00 $33.00 $40.00 $60.00 $40.00 $60.00 $24.00 $4.50 $25.00 $30.00 $35.00 $50.00 $25.00 $30.00 $40.00 $12.00 NOW $83.00 $115.00 $1.00 $0.80 $0.80 $2.00 $229.00 $259.00 $185.00 $59.00 $149.00 $79.95 $54.00 $75.00 $59.95 $89.00 $179.00 $59.00 $44.95 $75.00 $159.00 $199.00 $89.00 $4.95 $39.95 $44.95 $4.95 $67.95 $52.95 $2.95 SAVE $36.00 $54.00 $1.50 $0.70 $0.70 $3.50 $100.00 $126.00 $84.00 $40.00 $100.00 $39.05 $45.00 $84.00 $30.00 $80.00 $120.00 $60.00 $25.00 $74.00 $110.00 $100.00 $50.00 $13.00 $20.00 $25.00 $8.00 $31.05 $37.00 $10.00 *Savings off original RRP - Limited Stock No rain checks, may not be available at all store locations - call your local Jaycar store to check stock 4 All savings are based on original recommended retail prices. in-store Massive Savings on Clearance Lines HARDCORE ELECTRONICS CLEARANCE Description 23 Piece Bit Set with Driver & Ratchet Handle 3 in 1 Knife/LED Torch/Bottle Opener Set 7" Linesman Pliers 8" Adjustable Wrench Adjustable Hole Saw 158 to 254mm Adjustable Hole Saw 63 to 177mm Assembly Tool Kit for Solar Power Connectors Assorted Bungee Cords - 25pcs Crimp Tool Compression Desoldering Braid Dispenser Desoldering Braid Dispenser Gun Screwdriver Cordless Ergononic 4.8V with Bits & Charger Epoxy Repair Putty Fuse Blade Mini 3A Pink with Lamp Indicator Glue 25ml Metal Epoxy Glue Fix-Lock Anerobic Handyman Laser Level Magnetic Wrist Tray Magnifier Lab Desktop Lamp Plug Line XLR/5P Silver/Black - Amphenol Plug Panel XLR/4P Silver - Amphenol Plug Panel XLR/5P Black - NEXUS Plug Panel XLR/5P Silver - Amphenol Proton Exchange Membrane (PEM) Fuel Cell - 600mW Proton Exchange Membrane (PEM) Fuel Cell- 300mW Screwdriver 6 in 1 set Screwdriver Cordless 3.6V with Charger Screwdriver Remover - Pack of 5 Screwdriver with LEDS set - 10 Bits Socket Line XLR/5P Silver/Black - Amphenol Socket Panel XLR/4P Lock Silver - Amphenol Socket Panel XLR/5P Lock Black - NEXUS Socket Panel XLR/5P Lock Silver - Amphenol Spare Tip SMD 2mm to suit TS-1700 (2 pieces) Wafercard PIC16F628+24LC64 - Emerald Wall Plate with 2 x HDMI Skts - White Wall Plate with HDMI Skt - White Cat No. TD-2029 TH-1901 TH-2308 TH-2312 TD-2522 TD-2520 TH-1930 HP-0636 TH-1802 NS-3040 NS-3042 TD-2492 NA-1520 SF-5050 NA-1516 NA-1502 ST-3113 TH-1971 QM-3529 PP-1070 PP-1044 PP-1078 PP-1072 ZM-9082 ZM-9080 TD-2028 TD-2495 TD-2079 TD-2091 PS-1074 PS-1046 PS-1079 PS-1076 TS-1701 ZZ-8820 PS-0286 PS-0285 WAS $34.95 $11.95 $14.95 $14.95 $79.95 $69.95 $9.95 $19.95 $79.95 $9.95 $79.95 $29.95 $5.95 $1.25 $5.95 $7.95 $39.95 $14.95 $49.95 $14.95 $11.95 $7.95 $17.95 $149.95 $99.00 $18.95 $13.95 $11.95 $22.95 $18.95 $16.95 $9.50 $24.95 $19.95 $14.95 $29.95 $19.95 IT & COMMS CLEARANCE Description 5.1 Active PC Speakers 240V Active Desktop Speaker for iPod® Adaptor Firewire 6P Plug - 4P Socket IEEE1394 Adaptor Null Modem D25 Plug - Socket Adaptor Plug D9 Serial - Plug PS2 Adaptor Socket D9 Serial - Socket PS2 Antenna 2.4GHz Flat Panel 10dB gain Antenna 2.4GHz Indoor Ceiling Mount 3dB Gain Antenna 2.4GHz Wireless Networking 5dB Gain Antenna 3.5GHz Flat Panel 12dB with Bracket Cable CAT5e Solid blue - Sold per metre Cable CAT6 Solid Grey - Sold per metre CD/DVD Labelling Kit Digital Microscope Mobile 90x Zoom Digital Microscope Mobile w/ Image Capture 90x Zoom Digital Pen Notetaker Docking Station for PSP® External Hard Drive Case 2.5" with Finger Print Security Gaming Headphones with Bass Shaker & Mic GPS Bluetooth Receiver Hub Motorised 3 Port Retractable MPEG-4 Player AV/SVID/VGA out, RC & PSU - No HDD Internet Digital TV Tuner IPTV Active Speaker for iPod® Shuffle Laptop Fingerprint ID PCMCIA Lead ATA133 IDE Internal - 900mm Black Lead PS2 Y-Adaptor Plug to 2 Socket Mobile Active Speakers for iPod® Plug Line BNC Gold Suits 75R Digital Coax Portable Active Speakers for iPod® & MP3 Players PowerPoint® Presenter with Remote Control PSP High Capacity Clip-On Battery Pack RS232 Mini Tester D25 Socket to D25 Plug USB Data Storage Bridge USB Hub 4 Port in-Desk Grommett USB Optical Mouse & VoIP Phone USB Optical Mouse Golf Themed with Mouse Mat USB Optical Mouse Waterproof USB Powered MP3 Speakers Webcam USB VGA Black & Silver Cat No. XC-5187 XC-5188 PA-0912 PA-0883 PA-0944 PA-0947 AR-3275 AR-3271 AR-3270 AR-3274 WB-2026 WB-2028 XC-4920 QC-3245 QC-3246 XC-0355 XC-5190 XC-4668 XC-4969 XC-4895 XC-4877 XC-4866 XC-4861 XC-5189 XC-4843 PL-0974 PL-0877 XC-5179 PP-0654 XC-5186 XC-5405 XC-5198 PA-0886 XC-4962 XC-4863 XM-5136 XM-5129 XM-5139 XC-5161 QC-3221 WAS $79.95 $59.95 $8.95 $8.95 $8.95 $8.95 $89.95 $49.95 $19.95 $119.95 $1.15 $1.95 $14.95 $199.00 $249.00 $179.00 $79.95 $99.00 $49.95 $149.00 $29.95 $169.00 $169.00 $19.95 $129.00 $35.00 $12.95 $79.95 $6.70 $39.95 $199.00 $119.95 $19.95 $59.95 $24.95 $59.95 $24.95 $39.95 $89.95 $34.95 NOW SAVE $19.95 $15.00 $6.95 $5.00 $6.95 $8.00 $6.95 $8.00 $44.95 $35.00 $36.95 $33.00 $5.95 $4.00 $12.95 $7.00 $49.95 $30.00 $6.95 $3.00 $49.95 $30.00 $14.95 $15.00 $2.95 $3.00 $0.35 $0.90 $2.45 $3.50 $3.95 $4.00 $9.95 $30.00 $5.95 $9.00 $29.95 $20.00 $4.95 $10.00 $4.25 $7.70 $0.95 $7.00 $6.55 $11.40 $49.95 $100.00 $40.00 $59.00 $11.95 $7.00 $7.95 $6.00 $5.95 $6.00 $14.95 $8.00 $6.95 $12.00 $6.95 $10.00 $1.50 $8.00 $7.95 $17.00 $4.95 $15.00 $8.95 $6.00 $19.95 $10.00 $11.95 $8.00 NOW $44.95 $34.95 $1.25 $1.45 $0.95 $0.75 $33.95 $24.95 $9.95 $49.95 $0.25 $0.45 $3.95 $129.00 $169.00 $99.00 $44.95 $49.00 $29.95 $79.00 $14.95 $99.00 $115.00 $9.95 $69.00 $20.00 $4.95 $34.95 $2.50 $11.95 $119.00 $64.95 $5.95 $19.95 $14.95 $29.95 $7.75 $19.95 $44.95 $19.95 SAVE $35.00 $25.00 $7.70 $7.50 $8.00 $8.20 $56.00 $25.00 $10.00 $70.00 $0.90 $1.50 $11.00 $70.00 $80.00 $80.00 $35.00 $50.00 $20.00 $70.00 $15.00 $70.00 $54.00 $10.00 $60.00 $15.00 $8.00 $45.00 $4.20 $28.00 $80.00 $55.00 $14.00 $40.00 $10.00 $30.00 $17.20 $20.00 $45.00 $15.00 * selected items in-store 2 Input Digital Thermometer This is an industrial quality, hand held two input thermometer. It features an easily read backlit display and measures temperatures from -50°C to +1,300°C. The unit is supplied with two temperature probes and holster. • 78(W) x 170(L) x 50(H)mm Was $99.95 Limited Stock $ $50 49 95 Cat: QM-1600 Trade Quality Digital Multimeter Ergonomically designed slim shape with one hand operating knob and buttons. It has overload protection, easy battery replacement, is compact, yet extremely rugged, this DMM would be an excellent investment for the apprentice to the professional tradesman. This meter is supplied with a protective holster and test lead. • Display: 4000 count • Category: Cat IV 600V • 164(L) x 82(W) x 44(D)mm Was $199 Limited Stock $60 Bench Laboratory Magnifier Lamp This laboratory magnifier lamp has a 115mm diameter lens that provides 3 x magnification and a stand that enables the magnifier lens to be positioned on almost any angle desired. • 22 Watt circular fluoro light • Maximum head reach 450mm • Base measures 200(W) x 280(D) x 40mm(H) • 240VAC operated Was $149 Limited Stock $ $ 139 Cat: QM-1623 $90 59 Cat: QM-3522 Off-line or Stand-by Uninterruptible Power Supplies Protect your valuable computer system and critical data from black-outs, brown-outs, and power surges. Battery back time is 10 minutes which lets you power-down without loss of data! The UPS is supplied with back up batteries, USB interface cable, and software. See our website for full specifications. Two models available: 650VA 1000VA Cat. MP-5200 Was $129 Limited Stock $40 $ $120 Cat. MP-5202 Was $249 Limited Stock 89 $ 129 Cat: MP-5200 Cat: MP-5202 3 Port Motorised Retracting USB Hub Just touch the top and your USB hub will rise from the surface of your desk to do your bidding. Touch it again and it lowers itself back into place and out of the way. It has 3 USB 2.0 ports and also acts as a cable grommet to keep all your computer cables neat and tidy. • Powered by USB • Mounting hole: 75mm • Mounting depth: 70mm • Diameter: 92mm Was $29.95 $ $15 14 95 Cat: XC-4877 Get ready for Australia Day! Show your true nationalistic colours on your desk. Fly the flag and Australians all let us rejoice...Ideal office desktop accessory! • Dimensions: 220(H) x 60(Dia)mm Was $14.95 Not available in New Zealand $ $8 6 95 Cat: GH-1945 *Savings off original RRP - Limited Stock No rain checks, may not be available at all store locations - call your local Jaycar store to check stock Free Call: 1800 022 888 for orders! www.jaycar.com.au 5 Audio / Visual HDMI to VGA/Component and LR Analogue Audio Converter Easily view HDMI signals on analogue displays that use VGA or component inputs. Converts your PC monitor into the main display for a Blu-ray player or gaming console such a as PS3. It will also convert LR analogue audio with a 3.5mm socket for use with most PC speakers and headphones. • Dimensions: 140(W) x 38(H) x 94(D)mm $ 149 Cat: AC-1605 Limited Stock Composite Video/S-Video to YCbCR/RGsB Format Converter Designed for converting Composite video / S-video signal such as iPod ®, DVD, X-Box® to the component RGsB for connecting to SDTV or projector. The simple plug and play unit automatically recognises the source system and has a power saving mode. • Suitable for worldwide video system of NTSC3.58, NTSC4.43, PAL, PAL-M, PAL-N and SECAM • Supports composite video and super video input • 5VDC Power supply included • 145(W) x 90(L) x 32(H)mm $ 149 Cat: AC-1629 Component/S-Video to HDMI Upscaler Upscale component or S-video signals to HDMI. Allows you to output to a wide range of resolutions from 480p to 1080p. The unit will accept input from a composite video source, S-video source, 3.5mm audio source and output it to HDMI. LEDs on the front panel indicate what video source is being used and what resolution is being ouput. $ • Motion adaptive 3D Y/C separation comb filter • Scales up component video or S-Video to HDTV 1080p format • Dimensions: 100(W) x 157(D) x 25(H)mm 299 Cat: AC-1627 Digital Toslink/Coax to Coax/Toslink Converter Most equipment manufacturers use different digital audio input/output formats and cannot be easily interfaced with one another. With our handy little digital audio converter, you will never be caught out with the wrong digital audio connection ever again. It will convert digital audio from either coax or Toslink inputs and outputs to Toslink or coax. It also has a built-in amplification feature: it can serve as a repeater of audio signals and extend (double) the transmitting distance. • LED power indicator • Supports two-way conversion: Coaxial to Toslink or Toslink to coaxial. • Compact and easy to setup • Dimension: 42(W) x 40(D) x 22(H)mm $ 59 95 Cat: AC-1601 Toslink Digital Optical 2 Way Splitter A digital optical 1-to-2 distributor featuring one Toslink input to two Toslink outputs. Mains power adaptor included. $ Power Supply: 5VDC 500mA Dimensions: 46(L) x 46(W) x 24(H)mm 69 95 Cat: AC-1613 Coaxial/Optical to Angled Audio Converter Connect a coaxial or optical (Toslink) audio source to this device and it will output to R/L composite analogue. Useful for connecting DVD/Blu-Ray players to displays or audio equipment that have no digital audio input. • Integrated digital interpolator filter and D-A converter • Stereo audio inputs • Dimensions: 42(W) x 40.5(D) x 22(H)mm $ 69 95 Cat: AC-1603 Also available: Component and Digital/Analogue Audio to HDMI Upscaler Cat. AC-1628 $369 Analogue to Digital Audio Converter Rectangular Cable Duct Available in two sizes and in convenient 1m lengths, the leads to your wallmounted plasma or LCD TV will be kept bundled up but easily accessible. The cover can be quickly removed and replaced for maintenance and can be painted to match the colour of your wall. 25 x 16mm x 1m Cat. HP-1330 $6.95 50 x 25mm x 1m Cat. HP-1332 $9.95 Convert a stereo analogue audio signal to coaxial and Toslink outputs simultaneously. It also supports uncompressed 2-channel LPCM (Linear Pulse Code Modulation) digital audio signal output with sampling rate at 48kHz. Both optical fibre and coaxial cables connected to the outputs of the unit can be run up to 5 metres whilst still providing a dependable and quality audio signal transmission. 79 $ 95 • Audio delay (150 min-seconds) • Noise free transmission Cat: AC-1611 • Easy to install and use • Power: 5VDC power adaptor included • Dimensions: 67(W) x 50(D) x 23(H)mm HDMI Leads with Extender Normally you can't run an HDMI cable over a maximum of about 5 metres without using a booster. These cables solve this problem by adding an extender to give you a range of 15 or 20m with no need for additional power. The connectors have gold plated contacts. HDMI 1.3 and HDCP compliant. 15m HDMI Lead with Extender Cat. WQ-7408 $139 Attractive contemporary design providing high quality digital reception. The panel can be wall mounted to minimise space usage. AC adaptor included. 20m HDMI Lead with Extender Cat. WQ-7409 $199 Economy HDMI Leads HDMI leads can cost an arm and a leg. If your budget doesn't extend too far, these leads are a cost-effective solution without compromising quality or performance. All have gold plated connectors and are fully HDMI v1.3b and HDCP compliant. WQ-7415 HDMI Lead Economy 1.5m $24.95 WQ-7416 HDMI Lead Economy 3m $34.95 WQ-7417 HDMI Lead Economy 5m $49.95 Touchscreen 8 in 1 LCD Remote Control Use the learning function or the pre-programmed code library to enrol each component or use the macro functions to program up to 100 keystrokes. For each different device, the LCD backlight is colour coded for easy recognition and you can change the device key layout as you like. Requires 4 x AA batteries. • Auto power-off after 10 minutes • Low power indicator • Size: 195(L) x 65(W) x 21(H)mm 6 Digital Indoor/Outdoor Antenna $ 59 95 Cat: AR-1728 • Frequency range: VHF - 174-230MHz, UHF - 470-862MHz • Antenna gain: 10dB $ • Total gain: 40dB Cat: LT-3137 • Impedance: 75 ohm • Output: F female connector • Dimensions: 502(L) x 235(W) x 76(H)mm 99 EXCELLENT FOR UNDER EAVES, BALCONIES & APARTMENTS 8 Way High End Powerboard with Surge Protection Ideal for home theatre and sensitive highend gear. With surge protection, filtering and a built-in circuit breaker for 8 mains outlets, this powerboard also has protection for telephone (1 input, two outputs so doubles as a splitter), data/network connection, satellite/cable TV, $ 95 and TV antenna. See website Cat: MS-4029 for details. 99 2 Year $50,000 Connected Equipment Warranty All savings are based on original recommended retail prices. Gadgets, Tools & More Robotic Chess Board 1.3MP Digital Video Sports Camera Equipped with a robotic arm and an enhanced high-speed program, it can teach you to play as well as improve your skills. Play against the Robot like a real opponent. • Suitable for novice to experienced players • 128 levels including training, tournament & problem solving levels up to mate-in-6 moves • Programmed in accordance with the International Chess Rules • Knows en-passant moves, castlings & pawn promotion • Check, stalemate & checkmate announcement • Board size: 380(W) x 380(D) x 40(H)mm You could make your own action sports video! The camera straps onto your helmet and has a super-sticky adhesive mount to keep it in place. It has simple one-button operation to start recording and uses SD cards up to 32GB for storage. Mountain biking, skateboarding, BMX, skydiving, bungee jumping etc. Requires 2 x AAA batteries. $ 299 Cat: GT-3516 Interactive Music Quiz Test your family and friends' music knowledge with this interactive music quiz that you control! Game options include 'name that track', 'beat the intro', 'name the artist' and 'sing the next line'. Or make up your own game - the possibilities are endless! • Speaker console with four team buzzers and LCD points display • Quizmaster controller with music start/stop button, points buttons, crowd sound effects, three music distortion buttons and volume control • MP3 player (not included) connection $ 95 to the Quizmaster controller • Requires 3 x AA batteries Cat: GE-4233 • Suitable for ages 8+ 49 6-in-1 Solar Educational Kit Build any one of six different projects from the parts in the kit. No tools, soldering or glue required. All the parts snap together with spring terminals for the wiring. The instructions are excellent with extremely clear illustrations detailing every step. The finished projects are solar powered, but can also be powered by the light from a household 50W halogen light. Projects: $ • Windmill • Car • Dog • Plane • Airboat • Revolving Plane 24 95 Clearly see what you're working on with this multifunctional laboratory magnifier. Included is an extension pole that transforms it from a desk top unit into a floor standing unit, also included is a detachable deskmounting clamp. Can be powered with the provided plug pack or 4 C size batteries which allows this unit to be used where mains is not available. • 20 high-brightness LEDs • 4 dioptre magnification • 127mm diameter lens • 1200mm floor mode height • 600mm desk mode height • Mains plugpack included • Base measures: 310(L) x 230(W)mm Mini 2 Channel IR Apache Helicopter Mini 2 Ch IR Apache Helicopter with robust moulded plastic construction to take the inevitable bumps and occasional crash. • 20 minute charge gives about 10 minutes flying time (recharges directly from the remote unit) • Requires 6 x AA batteries • 160mm long $ 95 • Recommended for ages 10+ 29 Cat: GT-3273 3 Channel Shark Helicopter with Alloy Frame All aluminium airframe, fuselage and landing gear make this chopper more than a toy and suitable for outdoor flying in calm conditions. A great challenge for the more experienced pilot. • Li-Po battery recharges in about 20 minutes to give about 10 minutes flight time • Remote requires 4 x AA batteries. • Trim control $ 95 • Plugpack charger included • 380mm long Cat: GT-3380 • Recommended for ages 14+ 79 $ Mini Keychain Speaker This keychain speaker will distribute the decibels! Compatible with any device that features a 3.5 mm headphone socket such as iPods ®, MP3 players, PDAs, portable games and computers. It comes with a USB connection to recharge the built-in battery. The ultimate in portability. 99 $ • USB and 3.5 - 3.5mm cable included • Measures: 25(W) x 25(H) x 25(D)mm Cat: QM-3542 19 95 Cat: XC-5178 Handheld USB 60X Microscope Pocket Wire Stripper $ 14 95 Cat: TH-1817 92 Piece 12V Rotary Tool Set Cat: TD-2451 99 Cat: QC-3238 44 LED Magnifier Lamp 39 95 $ Kitchen scales, clock and weather station rolled into one. It weighs contents in metric or imperial measure up to 3kg (6.6lb), and doubles as a wall clock that displays temperature and humidity. Funky orange design. Can sit on kitchen bench or be hung on the wall. Requires 3 x AAA batteries. $ 95 • Celsius & Fahrenheit display Cat: XC-0161 • Kg or lb • Size: 200(Dia) x 22(H)mm Suitable for ages 10+ $ $20 Kitchen Scales with Clock & Temp/Humidity Cat: KJ-8926 Strips anything from 2G to RG6 coax. Easy to use and small enough to take anywhere on the job. • 120mm long Storage media: 32GB SD card Video resolution: 640 x 480 <at> 30 fps Imaging sensor: 1.3MP Dimensions: 90(L) x 50(Dia)mm Was $119.00 Limited Stock Drill, saw, sand, polish, carve or grind in your workshop or out on the road. 90+ bits and attachments cover every possible task you'll ever need. The rotary tool is rated for 12V at 12,000 RPM. Ideal for hobby or professional use. See website for full list of attachments. • Case size: 240(L) x 200(W) x 70(D)mm A colour zoom CMOS video camera that is mounted in a microscope style housing. The system connects to your computer via the USB port and microscope images are viewed on your computer screen as either a snapshot or a video stream. Both can be saved for later viewing. The system has its own LED illuminators so there is always plenty of light for viewing. Accessories include specimen slides, eye dropper and tweezers. • Up to 640 x 480 image resolution • Maximum magnification 60X • Size: 100(L) x 38(Dia)mm $ 59 95 Cat: QC-3248 Computer Tool Kit All the essentials for doing some minor surgery to your PC. Don't forget your anti-static strap. Kit contents: • Driver bit handle • Bits: Slotted 3mm, 4mm, PH 0, 1,T10, T15 • Hex adaptors: 4mm, 5mm, Tweezers, IC extractor, Pearl catch Free Call: 1800 022 888 for orders! www.jaycar.com.au $ 19 95 Cat: TD-2150 7 Massive Savings on Clearance Lines * selected items in-store Listed below are a number of discontinued (but still good) items that we can no longer afford to hold in stock. We need more space in our stores! You can get most of these items from your local store but we cannot guarantee this. Please ring your local store to check stock. At these prices we won't be able to ship from store to store. Items will sell fast and stock is LIMITED - ACT now to avoid disappointment SECURITY PRODUCTS CLEARANCE Description 20 Metre 4-Pin DIN to Video/Power Lead 4 Input USB Video Recorder 4 Zone Wireless Alarm Kit Balun CAT5 S-Video Balun Component Video CAT5 Bellbox with Siren & Stobe Weatherproof 12VDC Camera 1.4GHz Pan/Tilt with Handheld Monitor Camera CMOS Colour Infrared Bullet Camera CMOS Colour with Inspection Gooseneck Camera Dome B&W 380TVL CCD Camera Dome Kit 2 Wire Cable & PSU Camera Kit 2.4 GHz Mini Wireless CMOS Camera Outdoor (IP57) IR B&W 380TVL CCD Camera Outdoor Bullet (IP57) B&W 380TVL CCD Camera Outdoor IP57 IR Colour with 2-Wire Kit Camera Pro B&W 380TVL CCD Camera Pro Colour 380TVL CCD Camera PTZ Dome Colour 480TVL CCD Camera Wireless 2.4GHz CMOS Colour 4CH Camera Wireless 2.4GHz CMOS Colour IR 420TVL 4CH Camera Wireless 5.8GHz CMOS Colour Camera Wireless 5.8GHz CMOS Colour CH3 with PSU Camera Wireless 5.8GHz CMOS with 4 Ch Receiver Camera Wireless PC/IP/Network 6 x IR MPEG4 Camera/Receiver Wireless 5.8GHz CMOS Colour 4CH Dual Output Video Distribution Amplifier DVR Economy MPEG4 4CH w/ 250GB HDD & Ethernet DVR SD with 2 x IR Colour Camera Kit with PSU & Leads Long Range AV Transmitter PIR Child / Pet Door Annunciator Receiver Wireless 2.4GHz Module Small Footprint RF Modulator for Audio/Video RFID Keypad Access Controller Spare Extender/Repeater Sensors for Wireless Alarm Kits Spare Remote Control for 8 Zone Alarm (LA-5477) Wall Plate balun VGA to RJ45 Wireless Strobe & Siren with Solar Charger 8 Zone 2 Wire Alarm Kit Cat No. QC-3097 QV-3081 LA-5134 QC-3423 QC-3682 LA-5309 QC-3279 QC-3096 QC-3389 QC-3472 QC-3264 QC-3569 QC-3490 QC-3467 QC-3266 QC-3310 QC-3298 QC-3500 QC-3595 QC-3565 QC-3571 QC-3573 QC-3570 QC-3398 QC-3572 QC-3438 QV-3079 QV-3098 QC-3425 LA-5166 QC-3599 LM-3872 LA-5123 LA-5139 LA-5479 LT-3034 LA-5307 LA-5477 WAS $29.95 $149.00 $89.95 $49.95 $44.95 $29.95 $399.00 $99.00 $199.00 $89.00 $129.00 $199.00 $169.00 $99.00 $149.00 $109.00 $249.00 $649.00 $169.00 $299.00 $179.00 $199.00 $269.00 $349.00 $299.00 $89.00 $649.00 $349.95 $179.00 $49.95 $29.95 $18.95 $169.00 $54.95 $24.95 $149.00 $199.00 $149.00 NOW $19.95 $79.00 $59.95 $29.95 $19.95 $17.95 $269.00 $55.00 $109.00 $59.00 $85.00 $129.00 $99.00 $69.00 $100.00 $69.00 $169.00 $449.00 $99.00 $159.00 $79.00 $82.00 $119.00 $199.00 $149.00 $59.00 $399.00 $159.95 $99.00 $25.95 $17.95 $9.95 $64.00 $37.95 $11.95 $69.00 $139.00 $99.00 SAVE $10.00 $70.00 $30.00 $20.00 $25.00 $12.00 $130.00 $44.00 $90.00 $30.00 $44.00 $70.00 $70.00 $30.00 $49.00 $40.00 $80.00 $200.00 $70.00 $140.00 $100.00 $117.00 $150.00 $150.00 $150.00 $30.00 $250.00 $190.00 $80.00 $24.00 $12.00 $9.00 $105.00 $17.00 $13.00 $80.00 $60.00 $50.00 WAS NOW $23.95 $6.95 $59.95 $29.95 $169.00 $115.00 $29.95 $13.95 $39.95 $19.95 $49.95 $34.95 $189.00 $119.00 $23.95 $12.95 $59.95 $32.95 $12.95 $3.50 $59.95 $39.95 $29.95 $14.95 SAVE $17.00 $30.00 $54.00 $16.00 $20.00 $15.00 $70.00 $11.00 $27.00 $9.45 $20.00 $15.00 LIGHTING & OUTDOORS CLEARANCE Description Headtorch Dynamo Powered Headtorch Waterproof Diving 30m 8 x LED Pest Repeller Industrial High Power Pest Repeller Solar Recharge - Blue Portable Jaffle Iron 24VDC Portable Stove 24VDC Solar Lighting System w/ 2 Lights Solar Powered LED Bicycle Tail Light Torch 5 in 1 Dynamo with Radio & Siren Torch Keyring Dynamo Powered Torch LED 1.5W Torch Solar Rechargeable Cat No. ST-3346 ST-3074 YS-5524 YS-5532 YS-2806 YS-2807 MP-4551 ST-3276 ST-3370 ST-3348 ST-3332 ST-3077 POWER PRODUCTS CLEARANCE Description Mains Dimmer with Panel 240V 400VA Powerboard 6 Way with Phone Line Filter Powerboard 8 Way Master/Slave with Phone Line Filter Solar Mobile Charger with Detachable Solar Panels Universal Mains Charger for iPod® YOUR LOCAL JAYCAR STORE Australia Freecall Orders: Ph 1800 022 888 NEW SOUTH WALES Albury Ph (02) Alexandria Ph (02) Bankstown Ph (02) Blacktown Ph (02) Bondi Junction Ph (02) Brookvale Ph (02) Campbelltown Ph (02) Coffs Harbour Ph (02) Croydon Ph (02) Erina Ph (02) Gore Hill Ph (02) Hornsby Ph (02) Liverpool Ph (02) Newcastle Ph (02) Penrith Ph (02) Rydalmere Ph (02) Sydney City Ph (02) 6021 9699 9709 9678 9369 9905 4620 6651 9799 4365 9439 9476 9821 4965 4721 8832 9267 6788 4699 2822 9669 3899 4130 7155 5238 0402 3433 4799 6221 3100 3799 8337 3121 1614 Cat No. PS-4082 MS-4036 MS-4062 MB-3588 MB-3652 Taren Point Tweed Heads Wollongong VICTORIA Cheltenham Coburg Frankston Geelong Hallam Melbourne Ringwood Springvale Sunshine Thomastown Weribee QUEENSLAND Aspley Caboolture Cairns Capalaba Ipswich WAS $29.95 $33.95 $64.95 $69.95 $29.95 NOW $19.95 $19.95 $44.95 $34.95 $18.95 SAVE $10.00 $14.00 $20.00 $35.00 $11.00 Ph (02) 9531 7033 Ph (07) 5524 6566 Ph (02) 4226 7089 Ph Ph Ph Ph Ph Ph Ph Ph Ph Ph Ph (03) 9585 5011 (03) 9384 1811 (03) 9781 4100 (03) 5221 5800 (03) 9796 4577 (03) 9663 2030 (03) 9870 9053 (03) 9547 1022 (03) 9310 8066 (03) 9465 3333 1800 022 888 Ph Ph Ph Ph Ph (07) (07) (07) (07) (07) 3863 5432 4041 3245 3282 0099 3152 6747 2014 5800 Sorry - NO Rainchecks Quad Processor with 2 CMOS Colour Cameras & Remote Control Add a monitor or plug into your TV and you have a complete surveillance system. With 2 colour IR cameras, this processor turns any standard TV or monitor into a mulitplexer. It can display a single camera view, or multiple combinations of different camera views including one or two picture-inpicture or automatic sequencing. Was $349 $ 149 Cat: QV-3095 $200 Fingerprint ID Access One unit can be used to control a single door or access point, or multiple units may be used on a site and connected to a PC via RS232, RS485 or Ethernet connection. In addition to controlling a door strike, the controller can also control an alarm to alert of any attempt to force entry or tamper with the unit. Up to 500 users can be enrolled and each can have access restricted to certain times. Software included. $ • 12VDC 3A relay output • Requires 9VDC <at> 500mA Cat: LA-5121 • Dimensions: 180(L) x 82(W) x 55(H)mm Was $499 299 $200 Handheld Micro Inspection Camera The new Digitech handheld micro inspection camera allows you to perform a detailed visual inspection in hard to reach areas. Its pistol grip design and detachable 2.4GHz monitor make it easy to locate and diagnose the unreachable. Camera: • Image sensor: CMOS • Resolution: 704 x 576 pixels $ 299 Cat: QC-8700 Monitor: • LCD Screen Type: 2.5" TFT-LCD • Effective pixels: 480 x 240 Economy 4 Channel H264 DVR A combined multiplexer and digital video recorder that delivers quality image reproduction at a touch of a button. It accepts up to 4 video inputs and its incorporated Ethernet capability enables the unit to be accessed (with password protection) via the Internet via a standard web browser. The unit features H264 compression, VGA monitor connection, motion trigger recording, video loss detection, remote network record and USB back-up support. The unit comes fitted with a 250GB HDD and includes software & manual disc, power supply and quick start guide. • Size: 343(W) x 59(H) x 223(D)mm Also available: $ 599 Cat: QV-8101 250GB HDD Included Economy 16 Channel MPEG-4 DVR with 500GB Hard Drive Cat. QV-8102 $999 Mackay Ph (07) 4953 0611 Maroochydore Ph (07) 5479 3511 Mermaid Beach Ph (07) 5526 6722 Townsville Ph (07) 4772 5022 Underwood Ph (07) 3841 4888 Woolloongabba Ph (07) 3393 0777 AUSTRALIAN CAPITAL TERRITORY Belconnen Ph (02) 6253 5700 Fyshwick Ph (02) 6239 1801 TASMANIA Hobart Ph (03) 6272 9955 Launceston Ph (03) 6334 2777 SOUTH AUSTRALIA Adelaide Ph (08) 8231 7355 Clovelly Park Ph (08) 8276 6901 Gepps Cross Ph (08) 8262 3200 WESTERN AUSTRALIA Maddington Ph (08) 9493 4300 Midland Ph (08) 9250 8200 Northbridge Ph (08) 9328 8252 Rockingham Ph (08) 9592 8000 NORTHERN TERRITORY Darwin Ph (08) 8948 4043 NEW ZEALAND Christchurch Ph (03) 379 1662 Dunedin Ph (03) 471 7934 Glenfield Ph (09) 444 4628 Hamilton Ph (07) 846 0177 Hastings Ph (06) 876 0239 Manukau Ph (09) 263 6241 Newmarket Ph (09) 377 6421 Palmerston Nth Ph (06) 353 8246 Wellington Ph (04) 801 9005 Freecall Orders Ph 0800 452 922 Prices valid to 23rd January 2010 Arrival dates of new products in this flyer were confirmed at the time of print. Occasionally these dates change unexpectedly. Please ring your local store to check stock details. *Savings off original RRP - Limited Stock No rain checks, may not be available at all store locations - call your local Jaycar store to check stock 8 Free Call: 1800 022 888 for orders! www.jaycar.com.au PRODUCT SHOWCASE Is everything i-something these days? Meet the i-Touch! Want to integrate a 2.8” 320x240 pixel, 262,144 colour, LED backlit, QVGA, touchscreen display in your next product or project? Take a look at the iTouch from Pymble Software. It runs off a 16 MIPS PIC24FJ128GA010, in-system programable (PX-200 & PX-700 USB ISP also available) and supports Microchip’s library files. The main clock is at 8MHz and 32.768kHz for the RTCC (Real-Time Clock and Calendar) module. The iTouch features: • 4 Analog inputs. Supports 0 to +3.3V and 7-Digital input/output support +5V tolerance • 256 Kb serial EEPROM; 25LC256 for saving the display configuration and general purpose. • SD/MMC card interfacing circuit. • USB-to-serial converter circuit. • On-board TC1047 temperature sensor • Board size is 8 x 6.4 cm. There’s a YouTube video of the iTouch in action on http:// pymblesoftware.com/store/index.php/itouch.html It sells for $179.95 and if you mention Contact: you saw it in SILICON Pymble Software Pty Ltd C HIP they’ll give PO Box 121, Pymble NSW 2073 you free shipping Tel: (02) 9983 0308 Web: http://pymblesoftware.com/store Australia-wide. Picotest 6.5 digit DMMs have ultra-fast DAQ rate The new Picotest M3510A/3511A 6.5 digit digital multimeters have very fast data acquisition rates; up to 50,000 readings per second (M3510A) and 10,000 readings per second (M3511A) as well as dual displays. The Picotest M3510A is also capable of measuring temperature using RTDs and thermocouples with simultaneous readout of voltage and temperature. With a USB port, they’re suited to R&D, scientific as well production and service tasks. Importantly, the Picotest instruments are equipped with USBTMC (USB Test & Measurement Class) compliant port, a protocol built on top of USB allowing GPIB-like communication with USB devices. From the user’s point of view, the USB device behaves just like a GPIB device. The USBTMC protocol supports service request, triggers and other GPIB specific operations. With high accuracy (±0.012% of reading over 24 hours) and stability, voltage is measured to 1000V Contact: Westek Electronics Pty Ltd DC (750V AC), U/2 6-10 Maria St, Laverton North Vic 3026 current to 3A AC/ DC and frequency/ Tel: (03) 9369 8802 Fax: (03) 9369 8006 Website: www.westek.com.au period to 300kHz. USB Camera Microscope has many applications The Active Components USB Microscope is a very useful tool for inspecting PC boards and checking the quality of solder joints. Other applications include checking for counterfeiting, educational research or any general macro (close-up) photography. A crystal clear image is produced with the help of four built-in white LEDs and a two megapixel image sensor. Optical zoom ranges between 1 and 60 times and adjustments can easily be made to the focus and light intensity using the thumb wheels on the side of the device. The microscope camera runs while connected to a Laptop or Desktop PC and takes only siliconchip.com.au a few minutes to set up. The software enables features such as on-screen distance/ angle measurement and still image or video capture. The software, tripod and a USB cable are all included in this package, available Contact: for sale online (see Active Components (NZ) Ltd website at right), PO Box 100-544, NSMC, Auckland, NZ priced at $AU80.95 Tel: (64-9) 443 9500 Fax: (64-9) 443 9502 (or $NZ99.95) each. Website: www.activecomponents.com January 2010  57 SERVICEMAN'S LOG Relay standards: there’s no such thing Can a standard 4-pin 12V relay be all that difficult to diagnose? Well, not really but you can really be caught out if you assume that all relays conform to the same standard, particularly in the automotive trade. My first story this month is from my friend in the automotive trade and concerns an interesting relay fault in an old Ford. I’ll let him tell it in his own words . . . We recently had an old car into the workshop with a “battery drain” problem. The symptoms were simple enough. If the car was left unused for more than 36 hours, the battery didn’t have enough charge remaining to start the car. The car in question was a 1976 XB Fairmont. These old girls are now so ancient that they qualify for HCRS (Historic Concessional Registration Scheme, in NSW) or in plain English, “Vintage Rego”. Now I really do feel old! This was a classic case of an older technician passing a supposedly simple job to a junior “new-age” technician, thinking that he could see firsthand how simple cars once were. The only electronics on board a 1976 Ford are inside the (AM) car radio and the 35A alternator. There was no EFI, ABS, ECU, sat-nav or burglar alarm. In fact, this car didn’t even have airconditioning or power steering. And while it was light-years ahead of a 1953 FJ Holden, this 1976 Ford illustrates just how far we have come in the last 33 years. Anyway back to the problem at hand. With a car this simple, how easy would it be for our young tech (let’s call him John) to solve a problem as mundane as the battery going flat? Admittedly, this was on an older car that he wasn’t familiar with but it should all be routine. Well, at least it started out well. He first carried out a battery load test and then checked the alternator charge rate to verify that that side of the system ~HOW MANY TIMES HAVE YOU HAD TO TRIM THE FIGURES ON A JOB SHEET...? 58  Silicon Chip Items Covered This Month • Relay standards – no such thing • Resurrecting a PC was all good. John then quickly found that with all the Ford’s electrical devices switched off, his multimeter indicated a constant current drain of more than 180mA from the battery. From there, his next step was to check that all the usual suspects were definitely off. By “usual suspects” I mean those little convenience items such as boot lights, glovebox lights and other “courtesy” features that cause so much grief in draining car batteries if they’re not working properly. In fact, in my experience, these “convenience” items can be very inconvenient at times. The only item on board that should be drawing current with all systems shut down is the clock but these oldschool mechanical timepieces don’t draw current continuously. Instead they “wind up” as and when required, so for the majority of the time their current draw is zero. Remember, this was before the days of electronic radio station presets and all manner of other memorybased devices. John’s next step was to remove each of the fuses in the fusebox. This is done on a one-by-one basis while checking the current drain at the battery, to see which branch is at fault. And yet, with all the fuses extricated, we still had a 180mA constant drain which was a real surprise, especially as these old Fords were quite well designed electrically. A quick check of the siliconchip.com.au wiring schematic showed that the only items remaining in circuit, with all fused circuits disabled, were the starter motor and the alternator. We then took a closer look at this area and this revealed that some aftermarket wiring had been added to the alternator output terminal, to supply a pair of auxiliary driving lights. This extra wiring had been fitted decades ago, probably by the selling dealer’s workshop when the car was new. The workmanship was top-notch, obviously performed in a more leisurely era when labour rates were something like $10 per hour and a tradesman’s pride took precedence over a “quick buck”. In fact, it looked so good to John that he had assumed it to be factory-installed. These days, any aftermarket wiring is immediately suspect. It is generally a little untidy (by comparison) and far more likely to cause a problem than any part of the factory harness. The driving lights were powered directly from the alternator output via a relay. This relay was switched by a dash-mounted toggle switch which in turn was switched by the high-beam column stalk. The relay utilised was the common garden-variety Bosch 4-pin unit that has been used in the industry for at least four decades. In this case, it was installed in a chassis-mount socket that had been attached to the inner guard, adjacent to the alternator. This meant that the relay could be simply unplugged from its socket, if required, so John did just that to reveal a sudden drop in battery drain. Eureka! – but what was the cause. After all, 4-pin relay wiring doesn’t come much simpler? There’s just a 12V supply, an earth, a switching wire from the dash and a wire to the lights themselves. All these circuits checked siliconchip.com.au out individually but – and it’s a big but – John failed to notice that while the driving lights still worked, the relay didn’t “click” as it should have when switched on. At this point, he asked me for help as he had run out of ideas. In fact, I have taught John to ask for help if required, especially when I’m charging my clients $100 per hour plus GST for his time on the job. How many times have you had to “trim” the figures on a job sheet because time has been spent on a wild goose chase and it isn’t possible (or ethical) to charge the client for that portion? I immediately noticed two things. First, as already mentioned, the relay wasn’t making an audible “click” when the driving lights were switched on and second, the relay itself was brand new. I noticed this “newness” because about the only design change that Bosch has made to these relays in the last few decades is that they now use a black plastic casing, whereas the older style relays were built into a zinc-plated pressed metal case. And that’s when the penny dropped, or was it a case of deja vu. The root cause was that somebody had quite recently fitted an incorrect replacement relay. It still plugged into the socket correctly but the connections were now electrically “incorrect”. In the automotive industry, one thing I have learnt is that the word “standard” doesn’t necessarily mean “standard”, because everyone has their own “standard”. The problem is that these particular relays come in two different base configurations. In other words, there’s one base layout but two different configurations. Confused yet? The base on the original relay fitted to the Ford has pins 30, 85, 86 & 87 as shown in Fig.1. Pins 85 & 86 are the coil connections, while pins 30 & 87 86 85 30 87 Fig.1: the base layout of the relay originally fitted to the old Ford Fairmont for the driving lights. Note the locations of pins 30 & 86. 30 86 85 87 Fig.2: the base layout for the replacement relay. Both relays use the DIN standard pin numbering scheme (and they fit the same socket) but the locations of pins 30 & 86 are transposed (the layout in Fig.2 is now the most common). are the relay contacts. This base layout was common in the 1970s but is still seen on occasions. The more recent layout is shown in Fig.2. As can be seen, both relays use the DIN standard pin numbering but the locations of pins 30 & 86 are transposed. And so, with the new relay plugged in, the full-time 12V supply (from the alternator) held the relay “on” January 2010  59 Serr v ice Se ceman’s man’s Log – continued continuously, regardless of the dash switch operation. The driving lights were still switched on and off by the dash switch but the relay’s purpose in life was negated. In fact, the poor old dash switch was probably working at or near its maximum current rating, trying to supply the driving lights. Meanwhile the relay was being held on 24 hours a day drawing 180mA, conveniently (or rather inconveniently) draining the battery. We replaced the relay with the correct type and the old Ford was back in business. So that’s life sometime in the automotive business. It really is easy for something simple like that to waste a lot of time. Now for one of my own stories. Despite my hassles, I certainly didn’t make any money out of this one. Ever a sucker for punishment Ever a sucker for punishment, I took on the repair of yet another PC, this time for a friend. I’ve really got to stop doing this; PCs can be a great time- Servicing Stories Wanted Do you have any good servicing stories that you would like to share in The Serviceman column in SILICON CHIP? If so, why not send those stories in to us? In doesn’t matter what the story is about as long as it’s in some way related to the electronics or electrical industries, to computers or even to car electronics. We pay for all contributions published but please note that your material must be original. Send your contribution by email to: editor<at>siliconchip.com.au and be sure to include your full name and address details. 60  Silicon Chip waster. The only trouble is, repairs to CRT TV sets have all but ceased and I’ve got to make money somehow. The unit in question was a Dell Optiplex CX620 that my friend purchased at an auction. Apparently it was an exuniversity computer which he bought cheap, sight unseen. Its hardware specifications weren’t too bad and included a 3.2GHz Intel P4 CPU, 1GB of RAM and a 160GB SATA 7200RPM hard drive. It also boasted a good AGP video card with a DVI socket. Eventually, when I found time, I hooked it up to a monitor, USB keyboard and mouse and fired it up. It turned out that the computer was configured to work on a network which had multiple user names, passwords and devices to select. I selected “Administrator” and the name of this computer but I didn’t know the password so I was stuck. In the end, I had to dig out my Offline NT Password & Registry Editor utility. This is a Linux utility which goes on a CDROM boot disk. When you boot the machine, it automatically takes you into the C:\windows\ system32\config\sam configuration file and allows you to edit the hives passwords and permissions and to reset the counters. I set the password to blank for the Administrator and now I could boot up into XP Pro after hitting CTRL + ALT + DEL to log on. The next thing to do was to interface it to my wireless router via a USB2 dongle (Hawking HWUS4G 802.11g Mini Wireless LAN). I then got onto the Internet and downloaded the latest Dell drivers and patches, as well as the Microsoft Updates. And that was when I found I was in all sorts of trouble. The security settings in the machine were all wrong and what’s more, I couldn’t edit them. I couldn’t set the machine for automatic updates and I couldn’t do much with the User setting either. I got onto the Microsoft Update site and noticed that after downloading the X86 32-bit Windows Update Agent I got an error code: OX8024D007. I was also getting “Chassis Intrusion Detected” error messages as well. The only thing I could successfully download was from the Dell website and I noticed that the BIOS I had was A03 and the current version was A11, so I thought this would be a good place to start. Well, true to form I was wrong – very wrong. I followed the instructions very siliconchip.com.au siliconchip.com.au ACOUSTICS SB carefully but when it came to rebooting, it didn’t! All I got was solid green LEDs 3 & 4 and a 3-1-2 beep code during POST (Power-On Self Test). According to the manual, this implied either a RAM problem or a Master DMA register failure. I tried swapping the RAM over but nothing I did would let me boot the machine. I even removed the video card and used the on-board VGA socket but no luck. I then trawled the web on my own computer but I couldn’t find anything sensible and practical. And then I had an idea. I turned the computer off, unplugged it from the mains and removed the back-up battery for half an hour. I then replaced everything and switched it back on. It rebooted, much to my relief, so I got into the new BIOS and reset the intrusion alarm. That was one annoying problem solved. Back in Windows, I opened Internet Explorer and noticed it was still version 7.0. I couldn’t use Windows Update but I could separately download IE 8.0 from the Microsoft Download Site. I did this but it took three attempts before it installed correctly! This machine clearly had a few issues. This time, when I rebooted and went back into IE 8, Microsoft Updates was now working properly and I was able at last to download the 30 or so updates that were available. And with each succeeding update, the machine gradually came good. Booting and closing down had previously been a bit of a problem. To close down, I always had to log off first because the option to go straight to shut down wasn’t coming up. Similarly, the option to restart the machine had also gone AWOL. With the updates, this was now all fixed but I could not switch off the log-on procedure (ie, CTRL + ALT + DEL) until I rediscovered “Powertoys” for XP. This is a series of useful utilities, including one called “TweakUI”. Using this, I was able to make the computer boot straight into Windows and close down/restart properly as per normal. But I was not completely out of the woods yet. Microsoft Updates would not let me install MS SQL Server 2005 Express Edition and instead left me with an error code. Surprisingly, aid came from an unexpected quarter. Forgive me if I appear quite cynical when it comes to software help, let alone Microsoft Help, but when I emailed Microsoft they were actually extremely helpful. The assistance even had a distinct Indian flavour, with beautifully polite and correctly-written English prose! My Indian friend suggested I remove all of MS SQL Server 2005, the KB960089 security update, Compact Edition (ENV), Native Client, Support Files and VSS Writer (just removing the main program doesn’t fix it). The advice was to then reboot and download and reinstall MS SQL Server 2005 again. I did that, then rebooted and then ran MS Update again. And this time, XP Service Pack 3 (SP3) installed correctly. The computer now works well but I don’t think my mate really deserves me putting up with all this grief! In hindsight, it probably would have been a damn sight quicker to reformat the hard drive and reinstall everything. When will I ever learn not to take on PC repairs? SC dynamica January 2010  61 A precision Temperature Logger and Controller, Pt.1 By LEONID LERNER This Temperature Logger & Controller is based on the Dick Smith Electronics Q1437 digital thermometer. It records & displays two temperature channels once a second on a PC over a period of up to 12 hours. With appropriate thermocouples, temperatures from -200°C to +1300°C can be recorded, with the display range, resolution, and temperature program adjustable in real time while the data is being logged. A S WELL AS PROVIDING precise temperature logging, the project will control a 230V AC heater rated up to 10A, in response to the temperature readings in on/off mode and a time-temperature regime set with up to four set points. The accuracy of the instrument is 0.1% (excluding probe error) and its precision is 0.1°C over the entire range. The logger/controller interfaces to your PC through the parallel port using a standard DB25 connector. The precursor to this project was the PID Temperature Controller featured in the July 2007 issue which in turn was based on the Digital Thermometer/Thermostat featured in the August 2002 issue of SILICON CHIP and previously available as a kit from Dick Smith Electronics. That kit project has long been discontinued which made this comprehensive update necessary. This new project dispenses with the original microcontroller and its associated circuitry from the July 2007 design, with all functions now performed by the attached PC. This significantly simplifies hardware construction which now 62  Silicon Chip involves soldering less than a dozen discrete components. The down-side in eliminating the microcontroller is that the device can no longer be operated stand-alone. In practice, this is not a serious inconvenience since the controller will mostly be used in the temperature logging mode, with the operator observing variations in real time. In this mode, the role of the microcontroller was, for the main part, that of a communications device. Its other functions, such as controlling the analog-todigital converter (ADC), are now performed by the DSE Q1437 digital thermometer, while the Triac control signal is generated by the PC. The improvements arise from the fact that temperature readings are now logged with the accuracy and precision of the DSE Q1437 digital thermometer. This is a professional instrument and is based on modern microprocessor technology with a super low-noise ADC and custom ambient temperature compensation circuitry, which will be described in greater detail below. The accuracy, reproducibility and noise level of this insiliconchip.com.au strument have been found to be much superior to those available with the previous circuitry. Temperature control to within fractions of a degree is now possible in many cases. The fact that the Q1437 thermometer draws very little current enables it to be battery powered, eliminating power supply noise. This is a significant feature since a 0.1°C temperature precision for a type K thermocouple translates to a 4µV precise voltage measurement. Another new feature associated with the use of the Q1437 is that two temperature values can be logged at the same time. This is useful when recording the temperature of a fluid while controlling the temperature of the oven heating it. The device interfaces to the computer using the parallel port of the PC, which is still available on modern desktop machines. Although the USB port is now more common, this was deemed unsuitable because the interface uses several signal lines and multiplexing them onto a serial communication would require hardware which is almost entirely absent in a parallel port design. Moreover the logger captures data by running the PC for a very short period in “real-time”(ie, by disabling interrupts). siliconchip.com.au The USB port is not designed to operate in this fashion. Circuit description The circuitry consists of two independent blocks: the thermometer section and the Triac load controller. Since the Q1437 digital thermometer does not have a suitable interface we need to provide one by soldering three wires and a couple of capacitors to appropriate pins and attaching a suitable socket on the connection panel. This is connected to the parallel port of the PC. To do this, an understanding of the operation of the Q1437 is required, as outlined below. Fig.1 includes a block diagram of the internal circuitry of the Q1437 digital thermometer. Although the circuitry itself is complex, the basic operation as well as the functioning of the interface, can be easily understood. Differing temperatures between the junctions of the thermocouples TC1 and TC2 and their connections at the instrument generate a voltage difference and this is apJanuary 2010  63 148H THERMISTORS 9,10 5 THERMOCOUPLE 1 13   THERMOCOUPLE 2 22M 1  3 14 LTC2433 IN– ANALOG MULTIPLEXER MSP430F MICRO 11 12 9 680pF T 24 12 CS WR 32 x 4 LCD HT1621 DATA 32 x4 LCD CONTROLLER 2.5mm STEREO JACK PLUG B (SHIELDED STEREO CABLE) 25 13 (NEW) 2.5mm STEREO JACK SOCKET B R T R 680pF 22 10 230V AC INLET (MALE) CONTROLLER BOX 21 9 PC PRINTER PORT F1 10A 20 8 19 7 18 6 17 5 16 4 130 (SHIELDED MONO CABLE) 390 6 1 DB9F DB9M 5 5 15 3 14 2 3  OPTO1 MOC3041 3 A 2 E A2 G TRIAC1 BTA10A1 600B 39 1W 4 1k 10nF 250VAC X2 CLASS (BOX) 230V AC OUTLET (FEMALE) 1 E N 23 11 8 ANALOG TO DIGITAL CONVERTER 12  DB25M 5 9 7 IN+ N BIAS NETWORK 4 74HC4052 22M DSE Q1437 DIGITAL THERMOMETER SPI INTERFACE A CAUTION: ALL PARTS WITHIN RED SECTION OPERATE AT 230V AC SC 2010 TEMPERATURE LOGGER & PWM LOAD CONTROLLER Fig.1: the orange section at the top of this diagram is the (modified) DSE digital thermometer. The remainder is the interface to your PC and the power switching circuitry. Note that the parts & wiring in the red shaded section all operate at 230VAC. plied via custom thermistors (148H) to the inputs of the 74HC4052 analog multiplexer. If the thermistors were not present the thermocouple circuit would give zero voltage when the thermocouple junction is at ambient temperature, rather than at 0°C. The four thermistors and associated bias circuitry act to compensate for this by adding a potential difference with increasing ambient temperature in such a way that the total voltage behaves as if the reference end of the thermocouple WARNING! Most of the parts in this circuit operate at high voltage (ie, 230V AC) and contact could be lethal. Do not touch any part of the circuit while it is plugged into the mains and do not operate it outside its earthed metal case (see Pt.2 next month). Do not build it unless you are experienced and know exactly what you are doing. 64  Silicon Chip BTA10-600B A1 A2 G circuit was held at a constant 0°C. Next, the voltages generated by thermocouples 1 and 2 appear in turn at the outputs of the 74HC4052 analog multiplexer in response to signals sent by the MPS430F microcontroller. These voltages are applied differentially to the IN+/IN- inputs of the LTC2433 low-noise (1.45µV RMS) 16-bit delta-sigma ADC (analog-to-digital converter). This ADC can operate at reference voltages as low as 100mV and has a correspondingly low 5µV offset. In addition, it is ultra-linear with a maximum 0.16 LSB full-scale error and also incorporates integral 87dB (factor of 22,000) notch filters at mains frequency (50Hz and 60Hz). The converted digital temperature signal is passed serially via a 3-pin interface (pins 7, 8 & 9 of the LTC2433) to the MPS430F microcontroller. This is a very low power (280µA active, 1.6µA stand-by, 0.1µA RAM-retention mode) 16-bit microcontroller in a 64-pin QFP (quad flat package). The controller has three main functions: it reads the keyboard, gathers voltage data from the ADC, translates the data to temperature and passes it for display to the siliconchip.com.au Fig.2: the GUI is quite intuitive and you should have no problems driving it. C M Y CM MY CY CMY K Triac load controller The load controller is an opto-coupled Triac circuit with an RC snubber to reduce overshoot for inductive loads. The MOC3041 zero-crossing Triac driver minimises electrical noise and surge current when loads are close to resistive. The MOC3041 requires a current of 15mA to ensure turn-on and this is easily sourced from a single pin of the parallel port by a 130Ω resistor, dropping a nominal 2V. Triac switching is achieved in software by toggling pin siliconchip.com.au W3926 Marque Magnetics Ad.ai 7/13/07 3:36:14 PM Talk to a company that speaks your language • Technical Engineering support • Custom Design capability • Direct Replacement of ‘standard’ parts • Stocking options • NZ manufacturing facility • Company owned China manufacturing facility • ISO 9001 and ISO 13485 (medical) certified And all available to you! Ph: +64 9 818 6760 11 Culperry Road, Glendene, Auckland, New Zealand www.marque-magnetics.com W3926 HT1621 32-character 4-line LCD controller. This transfer is performed by means of three lines acting as inputs on the HT1621: the CS-bar (chip select) line, the WR-bar data write line and the data line. As evident from its 32x4 specification, the HT1621 contains a 128-bit RAM which it reads out sequentially at a rate fixed by an internal clock and outputs on multiplexed lines which drive the liquid crystal display (LCD). These 128 bits correspond to elements on the Q1437 LCD and are distributed essentially randomly, as this display does not correspond to a 32x4 format. The input side of the HT1621, which is independent of the output, is used to update the 128-bit data when new values are required. Different command modes are available to either update the data as a single 128-bit block or as individual values. The Q1437 uses the former mode exclusively, so the block of data written to the HT1621 is always of a fixed size – 173 bits. The extra 45 bits sent in each frame take the form of three 12-bit commands to initialise the HT1621 and a 9-bit command to instruct single block update. While the requisite bits are presented on the data line (pin 12), the WR-bar line driven by the microprocessor acts effectively as a clock, with a rising edge indicating good data on the data line. This signal is used by the software component of our interface to sense when to read the data. Data update on the input side of the HT1621 occurs fairly slowly at a rate of about eight updates per second, however the data itself is transmitted quickly with each data bit about 1.5µs wide. At this frequency, the effects of reflections due to inductance on the line connecting the Q1437 to the PC are significant and can result in false readings. The addition of 680pF capacitors between signal and ground on both the DATA and WR-bar lines at the parallel port input of the PC suitably damps the oscillations and provides reliable operation, with no false readings using a simple 2-core shielded cable connection. January 2010  65 Parts List –Temperature Logger and PWM Load Controller 1 Dick Smith Electronics Q1437 digital thermometer 1 PC board, 87 x 54mm, code 10101101 1 diecast aluminium case, Jaycar HB5040 to suit 1 IEC 3-pin male chassis-mount socket 1 IEC 3-pin female chassis mount socket 1 M205 safety fuse holder (Altronics S-5992, Jaycar PP4005) 1 10A M205 fuse 1 25-pin DB25M plug 1 9-pin DB9M plug 1 9-pin DB9F socket 1 2.5mm stereo jack socket and matching jack plug 1 BTA10-600B 600V 10A insulated tab Triac (do not substitute) 10 Nylon cable ties 1 MOC3041 zero-crossing Triac opto-isolator (OPTO1) Capacitors 1 10nF 250VAC class X2 2 680pF ceramic Resistors (0.25W, 1% unless stated) 1 1kΩ 1 390Ω 1 130Ω    1 39Ω 1W 5% Miscellaneous 1 solder lug, mains-rated cable, ribbon cable, 2-core shielded cable, sing-core shielded cable, heatshrink tubing, screws, nuts, lockwashers, solder. 2 of the parallel port, which drives the MOC3041 optoisolator. The Triac on-period is nominally set to one second, as established by the timer function of the Windows API. Since Windows is not a real-time operating system, precise timing can not be guaranteed, with a variation of typically 10% occurring in pulse width from cycle to cycle. This is not a problem for this present application since average duty cycle is still maintained to about 5%, while on/ off control is the main mechanism by which temperature is controlled, with duty cycle being a secondary control applied manually to reduce overshoot. Software There are two components to the project software. The main component is written in Visual C++ and provides the graphical user interface (GUI) to the device, which can be seen in Fig.2. It also analyses the data block acquired from the Q1437 digital thermometer, extracts the data corresponding to the two temperature channels, displays the temperature on the screen and graphs the data using the scales entered by the user. In addition, it operates the Triac load controller in accordance with the time-temperature program entered in the GUI. The second component consists of the data block capture routine and is written in assembly language. The reason for this is that the bit-width of the data frame is about 1.5µs, which is close to the 1µs response time of the standard parallel port, hence speed is of the essence for proper operation. In addition, code running under Windows is periodically interrupted to perform task switching, which if allowed in the course of data capture leads to missing bits and data corruption. Critical tasks can disable interrupts (except non-mask­ able interrupts) during their execution and restore them on completion and this does not interfere with Windows provided the task is brief. In our case, field acquisition takes up about 1ms with a period of about 1Hz, which is acceptable. For PCs running Windows 95/98, the above code presents no particular problems and the low-level assembly routine can be linked as part of the overall application. However, in later Windows versions, in particular Windows NT, XP etc, ordinary applications cannot suspend interrupts, while direct port access to individual applications can only be granted by code running at operating system privilege (ring-0). Moreover, in Windows XP, changes made to the IOPL flag bits controlling port access at ring-0 level are restored by the operating system upon return to the application, making these flags essentially redundant. For this reason, the assembler code is incorporated in its entirety into a device driver file (.sys file), which is installed and registered the first time the main program is run, subsequently performing access to the ports and passing data to the main routine. What’s coming? That’s all we have space for this month. Next month, we’ll show you how to wire up the interface to the digital thermometer and give the full construction details for the SC Temperature Logger & Controller. into VIDEO/TV/RF? Television & Video Technology – by KF Ibrahim New edition has a full and compre-hensive guide to video and TV tech-nology including HDTV and DVD, $ 58 starting with fundamentals. $ 70 NEW LOW PRICE! DVD Players and Drives $ 95 NEW LOW PRICE! $ 85 – by KF Ibrahim DVD technology and applications - ideal for engineers, technicians, students, installation and sales staff. Practical Guide To Satellite TV – by Garry Cratt The book written by an Aussie for Aussie conditions. Everything you need to know – including what you cannot do! 7th ed. $ 49 Hands-On Zigbee – by Fred Eady $ 96 50 NEW LOW PRICE! $ 75 An in-depth look at the clever little 2.4GHz wireless chip that’s starting to be found in a wide range of equipment from consumer to industrial. There’s something to suit every RF fan in the SILICON CHIP reference bookshop: see the bookshop pages in this issue $ 75 RF Circuit Design – by Chris Bowick A new edition of this classic RF NEW LOW PRICE!design text - tells how to design and integrate RF components $ 74 into virtually any circuitry. Practical RF H’book – by Ian Hickman $ reference work for technic90 Aians, engineers, students and NEW LOW PRICE! 73 $ the more specialised enthusiast. Covers all the key topics in RF that you need to understand. ! Audio ! RF ! Digital ! Analog ! TV ! Video ! Power Control ! Motors ! Robots ! Drives ! Op Amps ! Satellite 66  Silicon Chip siliconchip.com.au SILICON SILIC CHIP siliconchip.com.au YOUR DETAILS 6 MONTH SUBS AND AUTO RENEWAL NOW AVAILABLE Your Name_________________________________________________________ Order Form/Tax Invoice Silicon Chip Publications Pty Ltd ABN 49 003 205 490 PO BOX 139, COLLAROY NSW 2097 email: silicon<at>siliconchip.com.au Phone (02) 9939 3295 Fax (02) 9939 2648 This form may be photocopied without infringing copyright. (PLEASE PRINT) Address______________________________­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­___________________­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­___________________________________________________ Postcode__________ Daytime Phone No. ( )____________________ Email address ________________________________ Method of Payment: q EFT (ring or email for details) q Cheque/Money Order q PayPal q Visa Card q Master Card Card No.                                Card expiry date: Signature_________________________________________________ YOUR ORDER (SILICON CHIP PRINTED EDITION SUBSCRIBERS# QUALIFY FOR 10% DISCOUNT (except on subscriptions!) SIMPLY TICK THE ITEMS REQUIRED – DON'T FORGET TO FILL IN DETAILS ABOVE. WE'LL WORK THE TOTAL OUT FOR YOU AND SEND YOU A RECEIPT WITH YOUR ORDER SILICON CHIP SUBSCRIPTIONS (all prices include P&P) SILICON CHIP BOOKSHOP (P&P additional – See below) q AUSTRALIA 6 MONTHS (INC. GST) (NEW!).......................................................$49.50 q AUSTRALIA 12 MONTHS (INC. GST)..................................................................$94.50 q AUSTRALIA 12 MONTHS WITH BINDER (INC. GST) .......................................$111.00 q AUSTRALIA 24 MONTHS (INC. GST)................................................................$182.00 q AUSTRALIA 24 MONTHS WITH 2 BINDERS (INC. GST) .................................$215.00 q NEW ZEALAND 6 MONTHS (AIR MAIL) (NEW!)............................................ $AU55.00 q NEW ZEALAND 12 MONTHS (AIR MAIL)....................................................... $AU99.00 q NEW ZEALAND 24 MONTHS (AIR MAIL) ................................................... $AU196.00 q OVERSEAS (EXCEPT NZ) 6 MONTHS (AIR MAIL) (NEW!)............................. $AU75.00 q OVERSEAS (EXCEPT NZ) 12 MONTHS (AIR MAIL)...................................... $AU135.00 q OVERSEAS (EXCEPT NZ) 24 MONTHS (AIR MAIL) .................................... $AU260.00 NEW! CONVENIENT AUTOMATIC SUBSCRIPTION RENEWAL: q Tick here if you'd like us to automatically renew your subscription when it elapses q q q q q q q q q q q q q q q q q q q q q q q q q q q q    (ie, 6 month, 12 month or 24 month). We'll renew until you tell us to stop! BACK ISSUES/ARTICLE PHOTOCOPIES q SILICON CHIP BACK ISSUES*; SC/EA/ETI PHOTOCOPIES – includes P&P – $12.00 within Australia; $15.00 overseas *where in stock - photocopy of article supplied where issue is out of stock. EA/ETI: no back issues left, only photocopies available. Price is for each back issue or each article photocopy. Nominate issue and article required: Month:...................................... Year:......................... Article required:.................................................................................................................... Please attach list if more than one back issue or photocopy required. There is a 10% discount for ten or more back issues and/or photocopies (no further discount applies). SILICON CHIP MAGAZINE BINDERS q Embossed "SILICON CHIP", securely holds 12 months+ of issues Available in Australia only.......................................................................................$14.95 (P&P is $10.00 per order; buy five or more in one order for FREE P&P) P&P RATES: Subscriptions, back issues and project reprints: P&P included Binders (available Australia only): $10.00 per order; for 5 or more P&P is free. Books: Aust. $10 per order; NZ: $AU12 per book; Elsewhere $AU18 per book To eMAIL (24/7) Place silicon<at>siliconchip.com.au Your with order & credit card details siliconchip.com.au Order: OR FAX (24/7) This form (or a photocopy) to (02) 9939 2648 with all details AC MACHINES................................................................................................ $66.00 AMATEUR SCIENTIST CD .............................................................................. $62.00 AUDIO POWER AMPLIFIER DESIGN ............................................................ $95.00 BUILD YOUR OWN ELECTRIC MOTORCYCLE (NEW)....................................$47.95 DVD PLAYERS AND DRIVES ........................................................................ $95.00 ELECTRIC MOTORS AND DRIVES.................................................................. $60.00 ELECTRONIC PROJECTS FOR CARS (2003) – last few, shop-soiled – now... $2.95 HANDS-ON ZIGBEE ....................................................................................... $96.50 NEWNES GUIDE TO TELEVISION AND VIDEO TECHNOLOGY........................ $70.00 OP AMPS FOR EVERYONE.......................................................................... $120. 00 PERFORMANCE ELECTRONICS FOR CARS.................................................... $19.80 PIC IN PRACTICE........................................................................................... $65.00 PIC MICROCONTROLLERS - KNOW IT ALL................................................... $90.00 PIC MICROCONTROLLER - PERSONAL INTRO COURSE............................... $60.00 PRACTICAL GUIDE TO SATELLITE TV (7th edition)...................................... $49.00 PRACTICAL RF HANDBOOK .......................................................................... $90.00 PRACT. VARIABLE SPEED DRIVES/POWER ELECT...................................... $105.00 PROGRAMMING 16-BIT MICROCONTROLLERS IN C.................................... $90.00 RADIO, TV AND HOBBIES ON DVD-ROM ...................................................... $62.00 RF CIRCUIT DESIGN...................................................................................... $75.00 SELF ON AUDIO (2nd edition)........................................................................ $90.00 SOLAR SUCCESS - GETTING IT RIGHT EVERY TIME..................................... $47.50 SOLAR THAT REALLY WORKS ...................................................................... $42.50 SWITCHING POWER SUPPLIES A-Z (inc CD-ROM)..................................... $115.00 TV ACROSS AUSTRALIA ............................................................................... $49.95 USING UBUNTU LINUX.................................................................................. $27.00 VIDEO SCRAMBLING AND DESCRAMBLING............................................... $105.00 WINDOWS 7 FOR DUMMIES (NEW)..............................................................$37.95 #10% discount offer does not apply to online edition subscribers nor to website orders OR PAYPAL (24/7) OR Use PayPal to pay silicon<at>siliconchip.com.au *ALL ITEMS SUBJECT TO AVAILABILITY. PRICES VALID FOR MONTH OF MAGAZINE ISSUE ONLY. ALL PRICES INCLUDE GST PHONE – (9-5, Mon-Fri) MAIL OR This form to PO Box 139 Call (02) 9939 3295 with your credit card details January 2010  67 Collaroy NSW 2097 01/10 CIRCUIT NOTEBOOK Interesting circuit ideas which we have checked but not built and tested. Contributions from readers are welcome and will be paid for at standard rates. WO4 Q1 BC547 +5V E B 10 F 100k V+ C AC + DCC – DCC AC ~ 1000 F K A ZD1 5.6V A LED3 SENSOR 10k 6 3 22k TO PC 10k P0 P1 K P4 2 SER IN SETUP S1  LED1 K D1 1k K 560 560 7 TO BLOCK  A 470nF 1 Vdd DCC AC 1k 100nF 10k ~ A SIGNAL LEDS IC1 5 PICAXE P2 -08 4.7k B RLY1 C Q2 BC547 E P3 4 A BYPASS Vss  LED2 S2 8 K BC547 LEDS ZD1 D1: 1N4001 A K A K PICAXE-controlled slow-down for DCC model trains This PICAXE-controlled track switching circuit takes advantage of the “slow on DC” feature that most DCC (Digital Command Control) decoders have these days. When enabled, this feature will slow a train to a stop when the track signal changes from DCC pulses to pure DC. By detecting the presence of a train and then changing the track voltage from the DCC signal to DC, the train can be made to slow down and stop. Every DCC decoder has CVs (Configuration Variables) which are in the software and accessible by the operator. Most DCC systems allow the operator to program the CVs and as well as this there are a few standalone CV programmers available. The rate at which the train decelerates and then accelerates away is controlled by two CVs. CV3 controls the acceleration and CV4 the deceleration. All the user has to do is isolate a block of track at the 68  Silicon Chip required stopping point. An optical sensor placed at the start of the block will switch the voltage within the block to DC. After a few seconds delay (user-settable), the track signal is switched back to DCC and the train moves off. The result is quite realistic to watch. Install the optical sensor so that the block beginning is about two metres (depending on your layout size) from the required stopping point. A 2-aspect signal should also be placed at this point. Using trial and error, program the decoder’s CVs to stop the train at the signal. Place the optical detector about 1.5 loco lengths in from the isolated join. Now it is time to set the required stopping/wait time. Place the train a metre or two before the beginning of the block. Press and release the set-up button and then start the train. When the train crosses the isolated join, press and release K A B E C the set-up button again. The train will now slow and should then stop at the signal. When you are satisfied with the stationary time press and release the set-up button again. The track will now go back to DCC and the train will move off. The time just set is now stored in the PICAXE’s memory and will be loaded next time the system boots up. The unit will go to normal mode and that is it. Each time the train crosses the sensor it should slow and stop at the signal which is red. After your set time the signal will change to green and the train will move off. Note the alternative power arrangements for the circuit. As shown, the links at the top righthand corner allow it to be powered from low voltage (eg, 12VAC) from a separate transformer or from the DCC voltage applied to the track. The software for the PICAXE (DCC_Auto_stop.BAS) will be available on the SILICON CHIP website. Jeff Monegal, North Maclean, Qld. ($45) siliconchip.com.au TP1 TPC 1.2V NiMH CELL 4.7 CHEAP QUARTZ ALARM CLOCK + 1.5V 300mA TORCH GLOBE – TP2 Simple battery tester uses quartz clocks I have found quality problems with some rechargeable NiMH AA and AAA batteries. While Sanyo’s Eneloop and Varta AA batteries are very close to their marked or rated capacity, tests on a number of batteries of other makes indicate that the capacity marked on them in mAh appears to be imaginary and is not to be believed. What adds to the problem is the variation in capacity between individual batteries of the same make and type, even when purchased together, sometimes in 4-packs. Batteries are nearly always connected in series when used in digital cameras and other equipment. One battery going flat before the others, apart from being a nuisance, can cause the flat battery to become reverse charged, damage it and further affect its capacity Eneloop, Varta and Energizer appear to be fairly consistent in regard to the capacity of individual batteries of the same type although based on my tests, less well-known brands appear be quite inconsistent between cells in a given pack, as well as having less than their rated capacity. For example, from a 8-pack of brand-X AA cells, marked 2700mAh, the following test results were obtained: (1) faulty; (2) 1400mAh; (3) 1580mAh; (4) 1710mAh; (5) 1550mAh; (6) 1470mAh; (7) 1710mAh; (8) 1550mAh. Another 12-pack of AA batteries, marked 2500mAh, all gave problems from day one and were disposed of. Out of frustration, I made up a simple 4-cell battery tester, costing about $10.00. It uses four cheap quartz alarm clocks, usually available from bargain shops for around $2 each. Tests show that they stop running when the supply voltage drops to about 1V. Since it is nearly impossible to solder wires to the battery contacts in these, I made dummy batteries from pieces of dowelling and self-tapping screws. Also required are four 1.5V 300mA MES torch globes 1.2V NiMH CELL 4.7 CHEAP QUARTZ ALARM CLOCK + 1.5V 300mA TORCH GLOBE – TP3 1.2V NiMH CELL 4.7 CHEAP QUARTZ ALARM CLOCK + 1.5V 300mA TORCH GLOBE – TP4 1.2V NiMH CELL 4.7 1.5V 300mA TORCH GLOBE CHEAP QUARTZ ALARM CLOCK + – and MES lamp holders, four 4.7Ω 0.5W resistors and a 4-cell battery holder. I recycled a faulty 4-way AA-AAA battery charger which had good quality battery contacts. This allows testing and matching of both AA and AAA cells. Ordinary M3 screws were used for test points; handy for checking battery voltages during tests. The resulting discharge current from 1.2V NiMH batteries with this set-up is close to 500mA. Operation is extremely simple: set the clocks to 12 and insert freshly charged batteries. When the globes extinguish, read the elapsed time in hours and minutes. You can calculate capacity in mAh by multiplying the elapsed time in hours (with minutes expressed as a decimal) by 500. While measuring the actual battery capacity in mAh is useful, accurate matching of cells to be used in series is more important. Matched sets of batteries should be marked and always used together. All matched sets should be given a capacity test every few months to ensure that they have not deteriorated and are still closely matched. Poul Kirk, South Guildford, WA. ($40) Issues Getting Dog-Eared? Keep your copies of SILICON CHIP safe, secure and always available with these handy binders REAL VALUE AT $14.95 PLUS P & P Available Aust, only. Price: $A14.95 plus $10 p&p per order (includes GST). Just fill in and mail the handy order form in this issue; or fax (02) 9939 2648; or call (02) 9939 3295 and quote your credit card number. siliconchip.com.au January 2010  69 Circuit Notebook – Continued Bathroom fan/timer has single switch operation This bathroom/toilet fan timer was developed because of the difficulty in installing extra wiring for a separate switch to control the fan. Not only did the fan need to be switched on but it also needed to run for a time after the light switch was turned off. The solution involved a Triac controlled by an optoisolator and a 4541 oscillator/programmable timer. A 4-wire connection is used to the existing bathroom lamp which picks up the 230VAC Active lead, the Neutral, Earth and also the “switched” Active from the existing light switch. The switched Active (SA) is used to both switch on the fan and initiate the timing function. The SA signal is coupled via two 47nF 250VAC X2 capacitors to the LED in a 4N25 optocoupler, OPTO1. The two paralleled capacitors limit the current through the LED to about 9mA. The 220kΩ resistors across the 47nF capacitors provide a discharge path when the power is turned off. Diode D1, connected in inverseparallel across the LED in OPTO1, is there to provide current flow during the negative half-cycles of the mains waveform while LED1 is included to give a visual cue that the circuit is working, during a bench test. When OPTO1 is turned on by the SA signal, it turns off transistor Q1 which is normally held on by its 10kΩ and 4.7kΩ base bias resistors. Since it is effectively being switched by a 50Hz rectified signal, diode D4 and its associated 10µF capacitor is used as current pump to apply a high signal to the master reset (MR) pin of the 4541 oscillator/timer, IC1. IC1 is configured as a retriggered “one shot” timer so that while MR (pin 6) is held high, the timer is continuously retriggered (Q held high). When pin 6 goes low, the one shot delay timer function takes over and 65,536 oscillator pulses are counted before the ‘Q’ output goes low again. The resistors and capacitor connected to pins 1, 2 & 3 set the oscillator frequency so that 65,536 pulses represents a period of about 4.5 minutes. While pin 8 is high for the 4.5 minute period, it turns on transistor Q2 to drive the LED in a MOC3041 zero voltage switching optoisolator (OPTO1) and this, in turn, gates on the Triac (TRIAC1) to drive the fan. Your old mobile phone battery can power a LED torch Next time you change your phone or your phone battery, save the battery and make use of it before it dies. Even if it doesn’t run your phone any more it will have enough capacity to make a bright and handy torch. Older phones used rechargeable Nicad or NiMH (usually 3.6V) batteries whereas recent ones have smaller, lighter 3.7V Li-ion units. Modern 5mm high-brightness white LEDs are economical to run and well matched to phone batteries since they have a typical forward voltage, Vf, of 3.3V <at> 20mA. Li-ion batteries charge up to about 4.1V and fall to 3.7V. Similarly, a Nicad or NiMH 2-cell battery will charge to about 3.6V and discharge 70  Silicon Chip Jef is th f Thoma is s winn month’ s er o Pea fa k At l a s Inst rum Test ent At first switch-on, the circuit will operate as the timer will be triggered initially, however it should switch off again after the (4.5 minute) time delay. After that, the load can be switched on using a test switch for the SA input. The power to the load should be switched off about 4.5 minutes after the test switch is turned off. You will be able to observe the operation of the switch and the power to the load by watching the indicator LEDs on the board. Any troubleshooting must be carried out with the power turned off and the circuit disconnected from the mains supply. Note that the final connection to the house wiring should be made by a licensed electrician. Jeff Thomas, Falls Creek, NSW. WARNING: all parts within the red shaded area of the circuit operate at high voltage (ie, 230VAC) and contact could be fatal. DO NOT build this circuit unless you are very experienced with high-voltage circuits and construction techniques and R1 R2 MOBILE PHONE BATTERY to less than 2.5V in A A phone use.  LED1  LED2 Rather than deK K sign a fancy boost regulator to cope LED1, LED2: 5mm HI BRIGHTNESS with these voltage R1, R2: USE 33 FOR LITHIUM-ION BATTERY, OR 27  FOR NICAD WHITE LEDS ranges, the simple OR NIMH BATTERIES K approach is to conLEDS nect the battery to A the white LED via 33Ω resistor in the case of Li-ion batwill run for tens of hours, even on a teries and 27Ω for Nicad and NiMH small battery. 2-cell batteries. This results in a LED The accompanying photo shows current of about 12-24mA. two torches with different battery However there is no need to wait styles and polarities. The battery for the LED to become dim – just terminals may to be top or endcharge the battery more frequently! mounted. In either case, an improTwo LED/resistor pairs in parallel vised “L” shaped plastic sled runs provide a brilliant white light and along the side of the battery carrying siliconchip.com.au D2 T1 (IN T1) A REG1 7812 K 15V 275V 14 GND 1000 F 230V MOV2 +12V OUT IN 15V 13 10 F 220nF D3 A 56k K 68nF 5VA 47nF OPTO1 4N25 47nF MAINS INPUT 220k SA 1 220k  MOV1 N 275V E D1 330k A A 10k E E N 10nF 275V X2 F1 2A A OUTPUT TO FAN K A2 10 MR AR MODE Vss 7 K  2.2k A +12V  2 4 G C 330 D2,D3: 1N4004 A 10 F Rs IC1 4541B 1 Q2 BC548 4.7k B E 47k BT137X-600 K K A 7812 BC548 LEDS A 5 220k Ctc 8 LED2 OPTO2 MOC3041 CAUTION: ALL WIRING WITHIN RED SECTION OPERATES AT 230V AC D1,D4: 1N4148 3 6 K Q1 BC548 2 Q 2 6 A1 C 12 A0 9 PH 1 Rtc  LED1 330 TRIAC1 BT137X600 B 4 K 39 D4 A 4.7k 5 K A 220nF 10k 120k Vdd A1 B E GND IN C GND OUT A1 A2 G know exactly what you are doing. Note also that the circuit should be fully isolated inside a suitable plastic case, to prevent accidental contact with the mains. In addition, it’s important that no copper tracks run through the middle of either of the two opto-isolators (ie, OPTO1 & OPTO2), as this would compromise the isolation between the high and low-voltage sections of the circuit. a small square of perf board with it. The LEDs are soldered side by side on the board pointing forwards. Contact with the battery terminals is made by pieces of springy brass which are soldered to the board. Even component pigtails will do as the picture shows. A rubber band holds the assembly together and provides sufficient tension so that the sled runs parallel to the side of the battery when pushed forwards or back with the thumb. Moving the sled by a millimetre is enough to turn the light off or on as its contacts mate with the battery terminals. Bend the contact wires to tension them and turn their tips up like the runners of a sled so that they will glide across the battery surface and its terminals without snagging. For top-mounted terminals a non- conductive shim inserted between the rear of the board and the sled can help angle the board down at the front to make better contact. To charge the battery, first remove the rubber band to separate the sled from the battery and use the original charging set-up John Crichton, Orange, NSW. ($35) siliconchip.com.au January 2010  71 Circuit Notebook – Continued PICAXE digital clock and switch control This circuit is basically a digital clock with an hours and minutes display. It has an alarm on/off function which can be set to turn a power point on and off at any preset time. The heart of the clock is a PICAXE28X1 which is synchronised to the mains frequency by the connection of positive half-wave rectified mains pulses to pin 11 (C0). By using the mains frequency as the timebase the clock will always be correct and never need adjusting, unless there has been a power blackout. The digital display is multiplexed, with only digit being driven at any tone time. This relies on human vision persistence to provide a continuous display of all four digits which are common-cathode 7-segment LED displays. Each digit cathode is driven from a separate output on the PICAXE Each digit to be displayed is in BCD format from outputs 4-7 which are buffered by a ULN2803 before being fed to a 4511 BCD to 7-segment decoder/driver. Switches S1 & S2 connect voltage dividers to the analog inputs A0 and A1 and are used in conjunction with switch S3 to set the clock time and alarm on and off times. So to set the minutes of clock time, S1 is switched to the “clock time” position and S2 is moved to the “minutes” position. At this point, only the minutes digits will be displayed and they can be advanced using the “set time” pushbutton switch, S3. Similarly, the hours can be set by turning S2 to the “hours” position. The alarm on and off time can similarly be set by changing S1 to the appropriate position. Selecting “run” with switch S2 returns the circuit to normal clock operation. While setting alarm or clock times, the time will be displayed in 24-hour format but when in “run” mode it will be in 12-hour format with PM being indicated by a lit decimal point on the hours digit. When setting the alarm on/off times the program still maintains the correct time so that when returned to the “run” condition the clock will still be correct. But when adjusting the clock time itself (S1 on “clock time” and S2 on either “minutes “ or “seconds”) the program assumes you are setting the clock and so cannot update the old time any more. When the “run” condition is selected, the program starts the clock with the newly entered time. A situation can arise however, where the clock is on the correct time and the user merely wishes to change the alarm on/off time. If switch S1 has been left on “clock time” from some previous operation and switch S2 is moved away from “run” then the clock program ceases to keep the correct time and will have to be set again. The correct procedure is to set S1 first to either alarm on or off and then move S2 away from the “run” position. That way the clock will continue to keep correct time. A better solution may be to use a set of pushbutton switches for S1 so that “clock time” is only set by a deliberate action. Switch S4 enables or disables the alarm function. When enabled, power will be connected to the 240VAC mains-rated relay via output C4 (pin 15) and transistor Q2 when the time set for “alarm on” is reached and will be disconnected when the “alarm off” time is reached. Also, at the “alarm off” time, the buzzer will sound, as controlled by output C5 (pin 16) and transistor Q1. Switch S5 will turn the buzzer off or alternatively, ensure the buzzer does not sound at all if it is left in the “off” position. If the alarm function is enabled, the decimal point on the minutes display is lit. This circuit has the ability to be easily extended to control another two relay outputs, each with their own on/off times, by adding four switch positions to switch S1 and employing the unused C-port outputs on the PICAXE (C3 is already spare and C7 can be freed by driving the decimal point directly from S4). Naturally, this would require alterations to the software. The software will be available on the SILICON CHIP website. Jack Holliday, Nathan, Qld. ($50) Editor’s note: this circuit may seem very similar to one by the same submitted by Jack Holliday in the September 2009 issue. However, that design was for a 6-digit PICAXE timer – it was not a clock. Contribute And Choose Your Prize As you can see, we pay good money for each of the “Circuit Notebook” items published in SILICON CHIP. But there are four more reasons to send in your circuit idea. Each month, the best contribution published will entitle the author to choose the prize: an LCR40 LCR meter, a DCA55 Semiconductor Component Analyser, an ESR60 Equivalent Series Resistance Analyser or an SCR100 Thyristor & Triac Analyser, with the compliments of Peak Electronic Design Ltd – see 72  Silicon Chip www.peakelec.co.uk So now you have even more reasons to send that brilliant circuit in. Send it to SILICON CHIP and you could be a winner. You can either email your idea to silicon<at>siliconchip.com.au or post it to PO Box 139, Collaroy, NSW 2097. siliconchip.com.au siliconchip.com.au January 2010  73 A E N N E CLOCK ICSP SOCKET 230V A K T1 0V 19 22k RLY1/1 9V A K 0V 8 SER.IN SER.OUT OSC1 17 21 22 23 24 25 26 27 28 – ~ ~ BR1 4.7nF 18 C7 16 C5 15 C4 11 C0 C6 OUT0 OUT1 OUT2 OUT3 OUT4 OUT5 OUT6 OUT7 +V 20 IC1 PICAXE 28X1 OSC2 A0 A1 C3 A2 A3 C1 C2 1 RESET 1k ZD1 4.7V 10k 7 6 2 9 10 2 3 14 4 5 1 22k 10k RUN S2 S1 MODE FUNCTION D1 1N4148 3 MIN HRS ALRM OFF ALRM ON FUSE (TO SUIT LOAD) 4.7k 4.7k 4.7k 12 13 S4 ALARM ON/OFF + 8 8B 7 7B 6 6B 5 5B 4 4B 3 3B 2 2B 1 1B 1000 F 25V 4x 4.7k IN GND OUT REG1 7805 10k 10k 2x 470 8C 11 7C 12 6C 13 5C 14 4C 15 3C 16 2C 17 1C 18 10 +12V E 9 COM IC2 ULN2803 100nF B Oe DB E C +5V EL DA 9 15 14 + BUZZER – 13 12 11 100nF Q1 BC548 8 Vss Oa Ob Oc 10 IC2 Od 4511B DD DC Of Og LT BI 1000 F 16V 5 7 1 2 6 3 4 16 Vdd +12V 7x 270 e f K A K D2: 1N4004 A K d g a 8 3 D1, ZD1 BUZZER ON/OFF S5 7 6 4 2 1 9 10 B A K B 8,3 DISP3 C BC548 5 DISP2 E 100nF (DISP2 & 3 NOT SHOWN) 8,3 D2 1N4004 +12V dp c b DISP1 HOURS x10 The circuit is based on a PICAXE28X1 microcontroller and is a complete digital clock with alarm on/off feature. The display is multiplexed and the timing for the clock is derived from the 50Hz mains frequency. AC OUT AC IN A 4.7k 4.7k +5V 4.7k S3 SET TIME +5V f IN Q2 BC548 RLY1 e GND E C 7 6 4 2 1 9 10 OUT 7805 8 3 K d g a c b 5 dp DISP4 MINUTES GND SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.altronics.com.au/ SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.altronics.com.au/ SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.altronics.com.au/ SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.altronics.com.au/ Pt.2: By JOHN CLARKE Voltage Interceptor For Cars With ECUs Last month, we described the circuits for both the Voltage Interceptor and its companion Pushbutton Controller. This month, we give the full construction details and describe how the device is installed and used. A LL THE PARTS for the Voltage Interceptor are mounted on a PC board coded 05112091 and measuring 105 x 87mm. This is housed in a diecast box measuring 119 x 94 x 34mm. Two cable glands at one end of the box provide access for the power supply wiring and for the input and output wiring. Before mounting any parts, check the PC board for any defects such as shorted tracks or breaks in the copper. Check also that the corners opposite the terminal end of the PC board have been shaped to clear the internal corner sections of the box. The shape required is outlined using thin tracks on the underside of the board. Fig.5 shows the PC board parts layout. Begin by installing the six wire links and the resistors, taking care to ensure they each go in their correct place. We used 0Ω resistors for the links in our prototype but you can use 0.7mm-diameter tinned copper wire 78  Silicon Chip instead. Table 2 shows the resistor colour codes but you should also use a digital multimeter to check each one before installing it, as some colours can be difficult to read. Once the resistors are in, install the 2-way pin header for LK1, then install PC stakes at test points TP1-TP5. Follow these with the diodes, zener diodes and IC sockets, taking care to ensure that these parts are all correctly oriented. Don’t install the ICs yet – that step comes later. The capacitors are next on the list. Note that seven of these are electrolytic types and must be installed with the polarity shown. The remaining polyester types can be installed either way around. Now for regulator REG1. As shown, this is mounted horizontally on a small heatsink, with its leads bent through 90°. To do this, first bend its two outer leads down through 90° about 8mm from its body and its centre lead down about 6mm from its body. That done, secure the regulator and its heatsink to the PC board using an M3 x 6mm screw, lock washer and nut, then solder its leads. Note: do not solder REG1’s leads before tightening its mounting screw. If you do, you could stress and crack its copper pads as the screw is tightened. Transistors Q1-Q4 can go in next (don’t get them mixed up), followed by LED1. The latter should be installed with the top of its body 10mm above the surface of the PC board. It goes in with its cathode lead (the shorter of the two) towards the top edge of the PC board (note: this lead is also adjacent to the “flat” side of the LED body). Completing the PC board The PC board assembly can now be completed by installing the seven trimpots (VR1-VR7), the two 2-way screw terminal blocks, the DB25 socket and the relay. siliconchip.com.au TO PUSHBUTTON CONTROLLER 10nF 10  1W 20k IC4 PIC16F88-I/P TU O E GATL OV REIFID O M 19001150 2.2k TP4 120 22k 10k IC1 10k VR6 LMC6482 ZD4 1nF 10k 20k 10nF 5.6V D2 RELAY1 NI C OUTPUT NO NC INPUT 4004 LK1 1k TP2 VR2 100k 470 10 F Q1 BC337 CON2 LOCK VR4 1k TP1 BC547 Q3 BC337 100 7.5V VR1 500 REG1 LM317 Q2 D3 ZD3 TP3 VR3 1k GND 43k 100 F 10k D4 4148 470k 100nF 1M 10nF 100nF 10nF 10nF 100nF 10k VR5 IC2 50k TP5 LMC6482 220 VR7 50k 10k 150 IC3 10k 100 F 10nF 16V 4004 BC327 100 F 4148 10k 10k 100k D1 Q4 1k 1k + ZD1 2x 100 F 15V A 10 F +12V 2.2k LED1 CON1 0V ZD2 CON3:DB25 - Orient the trimpots with their adjusting screws positioned as shown on Fig.5 (so that the voltages increase with clockwise rotation) and be sure to use the correct value at each location. They may be marked with a code rather than the actual value in ohms, ie, 501 for the 500Ω trimpot, 102 for the 1kΩ trimpots, 103 for the 10kΩ trimpots, 503 for the 50kΩ trimpot and 104 for the 100kΩ trimpot. The 2-way screw terminal blocks are straightforward – just make sure their openings face outwards. Once they’re in, the DB25 socket can be fitted. This must be mounted with a split washer under each mounting screw to increase its height. The first step is to fit these mounting screws and the washers in place and secure them by winding on nuts on the underside of the PC board. That done, the DB25 socket is then fitted into place and two extra extension screws then fitted from the top to hold it in place. The socket’s pins are then soldered to the PC board. Finally, complete the board by installing the relay. LMC6482 10k 9.1k 10k 10nF Fig.5: install the parts on the PC board as shown here to build the Voltage Interceptor unit. The assembly is straightforward but make sure that all polarised parts (semiconductors, electrolytics etc) are correctly oriented. Fitting it in a case This step is easy. First, slide the completed board assembly into the case and use it as a template to mark out its four corner mounting holes. That done, remove the board and drill these holes to 3mm. Deburr each hole using an oversize drill. You also have to drill two holes in one end of the box to accept the two cable glands. These are positioned in line with the screw terminal blocks and drilled and reamed to 12.5mm (ie, start with small pilot holes and then carefully enlarge each hole to size using a tapered reamer). The PC board can now be mounted in the case on M3 x 6mm tapped Nylon spacers and secured using eight M3 x 4mm screws. The PC board is housed inside a rugged diecast case and the external wiring leads brought in via cable glands. Initial checks For the time being, do not install ICs1-4 (these are installed later, after some intial checks). You should also leave the Pushbutton Controller disconnected. It’s now just a matter of following this step-by-step procedure to make the initial checks: Step 1: rotate VR6 clockwise by 20 turns to ensure that the sensitivity is set to maximum. siliconchip.com.au Step 2: connect a multimeter between TP1 and the GND test point and set the meter to a low DC volts range. Step 3: apply power and adjust VR1 for a reading of 5.0V on the meter. Step 4: adjust VR3 for a reading of 0V at TP3, then adjust VR4 so that TP4 is at 1.1V. This will ensure that the relay will switch on with a supply as low as 11V. Step 5: disconnect power and insert IC4 into its socket (watch the polarity). Step 6: reapply power and check that the voltage at TP1 is still 5V. Step 7: check that the voltage across ZD4 is 5.6V and that the voltage across Note: zener diodes ZD2 & ZD4 were incorrectly specified in the parts list last month. ZD2 should be a 15V 1W zener diode, while ZD4 should be rated at 5.6V 1W – see Fig.5. January 2010  79 ZD3 is -7.5V. The voltage across ZD2 should be about 0.7V less than the supply voltage. Step 8: if all is correct, disconnect the power and install ICs1-3 into their sockets. Step 9: plug the Pushbutton Controller into the DB25 socket. Note that the lead used must be one that connects all pins from one end to the other in sequence, so that pin 1 connects to pin 1, pin 2 to pin 2 and so on. Some leads do not connect all pins and some swap pin connections. These leads are not suitable. Step 10: reapply power and check that the Pushbutton Controller shows characters on the screen. Adjust trimpot VR1 on the Pushbutton Controller to set the display contrast. The initial display with the LOCK link out should show OUTPUT 0 (dV) on the top line and INPUT 0 (RUN) on the lower line. The ‘0’ after the INPUT may be a number other than 0. If the display shows just blocks on the top line, then there is probably a missing or shorted connection on one of the DB25 connections. Check pins 6, 8, 10, 11, 12 & 13 on the DB25 connector for continuity back to the Pushbutton Controller’s LCD at pins 4, 6, 14, 13, 12 & 11 respectively. Also, check that pins 6, 8, 10, 11, 12 & 13 on the DB25 connector in the Voltage Interceptor connect to pins 17, 16, 13, 12, 11 & 10 (respectively) of IC4. Step 11: check that the switches operate correctly. Pressing the RUN/VIEW switch should cause the display to show VIEW instead of RUN on the lower line. That done, check that the OUTPUT values can be adjusted using the UP and DOWN switches. The fast UP and DOWN switches will change the values in increments of four and the range is ±127. Now check that the INPUT values can be adjusted using the LEFT and RIGHT switches. The range here is from 0-255. Finally, pressing the RESET switch for 4s should reset all OUTPUT values to 0. The word RESET appears on the top line when this occurs. Adjustments Before using the Voltage Interceptor, you first need to check out the sensor it’s to be used with and make some adjustments. This involves determining the voltage range that the sensor outputs under all driving conditions. In practice, you will be able to get some idea of the maximum range available by checking the supply rail to the sensor (if it has power applied to it). For example, a MAP sensor or airflow meter that has a 5V power supply will have an output within the range of 0-5V. Often however, the output voltage range will be restricted to a somewhat narrower range, eg, 0.5-4.5V. And a narrowband oxygen sensor will only output a maximum of about 900mV. Connecting a multimeter to the sensor’s output and measuring the voltage under driving conditions is the best way to determine its output range. The driving conditions should include full power at high and low RPM and engine overrun at high and low RPM. Once you have the determined the voltage range from the sensor, you can proceed with the adjustments to the Voltage Interceptor, as follows: Step 1: connect a 10kΩ linear potentiometer to the input of the Voltage Interceptor as shown in Fig.8. If the sensor provides an output that does not go above 5V, connect the top of the potentiometer to the 5V test point (TP1). Conversely, if the sensor output goes above 5V, connect the top of the potentiometer to +12V (ie, at CON1). Step 2: apply power to the Voltage Interceptor and check that the relay switches on, as indicated by LED1. Step 3: reset all the adjustment values by pressing the Reset switch on the Pushbutton Controller for four seconds (ie, until RESET is indicated on the LCD). Step 4: adjust VR5 so that the voltage at TP5 is as close to 0V as possible. Step 5: adjust the external pot so that the input voltage to the Voltage Interceptor (ie, the voltage on the pot’s wiper) is at or just above the maximum voltage output by the sensor. Pushbutton controller assembly The Pushbutton Controller assembly is shown in Fig.6. Start by installing the three wire links, including the one under the DB25 socket. That done, solder in the dual-inline 14-pin header for the LCD module, taking care to avoid solder bridges between adjacent pins. The SIL resistor array is next. This will have a pin 1 indication at one end (usually a dot) and this end must go towards trimpot VR1. Note that all the top seven holes must be used, leaving some free adjacent to VR1 if the array does not have 10-pins. IC1 can now be installed, taking care to ensure it is correctly oriented. Install the two 10kΩ resistors, trimpot VR1 and switches S1-S9. Note that each of these switches must go in with its flat side to the left – see Fig.6. We used white and black switches as indicated on the overlay. S10 is a smaller pushbutton switch that will only fit with the correct orientation. The 10µF capacitor is next on the list. This must be mounted on its side to provide clearance when the lid is on (see photo). Take care with the polarity of this capacitor. The DB25 right-angle socket can now go in. Make sure it is seated flat against the board and take care to avoid solder bridges between its pins. Finally, the LCD module can be installed by pushing it down onto its 14-pin DIL header. Push it all the way down until it is correctly seated against the header, then solder the header pins to the top of the module’s PC board. Fig.7 shows how the PC board is mounted in its case. If you are building Table 1: Resistor Colour Codes: Pushbutton Controller o o No.   2 80  Silicon Chip Value 10kΩ 4-Band Code (1%) brown black orange brown 5-Band Code (1%) brown black black red brown siliconchip.com.au Fig.6: the parts layout for the Pushbutton Controller PC board. Install the three links first and note that the switches, IC and 10m mF electrolytic capacitor are polarised. The LCD is connected via a 14-way DIL pin header. The PC board mounts inside the case on four M3 x 12mm spacers and is secured using M3 screws, nuts and flat washers – see Fig.7. Note how the 10m mF capacitor is mounted on its side, so that it clears the front panel. a kit, the case will be supplied pre-drilled and with a screen-printed front panel. If not, then holes will need to be drilled in the base of the case for the four board mounting holes and a cut-out made to accommodate the DB25 socket in the side of the case. In addition, the lid will require holes for the switches, a cutout for the LCD and a clearance slot for the DB25 socket. A full-size artwork for the front panel (in PDF format) can be downloaded from the SILICON CHIP website. Note that S10’s access hole in the lid should only be about 3mm in diameter, just sufficient for a small probe to actuate the switch. siliconchip.com.au Fig.7: this cross-sectional diagram shows how the PC board for the Pushbutton Controller is mounted in the case. Note how the top edge of the LCD module is supported on two M3 flat washers. January 2010  81 Table 2: Resistor Colour Codes: Voltage Interceptor o o o o o o o o o o o o o o o o o No. 1 1 1 1 1 2 10 1 2 3 1 1 1 1 1 1 Value 1MΩ 470kΩ 100kΩ 43kΩ 22kΩ 20kΩ 10kΩ 9.1kΩ 2.2kΩ 1kΩ 470Ω 220Ω 150Ω 120Ω 100Ω 10Ω Step 6: adjust VR2 for 5V at TP2, then adjust VR7 so that the Interceptor’s output voltage is the same as its input voltage. Step 7: adjust the external potentiometer so that the voltage at the input to the Voltage Interceptor is at or just below the minimum voltage from the sensor. Step 8: measure the voltage at TP2, then adjust VR3 so that the voltage at TP3 is the same. Relay switching threshold There’s a possibility that an error code will be generated by the car’s ECU if the relay in the Voltage Interceptor turns on before the engine has started. An error code is usually indicated by a warning light or character on the car’s instrument panel. To prevent this error code, adjust VR4 so that the TP4 is at 1.3V. This will ensure that the relay trips only after the engine has started and when the alternator has increased the battery voltage above the 13V threshold. Conversely, if the Voltage Interceptor does not cause an error code, then leave VR4 at its previous (lower) setting. Setting VR4 to give 1.1V at TP4 will cause the relay in the Interceptor to turn on as soon as the ignition is switched on. Installation Just four external connections have to be made to the Voltage Interceptor. Two of these are for power (+12V and chassis earth), while the other two connections intercept the sensor output. The sensor’s output is connected 82  Silicon Chip 4-Band Code (1%) brown black green brown yellow violet yellow brown brown black yellow brown yellow orange orange brown red red orange brown red black orange brown brown black orange brown white brown red brown red red red brown brown black red brown yellow violet brown brown red red brown brown brown green brown brown brown red brown brown brown black brown brown brown black black gold to the Voltage Interceptor’s input and the output from the Voltage Interceptor is then connected to the sensor’s ECU wire. Note that the original sensor-to-ECU connection has to be broken for the Voltage Interceptor to intercept the signal, ie, the Interceptor is installed in series with this lead. Use automotive connectors for all wiring attachments and be sure to use automotive cable for the leads. The +12V rail for the unit should be derived from the switched side of the ignition and a suitable point can usually be found in the fusebox. The connection to the switched ignition supply should be made on the battery side of the fusebox (ie, before any fuses) and should be run to the Voltage Interceptor via a 1A inline fuse. The best location to mount the unit is inside the cabin, so that it remains cool. If you do install it in the engine bay, be sure to keep it well away from the engine and the exhaust system so that it is not unduly affected by heat. It can be secured in position using suitable brackets. Programming adjustments The Pushbutton Controller must be set to RUN in order to make real Table 3: Capacitor Codes Value 100nF 10nF 1nF µF Value IEC Code 0.1µF 100n .01µF 10n .001µF 1n0 EIA Code 104 103 102 5-Band Code (1%) brown black black yellow brown yellow violet black orange brown brown black black orange brown yellow orange black red brown red red black red brown red black black red brown brown black black red brown white brown black brown brown red red black brown brown brown black black brown brown yellow violet black black brown red red black black brown brown green black black brown brown red black black brown brown black black black brown NA time adjustments (see panel on using the Pusbutton Controller in Pt.1 last month). Before going further though, a word of warning: the Voltage Interceptor can cause engine damage if the programming adjustments are not done carefully and methodically. You have been warned. The best way to tune an engine using the Voltage Interceptor is with the car set up on a dynamometer and with a specialised engine tuner making the adjustments. Alternatively, you can also make initial adjustments under actual driving conditions, using suitable instruments to monitor performance. This is best done on a closed road (eg, a racetrack). However, do not use the Pushbutton Controller or closely monitor instruments while driving – leave those jobs to an assistant. Changes are made at the load sites where appropriate by using the Up and Down buttons on the Pushbutton Controller to assign values. It is not necessary to access every input load site to make changes though but you must keep a record of any sites that are actually assigned a value of 0. The VIEW display can then be selected later to manually adjust the output values between load sites that were not accessed during the tuning process. This is detailed later under the heading “Interpolating The Results”. Note that the input is likely to change during output adjustments. To minimise this, try to maintain constant engine conditions during programming. The unit locks onto the input value selected when an Up siliconchip.com.au MULTIMETER 4.750 CON1 0V 4148 - +12V DC VOLTS 4148 + 16V 15V CONNECTS TO TP1 IF SENSOR SIGNAL IS LESS THAN 5V, OR TO +12V IF SENSOR SIGNAL IS MORE THAN 5V 4004 – + 7.5V GND TP1 (5V) TP2 4004 INPUT TU O OUTPUT C NI E GATL OV REIFID O M 19001150 NO NC Fig.8: here’s how to connect an external 10kΩ potentiometer and a multi­meter to adjust the Voltage Interceptor. CON2 5.6V 10k LINEAR POTENTIOMETER TP5 or Down button is pressed so that the input load site will not alter during an adjustment, so take care to ensure that you have not drifted too far off the input load site by changing conditions. Releasing the Up or Down button will allow the latest load site to be displayed. involves the offset adjustment trimpot (VR5). This can produce a global voltage offset from zero. This could be useful for narrowband oxygen sensor modifications by allowing the output to be shifted higher (for a richer reading) or lower (for a leaner reading). Global changes As previously mentioned, the Voltage Interceptor can be used to adjust the signal from virtually any sensor that produces a varying output voltage. You will need to build a Voltage Interceptor unit for each sensor output you wish to modify. Let’s take a look at some of the changes you can make: The Voltage Interceptor can easily make global changes. Global changes affect the entire load map and can reduce the number of adjustments required using the Pushbutton Controller. A global change can be particularly useful where a sensor produces an overall lower voltage than required. For example, this could happen if a larger airflow meter is substituted for an original unit, resulting in less sensor output for a given airflow. So for example, if you want 20% more output from a sensor, then the output from the Voltage Interceptor should always be 20% higher than its input. This can be achieved simply by adjusting VR7 to give this effect. So, if a 4V signal is applied to the Interceptor’s input, then VR7 would be adjusted for a 4.8V output. Similarly, by winding VR7 back the other way, a global change can be made to reduce the input voltage by a fixed percentage to produce a lower output. A less likely global modification siliconchip.com.au Modifying sensor outputs (1) Changing The Oxygen Sensor Signal: a narrowband oxygen sensor signal can be modified but it may be difficult to make changes that have any real effect. That’s because an oxygen sensor produces such a steep response in its output as the air/fuel ratio changes. In addition, the ECU will respond to incorrect oxygen sensor signals by showing an error code. This will occur if the voltage swings from the sensor are incorrect or if the load site changes in the Interceptor are too radical. In the latter case, the injector duty cycle required to match the signal from the Interceptor may be outside the allowable range programmed into the ECU. In addition, any changes to the sensor signal may be ineffective while DMM POSITIVE LEAD GOES TO INPUT OR OUTPUT, OR TO TP2 OR TO TP5 (SEE TEXT) the engine control is in closed loop. That’s because the ECU can “learn” its way around the changes and restore mixtures to normal. (2) Changing Air/Fuel Mixtures: in order to correctly make mixture changes, you require an accurate air/fuel ratio meter to monitor the results. Note, however, that changes to an airflow meter signal may not affect mixture changes while the ECU is in closed loop mode. This mode occurs when the mixture is adjusted by the ECU by monitoring all relevant external sensors. If the signal from one sensor is altered by the Voltage Interceptor, this may be ignored by the ECU if it does not give results that are consistent with the other sensors. This means that any changes made by the Voltage Interceptor to the airflow meter signal will only affect the Changing The Sensitivity After making adjustments, you may find that you are only using a small range of output values, eg, less than ±10. If this is the case, adjusting VR6 anticlockwise will reduce the sensitivity and allow a higher range of values to be used with improved resolution. If you do alter VR6, then the adjustments will need to be redone. Note also that changing any of the other trimpots except VR4 will affect the entire map. January 2010  83 The PC board is mounted in the case on M3 x 6mm tapped Nylon spacers and the assembly secured using eight M3 x 4mm machine screws. Don’t forget to install LK1 in the LOCK position when programming is complete. mixture when the control is open loop (such as under power conditions). Be careful when making such adjustments because engine damage can easily occur if you get it wrong. (3) Reducing Turbo Boost Cuts: turbo boost is monitored using either an airflow meter or a MAP sensor. You will need a boost gauge in order to correctly make this modification. In this role, the Voltage Interceptor can be used to alter the sensor signal to prevent the ECU from reducing the boost above certain engine loads. By using the boost gauge, the load points where the boost is cut can be observed on the Pushbutton Controller and the output from the Interceptor reduced to overcome the boost cut as required. Check that air/fuel ratios are not changed at the same time, otherwise engine damage could occur. (4) Injector Changes: when larger than standard injectors are fitted, the airflow meter output signal can be reduced by the Voltage Interceptor to give the correct air/fuel mixtures. This will allow the ECU to operate within its normal range of input values to control the injector duty cycle. (5) Adjusting For A Larger Airflow Meter: substituting a larger airflow meter will give lower airflow readings than from the original unit. The Voltage Interceptor can be used to restore the signal to the normal range required by the ECU for correct fuel injector control. Interpolating the results After making adjustments to the Table 4: Mapped Values Load Site 10 11 12 13 14 15 16 17 18 Initial Value 30 0 0 12 8 0 0 0* 0 0* = mapped at 0; 0 = unmapped Table 1: initial values for load sites 1-18. The load sites with a value of 0 (ie, 11, 12, 15, 16 & 18) have been left unchanged (ie, they are unmapped). Table 5: Final Values Load Site 10 11 12 13 14 15 16 17 18 Final Value 30 24 18 12 8 5 2 0 0 Interpolated values shown in red. Table 2: the load site values after interpolation. The interpolated values are in red. 84  Silicon Chip Voltage Interceptor, there will often be load sites that were not accessed and changed. This is because there could be up to 256 individual sites and so only a representative number of sites are adjusted. However, it’s possible to interpolate between sites. To do this, first use the View display to look for any sites that were not changed. As previously stated, you should have kept a record of any sites that were actually mapped at 0. Any other sites with a value of 0 are unchanged (or unmapped) sites, while those sites that have a number other than 0 are obviously sites that have been adjusted. The job now is to make changes to the unmapped sites that sit between the adjusted sites. This involves interpolating the values so as to smooth out the changes between adjacent adjusted sites. Interpolation involves calculating the expected values. Sometimes you can guess what the value should be but it can also be calculated. The calculation is done by first dividing the difference between two adjusted sites by one plus the number of unadjusted sites between them. This gives the difference (or step) between each site. The example shown in Table 4 will illustrate this. Here, load sites 10, 11, 12 & 13 have values of 30, 0, 0 & 12 respectively. The difference between the two adjusted sites is 18 (30-12) and there are two unadjusted sites between them. In this case, we divide 18 by 3 (ie, 1 + 2(sites)) and this gives a difference of 6 between each site. As a result, load sites 11 & 12 would be changed to 24 (30-6) and 18 (24-6) respectively – see Table 5. For load sites 14-18, the output values are interpolated from an 8 at site 14 to a 0 at site 17. As indicated, site 17 is one that was mapped as a 0 and so this is kept at 0. This means that you must keep a record of any sites which were mapped at 0 when making the original adjustments, so that they can be distinguished from unaltered load sites later on. Finally, when all the adjustments have been made, the Lock jumper link (LK1) can be installed in the Voltage Interceptor to prevent any changes to the map. You can then either leave the Pushbutton Controller connected to view the map (in either Run or View display mode) or you can disconnect it altogether. SC siliconchip.com.au WI B Pt.3: By MAURO GRASSI Web S erver I n a B ox In Pt.2 last month, we showed you how to connect the WIB to a network and gave the step-by-step setting-up details. Most constructors will settle for the website provided but for those with special needs, this third article is for advanced users who want to customise the WIB to their requirements. O NE OF THE advantages of the WIB is that you can customise it by designing your own website if you wish. For the purposes of this article though, we’ll assume that you know the basics of website design. Instead, we’ll just give a few basic pointers on dynamic content and running CGI (Common Gateway Interface) commands. Designing your own website Basically, it’s up to you whether you use the website we have provided with the WIB or one of your own design. It’s Note: the three tables referred to in the text (Tables 1-3) are too large to include in this article. Instead, you can download them in PDF format from the SILICON CHIP website.You’ll find them in the downloads section for Jan 2010. just a matter of copying the website you wish to use to the memory card. When it comes to designing your own site, the best thing to do is to first examine the website we have provided and look at the source. We have used dynamic variables, as well as forms and Javascript. There are plenty of HTML introductory tutorials on the web. Also you can use a freeware HTML WYSIWYG (What You See Is What You Get) editor such as Kompozer which you can download from http://kompozer.net We used Kompozer to design the website provided with the WIB and you can change all its important settings if necessary. Dynamic content The WIB implements a simple system for dynamic content. For dynamic pages, a string of the form ~XX, where XX represents a hexadecimal code between 00 and FF, is replaced by the value of that variable. Table 2 on the SILICON CHIP website gives a list of the hexadecimal codes and their corresponding variables. Note that the files which are emailed are also considered dynamic content. For example, let’s say that we have siliconchip.com.au January 2010  85 An Example FTP Session . . . The Temperature is currently 26.5 degrees. As mentioned, any files sent by email, such as var0max.txt (on a maximum condition in variable #0), can also contain dynamic content. In order to show the ~ character you need to escape it by using the sequence ~~. For example ~~02 will translate to ~02 yet ~02 will translate to the Subnet Mask (refer to Table 2). The default var0max.txt file contains the following text: The ~1E is currently at ~D0, which is above the set maximum of ~1C! This is an automatically generated message, created on ~E2. Fig.27: an example FTP session. Here a file called “report.pdf” has been been uploaded to the WIB (via the Internet) using the “put” command. List Of Accepted FTP Commands CD: change directory. PWD: show the current directory. DELETE: delete a file. DIR: show the files in the current directory and the file sizes. LS: show only the name of the files in the current directory. PUT: send a file to the ethernet web server. GET: retrieve a file from the WIB. Fig.27 shows an example FTP session. Here the put command is being used to upload a file called report.pdf to the memory card in the WIB via the local network. The first step is to connect to the FTP server and that’s done by going to a command prompt and typing: ftp 192.160.0.34 The WIB’s local IP address has been used here but you would have to substitute the public IP address (or the hostname if you have set up dynamic DNS) if you want to access the WIB via the Internet (as shown in Fig.27). After that, it’s simply a matter of entering the username and password to log on and then issuing the command: put report.pdf a dynamically typed file containing the text: The ~1E is currently ~D0 degrees. From this, it follows that if the name 86  Silicon Chip MGET: retrieve a collection of files from the WIB. MPUT: send a collection of files to the ethernet web server. USER: specify the username for login. PASS: specify the password for login. OPEN: open an FTP connection to a remote server. QUIT: exit the current FTP session. The file should then upload to the WIB. If you get an error that says “Netout: connection reset by peers”, it means that the buffer in the Windows FTP client has overflowed and will have to be increased in size. To do that, quit the current FTP session (using the quit command), then restart it with the command: ftp -w:8192 192.168.0.34 and try uploading the file again. This will double the buffer size from the default. If you get the same error message, double it again by starting the FTP session using the command: ftp -w:16384 192.168.0.34 Similarly, if you want to download a file called report.pdf, use the command: get report.pdf of Variable 0 is set to “Temperature” and the current value for the temperature (derived from a temperature sensor connected to the first ADC input) is 26.5, then this would appear as: As before, ~1E will be replaced by the name of Variable 0, while ~D0 will be replaced by the current value of that variable. ~1C is replaced by the maximum set value, while ~E2 is the current time as determined by the SNTP module. In other words, the email would look like this example: The Temperature is currently at 30.0, which is above the set maximum of 28.0! This is an automatically generated message, created on Fri 28 August 2009 17:00:00. Therefore, by modifying this file and others like it, you can customise the emails that are sent as notifications. Running CGI commands from an HTML form It is possible to execute one of the commands in Table 1 from an HTML form. The commands are of the form: <command>?<name>=<value> Any system setting can then be defined using an HTML form by using the set command (see Table 1 on the SILICON CHIP website), the name of the variable (Table 2) and the new value, eg: set?NTPTimezone=0 will modify the time zone for SNTP to UTC time. An in-depth discussion of HTML forms is beyond the scope of this article but if you are interested you should look at the source code for the supplied website. A number of HTML forms are used to change the WIB’s settings. By imitating these, you can create complex websites. siliconchip.com.au Memory Card Special System Files The are several special system files on the memory card and these either have a “txt” extension or a “dat” extension. For security reasons, these two file extensions should always be set to private in the HTTP Settings (file permissions) – see text. This is the default but you can change this and open up your system to the public if that’s what you really want to do (not recommended!). You can also modify some of the special system files to customise the behaviour of the WIB. The relevant files are as follows: FTP connection, a change in the public IP address detected by the dynamic DNS client, and any email sending activities. log.txt: this file contains a human-readable log of system events since the last reset. It is emailed to the user each time there is a system reset. All important system events are logged, like an incoming test.txt: this file contains the body of the test email sent when the user presses the ‘Test Email’ button in the supplied website. It is used to test that the SMTP settings are correct. The settings.txt file The default settings can be overridden by a file named settings.txt. This file is stored in the root folder of the memory card. In operation, the firmware loads and parses this file at boot-up (or when there is a Master Reset). Each line should contain a statement of the form: <setting name> = <value> where <setting name> is one of the settings in Table 2 (provided it’s not read only), and <value> is the value to set. For example, to change the (default) gateway to 192.168.0.33 you would have a line in settings.txt that reads: Gateway = 192.168.0.33 This would override the default value but not the value that was last set through the web interface. Those values are instead stored in a file called values.dat but in binary form. Note that it is permissible to add any number of spaces before the equals sign for readability. For example, although the IP address settings name is IPAddress, you can validly set the IP Address by writing a line in your settings.txt file that looks like this: IP Address = 192.168.0.30 Restoring the defaults To restore the default values, you can simply delete the file values.dat and reset the WIB by clicking the Master Reset button (or reboot the WIB). siliconchip.com.au settings.txt: this file contains a humanreadable list of single line entries that override the system defaults. The user may modify this file to define new default values. values.dat: this file is used to store system settings in binary form and should not be modified. var0max.txt: this is the file that is emailed when variable #0 has exceeded its set maximum. var0min.txt: this is the file that is emailed when variable #0 is below the set minimum. var1max.txt, var1min.txt, var2max.txt, var2min.txt, var3max.txt, var3min.txt: similar to above but for variables #1, #2 and #3. var0log.txt: this is the file that holds the logged values of variable #0. This file is emailed if periodic logging is enabled for that variable. var1log.txt, var2log.txt, var3log.txt: similar to above but for variables #1, #2 and #3. Correction To Fig.9(b) of WIB Pt.2 ETHERNET PORT MODEM DYNAMIC IP ADDRESS INTERNET FIXED LOCAL IP ADDRESS (EG, 192.168.1.1) 192.168.0.34 WIB (FIXED IP ADDRESS) PC (DYNAMIC IP ADDRESS) MODEM PORT (EG, 192.168.1.2) ETHERNET PORT (LAN) ROUTER ETHERNET PORT (LAN) FIXED LOCAL IP ADDRESS (EG, 192.168.0.1) There isB anSEPARATE error in MODEM the IP addressing & ROUTER shown on Fig.9(b), page 84 of the December 2009 issue. The addressing shown will not work because a router will only forward packets between different networks, eg, from 192.168.0.x to 192.168.1.x on a class C network (and vice versa). This means that we must use IPs for two different networks on either side of the router, eg, use 192.168.1.1 for the Ethernet port on the modem, 192.168.1.2 on the modem port on the router and leave the LAN side of the router at 192.168.0.1 – see above. See also Notes & Errata, p101. Alternatively, you can go to the Basic Settings page of the supplied website and click the Restore Defaults button. Another option if you are creating your own website is to run the defaults command from an HTML file (see Table 1). You can also define the current settings as the defaults by clicking on the Create Defaults button and then resetting the WIB by clicking the Master Reset button (in the supplied default website) or by rebooting the SC WIB (power off and on). January 2010  87 Vintage Radio By RODNEY CHAMPNESS, VK3UG The impressive STC Capehart A8551 Radiogram Radiograms first came into being in the late 1920s and were produced in various formats up into the 1960s. During that time, they evolved from very basic units with a record playing mechanism on the top of the cabinet to units that had changers alongside the radio section. Some of the very latest units also included a TV set and/or a tape recorder and some even had a cocktail cabinet. T HE 5-BAND A8551 was probably the most up-market monophonic radiogram produced by STC. It dates from the mid 1950s and as can be seen from the photos, it is quite a big unit. In terms of construction, it is basically a large rectangular box with ball & claw feet on it. It is a beautiful piece of furniture and the owner of this magnificent deluxe radiogram, Peter Henstridge (see last month’s Vintage 88  Silicon Chip Radio), is to be congratulated for the quality of the cabinet restoration. A feature of the cabinet is that the doors can fold right back alongside the end panels, so that they are out of the way when the radiogram is in use. When closed, the speaker grill is still visible so that the set can continue operating without the sound being muffled. The size of the cabinet and the thick- ness of the timber mean that two strong people are required to move the unit around. The 12-inch (305mm) twincone speaker is housed in a sealed enclosure and this, along with the heavy timber construction, has been designed to ensure good sound quality. A plywood panel covers the back of the unit and the cables between the record changer and radio chassis run along a shelf at the back – see photo. siliconchip.com.au Fig.1: the circuit is a fairly conventional 8-valve superhet with an RF amplifier stage (V1) and a push-pull audio output stage (V6 & V7). In addition, an EM85 “magic-eye” tuning indicator is used. A Collaro 3-speed record changer is mounted at the top lefthand end of the cabinet. This unit comes in cream and maroon, which matches the finish of the cabinet. The radio receiver and its associated control panel are to the right, along with the switches for the various functions. Below the record changer and radio are two compartments for storing records. The receiver itself is much more elaborate than used in run-of-the-mill radiograms. It tunes both the broadcast band and a shortwave band from 4.815.6MHz. It also has three bandspread international shortwave bands, these being the 31, 25 & 19 metre bands. Six controls are located on the front of the receiver, on either side of the dial scale. Starting from top left, there are Treble, Bass and Volume controls, while the controls from top right are Tuning, Wave Band (five positions) and Selector (three positions). Circuit details From the foregoing, it’s apparent that this is an upmarket unit and is somewhat better than the average radiogram of the era. That not only applies to the cabinet but to the circuit used as well. Fig.1 shows the circuit details. The received signal is applied in parallel to both the broadcast and the shortwave tuned circuit primary windings. However, the secondaries are each individually switched. The bandspread shortwave bands are selected via series and parallel capacitors which are used in conjunction with the general coverage shortwave coil and tuning capacitor. The general shortwave tuning range is different to most dual-wave receivers, though. It tunes from 4.8-15.6MHz whereas most other dual-wave sets tuned from 6-18MHz. The output of the selected tuned circuit is applied to valve V1, a 6BA6 RF (radio frequency) amplifier. Its output is applied to another tuned circuit assembly (similar to the input tuned circuits) and then to V2, a 12AH8 frequency converter. Oscillator section The oscillator section of the converter employs yet another tuned circuit arrangement. This ensures that the oscillator always runs 455kHz higher than the incoming RF. Many readers will not be familiar with the 12AH8. It siliconchip.com.au is similar in characteristics to the more common 6AN7A but has a tapped 12V heater, so it can have either 6V or 12V applied to it. One point that STC makes is that the padder capacitors on shortwave are selected to make sure there is minimal frequency drift as the receiver warms up. Tuning drift during warm-up up is a very annoying problem with January 2010  89 Radio-Gram) and a volume control to valve V4, a 6BR7 low-noise pentode audio amplifier. The amplified audio is then applied to separate bass and treble controls before being fed to the first section of V5, a 12AX7. The second section of the 12AX7 is wired as a phase splitter and this produces two signals which are 180° out of phase. These signals drive a push-pull amplifier stage based on V6 and V7, both 6BW6 valves. This then drives a centre-tapped audio output transformer which in turn drives the 12-inch twin-cone speaker. Note that negative feedback is used to minimise distortion in the audio amplifier. This is done by feeding a sample of the output signal (ie, as applied to the speaker) back to one side of the tone control network. Power supply This view shows the A8551’s cabinet during restoration. The timber was in good condition but the finish had deteriorated quite markedly over the years. The record changer, chassis and loudspeaker were all removed from the cabinet to make the restoration easier. some receivers. My Kriesler 11-99, for example, is a delightful little receiver but it has this problem of drifting off station from cold. I’ll eventually get round to modifying it to overcome this problem but in the meantime, I’ll live with it. The output of the frequency converter consists of several mixing products but the one of interest is the difference 90  Silicon Chip between the signal frequency and the oscillator frequency, ie, 455kHz. This is applied via the first IF (intermediate frequency) transformer to the grid of V3, a 6N8 which amplifies the 455kHz IF signal. Its output then goes through another IF transformer stage and is then fed to a detector diode in the 6N8. From there, the resulting audio signal is fed through a switch (Off- As with the RF and audio circuitry, the power supply is a little more elaborate than seen in most domestic radios. First, there are four windings on the transformer: a 230-250V primary and three secondaries. These secondaries provide 6.3V for the heaters of all the amplifying valves, 5V for the filament of the 5Z4 rectifier and a centre-tapped high-tension (HT) output rated at 295V-0V-295V. The resulting DC HT line is filtered using a choke and two electrolytic capacitors and this then feeds the plates of the two 6BW6 audio output valves via the centre tap on the primary of the output transformer. The HT for the rest of the set is filtered using a resistor/ capacitor network, along with other decoupling networks for the low-level audio sections. Because this set has a better than average audio amplifier, a “hum-dinger” pot (R3) has been connected across the 6.3V heater winding, with the moving arm going to earth. This is adjusted to minimise any hum in the output. This is R33 at the bottom right of the circuit diagram. Automatic gain control Automatic gain control (AGC) or as it used to be called, automatic volume control (AVC) is also fitted to this receiver. As shown in Fig.1, a small mica capacitor is connected between the plate of V3 (6N8) and one of its diodes. Normally, the 6N8’s cathode is around 2.5V positive with respect to the chassis and the so diode is biased siliconchip.com.au off via R11, its DC return to chassis. However, if the RF signal exceeds 2.5V peak, a negative voltage will be produced at the diode’s output. This is then applied along the AGC line to valves V1, V2 & V3. This is a delayed AGC system, as the RF signal has to reach quite a reasonable level for AGC to occur. This is done to ensure good signal-to-noise ratios on weak signals. Magic eye Another feature of the circuit is the inclusion of an EM85 “magic eye” indicator to assist tuning. STC didn’t claim this as a valve, although many other manufacturers did in their receivers. Basically, it looks like an unusual 9-pin miniature valve. In this set, it is located just behind a small window in the back plate of the tuning dial, towards the righthand end. It produces a green “glow” that changes in shape according to the strength of incoming signals and this helps the user accurately tune stations. When the record changer is to be used, the selector switches power to it and a light is turned on to illuminate the changer’s enclosure. In addition, when the receiver is turned on, a red pilot lamp is illuminated in the middle of the cabinet (towards the bottom), so even if the doors are closed the user can see that the set is turned on. Despite its age, the chassis was in remarkably good condition and looked almost new after it was cleaned up. It’s a well-made unit and the top layout is clean and uncluttered. The restoration The cabinet finish wasn’t exactly in good condition when Peter obtained the old STC. As indicated earlier, veneered solid timber is used in its construction, so there were no shortcuts to be taken here. First, the chassis and other internals of the unit were removed and set aside, as were the doors, hinges and handles. Peter then set about stripping the finish off the timber with Accent Paint Stripper. This stripper is relatively mild and doesn’t stain the timber like some other paint strippers do. The cabinet was then lightly sanded with a fine grade of abrasive paper. The timber itself was in good condition and didn’t require any filling. Peter points out that in order to ensure that there is no damage to the veneer, a good-quality paint stripper tool must be used along with the paint stripper liquid. The next step was to mix a homesiliconchip.com.au All parts under the chassis of the STC A8551 radiogram are readily accessible despite the circuit complexity. Replacing the dial cord, the paper & electrolytic capacitors and two resistors restored the unit to full working operation. brew stain to match the radiogram’s original maple colour. Peter used a spirit-based Wattyl product, which is unfortunately now unavailable. This was mixed with an orange base stain and a little bit of black tint. However, some areas of the cabinet required a deeper tint than others, as these areas were almost white in colour after the paint stripper had done its job. Several layers of Wattyl Stylewood 50/50 grade clear lacquer were then ap- plied with a spray gun. And although not strictly necessary, the cabinet was sanded using 0000-grade steel wool between some layers. This ensured a really smooth finish and gave a really professional result. Peter makes the point that the lacquer should only be applied on warm days with low humidity or the results will be disappointing. He makes his own cabinet polish and this was then applied, after which the cabinet was January 2010  91 This view shows the fully-restored unit with the doors open and swung fully back along the sides of the cabinet. Note the two record storage areas. since dried out and any grease that remained had congealed into a sticky mess. As a result, the mechanism was well and truly seized up. The old grease was removed using kerosene, after which lanoline spray was used to lubricate the bearings and other parts. Some light machine oil was then applied to any bearings and shafts. In addition, oil was applied to the felt wick around the phosphorbronze motor bearings and this now runs smoothly again and will last for many years. Fortunately, the plater was in good condition and there were no flat spots on the rubber idler pulley. The latter was cleaned with methylated spirits on a clean cloth and the whole assembly given a light coat of lanoline to keep everything operating smoothly. Finally, the pick-up cartridge and styli were replaced. The mechanism was then tested and it all worked perfectly. Chassis restoration When the doors are closed, the speaker grill is still visible so that the set can continue operating without the sound being muffled. The cabinet finish is excellent and the old STC now looks like new. rubbed down with some good quality Orange Oil. This removed any excess polish and gave the cabinet an excellent finish. Next, the handles and hinges were all cleaned and polished. These were then given a coating of clear lacquer to keep them looking clean and reat92  Silicon Chip tached to the cabinet. Overhauling the changer Having completed the cabinet restoration, Peter’s next task was to overhaul the record changer. Because of its age, the oil that’s normally used to lubricate the moving parts had long It was now time to tackle the radiogram chassis. As previously stated, the receiver is quite a complex unit, with a total of nine valves. However, the chassis is quite large and is well laid out, with all parts easy to access (see photo). Even the wave-change switch and the components around it are relatively easy to get at. The paper and electrolytic capac­ itors were all replaced so that no unexpected problems would arise in the future. The resistors were largely within tolerance and only one or two needed replacement. The dial cord also needed replacement as it had broken but the valves were all in working order. Once this work had been done, the set was tested and it worked normally. It’s sensitivity was excellent and the quality of the audio was very good, so no work was required on aligning the RF and IF stages. In short, STC had really got it right and the amount of work required to get the chassis working again was quite minimal. Summary The quality of radiograms at the end of the mono era was quite variable. Some were just ordinary broadcast mantel receivers fitted into a larger cabinet with a bigger speaker. Although they did sound a little better siliconchip.com.au A rear view of the cabinet with the record changer and radiogram chassis mounted in position. The connecting cables between them run along a shelf at the back of the unit. This unit is much more elaborate that the average radiogram of the mid-1950s era. than the mantel set versions, they tended to be “bassy” in their response and could easily be driven into noticeable distortion if the volume control was wound up. However, there were a few radiograms like the STC Capehart where the chassis and the components were designed to give good-quality reproduction. This set uses negative feedback in the audio stage together with a pair of push-pull output valves and features a twin-cone 12-inch (30cm) speaker in a sealed enclosure, so STC was evidently serious about the audio quality. In addition, the RF (radio frequency) section of the set is quite sensitive and a nice touch is the compensation The Collaro 3speed automatic record changer required a good clean-up plus some fresh lubrication to make it run smoothly again. The pick-up cartridge and styli were also replaced. used in the oscillator tuned circuit to prevent drift on the shortwave bands as the set warms up. The only criticisms of this set are that it would have been quite expensive and it is big. However, it really is a beautiful piece of furniture and I would certainly like one in my collection if I had the room. Acknowledgement: photographs by SC Peter Henstridge. into MOTORS/CONTROL? Electric Motors and Drives – by Austin Hughes Fills the gap between textbooks and handbooks. Intended for nonspecialist users; explores all of the widely-used motor types. $ 60 Practical Variable Speed Drives – by Malcolm Barnes An essential reference for engineers and anyone who wishes to or use variable $ 105 design speed drives. AC Machines – by Jim Lowe Applicable to Australian trade-level courses including NE10, NE12 and parts of NE30. Covers all types of AC motors. $ 66 DVD Players and Drives – by KF Ibrahim DVD technology and applications with emphasis on design, maintenance and repair. Iideal for engineers, technicians, students, instal$ 95 lation and sales staff. There’s something to suit every microcontroller motor/control master maestroininthe the SILICON CHIP reference bookshop: see the bookshop pages in this issue Performance Electronics for Cars – from SILICON CHIP 16 specialised projects to make your car really perform, including engine modifiers and controllers, $ 80 instruments and timers. 19 Switching Power Supplies – by Sanjaya Maniktala Theoretical and practical aspects of controlling EMI in switching power supplies. Includes bonus CD$ ROM. 115 ! Audio ! RF ! Digital ! Analog ! TV ! Video ! Power Control ! Motors ! Robots ! Drives ! Op Amps ! Satellite siliconchip.com.au January 2010  93 Silicon Chip Back Issues January 1994: 3A 40V Variable Power Supply; Solar Panel Switching Regulator; Printer Status Indicator; Mini Drill Speed Controller; Stepper Motor Controller; Active Filter Design; Engine Management, Pt.4. February 1994:90-Second Message Recorder; 12-240VAC 200W Inverter; 0.5W Audio Amplifier; 3A 40V Adjustable Power Supply; Engine Management, Pt.5; Airbags In Cars – How They Work. March 1994: Intelligent IR Remote Controller; 50W (LM3876) Audio Amplifier Module; Level Crossing Detector For Model Railways; Voice Activated Switch For FM Microphones; Engine Management, Pt.6. April 1994: Sound & Lights For Model Railway Level Crossings; Dual Supply Voltage Regulator; Universal Stereo Preamplifier; Digital Water Tank Gauge; Engine Management, Pt.7. May 1994: Fast Charger For Nicad Batteries; Induction Balance Metal Locator; Multi-Channel Infrared Remote Control; Dual Electronic Dice; Simple Servo Driver Circuits; Engine Management, Pt.8. June 1994: A Coolant Level Alarm For Your Car; 80-Metre AM/CW Transmitter For Amateurs; Converting Phono Inputs To Line Inputs; PC-Based Nicad Battery Monitor; Engine Management, Pt.9. July 1994: Build A 4-Bay Bow-Tie UHF TV Antenna; PreChamp 2-Transistor Preamplifier; Steam Train Whistle & Diesel Horn Simulator; 6V SLA Battery Charger; Electronic Engine Management, Pt.10. August 1994: High-Power Dimmer For Incandescent Lights; Dual Diversity Tuner For FM Microphones, Pt.1; Nicad Zapper (For Resurrecting Nicad Batteries); Electronic Engine Management, Pt.11. September 1994: Automatic Discharger For Nicad Batteries; MiniVox Voice Operated Relay; AM Radio For Weather Beacons; Dual Diversity Tuner For FM Mics, Pt.2; Electronic Engine Management, Pt.12. October 1994: How Dolby Surround Sound Works; Dual Rail Variable Power Supply; Talking Headlight Reminder; Electronic Ballast For Fluorescent Lights; Electronic Engine Management, Pt.13. November 1994: Dry Cell Battery Rejuvenator; Novel Alphanumeric Clock; 80-M DSB Amateur Transmitter; 2-Cell Nicad Discharger. December 1994: Car Burglar Alarm; Three-Spot Low Distortion Sinewave Oscillator; Clifford – A Pesky Electronic Cricket; Remote Control System for Models, Pt.1; Index to Vol.7. January 1995: Sun Tracker For Solar Panels; Battery Saver For Torches; Dual Channel UHF Remote Control; Stereo Microphone Pre­amp­lifier. February 1995: 2 x 50W Stereo Amplifier Module; Digital Effects Unit For Musicians; 6-Channel LCD Thermometer; Wide Range Electrostatic Loudspeakers, Pt.1; Remote Control System For Models, Pt.2. DC-DC Converter For Car Hifi Systems, Pt.1; IR Stereo Headphone Link, Pt.2; Multi-Channel Radio Control Transmitter, Pt.8. November 1996: 8-Channel Stereo Mixer, Pt.1; Low-Cost Fluorescent Light Inverter; Repairing Domestic Light Dimmers.. December 1996: Active Filter For CW Reception; Fast Clock For Railway Modellers; Laser Pistol & Electronic Target; Build A Sound Level Meter; 8-Channel Stereo Mixer, Pt.2; Index To Vol.9. January 1997: Control Panel For Multiple Smoke Alarms, Pt.1; Build A Pink Noise Source; Computer Controlled Dual Power Supply, Pt.1; Digi-Temp Thermometer (Monitors Eight Temperatures). February 1997: PC-Con­trolled Moving Message Display; Computer Controlled Dual Power Supply, Pt.2; Alert-A-Phone Loud Sounding Telephone Alarm; Control Panel For Multiple Smoke Alarms, Pt.2. March 1997: 175W PA Amplifier; Signalling & Lighting For Model Railways; Jumbo LED Clock; Cathode Ray Oscilloscopes, Pt.7. April 1997: Simple Timer With No ICs; Digital Voltmeter For Cars; Loudspeaker Protector For Stereo Amplifiers; Model Train Controller; A Look At Signal Tracing; Pt.1; Cathode Ray Oscilloscopes, Pt.8. May 1997: Neon Tube Modulator For Light Systems; Traffic Lights For A Model Intersection; The Spacewriter – It Writes Messages In Thin Air; A Look At Signal Tracing; Pt.2; Cathode Ray Oscilloscopes, Pt.9. June 1997: PC-Controlled Thermometer/Thermostat; TV Pattern Generator, Pt.1; Audio/RF Signal Tracer; High-Current Speed Controller For 12V/24V Motors; Manual Control Circuit For Stepper Motors. July 1997: Infrared Remote Volume Control; A Flexible Interface Card For PCs; Points Controller For Model Railways; Colour TV Pattern Generator, Pt.2; An In-Line Mixer For Radio Control Receivers. October 1997: 5-Digit Tachometer; Central Locking For Your Car; PCControlled 6-Channel Voltmeter; 500W Audio Power Amplifier, Pt.3. November 1997: Heavy Duty 10A 240VAC Motor Speed Controller; Easy-To-Use Cable & Wiring Tester; Build A Musical Doorbell; Replacing Foam Speaker Surrounds; Understanding Electric Lighting Pt.1. September 1999: Autonomouse The Robot, Pt.1; Voice Direct Speech Recognition Module; Digital Electrolytic Capacitance Meter; XYZ Table With Stepper Motor Control, Pt.5; Peltier-Powered Can Cooler. October 1999: Build The Railpower Model Train Controller, Pt.1; Semiconductor Curve Tracer; Autonomouse The Robot, Pt.2; XYZ Table With Stepper Motor Control, Pt.6; Introducing Home Theatre. November 1999: Setting Up An Email Server; Speed Alarm For Cars, Pt.1; LED Christmas Tree; Intercom Station Expander; Foldback Loudspeaker System; Railpower Model Train Controller, Pt.2. December 1999: Solar Panel Regulator; PC Powerhouse (gives +12V, +9V, +6V & +5V rails); Fortune Finder Metal Locator; Speed Alarm For Cars, Pt.2; Railpower Model Train Controller, Pt.3; Index To Vol.12. January 2000: Spring Reverberation Module; An Audio-Video Test Generator; Parallel Port Interface Card; Telephone Off-Hook Indicator. February 2000: Multi-Sector Sprinkler Controller; A Digital Voltmeter For Your Car; Safety Switch Checker; Sine/Square Wave Oscillator. March 2000: 100W Amplifier Module, Pt.1; Electronic Wind Vane With 16-LED Display; Build A Glowplug Driver. May 2000: Ultra-LD Stereo Amplifier, Pt.2; LED Dice (With PIC Microcontroller); 50A Motor Speed Controller For Models. June 2000: Automatic Rain Gauge; Parallel Port VHF FM Receiver; Switchmode Power Supply (1.23V to 40V) Pt.1; CD Compressor. July 2000: Moving Message Display; Compact Fluorescent Lamp Driver; Musicians’ Lead Tester; Switchmode Power Supply, Pt.2. August 2000: Theremin; Spinner (writes messages in “thin-air”); Proximity Switch; Structured Cabling For Computer Networks. September 2000: Swimming Pool Alarm; 8-Channel PC Relay Board; Fuel Mixture Display For Cars, Pt.1; Protoboards – The Easy Way Into Electronics, Pt.1; Cybug The Solar Fly. October 2000: Guitar Jammer; Breath Tester; Wand-Mounted Inspection Camera; Subwoofer For Cars; Fuel Mixture Display, Pt.2. November 2000: Santa & Rudolf Chrissie Display; 2-Channel Guitar Preamplifier, Pt.1; Message Bank & Missed Call Alert; Protoboards – The Easy Way Into Electronics, Pt.3. January 1998: 4-Channel 12VDC or 12VAC Lightshow, Pt.1; Command Control For Model Railways, Pt.1; Pan Controller For CCD Cameras. December 2000: Home Networking For Shared Internet Access; White LED Torch; 2-Channel Guitar Preamplifier, Pt.2 (Digital Reverb); Driving An LCD From The Parallel Port; Index To Vol.13. February 1998: Telephone Exchange Simulator For Testing; Command Control For Model Railways, Pt.2; 4-Channel Lightshow, Pt.2. April 1998: Automatic Garage Door Opener, Pt.1; 40V 8A Adjustable Power Supply, Pt.1; PC-Controlled 0-30kHz Sinewave Generator; Understanding Electric Lighting; Pt.6. April 1995: FM Radio Trainer, Pt.1; Balanced Mic Preamp & Line Filter; 50W/Channel Stereo Amplifier, Pt.2; Wide Range Electrostatic Loudspeakers, Pt.3; 8-Channel Decoder For Radio Remote Control. May 1998: 3-LED Logic Probe; Garage Door Opener, Pt.2; Command Control System, Pt.4; 40V 8A Adjustable Power Supply, Pt.2. June 1995: Build A Satellite TV Receiver; Train Detector For Model Railways; 1W Audio Amplifier Trainer; Low-Cost Video Security System; Multi-Channel Radio Control Transmitter For Models, Pt.1. August 1999: Remote Modem Controller; Daytime Running Lights For Cars; Build A PC Monitor Checker; Switching Temperature Controller; XYZ Table With Stepper Motor Control, Pt.4; Electric Lighting, Pt.14. December 1997: Speed Alarm For Cars; 2-Axis Robot With Gripper; Stepper Motor Driver With Onboard Buffer; Power Supply For Stepper Motor Cards; Understanding Electric Lighting Pt.2; Index To Vol.10. March 1995: 2 x 50W Stereo Amplifier, Pt.1; Subcarrier Decoder For FM Receivers; Wide Range Electrostatic Loudspeakers, Pt.2; IR Illuminator For CCD Cameras; Remote Control System For Models, Pt.3. May 1995: Guitar Headphone Amplifier; FM Radio Trainer, Pt.2; Transistor/Mosfet Tester For DMMs; A 16-Channel Decoder For Radio Remote Control; Introduction To Satellite TV. July 1999: Build A Dog Silencer; 10µH to 19.99mH Inductance Meter; Audio-Video Transmitter; Programmable Ignition Timing Module For Cars, Pt.2; XYZ Table With Stepper Motor Control, Pt.3. June 1998: Troubleshooting Your PC, Pt.2; Universal High Energy Ignition System; The Roadies’ Friend Cable Tester; Universal Stepper Motor Controller; Command Control For Model Railways, Pt.5. July 1998: Troubleshooting Your PC, Pt.3; 15W/Ch Class-A Audio Amplifier, Pt.1; Simple Charger For 6V & 12V SLA Batteries; Auto­ matic Semiconductor Analyser; Understanding Electric Lighting, Pt.8. January 2001: How To Transfer LPs & Tapes To CD; The LP Doctor – Clean Up Clicks & Pops, Pt.1; Arbitrary Waveform Generator; 2-Channel Guitar Preamplifier, Pt.3; PIC Programmer & TestBed. February 2001: An Easy Way To Make PC Boards; L’il Pulser Train Controller; A MIDI Interface For PCs; Build The Bass Blazer; 2-Metre Groundplane Antenna; LP Doctor – Clean Up Clicks & Pops, Pt.2. March 2001: Making Photo Resist PC Boards; Big-Digit 12/24 Hour Clock; Parallel Port PIC Programmer & Checkerboard; Protoboards – The Easy Way Into Electronics, Pt.5; A Simple MIDI Expansion Box. April 2001: A GPS Module For Your PC; Dr Video – An Easy-To-Build Video Stabiliser; Tremolo Unit For Musicians; Minimitter FM Stereo Transmitter; Intelligent Nicad Battery Charger. August 1998: Troubleshooting Your PC, Pt.4; I/O Card With Data Logging; Beat Triggered Strobe; 15W/Ch Class-A Stereo Amplifier, Pt.2. May 2001: 12V Mini Stereo Amplifier; Two White-LED Torches To Build; PowerPak – A Multi-Voltage Power Supply; Using Linux To Share An Internet Connection, Pt.1; Tweaking Windows With TweakUI. September 1998: Troubleshooting Your PC, Pt.5; A Blocked Air-Filter Alarm; Waa-Waa Pedal For Guitars; Jacob’s Ladder; Gear Change Indicator For Cars; Capacity Indicator For Rechargeable Batteries. June 2001: Universal Battery Charger, Pt.1; Phonome – Call, Listen In & Switch Devices On & Off; Low-Cost Automatic Camera Switcher; Using Linux To Share An Internet Connection, Pt.2. September 1995: Railpower Mk.2 Walkaround Throttle For Model Railways, Pt.1; Keypad Combination Lock; Build A Jacob’s Ladder Display. October 1998: AC Millivoltmeter, Pt.1; PC-Controlled Stress-O-Meter; Versatile Electronic Guitar Limiter; 12V Trickle Charger For Float Conditions; Adding An External Battery Pack To Your Flashgun. July 2001: The HeartMate Heart Rate Monitor; Do Not Disturb Tele­ phone Timer; Pic-Toc – A Simple Alarm Clock; Fast Universal Battery Charger, Pt.2; Backing Up Your Email. October 1995: 3-Way Loudspeaker System; Railpower Mk.2 Walkaround Throttle For Model Railways, Pt.2; Build A Nicad Fast Charger. November 1998: The Christmas Star; A Turbo Timer For Cars; Build A Poker Machine, Pt.1; FM Transmitter For Musicians; Lab Quality AC Millivoltmeter, Pt.2; Improving AM Radio Reception, Pt.1. August 2001: DI Box For Musicians; 200W Mosfet Amplifier Module; Headlight Reminder; 40MHz 6-Digit Frequency Counter Module; Using Linux To Share An Internet Connection, Pt.3. December 1998: Engine Immobiliser Mk.2; Thermocouple Adaptor For DMMs; Regulated 12V DC Plugpack; Build A Poker Machine, Pt.2; Improving AM Radio Reception, Pt.2; Mixer Module For F3B Gliders. September 2001: Making MP3s; Build An MP3 Jukebox, Pt.1; PCControlled Mains Switch; Personal Noise Source For Tinnitus; Directional Microphone; Using Linux To Share An Internet Connection, Pt.4. January 1999: High-Voltage Megohm Tester; A Look At The BASIC Stamp; Bargraph Ammeter For Cars; Keypad Engine Immobiliser. November 2001: Ultra-LD 100W/Channel Stereo Amplifier, Pt.1; Neon Tube Modulator For Cars; Audio/Video Distribution Amplifier; Build A Short Message Recorder Player; Useful Tips For Your PC. July 1995: Electric Fence Controller; How To Run Two Trains On A Single Track (Incl. Lights & Sound); Setting Up A Satellite TV Ground Station; Build A Reliable Door Minder. August 1995: Fuel Injector Monitor For Cars; Build A Gain-Controlled Microphone Preamplifier; Identifying IDE Hard Disk Drive Parameters. November 1995: Mixture Display For Fuel Injected Cars; CB Trans­verter For The 80M Amateur Band, Pt.1; PIR Movement Detector. May 1996: High Voltage Insulation Tester; Knightrider LED Chaser; Simple Intercom Uses Optical Cable; Cathode Ray Oscilloscopes, Pt.3. June 1996: Stereo Simulator; Build A Rope Light Chaser; Low Ohms Tester For Your DMM; Automatic 10A Battery Charger. July 1996: VGA Digital Oscilloscope, Pt.1; Remote Control Extender For VCRs; 2A SLA Battery Charger; 3-Band Parametric Equaliser. August 1996: Introduction to IGBTs; Electronic Starter For Fluores­cent Lamps; VGA Oscilloscope, Pt.2; 350W Amplifier Module; Masthead Amplifier For TV & FM; Cathode Ray Oscilloscopes, Pt.4. September 1996: VGA Oscilloscope, Pt.3; IR Stereo Headphone Link, Pt.1; HF Amateur Radio Receiver; Cathode Ray Oscilloscopes, Pt.5. October 1996: Send Video Signals Over Twisted Pair Cable; 600W March 1999: Build A Digital Anemometer; DIY PIC Programmer; Build An Audio Compressor; Low-Distortion Audio Signal Generator, Pt.2. April 1999: Getting Started With Linux; Pt.2; High-Power Electric Fence Controller; Bass Cube Subwoofer; Programmable Thermostat/ Thermometer; Build An Infrared Sentry; Rev Limiter For Cars. May 1999: The Line Dancer Robot; An X-Y Table With Stepper Motor Control, Pt.1; Three Electric Fence Testers; Carbon Monoxide Alarm. June 1999: FM Radio Tuner Card For PCs; X-Y Table With Stepper Motor Control, Pt.2; Programmable Ignition Timing Module For Cars, Pt.1. How To Order: Just fill in and mail the handy order form in this is- sue; or fax (02) 9939 2648; or call (02) 9939 3295 and quote your credit card number. Price: $A12.00 each (including GST) in Aust. or $A15.00 each overseas. Prices include p&p. Email: silicon<at>siliconchip.com.au 10% OF SUBSCR F TO IB OR IF Y ERS OU BUY 10 OR M ORE January 2002: Touch And/Or Remote-Controlled Light Dimmer, Pt.1; A Cheap ’n’Easy Motorbike Alarm; 100W /Channel Stereo Amplifier, Pt.3; Build A Raucous Alarm; FAQs On The MP3 Jukebox. February 2002: 10-Channel IR Remote Control Receiver; 2.4GHz High-Power Audio-Video Link; Touch And/Or Remote-Controlled Light Dimmer, Pt.2; Booting A PC Without A Keyboard; 4-Way Event Timer. March 2002: Mighty Midget Audio Amplifier Module; 6-Channel IR Remote Volume Control, Pt.1; RIAA Pre­-­Amplifier For Magnetic Cartridges; 12/24V Intelligent Solar Power Battery Charger. April 2002:Automatic Single-Channel Light Dimmer; Pt.1; Water Level Indicator; Multiple-Output Bench Power Supply; Versatile Multi-Mode Timer; 6-Channel IR Remote Volume Control, Pt.2. May 2002: 32-LED Knightrider; The Battery Guardian (Cuts Power When the Battery Voltage Drops); Stereo Headphone Amplifier; Automatic Single-Channel Light Dimmer; Pt.2; Stepper Motor Controller. August 2002: Digital Instrumentation Software For PCs; Digital Storage Logic Probe; Digital Therm./Thermostat; Sound Card Interface For PC Test Instruments; Direct Conversion Receiver For Radio Amateurs. September 2002: 12V Fluorescent Lamp Inverter; 8-Channel Infrared Remote Control; 50-Watt DC Electronic Load; Spyware – An Update. October 2002: Speed Controller For Universal Motors; PC Parallel Port Wizard; Cable Tracer; AVR ISP Serial Programmer; 3D TV. November 2002: SuperCharger For NiCd/NiMH Batteries, Pt.1; Windows-Based EPROM Programmer, Pt.1; 4-Digit Crystal-Controlled Timing Module. December 2002: Receiving TV From Satellites; Pt.1; The Micromitter Stereo FM Transmitter; Windows-Based EPROM Programmer, Pt.2; SuperCharger For NiCd/NiMH Batteries; Pt.2; Simple VHF FM/AM Radio. January 2003: Receiving TV From Satellites, Pt 2; SC480 50W RMS Amplifier Module, Pt.1; Gear Indicator For Cars; Active 3-Way Crossover For Speakers. February 2003: PortaPal PA System, Pt.1; SC480 50W RMS Amplifier Module, Pt.2; Windows-Based EPROM Programmer, Pt.3; Fun With The PICAXE, Pt.1. March 2003: LED Lighting For Your Car; Peltier-Effect Tinnie Cooler; PortaPal PA System, Pt.2; 12V SLA Battery Float Charger; Little Dynamite Subwoofer; Fun With The PICAXE, Pt.2 (Shop Door Minder). April 2003: Video-Audio Booster For Home Theatre Systems; Telephone Dialler For Burglar Alarms; Three PIC Programmer Kits; PICAXE, Pt.3 (Heartbeat Simulator); Electric Shutter Release For Cameras. March 2005: Windmill Generator, Pt.4; Sports Scoreboard, Pt.1; Inductance & Q-Factor Meter, Pt.2; Shielded Loop Antenna For AM; Sending Picaxe Data Over 477MHz UHF CB; $10 Lathe & Drill Press Tachometer. September 2007: The Art Of Long-Distance WiFi; Fast Charger For NiMH & Nicad Batteries; Simple Data-Logging Weather Station, Pt.1; 20W Class-A Stereo Amplifier; Pt.5. April 2005: Install Your Own In-Car Video (Reversing Monitor); Build A MIDI Theremin, Pt.1; Bass Extender For Hifi Systems; Sports Scoreboard, Pt.2; SMS Controller Add-Ons; A $5 Variable Power Supply. October 2007: DVD Players – How Good Are They For HiFi Audio?; PICProbe Logic Probe; Rolling Code Security System, Pt.1; Simple Data-Logging Weather Station, Pt.2; AM Loop Antenna & Amplifier. May 2005: Getting Into Wi-Fi, Pt.1; Build A 45-Second Voice Recorder; Wireless Microphone/Audio Link; MIDI Theremin, Pt.2; Sports Scoreboard, Pt.3; Automatic Stopwatch Timer. November 2007: Your Own Home Recording Studio; PIC-Based Water Tank Level Meter, Pt.1: Playback Adaptor For CD-ROM Drives, Pt.1; Rolling Code Security System, Pt.2. June 2005: Wi-Fi, Pt.2; The Mesmeriser LED Clock; Coolmaster Fridge/ Freezer Temperature Controller; Alternative Power Regular; PICAXE Colour Recognition System; AVR200 Single Board Computer, Pt.1. December 2007: Signature Series Kit Loudspeakers; IR Audio Headphone Link; Enhanced 45s Voice Recorder Module; PIC-Based WaterTank Level Meter; Pt.2; Playback Adaptor For CD-ROM Drives; Pt.2. July 2005: Wi-Fi, Pt.3; Remote-Controlled Automatic Lamp Dimmer; Serial Stepper Motor Controller; Salvaging & Using Thermostats; Unwired Modems & External Antennas. January 2008: PIC-Controlled Swimming Pool Alarm; Emergency 12V Lighting Controller; Build The “Aussie-3” Valve AM Radio; The Minispot 455kHz Modulated Oscillator; Water Tank Level Meter, Pt.3 – The Base Station; Improving The Water Tank Level Meter Pressure Sensor. August 2005: Mudlark A205 Valve Stereo Amplifier, Pt.1; Programmable Flexitimer; Carbon Monoxide Alert; Serial LCD Driver; Enhanced Sports Scoreboard; Salvaging Washing Maching Pressure Switches. September 2005: Build Your Own Seismograph; Bilge Sniffer For Boats; VoIP Analog Phone Adaptor; Mudlark A205 Valve Stereo Amplifier, Pt.2; PICAXE in Schools, Pt.4. October 2005: A Look At Google Earth; Dead Simple USB Breakout Box; Studio Series Stereo Preamplifier, Pt.1; Video Reading Aid For Vision Impaired People; Simple Alcohol Level Meter; Ceiling Fan Timer. May 2003: Widgybox Guitar Distortion Effects Unit; 10MHz Big Blaster Subwoofer; Printer Port Simulator; PICAXE, Pt.4 (Motor Controller). November 2005: Good Quality Car Sound On The Cheap; Pt.1; PICAXE In Schools, Pt.5; Studio Series Stereo Headphone Amplifier; Build A MIDI Drum Kit, Pt.1; Serial I/O Controller & Analog Sampler. June 2003: PICAXE-Controlled Telephone Intercom; Sunset Switch For Security & Garden Lighting; Digital Reaction Timer; Adjustable DC-DC Converter For Cars; Long-Range 4-Channel UHF Remote Control. December 2005: Good Quality Car Sound On The Cheap; Pt.2; Building The Ultimate Jukebox, Pt.1; Universal High-Energy Ignition System, Pt.1; MIDI Drum Kit, Pt.2; 433MHz Wireless Data Communication. July 2003: Smart Card Reader & Programmer; Power-Up Auto Mains Switch; A “Smart” Slave Flash Trigger; Programmable Continuity Tester; Updating The PIC Programmer & Checkerboard. January 2006: Pocket TENS Unit For Pain Relief; “Little Jim” AM Radio Transmitter; Universal High-Energy Ignition System, Pt.2; Building The Ultimate Jukebox, Pt.2; MIDI Drum Kit, Pt.3; Picaxe-Based 433MHz Wireless Thermometer; A Human-Powered LED Torch. August 2003: PC Infrared Remote Receiver (Play DVDs & MP3s On Your PC Via Remote Control); Digital Instrument Display For Cars, Pt.1; Home-Brew Weatherproof 2.4GHz WiFi Antennas; PICAXE Pt.7. September 2003: Robot Wars; Krypton Bike Light; PIC Programmer; Current Clamp Meter Adapter For DMMs; PICAXE Pt.8 – A Data Logger; Digital Instrument Display For Cars, Pt.2. October 2003: PC Board Design, Pt.1; JV80 Loudspeaker System; A Dirt Cheap, High-Current Power Supply; Low-Cost 50MHz Frequency Meter; Long-Range 16-Channel Remote Control System. November 2003: PC Board Design, Pt.2; 12AX7 Valve Audio Preamplifier; Our Best Ever LED Torch; Smart Radio Modem For Microcontrollers; PICAXE Pt.9; Programmable PIC-Powered Timer. December 2003: PC Board Design, Pt.3; VHF Receiver For Weather Satellites; Linear Supply For Luxeon 1W Star LEDs; 5V Meter Calibration Standard; PIC-Based Car Battery Monitor; PICAXE Pt.10. January 2004: Studio 350W Power Amplifier Module, Pt.1; HighEfficiency Power Supply For 1W Star LEDs; Antenna & RF Preamp For Weather Satellites; Lapel Microphone Adaptor For PA Systems; PICAXE-18X 4-Channel Datalogger, Pt.1; 2.4GHZ Audio/Video Link. February 2004: PC Board Design, Pt.1; Supply Rail Monitor For PCs; Studio 350W Power Amplifier Module, Pt.2; Shorted Turns Tester For Line Output Transformers; PICAXE-18X 4-Channel Datalogger, Pt.2. February 2008: UHF Remote-Controlled Mains Switch; UHF Remote Mains Switch Transmitter; A PIR-Triggered Mains Switch; Shift Indicator & Rev Limiter For Cars; Mini Solar Battery Charger. March 2008: The I2C Bus – A Quick Primer; 12V-24V High-Current DC Motor Speed Controller, Pt.1; A Digital VFO with LCD Graphics Display; A Low-Cost PC-to-I2C Interface For Debugging. April 2008: Charge Controller For 12V Lead-Acid Or SLA Batteries; Safe Flash Trigger For Digital Cameras; 12V-24V High-Current DC Motor Speed Controller, Pt.2; Two-Way Stereo Headphone Adaptor. May 2008: Replacement CDI Module For Small Petrol Motors; High-Accuracy Digital LC Meter; Low-Cost dsPIC/PIC Programmer; High-Current Adjustable Voltage Regulator. June 2008: DSP Musicolour Light Show, Pt.1; PIC-Based Flexitimer Mk.4; USB Power Injector For External Hard Drives; Balanced/Unbalanced Converter For Audio Signals; A Quick’n’Easy Digital Slide Scanner. July 2008: DSP Musicolour Light Show, Pt.2; A PIC-Based Musical Tuning Aid; Balanced Mic Preamp For PCs & MP3 Players; Bridge Adaptor For Stereo Power Amplifiers. February 2006: PC-Controlled Burglar Alarm, Pt.1; A Charger For iPods & MP3 Players; Picaxe-Powered Thermostat & Temperature Display; Build A MIDI Drum Kit, Pt.4; Building The Ultimate Jukebox, Pt.3. August 2008: Ultra-LD Mk.2 200W Power Amplifier Module, Pt.1; Planet Jupiter Receiver; LED Strobe & Contactless Tachometer, Pt.1; DSP Musicolour Light Show, Pt.3; Printing In The Third Dimension. March 2006: The Electronic Camera, Pt.1; PC-Controlled Burglar Alarm System, Pt.2; Low-Cost Intercooler Water Spray Controller; AVR ISP SocketBoard; Build A Low-Cost Large Display Anemometer. September 2008: Railpower Model Train Controller, Pt.1; LED/Lamp Flasher; Ultra-LD Mk.2 200W Power Amplifier Module, Pt.2; DSP Musicolour Light Show, Pt.4; LED Strobe & Contactless Tachometer, Pt.2. April 2006: The Electronic Camera, Pt.2; Studio Series Remote Control Module (For A Stereo Preamplifier); 4-Channel Audio/Video Selector; Universal High-Energy LED Lighting System, Pt.1; Picaxe Goes Wireless, Pt.1 (Using the 2.4GHz XBee Modules). October 2008: USB Clock With LCD Readout, Pt.1; Digital RF Level & Power Meter; Multi-Purpose Timer; Railpower Model Train Controller, Pt.2; Picaxe-08M 433MHz Data Transceiver. May 2006: Lead-Acid Battery Zapper; Universal High-Energy LED Lighting System, Pt.2; Passive Direct Injection (DI) Box For Musicians; Picaxe Goes Wireless, Pt.2; Boost Your XBee’s Range Using Simple Antennas. June 2006: Pocket A/V Test Pattern Generator; Two-Way SPDIF-toToslink Digital Audio Converter; Build A 2.4GHz Wireless A/V Link; A High-Current Battery Charger For Almost Nothing. July 2006: Mini Theremin Mk.2, Pt.1; Programmable Analog On-Off Controller; Studio Series Stereo Preamplifier; Stop Those Zaps From Double-Insulated Equipment. November 2008: 12V Speed Controller/Lamp Dimmer; USB Clock With LCD Readout, Pt.2; Wideband Air-Fuel Mixture Display Unit; IrDA Interface Board For The DSP Musicolour; The AirNav RadarBox. December 2008: Versatile Car Scrolling Display, Pt.1; Test The salt Content Of Your Swimming Pool; Build A Brownout Detector; Simple Voltage Switch For Car Sensors. January 2009: Dual Booting With Two Hard Disk Drives; USB-Sensing Mains Power Switch; Remote Mains Relay Mk.2; AM Broadcast Band Loop Antenna; Car Scrolling Display, Pt.2; 433MHz UHF Remote Switch. August 2006: Picaxe-Based LED Chaser Clock; Magnetic Cartridge Preamplifier; An Ultrasonic Eavesdropper; Mini Theremin Mk.2, Pt.2. February 2009: Digital Radio Is Coming, Pt.1; Tempmaster Electronic Thermostat Mk.2; 10A Universal Motor Speed Controller Mk.2; Programmable Time Delay Flash Trigger; Car Scrolling Display, Pt.3. March 2004: PC Board Design, Pt.2; Build The QuickBrake For Increased Driving Safety; 3V-9V (or more) DC-DC Converter; ESR Meter Mk.2, Pt.1; PICAXE-18X 4-Channel Datalogger, Pt.3. September 2006: Transferring Your LPs To CDs & MP3s; Turn an Old Xbox Into A $200 Multimedia Player; Build The Galactic Voice; Aquarium Temperature Alarm; S-Video To Composite Video Converter. March 2009: Reviving Old Laptops With Puppy Linux; Digital Radio Is Coming, Pt.2; A GPS-Synchronised Clock; Theremin Mk.2; Build A Digital Audio Millivoltmeter; Learning about Picaxe Microcontrollers. April 2004: PC Board Design, Pt.3; Loudspeaker Level Meter For Home Theatre Systems; Dog Silencer; Mixture Display For Cars; ESR Meter Mk.2, Pt.2; PC/PICAXE Interface For UHF Remote Control. October 2006: LED Tachometer With Dual Displays, Pt.1; UHF Prescaler For Frequency Counters; Infrared Remote Control Extender; Easy-ToBuild 12V Digital Timer Module; Build A Super Bicycle Light Alternator. April 2009: Digital Radio Is Coming, Pt.3; Wireless Networking With Ubuntu & Puppy Linux; Remote-Controlled Lamp Dimmer; School Zone Speed Alert; USB Printer Share Switch; Microcurrent DMM Adaptor. May 2004: Amplifier Testing Without High-Tech Gear; Component Video To RGB Converter; Starpower Switching Supply For Luxeon Star LEDs; Wireless Parallel Port; Poor Man’s Metal Locator. November 2006: Radar Speed Gun, Pt.1; Build Your Own Compact Bass Reflex Loudspeakers; Programmable Christmas Star; DC Relay Switch; LED Tachometer With Dual Displays, Pt.2; Picaxe Net Server, Pt.3. June 2004: Build An RFID Security Module; Simple Fridge-Door Alarm; Courtesy Light Delay For Cars; Automating PC Power-Up; Upgraded Software For The EPROM Programmer. December 2006: Bringing A Dead Cordless Drill Back To Life; Cordless Power Tool Charger Controller; Build A Radar Speed Gun, Pt.2; Super Speedo Corrector; 12/24V Auxiliary Battery Controller. May 2009: A 6-Digit GPS-Locked Clock, Pt.1; 230VAC 10A Full-Wave Motor Speed Controller; Precision 10V DC Reference For Checking DMMs; UHF Remote 2-Channel 230VAC Power Switch; Input Attenuator For The Digital Audio Millivoltmeter; Drawing Circuits In Protel Autotrax. July 2004: Silencing A Noisy PC; Versatile Battery Protector; Appliance Energy Meter, Pt.1; A Poor Man’s Q Meter; Regulated High-Voltage Supply For Valve Amplifiers; Remote Control For A Model Train Layout. January 2007: Versatile Temperature Switch; Intelligent Car AirConditioning Controller; Remote Telltale For Garage Doors; Intelligent 12V Charger For SLA & Lead-Acid Batteries. August 2004: Video Formats: Why Bother?; VAF’s New DC-X Generation IV Loudspeakers; Video Enhancer & Y/C Separator; Balanced Microphone Preamp; Appliance Energy Meter, Pt.2; 3-State Logic Probe. February 2007: Remote Volume Control & Preamplifier Module, Pt.1; Simple Variable Boost Control For Turbo Cars; Fuel Cut Defeater For The Boost Control; Low-Cost 50MHz Frequency Meter, Mk.2. September 2004: Voice Over IP (VoIP) For Beginners; WiFry – Cooking Up 2.4GHz Antennas; Bed Wetting Alert; Build a Programmable Robot; Another CFL Inverter. March 2007: Programmable Ignition System For Cars, Pt.1; Remote Volume Control & Preamplifier Module, Pt.2; GPS-Based Frequency Reference, Pt.1; Simple Ammeter & Voltmeter. October 2004: The Humble “Trannie” Turns 50; SMS Controller, Pt.1; RGB To Component Video Converter; USB Power Injector; Remote Controller For Garage Doors & Gates. April 2007: High-Power Reversible DC Motor Speed Controller; Build A Jacob’s Ladder; GPS-Based Frequency Reference, Pt.2; Programmable Ignition System, Pt.2; Dual PICAXE Infrared Data Communication. November 2004: 42V Car Electrical Systems; USB-Controlled Power Switch (Errata December 2004); Charger For Deep-Cycle 12V Batteries, Pt.1; Driveway Sentry For Cars; SMS Controller, Pt.2; PICAXE IR Remote Control. May 2007: 20W Class-A Amplifier Module, Pt.1; Adjustable 1.3-22V Regulated Power Supply; VU/Peak Meter With LCD Bargraphs; Programmable Ignition System For Cars, Pt.3; GPS-Based Frequency Reference Modifications; Throttle Interface For The DC Motor Speed Controller. December 2004: Build A Windmill Generator, Pt.1; 20W Amplifier Module; Charger For Deep-Cycle 12V Batteries, Pt.2; Solar-Powered Wireless Weather Station; Bidirectional Motor Speed Controller. June 2007: 20W Class-A Amplifier Module, Pt.2; Knock Detector For The Programmable Ignition; 4-Input Mixer With Tone Controls; Frequency-Activated Switch For Cars; Simple Panel Meters Revisited. January 2005: Windmill Generator, Pt.2; Build A V8 Doorbell; IR Remote Control Checker; 4-Minute Shower Timer; The Prawnlite; Sinom Says Game; VAF DC-7 Generation 4 Kit Speakers. July 2007: How To Cut Your Greenhouse Emissions, Pt.1; 6-Digit Nixie Clock, Pt.1; Tank Water Level Indicator; A PID Temperature Controller; 20W Class-A Stereo Amplifier; Pt.3; Making Panels For Projects. February 2005: Windmill Generator, Pt.3; USB-Controlled Electrocardiograph; TwinTen Stereo Amplifier; Inductance & Q-Factor Meter, Pt.1; A Yagi Antenna For UHF CB; $2 Battery Charger. August 2007: How To Cut Your Greenhouse Emissions, Pt.2; 20W Class-A Stereo Amplifier; Pt.4; Adaptive Turbo Timer; Subwoofer Controller; 6-Digit Nixie Clock, Pt.2. June 2009: Mal’s Electric Vehicle Conversion; High-Current, HighVoltage Battery Capacity Meter, Pt.1; GPS Driver Module For The 6-Digit Clock; A Beam-Break Flash Trigger; Hand-Held Digital Audio Oscillator. July 2009: The Magic Of Water Desalination; Lead-Acid Battery Zapper & Desulphator; Hand-Held Metal Locator; Multi-Function Active Filter Module; High-Current, high-Voltage Battery Capacity Meter, Pt.2. August 2009: Converting A Uniden Scanner To Pick Up AIS Signals; An SD Card Music & Speech Recorder/Player; Lead-Acid/SLA Battery Condition Checker; 3-Channel UHF Rolling-Code Remote Control, Pt.1. September 2009: High-Quality Stereo Digital-To-Analog Converter, Pt.1; WideBand O2 Sensor Controller For Cars, Pt.1; Autodim Add-On For The GPS Clock; 3-Channel UHF Rolling-Code Remote Control, Pt.2. October 2009: Universal I/O Board With USB Interface; High-Quality Stereo Digital-To-Analog Converter, Pt.2; Digital Megohm & Leakage Current Meter; WideBand O2 Sensor Controller For Cars, Pt.2. November 2009: Web Server In A Box, Pt.1; Twin-Engine SpeedMatch Indicator For Boats; High-Quality Stereo Digital-To-Analog Converter, Pt.3; A Dead-Simple Masthead Amplifier. December 2009: Voltage Interceptor For Car Sensors, Pt.1; One-OfNine Switch Position Indicator; Capacitor Leakage Meter With LCD; Big 7-Segment LED Panel Meter Display; Web Server In A Box, Pt.2. NOTE: issues not listed have sold out. We can supply photostat copies of articles from sold-out issues for $A12.00 each within Australia or $A15.00 each overseas (prices include p&p). When supplying photostat articles or back copies, we automatically supply any relevant notes & errata at no extra charge. A complete index to all articles published can be downloaded from www.siliconchip.com.au ALL S ILICON C HIP SUBSCRIBERS – PRINT, OR BOTH – AUTOMATICALLY QUALIFY FOR A REFERENCE $ave 10%ONLINE DISCOUNT ON ALL BOOK OR PARTSHOP PURCHASES. CHIP BOOKSHOP 10% (Does not apply to subscriptions) SILICON For the latest titles and information, please refer to our website books page: www.siliconchip.com.au/Shop/Books PIC MICROCONTROLLERS: know it all SELF ON AUDIO Multiple authors $85.00 The best of subjects Newnes authors have written over the past few years, combined in a one-stop maxi reference. Covers introduction to PICs and their programming in Assembly, PICBASIC, MBASIC & C. 900+ pages. PROGRAMMING and CUSTOMIZING THE PICAXE By David Lincoln (2nd Ed, 2011) $65.00* A great aid when wrestling with applications for the PICAXE See series of microcontrollers, at beginner, intermediate and Review April advanced levels. Every electronics class, school and library should have a copy, along with anyone who works with PICAXEs. 300 pages in paperback. 2011 PIC IN PRACTICE by D W Smith. 2nd Edition - published 2006 $60.00* Based on popular short courses on the PIC, for professionals, students and teachers. Can be used at a variety of levels. An ideal introduction to the world of microcontrollers. 255 pages in paperback. PIC MICROCONTROLLER – your personal introductory course By John Morton 3rd edition 2005. $60.00* A unique and practical guide to getting up and running with the PIC. It assumes no knowledge of microcontrollers – ideal introduction for students, teachers, technicians and electronics enthusiasts. Revised 3rd edition focuses entirely on re-programmable flash PICs such as 16F54, 16F84 12F508 and 12F675. 226 pages in paperback. A collection of 35 classic magazine articles offering a dependable methodology for designing audio power amplifiers to improve performance at every point without significantly increasing cost. Includes compressors/limiters, hybrid bipolar/FET amps, electronic switching and more. 467 pages in paperback. SMALL SIGNAL AUDIO DESIGN By Douglas Self – First Edition 2010 $95.00* The latest from the Guru of audio. Explains audio concepts in easy-to-understand language with plenty of examples and reasoning. Inspiration for audio designers, superb background for audio enthusiasts and especially where it comes to component peculiarities and limitations. Expensive? Yes. Value for money? YES! Highly recommended. 558 pages in paperback. AUDIO POWER AMPLIFIER DESIGN HANDBOOK by Douglas Self – 5th Edition 2009 $85.00* "The Bible" on audio power amplifiers. Many revisions and updates to the previous edition and now has an extra three chapters covering Class XD, Power Amp Input Systems and Input Processing and Auxiliarly Subsystems. Not cheap and not a book for the beginner but if you want the best reference on Audio Power Amps, you want this one! 463 pages in paperback. DVD PLAYERS AND DRIVES by K.F. Ibrahim. Published 2003. $71.00* OP AMPS FOR EVERYONE By Bruce Carter – 4th Edition 2013 $83.00* This is the bible for anyone designing op amp circuits and you don't have to be an engineer to get the most out of it. It is written in simple language but gives lots of in-depth info, bridging the gap between the theoretical and the practical. 281 pages, PROGRAMMING 32-bit MICROCONTROLLERS IN C By Luci di Jasio (2008) $79.00* Subtitled Exploring the PIC32, a Microchip insider tells all on this powerful PIC! Focuses on examples and exercises that show how to solve common, real-world design problems quickly. Includes handy checklists. FREE CD-ROM includes source code in C, the Microchip C30 compiler, and MPLAB SIM. 400 pages paperback. PRACTICAL GUIDE TO SATELLITE TV By Garry Cratt – Latest (7th) Edition 2008 $49.00 Written in Australia, for Australian conditions by one of Australia's foremost satellite TV experts. If there is anything you wanted to know about setting up a satellite TV system, (including what you can't do!) it's sure to be covered in this 176-page paperback book. NEWNES GUIDE TO TV & VIDEO TECHNOLOGY By KF Ibrahim 4th Edition (Published 2007) $49.00 It's back! Provides a full and comprehensive coverage of video and television technology including HDTV and DVD. Starts with fundamentals so is ideal for students but covers in-depth technologies such as Blu-ray, DLP, Digital TV, etc so is also perfect for engineers. 600+ pages in paperback. RF CIRCUIT DESIGN by Chris Bowick, Second Edition, 2008. $63.00* The classic RF circuit design book. RF circuit design is now more important that ever in the wireless world. In most of the wireless devices that we use there is an RF component – this book tells how to design and integrate in a very practical fashion. 244 pages in paperback. A guide to DVD technology and applications, with particular focus on design issues and pitfalls, maintenance and repair. Ideal for engineers, technicians, students of consumer electronics and sales and installation staff. 319 pages in paperback. See Review March 2010 See Review Feb 2004 SWITCHING POWER SUPPLIES A-Z by Sanjaya Maniktala, Published April 2012. $83.00 Thoroughly revised! The most comprehensive study available of theoretical and practical aspects of controlling and measuring EMI in switching power supplies. ELECTRIC MOTORS AND DRIVES By Austin Hughes & Bill Drury - 4th edition 2013 $59.00* This is a very easy to read book with very little mathematics or formulas. It covers the basics of all the main motor types, DC permanent magnet and wound field, AC induction and steppers and gives a very good description of how speed control circuits work with these motors. Soft covers, 444 pages. AC MACHINES By Jim Lowe Published 2006 $66.00* Applicable to Australian trades-level courses including NE10 AC Machines, NE12 Synchronous Machines and the AC part of NE30 Electric Motor Control and Protection. Covering polyphase induction motors, singlephase motors, synchronous machines and polyphase motor starting. 160 pages in paperback. PRACTICAL VARIABLE SPEED DRIVES & POWER ELECTRONICS Se e by Malcolm Barnes. 1st Ed, Feb 2003. $73.00* Review An essential reference for engineers and anyone who wishes to design or use variable speed drives for induction motors. 286 pages in soft cover. Feb 2003 BUILD YOUR OWN ELECTRIC MOTORCYCLE PRACTICAL RF HANDBOOK by Ian Hickman. 4th edition 2007 $61.00* by Douglas Self 2nd Edition 2006 $69.00* by Carl Vogel. Published 2009. $40.00* A guide to RF design for engineers, technicians, students and enthusiasts. Covers key topics in RF: analog design principles, transmission lines, couplers, transformers, amplifiers, oscillators, modulation, transmitters and receivers, propagation and antennas. 279 pages in paperback. Alternative fuel expert Carl Vogel gives you a hands-on guide with the latest technical information and easy-to-follow instructions for building a two-wheeled electric vehicle – from a streamlined scooter to a full-sized motorcycle. 384 pages in soft cover. *NOTE: ALL PRICES ARE PLUS P&P – AUSTRALIA ONLY: $10.00 per order; NZ – $AU12.00 PER BOOK; REST OF WORLD $AU18.00 PER BOOK PAYPAL (24/7) INTERNET (24/7) MAIL (24/7) PHONE – (9-5, Mon-Fri) eMAIL (24/7) FAX (24/7) To ilicon Chip Use your PayPal account www.siliconchip. Call (02) 9939 3295 with silicon<at>siliconchip.com.au Your order and card details to Your order to PO Box 139 Place96  S com.au/Shop/Books silicon<at>siliconchip.com.au Collaroy NSW 2097 with order & credit card details with order & credit card details (02) 9939 2648 with all details Your You can also order and pay for books by cheque/money order (Mail Only). Make cheques payable to Silicon Chip Publications. Order: ALL TITLES SUBJECT TO AVAILABILITY. PRICES VALID FOR MONTH OF MAGAZINE ISSUE ONLY. ALL PRICES INCLUDE GST ALL S ILICON C HIP SUBSCRIBERS – PRINT, OR BOTH – AUTOMATICALLY QUALIFY FOR A REFERENCE $ave 10%ONLINE DISCOUNT ON ALL BOOK OR PARTSHOP PURCHASES. CHIP BOOKSHOP 10% (Does not apply to subscriptions) SILICON For the latest titles and information, please refer to our website books page: www.siliconchip.com.au/Shop/Books PIC MICROCONTROLLERS: know it all SELF ON AUDIO Multiple authors $85.00 The best of subjects Newnes authors have written over the past few years, combined in a one-stop maxi reference. Covers introduction to PICs and their programming in Assembly, PICBASIC, MBASIC & C. 900+ pages. PROGRAMMING and CUSTOMIZING THE PICAXE By David Lincoln (2nd Ed, 2011) $65.00* A great aid when wrestling with applications for the PICAXE See series of microcontrollers, at beginner, intermediate and Review April advanced levels. Every electronics class, school and library should have a copy, along with anyone who works with PICAXEs. 300 pages in paperback. 2011 PIC IN PRACTICE by D W Smith. 2nd Edition - published 2006 $60.00* Based on popular short courses on the PIC, for professionals, students and teachers. Can be used at a variety of levels. An ideal introduction to the world of microcontrollers. 255 pages in paperback. PIC MICROCONTROLLER – your personal introductory course By John Morton 3rd edition 2005. $60.00* A unique and practical guide to getting up and running with the PIC. It assumes no knowledge of microcontrollers – ideal introduction for students, teachers, technicians and electronics enthusiasts. Revised 3rd edition focuses entirely on re-programmable flash PICs such as 16F54, 16F84 12F508 and 12F675. 226 pages in paperback. A collection of 35 classic magazine articles offering a dependable methodology for designing audio power amplifiers to improve performance at every point without significantly increasing cost. Includes compressors/limiters, hybrid bipolar/FET amps, electronic switching and more. 467 pages in paperback. SMALL SIGNAL AUDIO DESIGN By Douglas Self – First Edition 2010 $95.00* The latest from the Guru of audio. Explains audio concepts in easy-to-understand language with plenty of examples and reasoning. Inspiration for audio designers, superb background for audio enthusiasts and especially where it comes to component peculiarities and limitations. Expensive? Yes. Value for money? YES! Highly recommended. 558 pages in paperback. AUDIO POWER AMPLIFIER DESIGN HANDBOOK by Douglas Self – 5th Edition 2009 $85.00* "The Bible" on audio power amplifiers. Many revisions and updates to the previous edition and now has an extra three chapters covering Class XD, Power Amp Input Systems and Input Processing and Auxiliarly Subsystems. Not cheap and not a book for the beginner but if you want the best reference on Audio Power Amps, you want this one! 463 pages in paperback. DVD PLAYERS AND DRIVES by K.F. Ibrahim. Published 2003. $71.00* OP AMPS FOR EVERYONE By Bruce Carter – 4th Edition 2013 $83.00* This is the bible for anyone designing op amp circuits and you don't have to be an engineer to get the most out of it. It is written in simple language but gives lots of in-depth info, bridging the gap between the theoretical and the practical. 281 pages, PROGRAMMING 32-bit MICROCONTROLLERS IN C By Luci di Jasio (2008) $79.00* Subtitled Exploring the PIC32, a Microchip insider tells all on this powerful PIC! Focuses on examples and exercises that show how to solve common, real-world design problems quickly. Includes handy checklists. FREE CD-ROM includes source code in C, the Microchip C30 compiler, and MPLAB SIM. 400 pages paperback. PRACTICAL GUIDE TO SATELLITE TV By Garry Cratt – Latest (7th) Edition 2008 $49.00 Written in Australia, for Australian conditions by one of Australia's foremost satellite TV experts. If there is anything you wanted to know about setting up a satellite TV system, (including what you can't do!) it's sure to be covered in this 176-page paperback book. NEWNES GUIDE TO TV & VIDEO TECHNOLOGY By KF Ibrahim 4th Edition (Published 2007) $49.00 It's back! Provides a full and comprehensive coverage of video and television technology including HDTV and DVD. Starts with fundamentals so is ideal for students but covers in-depth technologies such as Blu-ray, DLP, Digital TV, etc so is also perfect for engineers. 600+ pages in paperback. RF CIRCUIT DESIGN by Chris Bowick, Second Edition, 2008. $63.00* The classic RF circuit design book. RF circuit design is now more important that ever in the wireless world. In most of the wireless devices that we use there is an RF component – this book tells how to design and integrate in a very practical fashion. 244 pages in paperback. A guide to DVD technology and applications, with particular focus on design issues and pitfalls, maintenance and repair. Ideal for engineers, technicians, students of consumer electronics and sales and installation staff. 319 pages in paperback. See Review March 2010 See Review Feb 2004 SWITCHING POWER SUPPLIES A-Z by Sanjaya Maniktala, Published April 2012. $83.00 Thoroughly revised! The most comprehensive study available of theoretical and practical aspects of controlling and measuring EMI in switching power supplies. ELECTRIC MOTORS AND DRIVES By Austin Hughes & Bill Drury - 4th edition 2013 $59.00* This is a very easy to read book with very little mathematics or formulas. It covers the basics of all the main motor types, DC permanent magnet and wound field, AC induction and steppers and gives a very good description of how speed control circuits work with these motors. Soft covers, 444 pages. AC MACHINES By Jim Lowe Published 2006 $66.00* Applicable to Australian trades-level courses including NE10 AC Machines, NE12 Synchronous Machines and the AC part of NE30 Electric Motor Control and Protection. Covering polyphase induction motors, singlephase motors, synchronous machines and polyphase motor starting. 160 pages in paperback. PRACTICAL VARIABLE SPEED DRIVES & POWER ELECTRONICS Se e by Malcolm Barnes. 1st Ed, Feb 2003. $73.00* Review An essential reference for engineers and anyone who wishes to design or use variable speed drives for induction motors. 286 pages in soft cover. Feb 2003 BUILD YOUR OWN ELECTRIC MOTORCYCLE PRACTICAL RF HANDBOOK by Ian Hickman. 4th edition 2007 $61.00* by Douglas Self 2nd Edition 2006 $69.00* by Carl Vogel. Published 2009. $40.00* A guide to RF design for engineers, technicians, students and enthusiasts. Covers key topics in RF: analog design principles, transmission lines, couplers, transformers, amplifiers, oscillators, modulation, transmitters and receivers, propagation and antennas. 279 pages in paperback. Alternative fuel expert Carl Vogel gives you a hands-on guide with the latest technical information and easy-to-follow instructions for building a two-wheeled electric vehicle – from a streamlined scooter to a full-sized motorcycle. 384 pages in soft cover. *NOTE: ALL PRICES ARE PLUS P&P – AUSTRALIA ONLY: $10.00 per order; NZ – $AU12.00 PER BOOK; REST OF WORLD $AU18.00 PER BOOK PAYPAL (24/7) INTERNET (24/7) MAIL (24/7) PHONE – (9-5, Mon-Fri) eMAIL (24/7) FAX (24/7) To siliconchip.com.au Use your PayPal account www.siliconchip. Call (02) 2010  97 9939 3295 with silicon<at>siliconchip.com.au Your order and card details to Your order to PO Box 139 January Place com.au/Shop/Books silicon<at>siliconchip.com.au Collaroy NSW 2097 with order & credit card details with order & credit card details (02) 9939 2648 with all details Your You can also order and pay for books by cheque/money order (Mail Only). Make cheques payable to Silicon Chip Publications. Order: *ALL TITLES SUBJECT AVAILABILITY. PRICES VALID FOR MONTH MAGAZINE ISSUE ONLY. ALL PRICES INCLUDE GST ALL TITLES SUBJECT TOTO AVAILABILITY. PRICES VALID FOR MONTH OFOF MAGAZINE ISSUE ONLY. ALL PRICES INCLUDE GST ASK SILICON CHIP Got a technical problem? Can’t understand a piece of jargon or some technical principle? Drop us a line and we’ll answer your question. Write to: Ask Silicon Chip, PO Box 139, Collaroy Beach, NSW 2097 or send an email to silicon<at>siliconchip.com.au NiMH cells can charge up to 2V I have built the Fast NiMH Charger featured in the September 2007 issue and I have a question regarding the output voltage. Nowhere in the article does it indicate where one sets the output voltage for the unit. When I hook it up to my NiMH cells it basically charges a 7.2V bank at 12V. It seems to follow all the correct cut-off procedures etc but it still worries me that I am charging the batteries at this level. Any suggestion will be greatly appreciated. (D. B., via email). • The charging voltage depends on charge rate and the amount of cell charge. Typically, the cell voltage can rise to 2V when charging. So for your 7.2V battery with six cells it is normal for the battery to be at 12V while charging. End of charge is detected by the temperature rise. Note that NiMH and Nicad cells are very different to lead-acid batteries where it is the voltage that determines end of charge. Residual voltage in Screecher car alarm I completed the Screecher car alarm kit described in the January 1999 issue of Electronics Australia. The alarm is connected to IN1 to the door switch and is working but I have one issue. There is a residual voltage of 1.7V which lights the LED when the unit is not powered and the doors are closed. Currently the alarm is working with the LED disconnected. Could you please provide me guidance on what could I do to remove this residual voltage and allow me to use the LED as per normal operation for the alarm kit? (C. L., via email). • Try connecting a 4.7kΩ resistor between the base and emitter of transistor Q1, the LED driver. Fast charger will not terminate I am having troubles with the Fast NiMH Charger featured in the September 2007 issue. I am charging four Nicad sub-C cells in a 1.8Ah battery pack. I set up the charger as in the text of the article with a 600mA charge, 1.25V on VR2 and I also tried the 2.5V setting, as recommended. VR1 is at 5V to give five hours and links LK1-2-3 not on. While monitoring the voltage across the battery I can see the peak and its turn down while charging. I also monitored the temperature of the cell with an RTD temperature instrument where the thermistor is fitted. The two readings above were taken every five minutes. The temperature rise was only 3°C in five minutes (at best) but most of the time it was 1°C in five Advice Wanted On HDTV Antenna Installation I have recently purchased a HDTV and need to install an antenna plus cabling. Can you please advise as to what I may need to do an installation, ie, antenna, cabling, terminations etc? I live Canberra. (M. F., Chifley, ACT). • If you presently have good analog TV reception, there is little reason to change your antenna installation. Apart from that, it is not really possible for us to give you detailed 98  Silicon Chip advice on a complete installation, particularly as you may need multiple sockets, splitters and a masthead amplifier and so on. It all depends on your particular requirements. However, we do sell a good reference book which will guide you in choosing the necessary hardware. Called “TV Across Australia”, it is available from SILICON CHIP for $49.95 plus $10 postage and packing. minutes. I terminated the test at a battery temperature of 50°C. Is there something I am missing, eg, does the 55°C stop charging? Or does the 5-hour time limit stop charging? If so, that means the battery will get very hot because at this stage only about 2.5 hours has passed. (F. N., via email). • Charging will stop at 55°C. If the cell temperature rise is less than the dT/dt setting, then the charger will not stop charging until the cell reaches 55°C or the timer times out. Maybe you should set dT/dt to 0.5°C per minute and then it should switch off when charged. You can reduce the timeout period to suit the cells. This will ensure the charger switches off even if the dT/dt detection is not tripped. We presume the cells are 1.8Ah and so the 600mA charge rate is OK. The dT/dt rise for the cells will be higher with a higher charge current. Your 600mA charge current setting does not appear to give sufficient heat rise at the end point. Check that the supply you are using does actually deliver 600mA. Frequency switch controls bike headlight A few months ago I bought a Frequency Switch kit, as published in the June 2007 issue. We mounted it on a motorbike to turn on the headlight at an engine of speed 1000 RPM. The frequency ranges for this kit are 10100Hz (600-6000 RPM) and 50-500Hz (3000-30,000 RPM). We used the first one but in fact engine speed is up to 14,000 RPM and the headlight starts blinking at 6000 RPM. We need a range of 1000-14,000 RPM. Can I adjust trimpot VR2 to set a suitable range (somewhere between first and second)? Or would you advise the use of an additional (locking) relay? (J. V., Estonia). • Adjusting trimpot VR1 should set the unit to cover the range from 100014,000 RPM. You could set the relay to latch when 1000 RPM is reached by connecting the common (COM) terminal of one of the siliconchip.com.au contacts to ground and the normally open (NO) contact to the anode of diode D4. The second contact set of the relay switches the headlight. Digital thermostat wanted I am working on a Ford 1993 NC II Fairlane and I want to install a separate transmission cooler because the radiator cooler is shedding brass fragments. I want a digital/LED temperature gauge and an electronic sender to install in the return pipe from the transmission. I am also looking for an electronic thermostat to switch on a 12V electric cooling fan, preferably in the same circuit. (L. W., Ashbury, NSW). • The High-Temperature Digital Thermometer, as featured in SILICON CHIP’s Performance Electronics for Cars, would do the job. This has an adjustable temperature switch and temperature display and is sold as a kit by Jaycar Electronics (Cat. KC-5376). Note that the temperature probe must be an insulated type as detailed in the article. A non-insulated probe would need to be isolated from the return pipe of the transmission. Ultrasonic cleaners need little explanation I was wondering if it would be possible for SILICON CHIP to do a project on ultrasonic cleaners, as learning while building a project is always the best way to understand the principles involved. (J. G., Doveton, Vic). • There’s really not much to ultrasonic cleaners. Basically you have a stainless steel tank with a piezoelectric transducer epoxied to the bottom. The piezo is fed with a high power ultrasonic signal which passes through the cleaning solution (usually a weak detergent) to shake all the dirt out of the object being cleaned in the tank. However, we will look at the feasibility of doing an ultrasonic cleaner project. Non-contact tachometer wanted for chainsaw Would you consider producing a construction article to make a non contact electronic tacho? My specific requirement is to measure the RPM of a chainsaw where there is no ready access to the spark plug or lead while the siliconchip.com.au Speedo Corrector For A Nissan Patrol I have recently put together the Speedo Corrector from the December 2006 issue and have connected it to a 2000 Nissan Patrol. The initial set-up and validity check works fine and I can get a 1Hz output from the LED using either LK1 or LK2 with S1 at “2” and S2 at “A”. However, if I reposition switch­es S1 & S2 back to “0” I can only get an output at the speedo using LK1 (5V path). Also, I have found that I must utilise LK4 to make the speedo work (no problem with this) but then the speedo bounces, ie, it will give an output for a few seconds before falling away to 0, then come back again. As the speed increases above about 70km/h, the speedo falls away altogether. I cannot get the speedo to give a steady or linear output. I have checked the switched DC input to the Speedo Corrector and confirmed 14.5V (engine running). chainsaw is assembled and running. I imagine it may be feasible to use some form of capacitive coupling to a probe near the spark plug cable and display the RPM on an analog meter without undue complexity or cost. The unit could, of course, be made more versatile by accommodating both 2-stroke, 4-stroke and multi-cylinder motors. (A. G., Bankstown, NSW). • We published a LED Strobe & Tach­ ometer in the August & September 2008 issues. This is directly suited to your application. Running the Mixture Display from 9V I am currently making your Mixture The earth is sound (no resistance) and I have removed the input/output wires from the kit and connected them together via terminal strip to see if the speedo functions as it did. This was OK and proved the wiring connections at the instrument cluster. I also tried introducing the “Lag” correction but this did not solve the problem. I have double-checked the discrete components and solder connections and cannot find an obvious error. Is there any assistance you can provide? (D. O., via email). • Nissans usually require an AC signal for the speedometer. So use LK5 and try the LK1 and LK2 positions for correct running. If that does not work, check the transistor types at Q5 and Q6 and check the polarity orientation for the 100µF capacitor at the collector of Q6. Display kit for fuel-injected cars. I plan to use it on my super kart. Will this kit work with a 9V battery or does it require 12V? I am also looking for a temperature warning light circuit using a thermocouple. Do you have an article that I can download that has the circuit and part list? (J. J., Auckland, NZ). • The Mixture Display will run on 9V. If using a 216 type 9V battery, the display should be set only to dot mode not bargraph, as the current needs to be kept to a minimum. Current drain with dot mode is around 10mA. The High-Temperature Digital Thermometer as published in SILICON CHIP’s Performance Electronics for Cars and also sold as a kit by Jaycar (KC-5376) Why Is The PC Output Not As Loud As A CD Player? Why is it especially noticeable that the sound card output from a PC is not as loud as from a standalone CD player? Both should be putting out line level. I’ve heard this question asked a lot of times and although everyone has theories, most of them don’t hold true. I’m pretty certain that I know the reason but I’d like to hear it from the experts! You probably also have a much better way of explaining it. (C. M., via email). • Typical PC sound cards have a maximum output of 1V instead of 2V RMS as from DVD and CD players. This is a reduction of 6dB and is quite noticeable. January 2010  99 Beam Break Trigger Needs Longer Pulse After constructing the Bream Break Trigger from the June 2009 issue I didn’t have any luck getting it to trigger a camera, either directly or via the photoflash trigger kit. Unless I’m missing something, doesn’t the 10nF coupling capacitor between Q1 and Q2 lead to a time constant of mere microseconds? I didn’t measure the timing beforehand but after doing a rough calculation I placed a 1µF capacitor in parallel with the 10nF capacitor which lead to a trigger time of somewhere in the order of 10ms and all was fine with the photoflash trigger kit. I left it at that because it’s my intention to use it with the trigger kit. However, readers should be aware that some cameras require a longer pulse on their external trigger to fire. For example, my Canon EOS 450D seems to require a minimum duration of about 60ms in manual focus mode – presumably, if the pulse is shorter than the normal shutter lag time, it gets ignored. Other than that, they are a pair of excellent projects can be used without the display and relay. A LED is already included to light at a preset temperature. Mods for bass guitar preamplifier I was wondering if you have published a design for a bass guitar preamp or would it be possible to modify an existing guitar kit (like the 2-channel guitar preamp) to make the tone controls more suitable for a bass guitar and possibly add a 20Hz cut-off filter? (N. C., via email). • The 2-channel Guitar Preamplifier from November 2000 can be modified to suit a bass guitar. A 20Hz high-pass filter can be added by changing the 2.2µF capacitor ahead of the 10kΩ level potentiometer (VR1) to 820nF (0.82µF). Steeper roll-off can be included by changing the 2.2µF capacitor at pin 1 of IC1b to 820nF. The tone controls can be altered for responses at about 35Hz for Bass, 100Hz for Mid and 1kHz for Treble. For the Bass control, the 0.015µF (15nF) capacitor across VR2 is changed to 100  Silicon Chip and I am looking forward to exploring the possibilities they offer. (P. J., Lutana, Tas). • You are correct in that the effective trigger pulse width from the Beam Break Trigger will be only a little over 110µs, as determined by the 10nF capacitor and the total resistance of 11.1kΩ in the charging circuit. The pulse was actually made this short to prevent multiple triggering of the Time Delay Trigger published in the February 2009 issue. However, if you want to use the Beam Break Trigger to trigger a camera directly, that pulse width will be too narrow – as you have pointed out. Your remedy of increasing the capacitor value from 10nF to 1µF is fine but if this does not give sufficient lengthening of the trigger pulse for some cameras, the resistor from the gate of Q2 to ground can also be increased in value from its present value of 10kΩ. It could be increased to 22kΩ, 47kΩ or even 100kΩ if a much longer pulse is needed. 22nF. The .0027µF (2.7nF) capacitor across VR3 for the Mid control is changed to 27nF and the .012µF (12nF) at VR3’s wiper is changed to 120nF. The Treble control is changed with the .0015µF (1.5nF) capacitor at VR4’s wiper becoming 15nF. The same changes apply to channel 2. Beam Break Trigger should be more sensitive Having built both the Time Delay PhotoFlash Trigger & the Beam-Break Flash Trigger, I am wondering if the Break Beam trigger can be made more sensitive? The unit works very well but it will not detect water droplets falling past the sensor (although larger, heavier objects are no problem). If this is not possible, could your team look at another add-on photo gate trigger? I believe a Schmitt trigger works better for fast-moving objects such as droplets (B. C., Jewells, NSW). • We suspect that the main reason why the beam break trigger is not detecting water droplets is because the IR beam from the three LEDs in the IR light source is somewhat wider than the drops. As a result, the drops are not able to cause a significant decrease in the detected IR level as they pass through the beam. If this is the case, you may be able to achieve better operation by trying one or more of these ideas: (1) Turn the light source box on its side, so the beam will be wider in the vertical plane than in the horizontal plane. (2) Remove the two side IR LEDs, leaving just the centre one to provide a narrower and relatively circular beam. Note, however, that if you do this, the LEDs you remove will need to be replaced with wire links to complete the circuit. It would also be a good idea to replace the 820Ω series resistor with a 1kΩ resistor, to limit the current drawn by the single remaining LED. (3) Try cementing a short “beam confining tube” to the front of the IR light source, like the one on the front of the detector box. It should be of brass and preferably with its interior polished. (4) Try to place the IR input tube of the detector box as close as possible to the axis of the falling drops, so the drops will have maximum impact on the IR radiation entering the tube. (5) Try adding a small amount of coloured dye to the water source for the drops, so they’ll be less transparent to IR radiation. Measuring audio power with Energy Meter I am wondering if it is possible to modify the Appliance Energy Meter (SILICON CHIP, July & August 2004) so it can measure audio power through a resistive load? (G. M., via email). • It is possible. First, the voltage inputs connecting pins 6 & 7 of IC1 to the mains supply (via 2.2MΩ and 1kΩ resistor dividers) would need to be disconnected from the mains supply and connected instead to the amplifier output. Similarly, the current measurement resistors R1 and R2 (going to input pins 4 & 5 of IC1) would need to be disconnected from the mains and connected so that the amplifier load current flowed through the sense resistor, R1. Running the Luxeon Star Power from 6V I have put together a Luxeon Star Power kit and it is being used with siliconchip.com.au Notes & Errata LOCATING LUG UNDER IDC LINE CONNECTOR (MAIN BOARD END) LOCATING LUG 16-WAY IDC CABLE Above: here’s how to make the 16-way IDC cable for the OneOf-Nine Switch Position Indicator described in December 2009. One-of-Nine Switch Position Indicator, December 2009: the righthand and bottom sides of the diagram on page 35 were cropped off, omitting vital information on the IDC cable. A full diagram of the IDC cable, showing how the IDC line sockets are fitted, is shown above. Wideband Controller Pt.2, October 2009: under Step 13 on page 77, the article states that “The voltage between TP7 and TP GND should be 2.5V”. This sentence should refer to TP1, not TP7. pin 7 of IC1b should be connected between pins 7 & 6 of that IC; and (2) the 470Ω resistor in series with ZD4 should be connected to V+ instead of V++ (ie, after the 10Ω resistor). The PC board and parts layout diagram (Fig.5, January 2010) are correct. There are also several errors in the parts list: ZD2 should be a 15V 1W zener diode; ZD4 should be a 5.6V 1W zener diode; there should be six PC stakes (not five); and there should be seven 10nF MKT polyester capacitors (not six). Voltage Interceptor For Cars With ECUs, December 2009: there are two errors on the circuit diagram – (1) the 10nF capacitor connected to Web Server In A Box; December 2009: there is an error in the IP addressing shown on Fig.9(b) on page 84. The addressing scheme shown a 5W Luxeon. It works well but the question is, is the 7.5V on the circuit board an input or output? I would like to run the system on about 6V so I can use D-cell rechargeable batteries. Are there mods I can do or is there another kit? (E. P., via email). • The 7.5V is regulated from the 12V supply and is required for the low-voltage comparator (IC2a) and its reference. The main power required ranges from 11.5-17V. If you want to run it from 6V, then the circuit should work for a single LED but not for two LEDs in series. ZD1, the 7.5V zener diode, should be removed and the 750Ω resistor from diode D2 replaced with a wire link. You can stop the low IDC LINE CONNECTOR (DISPLAY END) will not work because a router will only forward packets between different networks (eg, from 192.168.0.x to 192.168.1.x on a class C network and vice versa). This means that we must use IPs for two different networks on either side of the router, eg, use 192.168.1.1 for the Ethernet port on the modem, 192.168.1.2 on the modem port on the router and leave the switch (or LAN) side of the router at 192.168.0.1. Alternatively, you could assign 10.0.0.1 to the modem, 10.0.0.2 to the modem port on the router and stick with 192.168.0.1 for the LAN side of the router. A corrected diagram is shown in Pt.3 of the WIB on page 87 of this issue. voltage comparator from switching off the circuit by removing link JP1. Flickering flame kit runs from batteries I have the Flickering Flame kit from Jaycar and was wondering how it is . . . continued on page 103 WARNING! SILICON CHIP magazine regularly describes projects which employ a mains power supply or produce high voltage. All such projects should be considered dangerous or even lethal if not used safely. Readers are warned that high voltage wiring should be carried out according to the instructions in the articles. When working on these projects use extreme care to ensure that you do not accidentally come into contact with mains AC voltages or high voltage DC. If you are not confident about working with projects employing mains voltages or other high voltages, you are advised not to attempt work on them. Silicon Chip Publications Pty Ltd disclaims any liability for damages should anyone be killed or injured while working on a project or circuit described in any issue of SILICON CHIP magazine. Devices or circuits described in SILICON CHIP may be covered by patents. SILICON CHIP disclaims any liability for the infringement of such patents by the manufacturing or selling of any such equipment. SILICON CHIP also disclaims any liability for projects which are used in such a way as to infringe relevant government regulations and by-laws. Advertisers are warned that they are responsible for the content of all advertisements and that they must conform to the Trade Practices Act 1974 or as subsequently amended and to any governmental regulations which are applicable. siliconchip.com.au January 2010  101 MARKET CENTRE Cash in your surplus gear. Advertise it here in SILICON CHIP ELNEC IC PROGRAMMERS High quality Realistic prices Free software updates Large range of adaptors Windows 95/98/Me/NT/2k/XP C O N T R O L S Tough times demand innovative solutions! VIDEO - AUDIO - PC distribution amps - splitters digital standards converters - tbc's switchers - cables - adaptors genlockers - scan converters bulk vga cable - wallplates DVS5c & DVS5s High Performance Video / S-Video and Audio Splitters CLEVERSCOPE USB OSCILLOSCOPES 2 x 100MSa/s 10bit inputs + trigger 100MHz bandwidth 8 x digital inputs 4M samples/input Sig-gen + spectrum analyser Windows 98/Me/NT/2k/XP Made in Australia, used by OEMs world-wide splat-sc.com QUEST ® Quest AV® IMAGECRAFT C COMPILERS ANSI C compilers, Windows IDE AVR, TMS430, ARM7/ARM9 68HC08, 68HC11, 68HC12 MD12 Media Distribution Amplifier VGA Splitter VGS2 HQ VGA Cables MARKET CENTRE 1 AWP1 A-V Wallplate GRANTRONICS PTY LTD Come to the specialists... www.grantronics.com.au ® QUESTRONIX ® Quest Electronics Pty Limited abn 83 003 501 282 t/a Questronix FOR SALE RCS RADIO/DESIGN is at 41 Arlewis St, Chester Hill 2162, NSW Australia and has all the published PC boards from SC, EA, ETI, HE, AEM & others. Ph (02) 9738 0330. sales<at>rcsradio.com. au; www.rcsradio.com.au SHIELDED (SCREENED) ROOM: 2.5-metres cube, Belling-Lee type TA3. Dismantled in Auckland ready for shipping, $2000. Contact +64 9 811 8990 or stuar37<at>attglobal.net LEDs! Nichia, Cree and other brand name LEDs at excellent prices. LED drivers, including ultra-reliable linear driver options. Many other interesting and hard-to-find electronic items! www.ledsales.com.au PCBs MADE, ONE OR MANY. Any format, hobbyists welcome. Sesame Electronics Phone (02) 9593 1025. sesame<at>sesame.com.au www.sesame.com.au AC~DC SERVICE MANUALS www. acdcmanuals.com – thousands of downloadable service manuals for most brands and models including CTV, DVD, LCD, Plasma, VCR, Dryers, Fridges, Vacuum Cleaners, Vintage Radio, Washing Machines and many more. The must CLASSIFIED ADVERTISING RATES Advertising rates for these pages: Classified ads: $29.50 (incl. GST) for up to 20 words plus 85 cents for each additional word. Display ads: $54.50 (incl. GST) per column centimetre (max. 10cm). Closing date: 5 weeks prior to month of sale. To book your classified ad, email the text to silicon<at>siliconchip.com.au and include your name, address & credit card details, or fax (02) 9939 2648, or phone (02) 9939 3295. 102  Silicon Chip Products, Specials & Pricelist at www.questronix.com.au fax (02) 4341 2795 phone (02) 4343 1970 email: questav<at>questronix.com.au have website for all Techs, Electricians and Restorers! KIT ASSEMBLY KEITH RIPPON KIT ASSEMBLY & REPAIR: * Australia & New Zealand; * Small production runs. Phone Keith 0409 662 794. keith.rippon<at>gmail.com WANTED WANTED: EARLY HIFIs, AMPLIFIERS, Speakers, Turntables, Valves, Books, Quad, Leak, Pye, Lowther, Ortofon, SME, Western Electric, Altec, Marantz, McIntosh, Tannoy, Goodmans, Wharfedale, radio and wireless. Collector/ siliconchip.com.au Ask SILICON CHIP – continued OzComfile BASIC and LADDER Multi-Tasking Processor Development Software FREE to all customers Proto Boards-Starter kits – TOUCHSCREENS CE TOUCHSCREENS – 7”, 10” & 15” And more! Industrial quality December Special Start Kit 220: $140.00 www.ozcomfile.com.au Start Kit 220 Distributors for Comfile Technology at for Australian KitStop 3cm Ads gazine 2010 Battery Packs & Chargers Siomar Battery Engineering www.batterybook.com Phone (08) 9302 5444 Modules 537 Kits, and Boxes 3” 5” 7” Innovative & affordable projects for hobby, school & industry Shop on-line at: www.kitstop.com.au electronics-the fun starts here 9” Super Bright Displays January 2010 Silicon Chip Binders $14 REAL VALUE AT Stop your issues getting dog-eared .95 PLUS P &P Modules 537 Kits, and Boxes Price: $A14.95 plus $A10.00 p&p per order (inc GST). Buy five and get them postage free. Available in Australia only. Call (02) Innovative & affordable 9939 3295 quote your credit card number. projects for&hobby, school & industry Shop on-line at: 30 Amp 12/24V PWM www.kitstop.com.au Hobbyist will pay cash. (07) 5471 1062. electronics-the fun starts here johnmurt<at>highprofile.com.au February 2010 CUSTOMERS WANTED: Truscotts Electronic World – large range of semiconductors and passive components for industry, hobbyist and amateur projects including Drew Diamond. 27 The Mall, South Croydon, Melbourne. Phone (03) Stop Watch, Kits, Modules Clock & 9723 3860. andsales<at>electronicworld. Boxes Timer com.au Innovative & affordable to 537 projects for hobby, siliconchip.com.au school & industry Shop on-line at: www.kitstop.com.au electronics-the fun starts here 0.01 sec Jacobs Ladder used as gas igniter We are currently using your Jacobs Ladder Mk.1 version (SILICON CHIP, September 1995) as a substitute highenergy igniter for a small gas turbine and have been reasonably pleased with the results for static testing. However, we require the spark to be of a higher intensity (hotter and fatter) for our application to properly function, plus we only need it to fire a couple of times a second, although it would be immaterial if the spark were increased in intensity. We also note that the Mk.1 version has been superseded by the bulkier Mk.2 version (SILICON CHIP, April 2007) that we have yet to try, only because the weight of the unit with the larger, heavier Commodore coil, makes it unsuitable for our application. So can we get more “grunt” from the unit to get a hotter spark and reduce the number of “firings” and can we use a coil of the same configuration as the Mk.1 uses in the Mk.2? We have been able to utilise a small motorcycle coil with our Mk.1 . . . continued from page 101 powered and where I can purchase that item from? Also, does the lamp base have negative and positive leads or are they unpolarised? (P. G., via email). • The Flickering Flame can be powered from any 12V DC source capable of supplying enough current for the light use. A 12V 20W halogen lamp was specified, so any source capable of delivering 2A would be fine – either a battery or a plugpack supply. The prototype used a supply made up from six 2V 5A SLA cells connected in series. Finally, halogen lamps are not polarised. Quiz game with logging I’d like to build a quiz show console for kids that has three to four buzzers – think Sale of the Century. I’d like unit, which places it in a weight and size category we can handle. (A. R., Dandenong, Vic). • Both versions of the Jacobs Ladder arrangements are the same, especially in the way the 555 timer works, and this is where changes are required. For two sparks per second replace the 330nF capacitor at pins 2 and 6 of IC1 (the 555 timer) with a 1µF MKT polyester. The resistor between pin 7 and the pin 8 supply should be 470kΩ. The resistor between pins 2 and 6 and to pin 7 can be changed to a value of 5.6kΩ. This value sets the “dwell” (or coil charging period) and can be adjusted to set the spark intensity. A larger value will increase the dwell period and so provide a greater spark. For some coils, the nominal 4ms dwell may be too long, causing heating in the coil. If so, the 5.6kΩ resistor can be decreased in value to reduce the dwell so that the coil does not heat up but still delivers the required spark intensity. You can use a motorcycle coil in the circuit instead of the Commodore coil. to get the output of the first buzzer pushed into a computer so I can log scores, depending on if they get the correct answer. I haven’t been able to find anything on the market that can do this or any circuit diagrams. Do you have any suggestions on how this could be built and how I can get around problems such as buzzer bounce? (P. M., via email). • We have published many quiz game circuits, in April 1988, April 1998, January 1990, July 1991, November 1991, December 1991, July 1993, March 1994 and December 2004. Each have an output that is latched when the first button is pressed. So a computer could monitor the latched output rather than the actual pushbutton. This would avoid the problem with switch contact bounce etc. We have not published a computerSC based adjudicator for games. January 2010  103 Do you eat, breathe and sleep TECHNOLOGY? Opportunities exist for experienced Sales Professionals & Store Management across Australia & NZ Jaycar Electronics is a rapidly growing, Australian owned, international retailer with more than 60 stores in Australia and New Zealand. Due to our aggressive expansion program we are seeking dedicated sales professionals to join our retail team to assist us in achieving our goals. We pride ourselves on technical expertise from our staff. Do you think that the following statements describe you? Please put a tick in the boxes that do:  Knowledge of core electronics, particularly at a component level  Retail experience, highly regarded  Assemble projects or kits yourself for your car, computer, audio etc  Have energy, enthusiasm and a personality that enjoys helping people  Opportunities for future advancement and development  Why not do something you love and get paid for it? Please email us your applicaton & CV in PDF format, including location preference. We offer a competitive salary, sales incentive and have a generous staff purchase policy. Applications should be emailed to jobs <at> jaycar.com.au Jaycar Electronics is an Equal Opportunity Employer & actively promotes staff from within the organisation. Advertising Index AC-DC Service Manuals............... 102 Active Components......................... 59 Alternative Technology Assoc........... 7 Altronics..................................... 74-77 Amateur Scientist CDs.................. IBC Aust. Valve Audio Transformers..... 102 Dick Smith Electronics............... 26-27 Emona Instruments........................... 5 Grantronics................................... 102 High Profile Communications........ 102 Instant PCBs................................. 102 Jaycar............................IFC,49-56,104 Keith Rippon................................. 102 Kitstop........................................... 103 LED Sales..................................... 102 Little Bird Electronics...................OBC Marque Magnetics.......................... 65 MicroZed Computers...................... 11 Ocean Controls................................. 6 OzComfile..................................... 103 PCBCART......................................... 7 PCBCORE...................................... 11 into RF? DOWNLOAD OUR CATALOG at www.iinet.net.au/~worcom There’s something to suit every radio frequency fan in the SILICON CHIP reference bookshop RF Circuit Design – by Chris Bowick A new edition of this classic RF design text - tells how to design and integrate RF components into virtually any circuitry. $ 75 Practical RF H’book WORLDWIDE ELECTRONIC COMPONENTS PO Box 631, Hillarys, WA 6923 Ph: (08) 9307 7305 Fax: (08) 9307 7309 Email: worcom<at>iinet.net.au Silicon Chip Circuit Ideas Wanted Do you have a good circuit idea? If so, sketch it out, write a brief description of its operation & send it to us. Practical Guide To Satellite TV Provided your idea is workable & original, we’ll publish it in Circuit Notebook & you’ll make some money. We pay up to $100 for a good circuit idea or you could win some test gear. 49 You’ll find many more technical titles in the SILICON CHIP reference bookshop – see elsewhere in this issue 104  Silicon Chip RCS Radio.................................... 102 RF Modules................................... 104 RF Power........................................ 15 Roland DG Australia....................... 39 ScreenScope (Diamond Systems).... 3 – by Ian Hickman A reference work for technicians, engineers, students and the more specialised enthusiast. Covers all the key topics in RF that you $ need to understand 90 – by Garry Cratt The reference written by an Aussie for Aussie conditions.Everything you need to know. $ Quest Electronics.......................... 102 Silicon Chip Publications, PO Box 139, Collaroy, NSW 2097. Sesame Electronics...................... 102 Silicon Chip Binders...................... 103 Silicon Chip Bookshop............... 96-97 Silicon Chip Order Form................. 67 Silicon Chip Subscriptions.............. 41 Siomar Battery Industries............. 103 Soundlabs Group.............................. 9 Splat Controls............................... 102 Truscotts Electronic World............. 103 Wagner Electronics......................... 61 WiFi Products.................................. 65 Worldwide Elect. Components...... 104 PC Boards Printed circuit boards for SILICON CHIP designs can be obtained from RCS Radio Pty Ltd. Phone (02) 9738 0330. Fax (02) 9738 0331. siliconchip.com.au STIC FANTAIDEA GIFT UDENTS FOR SFT ALL O S! AGE THEAMATEUR SCIENTIST An incredible CD with over 1000 classic projects from the pages of Scientific American, covering every field of science... NEW VERSION 4 – JUST RELEASED! GET THE LATEST VERSION NOW! Arguably THE most IMPORTANT collection of scientific projects ever put together! This is version 4, Super Science Fair Edition from the pages of Scientific American. As well as specific project material, the CDs contain hints and tips by experienced amateur scientists, details on building science apparatus, a large database of chemicals and so much more. ONLY 62 $ 00 PLUS $10 Pack and Post within Australia NZ P&P: $AU12.00, Elsewhere: $AU18.00 “A must for every science student, science teacher, science lab . . . or simply for those with an enquiring mind . . .” Just a tiny selection of the incredible range of projects: ! Build a seismograph to study earthquakes ! Make soap bubbles that last for months ! Monitor the health of local streams ! Preserve biological specimens ! Build a carbon dioxide laser ! Grow bacteria cultures safely at home ! Build a ripple tank to study wave phenomena ! Discover how plants grow in low gravity ! Do strange experiments with sound ! Use a hot wire to study the crystal structure of steel ! Extract and purify DNA in your kitchen !Create a laser hologram ! Study variable stars like a pro ! Investigate vortexes in water ! Cultivate slime moulds ! Study the flight efficiency of soaring birds ! How to make an Electret ! Construct fluid lenses ! Raise butterflies as experimental animals ! Study the physics of spinning tops ! Build an apparatus for studying chaotic systems ! Detect metals in air, liquids, or solids ! Photograph an ant's brain and nervous system ! Use magnets to make fluids into solids ! Measure the metabolism of an insect . . . ! and many, many more (a thousand more, in fact!) See the V2 review in SILICON CHIP, October 2004. . . or read on line at siliconchip.com.au This is the ALL-NEW Version 4 . . . it’s even BETTER! HERE’S HOW TO ORDER YOUR COPY: BY PHONE:* (02) 9939 3295 9-5 Mon-Fri BY FAX:# <at> (02) 9939 2648 24 Hours 7 Days BY EMAIL:# silicon<at>siliconchip.com.au 24 Hours 7 Days BY MAIL:# BY PAYPAL:# PO Box 139, Collaroy NSW 2097 silicon<at>siliconchip.com.au 24 Hours 7 Days * Please have your credit card handy! # Don’t forget to include your name, address, phone no and credit card details. BY INTERNET:^ siliconchip.com.au 24 Hours 7 Days ^ You will be prompted for required information There’s also a handy order form inside this issue. Exclusive in SILICON Australia to: CHIP siliconchip.com.au siliconchip.com.au January 2010  105