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SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings.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 www.siliconchip.com.au Vol.19, No.2; February 2006 FEATURES    8 Review: Epson EMP-TWD1 LCD Projector Looking for an all-in-one LCD projector and DVD player with stereo speakers? The Epson EMP-TWD1 really is a clever box of tricks – by Barrie Smith 12 Electric-Powered Model Aircraft Model aeroplanes powered by Li-PO batteries are taking over from noisy models powered by internal combustion engines – by Bob Young Electric-Powered Model Aircraft – Page 12. 42 Do-It-Yourself Electronic Servicing Some useful hints and tips but you need some basic test gear – by David Reid 72 ZigBee: The New Wireless Standard Move over Bluetooth, move over Wifi, ZigBee is on the way – by Stan Swan PROJECTS TO BUILD PC-Controlled Burglar Alarm – Page 26. 26 PC-Controlled Burglar Alarm System Fancy a fully-featured alarm control panel with dialler capabilities? This unit is PC-programmed and can control eight zones – by Trent Jackson 36 Build A Charger For iPods & MP3 players This clever unit lets you charge your iPod or MP3 player without connecting it to your PC’s USB port – by John Clarke 62 PICAXE-Powered Thermostat & Temperature Display It’s extremely simple, has a 3-digit LED display and comes in three versions – by Michael Jeffery 74 Adding Infrared To Your Microbric Viper Make your Viper run hands-free with this simple add-on – by Ross Tester Charger For iPods And MP3 Players – Page 36. 78 Build A MIDI Drum Kit; Pt.4 Installing and running the software – by John Clarke 88 Building The Ultimate Jukebox; Pt.3 Final article shows you how to build and install the electronics. What a blast! – by Ross Tester SPECIAL COLUMNS 48 Serviceman’s Log Metz TVs and car engine management – by the TV Serviceman 66 Circuit Notebook (1) Morse Code Identification Unit; (2) Automatic Soldering Iron Controller; (3) Improved Speed Sensor 94 Salvage It! Making an adjustable loud screamer – by Julian Edgar 98 Vintage Radio Brian Lackie’s wireless museum – by Rodney Champness DEPARTMENTS   2   4 61 96 Publisher’s Letter Mailbag Order Form Product Showcase siliconchip.com.au 104 107 110 112 Ask Silicon Chip Notes & Errata Market Centre Ad Index PICAXE-Powered Thermostat And Temperature Display – Page 62. February 2006  1 SILICON CHIP www.siliconchip.com.au Publisher & Editor-in-Chief Leo Simpson, B.Bus., FAICD Production Manager Greg Swain, B.Sc.(Hons.) Technical Editor Peter Smith Technical Staff John Clarke, B.E.(Elec.) Ross Tester Jim Rowe, B.A., B.Sc, VK2ZLO Reader Services Ann Jenkinson Publisher’s Letter Most home theatre systems are not worth watching There is no doubt that if it wasn’t for the booming sales of plasma TV sets and home theatre systems, most electrical retailers would be having a difficult time. But while plasma and rear projection TV sales are going through the roof, one has to wonder whether the buyers realise that they are getting an inferior result; they are spending many thousands of dollars in setting up home theatre systems but the “home theatre” experience is anything but. For a start, how many cinemas have you been to where you could obscure the entire screen by holding your hand 30cm in front of your face? Advertising Enquiries Lawrence Smith Benedictus Smith Pty Ltd Phone (02) 9211 8035 Fax: (02) 9211 0068 lawrence<at>benedictus-smith.com For a real home cinema experience, you must have a large screen, not something only a metre or so wide. By large, I mean a screen three or four metres wide. If the picture occupies most of one end of your viewing room, so much the better. You want a BIG picture; nothing else will give you the visual impact that you get in a real theatre. Have a look at page 8 of this issue – that’s a reasonably large picture in an admittedly very large room. Regular Contributors Brendan Akhurst Rodney Champness, VK3UG Julian Edgar, Dip.T.(Sec.), B.Ed, Grad.Dip.Jnl Mike Sheriff, B.Sc, VK2YFK Stan Swan You cannot get that sort of picture from any current plasma or LCD TV, either now and probably never. The only way to get it is to purchase an LCD or DLP projector. Now you might think that is impractical but the fact is that you can buy one of the best currently available high-definition LCD projectors, the Panasonic PT-AE900E, for substantially less than the price of many standard definition plasma and rear projection TV sets. 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 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: $83.00 per year in Australia. For overseas rates, see the subscription page in this issue. Editorial office: Unit 8, 101 Darley St, Mona Vale, NSW 2103. Postal address: PO Box 139, Collaroy Beach, NSW 2097. Phone (02) 9979 5644. Fax (02) 9979 6503. E-mail: silchip<at>siliconchip.com.au This sort of projector will provide a visual experience and picture quality which is even better than your local cinema. In fact, let’s not beat around the bush; the picture quality in many cinemas is downright poor compared with the picture quality that can already be obtained from the above projector and a good-quality DVD player with a “component video” or HDMI (high definition multimedia interface) connection. When high-definition DVD players arrive within the next year or so, the picture quality will be even better. Admittedly, there are some drawbacks. Typically, LCD and DLP projectors can only be used in a darkened room (we used our “photographer’s licence” in taking the photo on page 8 – the room was not that well-lit). And replacing the special high pressure mercury lamp in a typical LCD projector is very expensive – something you will need to do every couple of thousand hours or so. Nor would you want to watch normal TV programs with such a setup. In truth though, most TV programs are not worth watching in any format! So when you wander past all those fancy bright plasma and LCD TV sets in your local electrical retailer, don’t be tempted to buy or at least, not yet. Remember, they will continue to get cheaper and high-definition DVD players are coming soon, to render any standard definition set obsolete. But if you hanker for a real home-theatre experience, go to a retailer who can demonstrate high-definition LCD and DLP projectors right now. Anything else is going to be forgettable. Leo Simpson ISSN 1030-2662 * Recommended and maximum price only. 2  Silicon Chip siliconchip.com.au Innovative • Unique • Interesting • Hard to find products Cordless Bluetooth Barcode Scanner This cordless CCD scanner uses Bluetooth technology for reliable & accurate performance. Comes with Bluetooth dongle. Requires AA batteries (not included) Cat 1008178-7 $699 VGA Splitter/Booster Dual ADSL Router A powered VGA splitter that can run the second monitor up to 80m from the PC. Cat 3445-7 $199 Enhance reliability and double your ADSL capacity by using two different ISP's. Cat 10145-7 $214 Cordless Skype and Standard Phone What’s New? Pentium 4 with ISA Now supports LGA 775 CPUs! This industrial motherboard is based on the Intel i915G chipset. It supports LGA 775 Prescott processors and has 1 PCI Express x16, 1 PCI Express x1, 3 PCI, and 2 ISA slots. Cat 17096-7 $699 Broadband Video Phone No PC Needed! This cordless phone works with Skype Extend USB and can be used as a standard phone. 50m Cat 10172-7 Dualphone $199 Use inexpensive network Cat 10173-7 Extra handset $107 cable (not included) to extend any USB 1.1 device up to 50m from a PCMCIA PC. Cat 11666-7 $99 Dual Slot SMS I/O Controller Switch any electrical device on or off using SMS from any mobile phone. Cat 17087-7 $979 Connect a standard telephone & a television to the VideoPhone, plug in a standard Ethernet network cable connected to your broadband Internet connection & you are ready to conduct real-time video conferencing! Cat 10181-7 $499 Mini Personal Data Collector (MPDC) Stores up to 1000 barcodes The MPDC offers a portable scanning solution that includes the functionality of larger, bulkier units and features a 64 character LCD, Serial Interface and rechargeable batteries. Cat 9286-7 $399 for PC This Dual Slot PCMCIA adapter for PC allows a PCMCIA device to be used in a PC. The two built-in PCMCIA sockets in the 3.5" front Drive Unit connect to the PCI Interface Card. Cat 6482-7 $199 This unit allows the user to remotely control 7 Digital I/O ports and 1 RS232/422/485 port over LAN or WAN. Cat 15157-7 $329 Cordless Pen Mouse This cordless pen mouse is ideal for use in confined areas where a normal mouse cannot be used. It features a USB interface with a transmission distance up to 10m, and has a rechargeable battery. Cat 9287-7 $107 VGA Extender Extend VGA up to 130m over inexpensive STP cable. Cat 3441-7 $399 These devices allow Ethernet to go between rooms using a Cardbus to 240v wall socket. Easily RS422/485 share your broadband connection! Two units come Add RS422/485 ports to any in the box. laptop with this dual port card. Cat 11476-7 $199 Cat 2999-7 $329 This unique unit will allow a serial connection to become wireless using Blue Tooth. Cat 11920-7 $459 Not sure what product you require? Call us for friendly advice! Video to VGA Display any Composite or S-Video signal onto a CRT monitor. Cat 3479-7 $199 ask<at>mgram.com.au 1800 625 777 Digital & Analogue TV Tuner A unique TV tuner card that can receive the older Analogue transmissions and newer DVBT digital TV transmissions. Cat 3567-7 $199 www.mgram.com.au PCMCIA to Serial Add two serial ports to your notebook. Cat 2726-7 $269 USB Temp and Humidity Sensor IP KVM Attach this unit to any Control Multiple PCs with one console existing KVM and access (keyboard, mouse and monitor). all your machines Cat 11654-7 Two Way (shown above) $79 remotely with a web Cat 11655-7 Four Way $129 browser to a BIOS level. Cat 11656-7 Eight Way $449 Cat 11674-7 $899 Cat 11657-7 Sixteen Way $799 Sharp Cash Register A basic cash register that is suitable for small retail outlets. Cat 1008129-7 $289 EPROM Programmer This programmer connects to the LPT port and has a 32 pin ZIF socket. It will program from 16k to 8M. Cat 3159-7 $479 Measures the relative humidity and temperature and can graph the results on the included software. Cat 17090-7 $319 Dealer inquiries welcome Console Sharer Allows two workstations to operate the one PC. Supports PS/2 keyboard and mouse with VGA monitor. Cat 11667-7 $139 1800 625 777 ask<at>mgram.com.au www.mgram.com.au February All prices subject to change without notice. For current pricing visit our website. Pictures are indicative only. 2006  3 SHORE AD/MGRM0206 Compact 88 key keyboard with an integrated touch pad pointing device. It has two PS/2 connections for mouse and keyboard. Cordless model available. Cat 8751-7 $139 siliconchip.com.au Serial over Bluetooth • Normally delivered next day • Mini Keyboard with Touchpad KVM Switches Ethernet over Power Digital I/O to Ethernet MAILBAG Tribute to Ray Kelly I was most impressed by the article by Rodney Champness in the Vintage Radio section of the December 2005 issue. What a marvellous statement of historical facts on the efforts and background of Ray Kelly of the Historical Radio Society of Australia, and the creation of the HRSA. The detailed article is a tribute to a marvellous and gentle man with the foresight to realise the importance of radio, both as a part of our lives and as a technical, manufacturing and broadcasting enterprise in the development sense of Australia’s radio heritage. Ray was able to retain at least some of the finer examples of our radio history (the physical items and a plethora of printed data) before it was relegated to the many local tips. Because of the efforts of Ray and a small number of others, we all have a very clear and ongoing focus on Australia’s radio history. The article serves as a wonderful and timely tribute to Ray, as Member Number 1 of the HRSA. Sadly, as noted in last month’s issue, Ray Kelly passed away on Saturday, 19th November 2005. Graeme Dennes, via email. Nuclear power: we just need to wise up In regards to your Publisher’s Letter in the January 2006 for expansion of Australia’s nuclear power program, I’m sorry to say, as you probably are aware, it’s a foregone conclusion. Here in South Australia, the large expansion of Olympic Dam mine will ensure that. Maybe you should visit that site and have a drink of the water, after another recent incident. It’s easy to see fission nuclear power inevitably costs more, because an extremely dangerous product must be safely extracted, used, transported and contained following use for an indefinite period of time. And there is also the cost of storing large sections of future decommissioned plant. 4  Silicon Chip Worse still, all this will happen here, against the will of the majority. There is plenty of free SAFE energy from nuclear power below the Cooper Basin and Hunter Valley regions to name a few – several thousand times the amount we need to power this continent. We just need to wise up and get it. Jeff Peate, via email. Nuclear power has too many problems Your editorial about nuclear power in the January 2006 issue was as hot as the weather we are inflicting on ourselves. Yes we do need to come up with solutions to our growing consumption of power and resources. What we need is careful consideration of our options, not adherence to the “big toys for big boys” syndrome – especially a 50-year old relic that is still floundering with unending problems: public subsidy, (non) waste disposal, decommissioning and the enormous human tragedy of accidents like Chernobyl. The disposal in the NT you refer to is for low-level radioactive waste, such as medical, industrial and now consumables such as smoke detectors, which has been accumulating since the 1950s. It is not geared for reactor waste as you intimate in your editorial. The design approach is simply trenches in the ground. Paranoid? Yes and justly so, when someone with your position so happily expounds on a subject which you obviously have scant knowledge of. “There is no operational pollution”. Really, please explain what happens to the radioactive gases routinely vented from reactors. There are no known methods for sequestering these, in particular the inert gas isotopes. There are alternative options already available and working. As you say, solar and wind may only make up 20% of the mix. The salient point is they don’t yet. One simple policy change, deregulating the electricity market to allow individual homes to sell their excess power (as in Germany where their solar industry is now ten times Australia’s) could offset airconditioning demand, for example. At present, utilities give power credits to grid-interactive systems! Intelligence not gumption is called for. Rory Shannon, Goongerah, Vic. Comment: nuclear power stations do not routinely vent radioactive gases. And yes, Australia could do much more to use solar and wind power and be much more efficient in energy use. But we still need more power stations. BPL is bad technology Paul Budde’s comments on BPL in the January 2006 issue demonstrate only that he doesn’t have the foggiest idea about HF propagation. You cannot defeat the laws of physics. If you inject RF into unshielded wiring at ANY power level, you WILL create interference with wireless services using the same spectrum. That’s it, end of story. I don’t know where he gets 500,000 potential users from either. If he thinks it will be competitive to deploy BPL in areas where wireless or ADSL (forget cable) are not feasible, he had better do the sums again. Even if only 1% of broadband is supplied by BPL in this country, it could still make enough RF noise to make large sections of valuable spectrum unusable or greatly impaired for 1000s of kilometres. He mentions that it is deployed in many places, one of them Asia; carefully omitting the fact that the largest economy in Asia, Japan, has knocked it on the head for these reasons, as have siliconchip.com.au Atmel’s AVR, from JED in Australia Alternative approach to Jukebox JED has designed a range of single board computers and modules as a way of using the AVR without SMT board design Just thought you may be interested in my Jukebox/Arcade Machine. Just for interest, have you thought of using a keyboard hack with yours? This involves cutting up an old keyboard and wiring the circuit board to some buttons (1 to 9 and next random etc). This makes it very hard to damage and almost idiot-proof in operation. Chris Dunn, Nowra NSW. Comment: your Jukebox looks very impressive. We did not consider a keyboard hack as we wanted to keep the wiring as simple as possible. The AVR570 module (above) is a way of using an ATmega128 CPU on a user base board without having to lay out the intricate, surface-mounted surrounds of the CPU, and then having to manufacture your board on an SMT robot line. Instead you simply layout a square for four 0.1” spaced socket strips and plug in our pre-tested module. The module has the crystal, resetter, AVR-ISP programming header (and an optional JTAG ICE pad), as well as programming signal switching. For a little extra, we load a DS1305 RTC, crystal and Li battery underneath, which uses SPI and port G. See JED’s www site for a datasheet. other administrations in Europe. Most deployments at this stage are experimental. All of them are controversial! He only mentions Radio Amateurs and therefore implies that they are the only people who have expressed grave concerns and opposition. The Department of Defence (I hope they are not amateurs), Department of Civil Aviation, Australian Broadcasting Corporation and many others have great concerns. So please get real. BPL is BAD technology and no amount of spruiking will improve it. Horst Leykam, via email. but there are hundreds of older VCRs with transformer-based PSU designs sitting in junk heaps. National/Panasonic PSU modules are good because most of the time, they even insulate the mains parts of the PSU for you, making them even safer. Also worth stripping are the DC motors used for the carriage loading mechanism and tape guides cue-up. These are generally 12V motors, very useful if you are into robotics. Graeme Rixon, via email. AVR573 Single Board Computer Dead VCRs have useful power supplies Adaptive cruise control a major concern I read your article on Adaptive Cruise Control Systems (SILICON CHIP, September 2005) with a mixture of interest and deep concern. What percentage of “road accidents” are due to the stupidity, poor attitude and training of the driver, rather than “road conditions”? No level of technology applied to a motor vehicle will ever overcome the stupidity, etc of a driver. This brings me to my main concern about vehicle safety. Any system in the vehicle that allows the driver to reduce their concentration on driving is dangerous! Cruise control maintains a theoretical constant speed and the driver may be tempted to concentrate momentarily elsewhere. With ABS (Anti-Lock Braking System), the driver may be This board uses the AVR570 module and adds 20 An./Dig. inputs, 12 FET outputs, LCD/ Kbd, 2xRS232, 1xRS485, 1-Wire, power reg. etc. See www.jedmicro.com.au/avr.htm Don’t throw out dead VCRs. You can often strip the power supply from them. Typically they have at least one 12V rail you can use for projects. Generally, they also have a couple of 30-40V rails, and these can be used too, if you put a 3-terminal regulator such as a 7812 in front of them (not for high current or the regulator will self-destruct!). The rails are usually good for at least 1A, sometimes more. The mains transformer is all mounted and ready to go, so no dangerous mains wiring. In fact, with most VCRs, the mains lead plugs directly into a PCB header on the PSU module. I don’t recommend the use of switchmode PSUs (as they can bite!) siliconchip.com.au $330 PC-PROM Programmer This programmer plugs into a PC printer port and reads, writes and edits any 28 or 32-pin PROM. Comes with plug-pack, cable and software. Also available is a multi-PROM UV eraser with timer, and a 32/32 PLCC converter. JED Microprocessors Pty Ltd 173 Boronia Rd, Boronia, Victoria, 3155 Ph. 03 9762 3588, Fax 03 9762 5499 www.jedmicro.com.au February 2006  5 Mailbag: continued Anchoring wires to PC boards For some time now I have been going to make the following suggestion about terminating wires to PC boards. Most of your projects either use PC board stakes to which the wires are attached and soldered or have the wires inserted directly into holes from the top of the board, as with any other component pigtail. The problem with this approach is that with either method, the ‘flexing point’ for the wire is rigid due to the capillary action of the solder up the (stranded) wire. Any unnecessary movement of the board, as when fault-finding a newlyconstructed project, will flex the wire at this inflexible joint and it will inevitably break! I know! I design and build all sorts of gadgets, am lazy and most often just tack wires for external connections to the print! It is so frustrating trying to trace some boo-boo only to have an unnoticed broken connection adding to the problem! Years ago, in a more professional capacity, I used the wire termination techniques illustrated below (C&D). I suggest that this is a far more satisfactory arrangement and prevents the air turning blue when one finds an unexpected broken connection when chasing down another fault. Recently, I have reverted to this technique, even on some of your kit projects, with far less strain on my patience! Expensive? Yes, sometimes it is in a production situation when the added time required to thread the wire through an additional hole adds cost to some cost-critical unit! For home projects, this is of little importance. The added holes (of sufficient diameter to accept the insulated wire) may add a small cost to the PC board but in situations where PC stakes are contemplated, maybe a cost saving could be realised! Examples A and B show what I 6  Silicon Chip mean about direct soldering either to a PC board or to a pin. The methods shown in C (for leads which can exit from beneath the board) and D (for leads which must exit from above the board) are far more secure! The technique for the home constructor for making such a connection is to thread a convenient length through the “anchor hole”, sufficient to make the joint comfortably, then pull back the excess until everything is neat and tidy. Simple! In production situations where a solder bath is utilised, the wires were bundled on top of the board and threaded through the anchor holes later. Colin Hiscock, via email. Comment: we agree that wire flexing can cause fractures but your method of anchoring could lead to much frustration when they have to be disconnected, perhaps repeatedly. For that reason, in recent designs we have been using screw terminal blocks for wires which are likely to need easy disconnection, as in our amplifier modules. tempted to drive at speeds greater then conditions allow, thinking the braking system will handle any errors they may make. ESP (Electronic Stability Control) is even more insidious, as the driver may be tempted to corner at greater speeds or change lanes more aggressively. With Adaptive Cruise Control, again the necessity of driver concentration is reduced. The system maintains a safe distance from the vehicle ahead without driver input. The only means of reaching the safety goals as outlined in Fig.1 of your article would be to produce a fully computerised electronic traffic control system embedded in each lane of expressways, freeways and arterial roads. One would then have to hope the system would not “crash”. Col Hodgson, Wyoming, NSW. Comment: some drivers do relying on ABS to shorten braking times. However, for most drivers, technical innovations represent an improvement in driver safety and comfort. And on a long journey, cruise control is a real boon. Adaptive cruise control radar questions I read the interesting article on adaptive cruise control in the September 2005 issue. This raises questions regarding all those radar signals bouncing around the highways when these systems become more common. (1) How does one unit tell that it is receiving its own return signal and not one from the identical vehicle beside it? Is the signal coded in some way like the conversations in CDMA phone calls? (2) What happens to the police radar units with all these extra signals bouncing around in the field? Police claim to be able to detect radar detector detectors (if these are only receivers I don’t know how they can do this – can you explain?) So with all the extra pollution from ACC units, are there going to be erroneous speed offences issued? If the fixed speed camera on the Spit Hill can clock a bus going uphill doing more speed than its capable of on the flat, does this new technology open a Pandora’s box? siliconchip.com.au 2006 SILICON CHIP Excellence in Education Technology Awards SILICON CHIP magazine aims to promote the education, development and application of electronic technology in all fields throughout Australia. As part of that aim, we are announcing the SILICON CHIP Excellence in Education Technology awards, with a prize pool of $10,000. Separate awards will be made to students of secondary schools throughout Australia and to students of universities and TAFE colleges throughout Australia. The secondary school awards will have three categories: AWARD FOR EXCELLENCE (a) Best final year assignment of an individual student involving electronics technology (b) An award to the school sponsoring the winning individual student (c) Best school project involving electronics technology The university and TAFE college awards will have three categories: (a) Best project from a student as part completion of a degree, diploma or certificate in electronics or a related field (ie, mechatronics) (b) Best research project from a post-graduate student working in an area of applied electronics (c) An award to the university faculty or school sponsoring the best research project. Entries and judging The awards will be judged by the editorial staff of SILICON CHIP, convened as a judges panel. The decisions of the judges will be final. Entries for the 2006 awards will open 1st May 2006, with final submissions to be made by September 30th, 2006. All submissions will be confidential, until the winners are announced, in the December 2006 issue of SILICON CHIP. Each award will take the form of a cash prize and a commemorative plaque. All enquiries about these awards should be directed to the editor via email to: awards<at>siliconchip.com.au (3) Will all this additional “microwave” energy at ground level create a situation where the “technophobes” in our society claim that it is dangerous to children and other living things. As you are aware, they all have a shoe phone but don’t want the towers to make them work! Is the power output of ACC radar greater than a mobile phone tower when the inverse square law is taken into account in the relatively shorter distances involved? Brad Sheargold, Collaroy, NSW. Comments: these answers are directly quoted from the Bosch publication on Adaptive Cruise Control. (1) Radar sensors only interfere with one another if they are operating simultaneously within the same frequency band. A number of properties on the part of the radar sensors ensure that if this occurs, it only does so very sporadically. Firstly, the radar beam is only activated for the precise period that it is actually required. This alone reduces the likelihood of mutual insiliconchip.com.au terference to less than 10%. Secondly, the FMCW modulation ensures that for each time unit, only an effective bandwidth of less than 500kHz within the frequency range 76-77GHz is used. This makes mutual interference between radar sensors extremely unlikely. In addition, filtering and plausibility-checking of measured data ensures that interference signals do not cause the vehicle to react incorrectly. In practical terms, therefore, mutual interference between radar sensors is virtually impossible. (2) The ACC SCU produces a radar beam with a frequency in the range 76-77GHz. That is equivalent to a wavelength of approximately 4mm. Because of the high frequency of the beam, its effect on humans is comparable with that of heat radiation (infrared range). The average emitted power is approximately 1mW and is thus at least 500 times lower than the radiation from a mobile telephone. Research has shown that this level of radiation is absolutely uncritical in terms of its effect on sensitive parts of the human organism. Even pointing such a beam directly at the human eye has no known negative effects. (3) Police speed-enforcement equipment is not affected by ACC systems. As far as radar equipment is concerned, it operates at much lower frequencies (<35GHz). Washing machine pressure switches Your “Salvage It!” article on washing machine pressure switches has prompted me to write. As a Volunteer with Technical Aid to the Disabled Qld, I was asked to help a client who has MS and could not use her legs to control a sewing machine. Using a pressure switch and an old PMG switch modified to suit the purpose, Christine now is able to start and stop the machine, sucking on the tube to start and blow to stop. The amount of suck and blow determines the speed. Fred Nott, via email. February 2006  7 A/V Equipment Review Looking for an all-in-one LCD projector and DVD player with stereo speakers? This new unit from Epson has all that and more. by BARRIE SMITH Epson EMP-TWD1 Home Entertainment Projector A . . . A CLEVER BOX OF TRICKS 8  Silicon Chip HOME ENTERTAINMENT projector? Yes, it’s a mouthful but the alternative is to call this new piece of gear a “DVD player-cum-LCD projector” (an even bigger mouthful). The idea is simple but very appealing: build a good-quality DVD player into an elegant LCD projector, slip a pair of stereo speakers into the housing, and add some interfaces to deal with incoming audio and video plus some outputs for downstream audio – and you have it. I must say I was at first taken aback at the Epson’s appearance – it could have twinned with my Breville breadmaker! All white, box-shaped and with minimal styling, it would not go amiss in any hospital surgery. I feel sorry for those with extensive AV systems built into dark wooden cabinets. Then the penny drops. Aside from siliconchip.com.au sitting perfectly in those 21st century decors with bleached timber and gloss white finishes, the Epson is a piece of home entertainment equipment that could be sited virtually anywhere, in any room, both inside the home or out. You could even take it on vacation and use it in the hotel or holiday home. Business people will appreciate it as it has arguably the best arrangements of any projector to present the projected image from a wide choice of positions, with wide lateral and vertical centring as well as vertical keystone adjustment. You also gain in the connectivity stakes, with no need to run cabling from the DVD player to the output device – and the backlit remote control drives both. The DVD unit operates right out of the box, with no cables to connect and no settings to make. Merging Now that the industry is trying hard to put the mockers on VHS we can look forward to DVD as the main delivery medium in the home. The concept of combining a DVD player with a projector is a good one, removing the need for a separate player and the TV itself in one swoop. In this reviewing business, I’ve always had a soft spot for video projectors, mainly because I have a large, light-coloured wall in a living space that serves as an excellent screen for the week or two turnaround that a review of these devices demands. For more permanent installations, I would of course install a screen. You can’t really argue with a picture that extends 3.4 x 1.95 metres, with a diagonal of 3.92 metres. There’s nothing else to compare with it, neither plasma, LCD or one-box rear projection units. But the truth is, you still need an ordinary CRT set or similar for casual viewing as well; six and a half square metres of the ABC news before your eyes each night is a bit stressing! But get into a good movie, doco or live event (Dylan at the Domain, Sting in St Kilda or a rugby grand final) and big-screen viewing is incomparable. Possibly the only unfortunate aspect to the Epson is that it uses a late model DVD player (supplied by JVC) that delivers a 4:3 screen ratio picture while growling away in the shadows is the promise of 16:9 HD DVD units – that is, if Sony and Toshiba can become pals siliconchip.com.au The remote control handles a host of functions both for the projector itself and for the inbuilt DVD player. and merge their opposing formats; and that seems highly unlikely! That said, the projector does have three TFT active matrix LCD panels with 854 x 480 pixel resolution (16:9 ratio but not HD definition). You can set up a screen image in the 4:3 ratio or 16:9, with the latter achieved by a lateral expansion. Its maximum light output is 1200 ANSI lumens, adjustable down to 350 lumens to afford longer lamp life and a more appropriate output for very short projection throws. You could project a 2-metre screen image from as little as two metres away. In my own case, the throw was six metres with the 1.5x zoom lens set at the telephoto end and light output at maximum. Even in daylight, with the curtains closed, I could enjoy a bright and acceptable picture and at night-time, the image quality was very impressive indeed. Configuration This box of Epson tricks is just that but with some seemingly odd configu- How Big Is The Picture? It Depends On Distance Fig.1: this diagram shows the relationship between screen distance and picture size. You can’t beat a picture that’s several metres across the diagonal. February 2006  9 Some controls are located at the rear and on the top of the case but most are placed on the remote control. A fold-down panel at the front provides good access to the various inputs and outputs on the projector. Both S-video and composite video inputs are provided. ration aspects thrown into its design. At the front is the lens, offset to the right. Beneath it is a hinged panel which gives access to the signal interfaces, with jacks for composite video and stereo L+R inputs, S-video, optical audio output and an RCA output for a subwoofer. There are no audio outputs that you could link to an external stereo or surround sound system. You can, as I did, also run the output from a nearby VCR (linked to the antenna) to get broadcast programming, as well as run tapes when needed. The rear of the box has the disc loading tray, an open/close button, a 10  Silicon Chip headphone jack and, filling each corner, the speaker enclosures. Move topside and you find manual controls for zoom and focus, plus vertical and horizontal lens shift. A strip of buttons affords entrée to power on/ off, source switching, audio level and some DVD navigation functions. The vertical and horizontal image shift controls operate optically and are a big plus, enabling you to position the device off-centre, yet still be able to centre the projected image perfectly. There is digital keystone correction of the picture sides, accessed through the picture menu. However, just think about it: the lens is at the front, so the image is formed ahead of the unit. The disc tray is at the rear, so banish any thoughts of pushing the Epson hard up against a wall or cabinet back if you want to load a DVD. And don’t forget, the speakers are at the rear corners – same problem. I figure it this way: the ideal location for the EMP-TWD1 is mid-room, with sufficient throw to form a screen image, yet with the unit given sufficient back-space for the speaker output to be enjoyed by the audience, who should presumably be seated even further aft. The mid-room location would seem to be appropriate, as the lens’ focal length seems to be computed to work with relatively short throws; in my case, the 6-metre projector-distance was achieved only by setting the zoom at full telephoto. However, when midroom mounted, a 1.20m-wide image can be generated for a throw of just 1.50m. The output of the 2 x 10W sound system is quite respectable and uses a pair of 13.5 x 3cm speakers. What helps the sound quality is a simulated surround output that works quite well with movies and the like – but of course, it’s not a patch on a true multi-speaker surround system. There is an unusual degree of control of the audio output: three presets include Natural, Smooth and Off. I went for the latter, in spite of some invigorating guff in the manual about how JVC have come up with LFO modulation to correct “the alpha wave frequency fluctuation” that falls between the left and right channels of a stereo signal. And more: the remote allows you to not only vary the audio level but adjust the treble output. Picture control The unit will handle programming in NTSC 3.58/4.43/PAL/PAL-M /PALM/PAL60/SECAM standards. You also have the option of an interlaced or progressive-scan display. The EMPTWD1’s DVD player uses a “digital direct” reading system to produce smooth play and prevent blurred or pixellated images. This system processes the film source as progressive, without conversion to interlace. A useful feature in these days of digital cameras is the unit’s ability to project JPEG stills of any dimension up to 8192 x 7680 pixels. You can even run a slide show. siliconchip.com.au The DVD tray is located at the rear of the unit. Building the player into the main projector housing is a good idea. Picture quality can be adjusted in brightness, contrast, saturation, tint (for NTSC programming) and sharpness. Other picture presets include Dynamic, Living Room, Theatre and Theatre Black – the latter is useful in a completely darkened room and an internal filter creates more natural skin tones. Information can be called up on screen to inform you of the lamp hours accumulated, the text turning to yellow when the lamp needs changing. Lamp life is quoted as 2000 hours at high brightness and 3000 hours at the low setting. A replacement lamp costs $349. Remote This is a busy appliance. The remote’s 43 buttons are essential for more than the simplest of settings – and don’t forget that a complete tally of DVD controls is also found here. Then you find there’s a toggle switch: “Function” is the default setting for all operations. If your DVD displays chapter numbers, you switch over to toggle position “123” and punch in the numbers directly, instead of coursing around the screen to hit the thumbnail. Familiarising yourself with the remote’s buttons is the essence of the Epson; the range of control is exemplary and there are some unexpected and very human touches. An on-screen button displays the state of the DVD output: the bit rate, chapter number and running time. You can also set up a looped playback of a favourite scene or you can arrange playback of selected chapters in any siliconchip.com.au The knurled wheels on the top of the projector case give good control of the projected picture geometry. order. The Epson has also presets for auto-off and a sleep timer. If your luck matches mine, come Friday evening, it’s relax time, the DVD has been loaded, the movie has been running for a minute or two – then the phone rings. With the Epson, simply tap the “Break” button on the remote: the DVD stops, the screen washes to white with a small pulsing coffee-cup icon (so you don’t trip over the dog in the dark), and all systems await the master’s return. It’s a nice touch. Comments Having often sat patiently while a projector slowly warms up from a cold start, then seems to spend another eternity powering down, I was delighted to find that the Epson is a rapid operator – warm-up takes only 20 seconds until an image splashes onto the screen and cooling down takes just nine seconds. This can be partly attributed to the use of a cleanable, replaceable, external air-filter. Although we’re dealing with an SD (standard definition) picture, the on-screen quality is among the best I have seen, with bright, fully-saturated colour and excellent definition. There was no rainbow effect visible but there was some evidence of a screen-door effect, which “disappeared” after a few days of familiarity with the Epson. A smaller picture also helped diminish the latter. No fast-motion artefacts are SC apparent and the unit is quiet. Features & Specifications Disc formats: DVD video; Video and Super Video CD; Audio CD and CD-R/RW (MP3, WMA, JPEG); DVD-R/RW. Display: three 14mm TFT active matrix LCD panels. Resolution: 409,920 pixels (854 x 480). Light output: 1200 ANSI lumens. Focus, zoom, lens shift: manual. Lamp: UHE 135 watts. Power: 100-240V/50-60Hz AC; maximum draw 230 watts. Inputs: composite video and stereo audio, S-video. Outputs: subwoofer port; optical output; headphone jack. Audio: 10W + 10W RMS. Dimensions (WHD): 340 x 180 x 310 mm. Price: $2499.00. Contact: Epson Australia 1300 361 054 or www.epson.com.au February 2006  11 We build and test an electric ELECTRIC FLI Electric powered model aircraft are becoming very common – but they do present pitfalls, not just for the beginner but for the experienced modeller as well! In this article we review the electric scene and build and test an electricpower Piper Cub. How did it go? Read on. M uch has changed in the world of electric-powered, radio-controlled aircraft since SILICON CHIP last visited the subject back in 1992. If readers may pardon the play on words, electric flight is undergoing a quiet revolution; a revolution so radical that the economic viability of internal combustion (IC) motor manufacturers must surely be under threat. This startling transformation has come about as a result of a number of electric flight technologies coming of age almost simultaneously. Of these developments by far the most important are: 12  Silicon Chip [1] Application of Rare Earth magnets to brush motors [2] High power, low-on-resistance FETs [3] Microprocessor-controlled smart speed controllers and smart chargers. [4] Brushless motors [5] Battery technology improvement. Prior to 1992 electric flight was in the hands of a small group of dedicated contest flyers. Today’s electric flyers owe this group a huge debt of gratitude, for without them electric flight would be nowhere near as advanced. It was this group and in particular, Peter Blomart of Belgium, that established the internationally recognised class of F3E competitions in 1986. Since those early days of primitive hand made soft start switches and analog electronic speed control (ESC), progress has been staggering, to the point where the modern microprocessor speed controller can now distinguish between brush and brushless motors and configure itself accordingly. International R/C aerobatic competitions have long held their place as the most prestigious R/C events. While traditionally dominated by IC motors siliconchip.com.au Piper Cub IGHT By BOB YOUNG of ever larger capacity and power, it is increasingly common for electric powered models to snatch places from the IC brigade in these showcase events and it is here that the real threat to IC motor manufacturers is developing most rapidly. The radio-controlled boat boys have also been hard at it. Currently the fastest R/C boat in the world is electric, with a speed of 120.7 mph. In Australia, Ray Cooper of Victoria set a world record for electric-powered models in the distance to goal and return class with a flight of 54.3km (108.6km total), lasting 1 hour 22 minutes. siliconchip.com.au Across the world, R/C flyers are scrambling to emulate their international heroes. Manufacturers of electric motors are springing up like mushrooms and battery manufacturers are continuing to confound, with batteries that are lighter, with more capacity and higher cell voltages. Manufacturers of the chargers for these batteries are hardpressed to meet demand and so the bandwagon has been set in motion. With all this going on, the time has come to review this wonderful world of ultra mobile electrons in the most practical way possible: building and flying an electric powered model suitable for park flying on those quiet, wind-free evenings that are an R/C modeller’s special delight. World Models Piper J-3 Cub EP The kit chosen was selected for several reasons. Small enough to qualify as a park flyer, it is simple to build and fly and is reasonably priced. The kit includes a geared, brush motor (Speed 400) and thus can be controlled by a simple and economic ESC. It also uses a genuine lightweight 4-channel R/C system providing four proportional channels. However the real reason for the choice of this kit was that I have had a soft spot for Piper Cubs for a very long time. It is a very pretty aircraft, easy to fly and is one of the nicest aircraft for take-offs, landings and especially “touch and goes”. If the reader loves to watch a graceful aircraft land and takeoff then there is no better model than the Cub. This emotional approach to the kit purchase was to have a dramatic effect on the ultimate outcome of this whole project but more of that later. The Cub does have one small vice and that is adverse yaw during an aileron-only turn. This is largely as a result of the flat bottom wing section (Clark Y) and poor aileron design. To turn an aircraft, the aileron on the inside wing must be raised at the trailing edge and the outside aileron depressed. This reduces the lift on the inside wing tip and the wing starts to fall due to the unbalanced lift distribution. However with the reduction in lift, the drag at the inside tip is also reduced. Conversely, when the aileron on the outside wing goes down to lift that wing tip, the lift shoots up dramatically, as does the drag. The result is that the aircraft rolls in the direction of the turn but the nose is pulled around in the opposite direction by the badly unbalanced drag forces at each wing tip. This gives rise to a very awkward situation known as “adverse yaw”. However, there are several tricks that will help improve the flying characteristics of the Clark Y type wing. These include heavy differential aileron movement (more up than down) and coupled aileron/rudder mixing on either the transmitter or in the model (ie, turning using rudder and aileron together). Full size designers may resort to differential movement and designs such as the Frieze Aileron, which uses a complex hinge that allows the leading edge of the up-going aileron to protrude into the slipstream underneath the wing, thereby increasing the drag on the inside wing and balancing overall drag. However do not lose sight of the fact that these are only patches and they introduce other problems such The kit as she comes, straight out of the box. All of the difficult model work of past years – wing and body shaping, etc – is already done for you! February 2006  13 11.4V, 1800mah 3 cell Li-PO battery left rear. 3 cell ESC left front and two sizes of brushless motors. Two of the ultra mini servos fitted to the Cub. They’re significantly smaller than the servos you’re used to . . . as spoiling the rolling characteristics and reducing aerodynamic efficiency. As with all fixes, the real answer is in the initial design of the aircraft. The prime rule should be no flat bottom wings with simple centre-line aileron hinges on sport aircraft. Scale aircraft are a different matter. Why kit designers insist on using a flat bottom wing with simple centre-line aileron hinges on training and sports models is absolutely beyond me. They must subscribe to the theory that if you can fly this sort of trainer you can fly anything. They really are unpleasant to fly if the necessary precautions are not taken. Even a wing with a moderately curved underside (Semisymmetrical, eg, NACA 2415) will completely transform the flying characteristics of any model with a flat bottom wing section and may almost completely eliminate adverse yaw. While this is a diversion from the main topic it has been covered in detail because it is important for all tyro R/C modellers to understand the effects of flat bottom wings. It is the only factor that may spoil the delight of flying this really nice model. Nowhere in the Cub instructions does it warn of adverse yaw or mention the above precautions which is a pity as otherwise the Cub is a good value kit. The above applies to all R/C model aircraft, so do yourself a favour when purchasing your next trainer or sport model. Look for a model with a symmetrical or semi-symmetrical wing section. ings. No mention is made of the type of servos the kit was designed around and so the servo trays fitted in the wing were unsuitable for the servos used in this model. They had to be cut away and new ones fitted. Watch out for the cross-brace at the bottom of the servo well. This is actually a little pull out handle attached to the fine cotton pull-through used to pull the servo lead through the wing tunnel to the wing root. It is best to remove the servo connector and solder a 3-core ribbon cable extension lead long enough to reach the wing root plus an extra 75mm. When the wing halves are joined then splice the two 3-core cables together with a servo lead about 100mm long. This single servo lead then plugs into the receiver aileron socket. There is virtually no way that a servo connector can be threaded through the wing tunnel so conventional servo extensions and “Y” leads cannot be used. Remember here to set the aileron servos in such as manner that ailerons move up the recommended 10mm but contrary to the instructions only go down about 2mm, not 10mm. This can be achieved mechanically by offsetting the servo arm as shown in the relevant photo or by using the transmitter settings in computer radios. The rest of the wing assembly is straightforward enough with the exception of one final point. The wing uses a straight spar to join the two halves. It is a good idea when gluing the two halves together to place a moderate weight on the centre, giving the wing a very small amount of dihedral. A dead straight wing on a high wing model tends to Assembly The Cub is one of the new breed of kits called ARF (Almost Ready to Fly). This means that the manufacturer has already done all of the hard work. The model is almost completely built and fully covered in plastic shrink film when it comes out of the box. All that remains is some detail work and the installation of radio and motor. Thus for the enthusiastic tyro, building will typically take around 10-15 hours. The following is not meant as a detailed how-to of assembly, merely a guide to point out some of the difficulties and shortcomings in the kit and to help anyone building this model avoid the pitfalls. Assembly begins with the preparation of the two wing halves and it is here that the only real problem in assembly was encountered. The instructions are very poor and consist merely of photo sequences and a few odd draw14  Silicon Chip Engine Room with cowl removed showing the Speed 400 motor and gearbox as well as the folding prop. siliconchip.com.au look as if the wing tips are drooping and the slight dihedral eliminates the droopy look. The remaining assembly is routine but with two points of concern. The hinges used are sheet Mylar. Glue only one side into the model using super glue. Do not allow superglue to get across the hinge line, as this will make the hinge stiff and brittle. Do not attempt to coat the hinges on the control surfaces with super glue and then slide them into place. The glue goes off immediately it touches balsa. Instead, fit the control surfaces and then drill vertical holes down through the control surface and hinge ready to accept a normal household pin. Wick super glue down the hole and then slide in the pin. Nip off the pin flush to the underside of the control surface. Hinges should always be pinned into place. Do not rely on the glue to hold them. Many a good model has been lost in this manner. Lastly, the elevator and rudder pushrods are blued steel and they slide into long Mylar tubes, giving a fit quite high in friction. To avoid this, before inserting the pushrods into the tubes, use a piece of sandpaper to remove all of the blueing to take the surface back to bright steel. Then coat the pushrods with graphite lubricant before finally inserting them into the tubes. Motor and radio installation Conference and Tradeshow Theme: “Meet the Pioneers” & Update your skills Queen Victoria Museum and Art Gallery Precinct - Launceston, Tasmania Australia 2-4th March 2006 Sponsorship opportunities available now GUESS WHO’S COMING TO THE SHOW! Live from Launceston, Tasmania nication satellite commu V DrDish<at>T rldwide TV the unique wo mote channel to pro Come and be a part of the audience and ask the hard questions The conference program will also feature seven of the industries top keynote speakers Ideal program for new comers as well as experienced industry professionals. Make your way to Launceston Download these documents from Conferenceplus.com.au/satellite2006/ As stated previously the Cub is supplied with a geared Speed 400 motor and a folding prop. Fitting the motor and associated electronics is very straightforward. The folding prop is a curiosity, as few people would attempt to soar this sort of model. The folding prop is designed to reduce drag during gliding flight when the motor stops. An excellent range of wooden e-props designed especially for electric motors is now available and this model would no doubt benefit from one of them. The folding prop does have one advantage though: resistance to breakage in bad landings! The motor is already fitted with suppression capacitors, 100nF (0.1uF) across the two motor terminals and 100nF from each terminal to the motor case. A simple, economical speed controller (ESC) was chosen and wired in to place. Be sure to follow the polarity instructions carefully or on the first take-off you will be run over by an aeroplane flying in reverse! The modern breed of speed controllers, designed for use in conjunction with lithium-polymer batteries, are very interesting. They feature a mandatory low voltage cutoff to prevent the Li-POs falling below 2.4V per cell and destroying themselves. They also feature a BEC (Battery Elimination Circuit) to provide receiver and servo power. Be sure when choosing a speed controller (the kit does not provide the ESC) to specify the number of servos to be operated from the BEC. The Cub uses four servos. The ESC uses a microprocessor to control all of these functions. One additional feature of micro-controlled ESCs is a degree of input pulse monitoring. This checks the in- Engine Room with cowl removed showing the Speed 400 motor and gearbox as well as the folding prop. Radio Room. Note servos mounted but push-rods not yet fitted. siliconchip.com.au Exhibition space on sale now - Hurry it’s selling fast Register your interest to attend • Exhibition Booth Application • Register to attend on-line Event Managers: Conference – Plus PO Box 1144 Legana Tasmania 7277 Phone +61 (3) 6330 1444 Fax + 61 (3) 6330 2190 email info<at>conferenceplus.com.au February 2006  15 coming signal for noise and should the input pulse count exceed the specified number or change pattern dramatically then the ESC shuts down the motor drive. Another very good safety feature is that the ESC cannot operate accidentally when turned on. To function correctly the ESC must first be set to LOW throttle and then the ESC is armed and ready for use. Be careful on the first powerup, as it may be that the throttle channel is reversed with low at the top of the transmitter (TX). In this case use the TX channel reversing function to set LOW throttle with the stick down towards the bottom of the TX. Now we come to the electronically juicy part of this saga. Range reduction Our experience with the analog speed controller presented in the 1992 articles indicated that there will be a loss of usable transmitter range with an electric motor running, as against motor stopped. Our testing in 1992 confirmed that this range reduction would be in the order of 10-12%, due to the noise produced by the commutator and brushes of the motor. So we decided that anything in excess 85% of the engineoff range is an acceptable figure, with the ranges available from modern receivers. So imagine our surprise at the field one perfect spring morning for test flying, when we were confronted with 15% of the radio range on the throttle control. All of the flying Fuselage complete except for decals. Note the folding prop. 16  Silicon Chip No, it wasn’t a hard landing which tore the wings off . . . here the Cub is almost complete: motor, servos and radio installed and wings ready for fitting. controls worked well at the normal range but the throttle would run up to speed and cut off at about 15% of normal range. Obviously it was back to the drawing board. What had happened? Firstly in spite of my many years experience in R/C flying, the most fundamental rule of all had been ignored. That is, test everything at home before leaving for the field and that includes a retracted TX antenna range check with motor running and motor stopped, even though the motor running test is difficult to do on your own. This is especially true when preparing for any model’s first flight. So what had happened? Firstly, I’m an old power hound who likes models with only two speeds, stop and go very fast, and who believes that too much power is better than too little (you can always throttle back), so the Cub was fitted with an 11.4V 3 cell Li-PO battery. Thus the rating of the 8.4V Speed 400 motor was exceeded by the extra 3V. This is OK if one is prepared to accept abnormal motor wear. However the Speed 400 motor does not have good brush design and it arcs quite badly unless tuned properly. An old trick here was to time the motor in a darkened room for minimum arcing on the brushes. Clearly then the extra 3V was elevating the motor noise and this was getting into the speed controller and shutting it down via the pulse counting safety circuit. So we fitted a reverse-biased Schottky diode and a 40V varistor across the motor brushes as recommended in the 1992 articles but with little improvement. Where to from here? Change the receiver perhaps? The noise path was most likely coming down the receiver antenna and then through the receiver. Ultimately four brands of FM receivers were tried and located as far from the ESC and motor as possible; three imported brands and the original Silvertone. Three brands of TX were tried as well. These gave very little improvement and the results were still not acceptable for successful flying. It was then decided to change the operating voltage, reducing it to a 2-cell Li-PO battery delivering 7.2V. Unfortunately this introduced a complication in that the economical little speed controllers are set for the number of cells to be used. There is no built in facility for cut-off voltage adjustments. So a change in battery voltage called siliconchip.com.au Close-up of tailplane assembly showing control horns, pushrod connections and steerable tailwheel. Close-up of fin assembly showing the steerable tailwheel anchor/bearing plate. siliconchip.com.au www.elexol.com www.elexol.com www.elexol.com www.elexol.com www.elexol.com www.elexol.com and visibility problems, the last thing needed is a glitch or two to add to the misery. The result may very well be a smashed or lost model. I have four much flown and much cherished models approaching or exceeding 30 years old. One even has 30-year-old servos still fitted and functioning. The key to this sort of longevity is constant and effective servicing coupled with well-built airframes and a rigid pre-flight test procedure. This includes not accepting any shortfalls in performance. Models take too long to build and are too expensive to treat in an off-hand manner. Even the modern ARF still takes a lot of time to prepare ! W E ELEXOL Ether I/O 24 N www.elexol.com www.elexol.com www.elexol.com www.elexol.com UDP/IP-controlled digital input/output module featuring three 8-bit ports with 5V level signal lines. Each of the 24 lines can be independently programmed as either an input or an output. Connects to any TCP/IP protocol network. CT VIA CONNE TO TALK R ROUTE INTERNET TO ANYEVICE! D Supports ARP, BOOTP, DHCP, ICMP and UDP/IP protocols Standard 10BaseT Ethernet Interface; RJ45 connector 24 independently programmable signal lines with configurable CMOS, TTL or Schmitt Trigger thresholds and programmable pull-ups per line Easy connection by three 10-way box headers On-board 50MIPS flash micro-controller may be reprogrammed to suit specific applications Integrated switch-mode voltage regulator allows power supplies from 8-32VDC User 5V 500mA output to power external interface boards or sensors Compact module – 72 x 72 x 24mm Great range of I/O-24 peripherals, too ... CONNECTOR/ LED BOARD Provides screw terminal connections plus optional either pull up or pull down resistors and LED port status indication. OPTO INPUT RELAY OUTPUT SWITCH/PUSH BUTTON BOARD BOARD BOARD Provides 8 Opto Isolated inputs for each of the I/O-24 pins with LED indication. Provides 8 isolated relay contact outputs suitable for a variety of loads. Provides 8 switch/ push buttons with LED indicators showing the status of the I/O pin. Visit our web shop <at> www.elexol.com Elexol Pty Ltd Ph: (07) 5574 3988 Fax: (07) 5574 3833 (PO Box 5972, Bundall, Qld 4217) www.elexol.com www.elexol.com www.elexol.com www.elexol.com www.elexol.com www.elexol.com www.elexol.com www.elexol.com www.elexol.com www.elexol.com for a new ESC with a low voltage cut-off exceeding 4.8V. After fitting the new ESC and battery the same tests were conducted with the FM receivers. The range was a lot better (50 –60% depending upon the FM receiver used) but still not up to the 85% figure adopted originally as the acceptable standard. Finally in desperation a Silvertone AM receiver was fitted and this gave the desired range. The model was at long last ready for flying. In conclusion, then, what had caused all of the problems and what had fixed them? Firstly, had I used my head instead of my heart and purchased a kit fitted with a brushless motor and a more advanced ESC perhaps things may have been different. That is another story of course and we may yet see the Cub fitted with such a system. However, the exercise was to learn about the modern electric flight systems and how to make them work in spite of whatever shortfalls there were in that equipment. People do buy with their heart and especially with their pocket in mind. The Speed 400 is a common motor in kits and the economical little ESCs are very attractive to beginners feeling their way into electric flight. The problems began when the recommended motor voltage was exceeded. Not clearly understanding the operation of the safety circuit in the ESC compounded the matter. It took time for us to realise that it was the safety circuit cutting off the motor. The FM receiver performing poorly against the AM receiver is easily understood. The powerful AGC on the AM receiver keeps the receiver in a less sensitive state for approximately 80% of its range. Thus noise-induced spikes may be much reduced in AM receivers, depending upon the nature of the noise. AM receivers in spark ignition and electric models can often give the best results. Again, this is a trial-and-error process. Perhaps re-timing the motor would have reduced the spark noise, but that is not a job for inexperienced modellers. It was dropping the voltage that reduced the interference most dramatically. Maybe 50-60% of the range is acceptable for some modellers. These are, after all, small models and cannot been seen clearly at long ranges. However, beginners often let their models get out of hand at times and they can very quickly be blown down wind a great distance. For a beginner struggling with wind February 2006  17 Aileron servo mounted in wing. Note the offset on the servo arm at neutral to provide differential movement of the ailerons (for non-computer radio control systems). for flight. Too much to just squander with a casual attitude. Beside this, there is the safety issue to consider. An out-ofcontrol aircraft may be a health hazard. So think carefully about your decisions to fly or not fly. You can always come back another day – if you have a model to fly that is! Flying the Cub As expected, the model flew just like a Piper Cub, looking as pretty as a picture. Also as expected, despite the differential aileron built in during assembly there was still an excessive amount of adverse yaw during aileron turns. In the course of trimming the model, Coupled Aileron/ Rudder (CAR) will be called up in the TX program with a switch to enable/disable the CAR in flight. CAR is a function in the TX program whereby a small amount of rudder control is mixed into the aileron control to help initiate the turn and hold out the adverse yaw. The switch is desirable for aerobatics, to switch off the CAR in flight during rolls etc. The radio worked perfectly with no sign of interference from the motor in flight. Take-off power with the 2-cell Li-PO battery was marginal but once airborne there was ample power for climb and cruise. There would be no hope of getting off even a smooth grass strip. We used a tarred road for take-off. Take-offs on grass and aerobatics would definitely call for a 3-cell Li-PO battery to be fitted. The real surprise was the lack of down thrust. The model climbed on full power and dived when the throttle was cut. At least another 3 degrees of down thrust will be required to correct this effect. This will be a real pain to retrofit as the motor slides snugly into holes in two bulkheads. To use a flat bottom wing-section is a tragic error but to provide a pre-built fuselage with the incorrect thrustline is unforgivable. Why do kit manufacturers do this sort of thing? How on earth are beginners expected to fight their way through a maze of annoying little problems? These things are not all that serious and relatively easily fixed, certainly in the kit building stage but they make potentially nice models unpleasant to fly. Why spoil what is essentially a really nice kit with lack of attention to some of the fine detail? There are several ways to handle the lack of down thrust. First you can carve out the bulkheads and set the motor at the correct angle. This is the right way to do it aerodynamically. Or you can mix some elevator trim in with throttle so that when the throttle is opened the elevator moves down to compensate for the climb. Finally and for the experienced flyer only, try moving the CG back until the full aerobatic position is established. (Not for beginners.) However the nicest part of this whole story is being able to drive for five minutes to a large clear local area and fly without annoying people nearby. The model was as quiet as a church-mouse in flight. This is another priceless legacy of technological progress. So there you have it, a true, warts-and-all introduction to electric flight. Ready for take-off! The Piper Cub complete with decals (they’re all supplied in the kit) and ready to fly. The “bendy” propellor, so disconcerting to some, is clearly visible in this shot – it straightens up once it starts pushing air! 18  Silicon Chip siliconchip.com.au PRECAUTIONS WHEN USING Li-PO BATTERIES Li-PO batteries contain volatile and toxic chemicals. For your safety please read the following carefully. • NEVER leave batteries on charge unattended! It is also a good idea to place the battery in a steel or ceramic dish while charging and keep well away from inflammable materials. • Never leave the battery connected to the speed control as these units have a small leakage current. Do not allow batteries to fall below 2.4V either in use or by self-discharge. Always recharge batteries at least once every 3 months. Batteries that fall below 2.4V are ruined and will never work again. • IMMEDIATELY remove a Li-PO battery from a model if it is involved in a crash. Carefully inspect the battery for even the smallest of dents, cracks, splits, punctures or damage to the wiring and connectors. CAUTION! Cells may be hot! DO NOT allow the battery’s internal electrolyte to get in the eyes or on skin – wash affected areas immediately if they come in contact with the electrolyte. A Li-PO battery might not appear to be damaged after a crash but it could smoulder over a short amount of time and suddenly catch fire unexpectedly. If in doubt, place the battery in a fireproof location indefinitely. • Disconnect the battery IMMEDIATELY from the charger if it begins to swell, emits smoke or is warm to the touch! Place warm or hot batteries in a fire-safe location, such as a container made of metal (such as an empty ammunition box) or ceramic. Always monitor the area with a smoke or fire alarm, and have an “ABC type” fire extinguisher available at all times. • DO NOT set the battery charge rate to a value greater than the battery’s 1C value as permanent damage could result. Do not exceed a 9C discharge rate. • DO NOT allow LiPO cells to overheat at any time! Cells which reach greater than 140°‑F (60°C) can and USUALLY WILL become damaged physically and could possibly catch fire! Always inspect a battery which has previously overheated for potential damage and do not re-use if you suspect it has been damaged in any way. Do not leave a battery near a heat source above 80 °C (Stove, heater etc). siliconchip.com.au Leaking batteries must be kept away from naked flames. Keep the battery as cool as possible at all times, particularly when charging. • Always provide adequate ventilation around Li-PO batteries during charge, discharge, while in use and during storage. If a battery becomes overheated, remove it from the charger immediately and place it in a fireproof location until it cools. • Use a charge lead that is directly compatible with the “charge” connector on the Li-Po battery. It is strongly recommended to use pre-assembled charge leads. These can be found at most hobby retailers. • Do not use automotive chargers to power Li-PO chargers. • It is preferable to charge individual cells for best results (parallel charging). If series charging is used, do not attempt to charge more cells in series than the charger is designed for. • Always disconnect chargers from the input power source when not in use. • Keep out of reach of children. • Dispose of discarded batteries responsibly! WARNING!! You MUST NOT care for lithium-polymer (Li-PO) cells in the same way as other battery types!! It is very important to have a good understanding of the operating characteristics of Li-Po batteries – especially their exact rated voltage and maximum acceptable charge current. Always read the specifications printed on the label of your Li-Po battery prior to use. Failure to follow the care and handling instructions can quickly result in permanent damage to the batteries and its surroundings and even start a FIRE! Do not mistake lithium-polymer cells for other lithiumbased cell types (such as lithium-metal, lithium-phosphate, etc.), as other lithium hybrids have different care and handling characteristics . It is strongly recommended to use packs that have been assembled with built-in charge protection circuits. Such circuits help to regulate the maximum voltage per cell in the pack to ensure that that they do not accidentally become overcharged. SC February 2006  19 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 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 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 A PC-Controlled Burglar Alarm System Fancy a full-featured alarm control panel with dialler capabilities? This one is PCprogrammed and controlled and can handle up to eight zones. The PC only needs to be powered up for arming and disarming, or you can use an optional keypad. Pt.1: By TRENT JACKSON 26  Silicon Chip B URGLAR ALARM SYSTEMS are hardly new but this DIY PC-controlled unit is something different. It’s an extremely versatile unit but despite that, it’s not expensive. In fact, the most expensive component used is the case but there’s nothing special about the unit specified. If you already have a suitable case, or can make one using materials to hand, you’ll save yourself about $30.00. A feature of this unit is that you siliconchip.com.au control two separate door strikes. Defined privileges can be used so that only certain individuals can arm and/or disarm certain zones. This effectively restricts access to certain parts of the building to certain people. As such, this system is ideally suited to the small business looking for a serious alarm system at a budget price. Of course, that’s not to say that it isn’t suitable for domestic use as well. It’s just that the wide range of access control that’s built into the system makes it very attractive to the commercial end of the market. PC options don’t need a keypad to arm and disarm it – that’s done using a PC. And if you’re wondering about a power blackout preventing you from powering up your PC to disarm the system, don’t be too concerned – a hard-wired “key” (which plugs into a D9 connector on the front panel) can be used to disarm the entire system if there’s a blackout or computer malfunction. Alternatively, for those that want a traditional keypad, a suitable unit will siliconchip.com.au be presented in Pt.2 next month. The keypad is entirely optional, however, and you still must use a PC to initially program the unit (ie, for setup). Eight zones Most low-cost alarms only cater for five or six zones but this unit can handle up to eight! Each of these zones can be independently armed or disarmed and monitored by the Windows-based software. In addition, the unit can You don’t need to have your PC permanently powered up and connected to the system in order for the alarm to function – at least, not unless you require the software-based dialler function. Of course, if the computer is left running, the monitor can be switched off (eg, overnight) and that’s good practice in most cases. As mentioned, the alarm is programmed via the software interface and all entry and exit delay times (from 1-255 seconds) are fully definable for each zone. The siren times are also definable and are also set from 1-255 seconds. This is well within the NSW legal limit of 300s (five minutes) but it’s a good idea to check the noise pollution regulations in your state before setting the siren duration. The system automatically rearms after the siren duration has expired and will immediately retrigger if further sensors are tripped. However, you can set the maximum number of trips for any one zone from 1-5, so that a faulty sensor will eventually be locked out. You can also set the maximum number of trips for all sectors combined, in this case to any number from 1-10 (more on this next month). As is common with all units of this type, the system has full battery backup (via a rechargeable SLA battery). If there is a blackout, this should be sufficient to keep the system operating for 1-2 hours, assuming a modest amount of peripheral components hanging off it – ie, PIRs and any other sensors requiring power. Access control The software access control is what sets this unit apart from conventional alarm control panels. It allows for up to four “Owners”, eight “Admins” and February 2006  27 Fig.1: the block diagram for the PC-Controlled Alarm. A PIC microcontroller arms and disarms the zones, scans the sensors and controls the alarm outputs and door-strikes. It also relays logging information back to the PC. 16 “Users”, each group having different privileges. Owners have the power to do whatever they like with the system, while Admins have the power to create and delete users and have almost full control over the system. Users have defined degrees of access only. The software is easy to use and you’ll pick it up in seconds – see “Driving The Software” in Pt.2 next month for further information. Another key feature is the logging side of things. Picture this: you run a small company with several employees working different shifts. Maybe you have a punch card or similar system or perhaps you rely on complete faith. In either case, this system allows for such monitoring. Employees enter the building at the start their shift and key in their PIN. The software places a date and time stamp next to their name within the log. You can then review 28  Silicon Chip this log on a regular basis to ensure that things are as they should be. But wait – couldn’t someone just enter their PIN and then go to the pub for a couple of hours? Well, that’s not possible due to the fact that you can set the system up to automatically rearm itself again, so that the PIN has to be re-entered at regular intervals The software-driven dialler feature works in a similar fashion to Leon William’s PIC-based dialler published in SILICON CHIP in April 2003. It uses your PC’s modem to dial a preset number and generate a tone across the line. Hard-wired key As previously mentioned, the “hard wired key” is used to disarm the system if a PC is unavailable (eg, during a blackout). It’s really very simple and consists of nothing more than a D9 connector and backshell, with just a few wire links used inside to set an inverted 4-bit code. Only 4-bit – hang on, isn’t that going to be easy to crack? Well no, because the key needs to be inserted (and removed) a preset number of times, as defined within the software. So, for example, you could wire the key for a code of 7 and specify that it has to be inserted and removed four times to turn the alarm off. If there is too much time taken between inserting and removing the key (or if it is done too quickly), the system fails to disarm. In practice, you need to leave about one second between each insertion and removal. Note that the hard-wired key can only be used to disarm the system and is intended for emergency use only. It cannot be used to arm the alarm. The D9 socket used on the front of the unit also has the RS232 connections for the PC on it as well (these RS232 connections are wired in parallel with a screw terminal block on the main PC board). This means that you could siliconchip.com.au also use a notebook computer to disarm the system in the event of a power failure or other malfunction. Alternatively, you may decide that it better suits your needs to actually use this socket for controlling the system at all times, rather than wiring the PC to the internal RS232 terminals. Two holes in the back of the unit allow for cable entry and exit, including the cables to the sensors, the external siren and the PC’s RS232 interface. The hard-wired serial cable is terminated in a D9 connector at the PC end. Sensors Almost any sensor with NO (normally open) or NC (normally closed) contacts can be used with the system. However, you must configure the setup for each sensor (NO or NC) in the Windows-based software. Basically, you can allocate NO or NC sensors for each zone but you can’t mix NO and NC sensors on the same zone. When activated (ie, when a sensor trips and the unit is armed), the alarm sets off a piezo siren located inside the case (and capable of producing around 119dB of sound). In addition, an external siren and/or strobe can be connected to the unit. An internal tamper switch will also immediately trigger the alarm if the lid of the case is removed while any of the zones are armed. In addition, there are two alarm outputs (Alarm OutA and Alarm OutB) which can be connected to The SILICON CHIP SMS Controller. These outputs are active high – ie, they switch high when any zone is triggered. LED indicators As shown in the photos, the unit is based on two PC board assemblies – ie, a main control board and a display board. The display board mounts on the front of the unit and carries 18 indicator LEDs. Eight of these LEDs are used to show which zones are armed, while another eight indicate the status of each zone – ie, whether it has been triggered or not. The remaining two LEDs function as power on/off and data transmit/ receive (Tx/Rx) indicators. The main control board carries a PIC16F877A microcontroller, along with a simple but effective power supply which delivers +5V and +12V rails. siliconchip.com.au Main Features HARDWARE FEATURES SOFTWARE FEATURES • • Eight independent zones. • Each zone can be configured to handle NO (normally open) or NC (normally closed) sensors. Windows-based interface – works with Windows 9x, Me, 2000 & XP. • Independent entry and exit delays for zones (1-255 seconds). • Battery backup plus tamper switch. • Programmable dialler feature (via a PC and modem). • Internal siren plus output for external siren. Automatic rearming features. • Two door strike and two alarm outputs. • • • Programmed and armed/disarmed via a PC. • • Hard-wired key to disarm unit if there is a power failure. Data logging with save, open and print facilities. • • Optional keypad to arm and disarm unit. Software shows how to configure hard-wired key to match code. • Software is easy to drive. This supply also provides a constant 13.6V 20mA (approx.) trickle current to charge the backup battery. The main board also carries the RS232 interface (which connects to the PC), along with screw terminal connector’s for all the off-board wiring to the sensors, external siren, door strikes and alarm outputs. In addition, there are a number of header sockets to handle the connections between the main board and the display board, and to provide the Alarm OutA and Alarm OutB outputs. Circuit details Fig.1 shows a block diagram of the unit. As previously mentioned, it’s based on a pre-programmed PIC16F877A microcontroller. In operation, the PIC micro accepts instructions from the Windows-based Ability to create three types of groups (owners, admins and users), each with different access privileges. software to arm and disarm zones and constantly scans for triggered sensors. It also drives the siren, LED indicator and alarm outputs, and there’s provision to control two door strike mechanisms. Finally, the PIC also relays information back to the PC for monitoring and logging purposes. Fig.3 shows the full circuit details (minus the power supply). Port lines RB0-RB7 of microcontroller IC1 monitor the sensor inputs via 2.2kW input protection resistors. These lines all have 100kW pull-up resistors to ensure they don’t float. Further protection is provided by inbuilt voltage clamps inside the PIC micro, so no damage will result if you do accidentally hook up 12V to these inputs. You may need to reset the system if this happens, though. Fig.2: this is the main GUI (graphical user interface) for the Windows-based software. The software is easy to drive and you can customise the setup to suit your particular application (full details next month). February 2006  29 30  Silicon Chip siliconchip.com.au Fig.3: the PIC microcontroller forms the heart of the circuit. It monitors all the inputs, arms and disarms the various zones and drives the status and alarm LEDs via IC3 & IC4. It also drives the siren and door-strike outputs via Darlington transistors Q1-Q4. Fig.4: the power supply uses a bridge rectifier (D1-D4) and 3-terminal regulators REG1 and REG2 to derive +12V and +5V supply rails. A 12V SLA battery provides the battery backup and this is charged via D6 and a 180W 5W resistor. This involves disconnecting both the plugpack and the battery, and then waiting for 30 seconds or so before reapplying power. Four BD681 Darlington transistors (Q1-Q4) control the door strikes and sirens via ports RD2 & RD3 and RC4 & RC5, respectively. These each have diodes connected between their collectors and the +12V rail, to protect the transistors from back-EMF spikes – eg, when a door strike turns off. A word of caution regarding the door strikes – the 12V rail is good for about 1A but only briefly! A door strike will draw around 700mA or so when activated, so don’t try to operate both door strikes at the same time. Microswitch S1 and its associated 100kW pull-up resistor on RD4 provide the anti-tamper feature. This line is normally held high when the lid is secured to the unit. However, if the lid is removed, this switch closes and pulls RD4 low. If any zone is armed, this automatically arms all other zones and sounds both the internal and external sirens. If this happens, all zones must then be disarmed and only “admins” and “owners” can do this (unless a “user” has full access). Clock signals for the PIC are provided by crystal X1 (4MHz). The two 22pF capacitors hanging off it ensure siliconchip.com.au correct loading for the crystal, so that it starts reliably. Two 4040 binary counters, IC3 & IC4, are used to drive the indicator LEDs on the display board. These counters are clocked by the RA0 and RA3 outputs, while RA1 and RA4 provide the reset signals (note: RA4 requires a 100kW pull-up resistor due to the fact that this pin can sink current but cannot source it). IC3 drives the Status LEDs (green), while IC4 drives the Armed LEDs (red). The two counter circuits work in exactly the same way, so we’ll just concentrate on the way in which IC3 operates. First, note that transistor Q5 is controlled via RA2 on the PIC. This is the enable line and Q5 turns on (via a 1.2kW resistor) when RA2 goes high. Initially, RA0 briefly swings high to reset the counter, after which (depending on the status of the zones) it is clocked by RA1. During this time, Q5 is off and so LEDs11-18 are also all off. Now let’s assume that Zones 1 & 4 have been triggered. Zone 1 has a bit value of “1” while zone 4 has a value of “8”. This means that in order for their corresponding LEDs to be lit, nine clock pulses must be applied to IC3’s clock input, so that outputs O0 and O3 go high. IC1’s RA2 output then goes high and turns on transistor Q5 to light LEDs11 & 14. This arrangement eliminates the need for multiplexing and reduces the amount of wiring required. The associated 330W resistors set the LED currents to a safe level. Alarm & RS232 outputs Ports RE0 & RD1 provide the two alarm outputs and these go high when ever an alarm condition occurs. These outputs can thus be used to trigger an external circuit that requires an active high (eg, the SMS Controller). RC0-RC3 are used for the hard-wired key socket. Normally, these inputs are tied high using 4 x 100kW pull-up resistors. Inserting the key in the D9 key socket then pulls one or more of A “hard-wired key” (actually a D9 connector wired with a 4-bit code) can be used to disarm the alarm if there is a power blackout. February 2006  31 Fig.5: install the parts on the main PC board as shown here but don’t plug in PIC microcontroller IC1 until after the test procedure described in Pt.2. Take care with component orientation. these inputs low, depending on the 4-bit code wired into the key. As mentioned above, this socket is also wired to the RS232 Tx and Rx lines (in parallel with an on-board screw terminal block). Data communication – either via the serial port or key socket – is achieved via ports RC6 & RC7. These communicate with the PC via a MAX232 serial data buffer (IC2). LED10 provides Tx/ Rx indication and is driven by port RE1 via a 330W resistor. In operation, LED10 normally flash­ es at varying speeds, regardless as to whether a PC is connected or not. In fact, there’s a very good chance that the circuit is working correctly if this LED is showing activity. Power supply Fig.4 shows the power supply circuit. It’s based on 3-terminal regulators REG1 and REG2 which provide the required +12V and +5V rails. Power is derived initially from a standard 16VAC plugpack rated at 1.25A. This is fed to bridge rectifier 32  Silicon Chip D1-D4, the output of which is then filtered using a 2200mF electrolytic capacitor and fed to REG1 via diode D5. In addition, the filtered supply rail from the bridge rectifier is fed via D6 and a 180W 5W resistor to a regulator circuit based on zener diode ZD1 and diode D7. This gives a nominal +13.6V rail to recharge the SLA battery at a current of about 20mA. The 12V rail from REG1 is used to power all of the peripheral devices that are connected to the alarm panel – eg, PIRs, sirens, strobes and door strikes. The output from REG1 is also fed to REG2 and its 5V output powers the PIC microcontroller and other logic circuitry. LED1 and its associated 2.2kW current-limiting resistor provide power indication. Diode D5 is there to ensure that this LED can only be powered from the mains-derived supply and not by the battery. This serves as a useful indicator that mains power is present. Diodes D8 & D9 ensure that the battery only supplies power to the circuit in the event of a mains power failure. Here’s how it works: normally, the cathode side of D8 sits at +12V due to the output from REG1. D9’s anode will at most have 13.2V applied to it under load and so no current flows through D8 & D9 while ever mains power is applied. However, when the mains power is disconnected, D8 & D9 become forward biased and the battery supplies a nominal +12V rail to power the peripherals and REG2. Building it Building this unit is dead simple. Fig.5 shows the parts layout on the main PC board (code 03102061), while Fig.6 shows the display board assembly (code 03102062). Before actually mounting any parts, check the two PC boards carefully for etching defects. It’s rare that you will find any problems but it doesn’t hurt to make sure. Also, be sure that the cutouts have been made in the corners of the main control board. These cutouts are necessary for the siliconchip.com.au Table 1: Capacitor Codes Value μF Code EIA Code IEC Code 100nF 0.1µF   104 100nF 22pF   NA    22   22p board to clear the plastic pillars inside the specified case. That done, you can begin the assembly by installing the parts on the main PC board. Install the wire links first, followed by the resistors and MKT capacitors – just check the code tables to decipher their values. It’s also a good idea to check the resistor values using a digital multimeter as they are installed. Once those parts are in, you can install the diodes, zener diode ZD1 and the electrolytic capacitors. These parts are all polarised, so take care with their orientation. Crystal X1 can go in next. It’s installed flat against the PC board with its leads bent at right angles so that they go through the relevant holes in the PC board. A U-shaped wire loop is then fitted over the crystal and is also soldered to its case. This not only secures the crystal in place but also connects its metal case to earth. IC sockets are used for the two ICs and these can be installed next. Be sure to install them the correct way around (ie, with the notched ends as indicated), to guide you when it comes to plugging in the ICs later on. IC2 can be plugged in at this stage but leave IC1 out for now – it’s installed later, after the power supply has been checked out. Be sure to install IC2 the right way around. Fig.6: the display board assembly. Note that connector CON4 is mounted on the track (copper) side of the PC board, while the LEDs have their leads soldered after the board has been mounted on the front panel – see text. Table 2: Resistor Colour Codes o o o o o o siliconchip.com.au No. 14 16 2 16 1 Value 100kW 2.2kW 1.2kW 330W 180W 4-Band Code (1%) brown black yellow brown red red red brown brown red red brown orange orange brown brown brown grey brown brown 5-Band Code (1%) brown black black orange brown red red black brown brown brown red black brown brown orange orange black black brown brown grey black black brown February 2006  33 Par t s Lis t 1 main PC board, code 03102061, 151 x 115mm 1 display PC board, code 03101062, 123 x 188mm 1 D9 female connector 1 D9 male connector 1 D9 backshell 3 16-pin DIL IC sockets 1 40-pin DIL IC socket 2 TO-220 mini heatsinks (6073B type) 1 100mm length of tinned copper wire (for links) 1 1m length 10-way rainbow cable 6 small cable ties (100mm) 2 large cable ties (300mm) 1 internal siren (optional), Jaycar Cat. LA-5255 or equivalent 1 16VAC 1.25A plugpack 1 12V 1.3Ah SLA battery 1 microswitch with extended actuator, Jaycar Cat. SM-1039 or equivalent 1 IP65 ABS case, 240 x 158 x 90mm (Jaycar Cat. HB-6134 or equivalent) 1 front panel label to suit 1 4MHz crystal (X1) 4 12mm tapped standoffs 16 M3 x 6mm screws 2 M3 x 20mm screws 16 M3 nuts 4 M3 shakeproof washers 2 PC stakes Connectors 1 10-way SIL locking pin header, 2.54mm, straight entry 2 10-way SIL locking pin headers, 2.54mm, right-angle entry 2 10-way header plugs, 2.54mm 1 4-way SIL locking pin header, 2.54mm, straight entry Now for the two 3-terminal regulators. These must first be secured to mini-U heatsinks using M3 x 6mm screws, nuts and shakeproof washers. Tighten the nuts firmly, then install the two regulators as shown in Fig.5 and the photo (don’t get them mixed up!), making sure that their heatsinks are well clear of diodes D10 & D11. Note that the two regulators face in opposite directions to each other. Next, install two PC stakes for the battery “+” and “-” connections. These are located just below the 180W 5W 34  Silicon Chip 1 4-way SIL locking pin header, 2.54mm, right-angle entry 2 4-way header plugs, 2.54mm 3 2-way SIL locking pin headers, 2.54mm, straight entry 3 2-way SIL locking pin headers, 2.54mm, right-angle entry 6 2-way header plugs (2.54mm) 13 PC-mount 3-way screw terminal blocks (5mm pitch) Semiconductors 1 PIC16F877A microcontroller programmed with PCCBA.hex (IC1) 1 MAX232 serial transceiver (IC2) 2 CD4040B binary counters (IC3, IC4) 4 BD681 NPN Darlington transistors (Q1-Q4) 2 BC548 NPN transistors (Q5,Q6) 15 1N4004 diodes (D1-D15) 1 13V 1W zener diode (ZD1) 10 5mm red LEDs (LED2-10) 8 5mm green LEDs (LED1 & LED11-18) 1 7812 12V regulator (REG1) 1 7805 5V regulator (REG2) Capacitors 1 2200mF 25V electrolytic 1 1000mF 16V electrolytic 5 100mF 16V electrolytic 4 10mF 16V electrolytic 6 100nF MKT metallised polyester 2 22pF ceramic Resistors (0.25W, 1%) 14 100kW 17 330W 16 2.2kW 1 180W 5W 2 1.2kW resistor, to the left of ZD1 and to the right of D7, respectively. The main board assembly can now be completed by installing the various screw terminal blocks and PC headers. Important: the screw terminal blocks must be mounted with their wire access sides facing inwards. If you mount them the other way around, you will not be able to connect the leads when the board goes in the case. Display board Now for the display board assem- Table 3: Wiring Connectors Connector Leads Length CON1 - CON1 10-way 31cm CON2 - CON2 2-way 35cm CON3 - CON3 2-way 38cm CON4 - CON4 4-way 28cm bly – see Fig.6. Once again, start with the links and resistors, then install the capacitors, transistors, IC sockets and PC headers. The two ICs can then be plugged into their sockets, taking care to ensure that they are oriented correctly. Note that the pin headers on this board are all right-angle types and that CON4 is mounted on the copper (track) side of the board (see photo). Next, fit 12mm standoffs to the four corner positions, securing them with M3 x 6mm screws. That done, the LEDs can all go in but don’t solder their leads just yet. Instead, install them as indicated in Fig.6 (take care with their orientation), then carefully secure the board to the lid of the case using another four M3 x 6mm screws. Make sure none of the LEDs fall out while you are doing this. Finally, the LEDs can be pushed into their matching front panel holes and their leads soldered. Of course, the above procedure assumes that you are building the unit from a kit and the case comes predrilled. If not, you will have to drill the front panel and make the cutout for the keyswitch yourself. The best way to do that it to use the front panel as a template to mark out the hole positions (it can be downloaded from the SILICON CHIP website – www. siliconchip.com.au). Similarly, you will have to drill four holes in the base of the case to take the cable ties that are used to secure the battery, along with mounting holes for the internal siren (if used). Additional holes also have to be drilled in the side of the case (to let the siren sound out), Finally, two large holes are drilled in the base (to the right of the battery) for the external wiring. Final assembly The accompanying photos show how it all goes together. The first step is to secure the battery in position using siliconchip.com.au This is the fully-assembled display board. Note that this prototype version differs slightly from the final version shown in Fig.6. two 300mm-long cable ties. Make sure these are nice and tight – you don’t want the battery to come adrift. That done, you can secure the siren using M3 x 6mm screws and nuts and then install the tamper switch. As shown in the photos, the tamper switch is mounted on the lefthand side of the case, above the PC board. It’s positioned about 7mm below the lip and is secured using two M3 x 20mm screws and nuts. Once it’s in position, bend its actuator arm upwards in an arc, so that the arm is held down when the lid is fitted (ie, to hold the switch open). The PC board is secured to the base using two screws that go into integral pillars at either corner on the bottom. Another two screws which overlap the top edge of the board go into integral pillars in the centre of the case. The construction can now be completed by installing the wiring. This mainly involves fitting plug headers to lengths of multi-way (rainbow) cable to connect the two boards together – ie, for headers CON1-CON4. Table 3 shows the details for these cables. siliconchip.com.au Be sure to connect the leads to the plug headers correctly. It’s just a matter of connecting each lead to its matching pin on each header (ie, pin 1 to pin 1, pin 2 to pin 2, etc. In addition, you have to install the wiring between the D9 female socket and the keyswitch header, after which you can secure the socket to the front panel. You also have to install the wiring to the tamper switch, the internal siren and the battery. Note that there are three terminals on the tamper switch: COM, NO and NC. You have to connect the two leads from the terminal block to the COM and NC terminals, so that the switch goes open circuit when the actuator arm is held down by the lid. Use a red lead for the battery positive connection and a black lead for the negative connection. These two leads are soldered at one end to the PC stakes on the main PC board and are fitted with spade clips at the other end to match the battery terminals. It’s a good idea to cover the connections to the PC stakes with heatshrink tubing. This not only insulates them The microswitch is mounted about 7mm below the lip of the case. Bend its actuating arm upwards as shown, so that the switch is held open when the lid is in place. but also stops the wires from flexing and breaking at the solder connections. Finally, use cable ties to bind the wiring together, as shown in the lead photo. This not only keeps it tidy but also ensures that it folds back neatly into the case when the lid is closed. Next month That’s all we have space for this month. In Pt.2, we’ll give the test procedure, detail the software and describe the hard-wired key­switch and SC the optional keypad unit. February 2006  35 Charge your iPOD without connecting it to a computer! Build a charger for your or MP3 player By JOHN CLARKE This Charger can be used to charge your iPOD™ or MP3 player without connecting to your computer’s USB port. It can be powered using a DC plugpack or from 12V DC in your car and it can also be used to power any accessory normally run from a USB port. U SING THE USB PORT on your computer to charge your player’s batteries is not always practical. What if you do not have a computer available at the time or if you do not want to power up a computer just for charging? Or what if you are travelling? Chargers for iPODs and MP3 players are available but they are expensive and you need separate models for charging at home and in the car. SILICON CHIP’s new charger can be used virtually anywhere. While we call the unit a charger, it really is nothing more than a 5V supply that has a USB outlet. The actual charging circuit is incorporated within the iPOD or MP3 player itself, which only requires a 5V supply. As well as charging, this supply can run USB-powered accessories such as reading lights, fans and chargers, particularly for mobile phones. The supply is housed in a small plastic case with a DC input socket at one end and a USB type “A” outlet at the other end, for connecting to an iPOD or MP3 player when charging. A LED shows when power is available at the USB socket. Maximum current output is 660mA, more than adequate to run any USBpowered accessory. (The specification for the computer USB 2.0 port requires the USB port to deliver up to 500mA at an output voltage between 5.25V and 4.375V). Circuit details The circuit is based around an Fig.1(a): the basic scheme for a switchmode power supply. Voltage regulation is achieved by rapidly switching S1. 36  Silicon Chip MC34063 switchmode regulator. This has high efficiency so that there is very little heat produced inside the box, even when delivering its maximum output current. The circuit is more complicated than if we used a 7805 3-terminal regulator but since the input voltage could be 15V DC or more, the voltage dissipation in such a regulator could be 5W or more at 500mA. and 5W is far too much for a 7805, even with quite a large heatsink. Hence, we have taken the switchmode approach. This is illustrated in Fig.1(a) and involves a switch (S1), inductor L1, diode D1 and capacitor C1. When the switch is closed, current flows through inductor L1 into the load. The current (Path 1) slowly builds up from zero to the peak value, as shown in Fig.1(b). When this peak current is reached, the switch opens and current from the inductor flows through diode D1 to discharge the inductor energy into the load. This current path is shown as Path 2. Capacitor C1 is included to act as a reservoir of power to smooth out the voltage produced across the load. The output voltage is dependent on the load and the ratio of time that switch 1 is closed to when it is open. siliconchip.com.au iPOD It is also dependent on the peak current through L1 and the input voltage. This type of circuit can be very efficient because voltage control is achieved by rapidly switching the input. The small amount of power dissipated is mainly due to voltage losses in the switching device and diode D1. Fig.2 shows the full supply circuit, which is based on an MC34063 switchmode controller IC. Its internal schematic is shown in Fig.3. The switching function of S1 [in Fig.1(a)] is provided by the internal transistor (Q1). The internal oscillator sets the switching period, while the “Ipeak sense” limits the current flowing in inductor L1 by controlling the on-time for transistor Q1. The 1.25V reference and comparator provide a feedback arrangement to monitor and control the output voltage. Power from the DC socket passes through diode D2 and slide switch S1 to IC1. D2 protects against reverse Fig.1(b): this diagram shows the current through L1 when S1 is closed (blue) and opened (red). siliconchip.com.au Fig.2: the complete circuit is based on a dedicated MC34063 switchmode controller IC. February 2006  37 Fig.3: inside an MC34063 switchmode controller IC. The internal oscillator sets the switching period, while transistor Q1 does the switching. polarity and the adjacent Trans­ ient Voltage Suppressor (TVS1) clamps any fast spikes which may be riding on the input supply. Further filtering is provided by a 470mF low-ESR (Effective Series Resistance) capacitor. As previously described, current is switched to L1 using the internal transistor in IC1. In operation, the three paralleled 1W resistors between pins 6 & 7 monitor the current through L1. When the current reaches 1A, pin 7 becomes 300mV lower than pin 6 and the internal transistor switches off. The energy stored in L1 is then dumped into capacitor C1 via Schottky diode D1. The resulting output voltage is filtered using a 1000mF low-ESR capacitor. Output voltage control Pin 5 of IC1 monitors the output via a voltage divider consisting of a Fig.4: this switching waveform was measured across the output with an 8W resistive load, resulting in a current of 625mA. Note how the switching shows signs of “hunting”, as the circuit constantly maintains a 5V output. 1kW resistor, trimpot VR1 and a 560W resistor to ground. VR1 sets the output voltage to 5V. Zener diode ZD1 and the 10W resistor are included to catch any output overshoot voltages which can occur if the output load is suddenly reduced. As explained, the switching of L1 controls output regulation. If the load is suddenly reduced, the only way IC1 can stop any voltage rise is to prevent any switching of power to L1 and let capacitor C1 drop back to 5V. So, to prevent voltage overshoot, ZD1 begins to conduct when the voltage reaches 5.1V, with the current through it limited by its series 10W resistor. In normal circumstances, when the output voltage is correctly set to 5V, ZD1 will not conduct unless the voltage rises momentarily. However, if VR1 is set so that the output voltage is higher than 5V, ZD1 conducts Specifications Output voltage............................................................................................ 5V Output current.................................................... 660mA maximum for 5V out Input voltage range.................................................................9.5V to 15V DC Input current requirement................. 500mA for 9V in, 350mA for >12V input Input current with output shorted.................120mA at 9V in, 80mA at 15V in Output ripple...................................................14mV (from no load to 660mA) Load regulation..............................................25mV (from no load to 660mA) Line regulation..........................20mV change at full load from 9 to 18V input No load input current............................................................................. 20mA 38  Silicon Chip continuously. Because of this, the range of adjustment for VR1 has been deliberately restricted to limit the output to be no more than 6.5V, under worst-case conditions. This worst-case setting occurs when VR1 is set fully clockwise (towards the 560W resistor) and when VR1 is 20% high in value and the reference for IC1 is at its maximum at 1.32V (typically, IC1’s reference is 1.25V but this could be anywhere within the range of 1.18V to 1.32V). With 6.5V at the output, there will be 140mA through ZD1 and the 10W resistor. Dissipation in ZD1 will be 0.7W (below its 1W rating), while dissipation in the 10W 0.5W resistor will be 0.2W. When VR1 is set correctly, the output is protected against producing transients above 5V. Should the output become shorted, the fault current will be limited to a safe value at or below 120mA, as set by the paralleled current sense resistors. Construction All the components for the charger are mounted on a PC board coded 14102061 and measuring 79 x 47mm. This board is mounted upside down in a small plastic case measuring 83 x 54 x 31mm.The screw covers for the lid then serve as rubber feet. Begin construction by checking the PC board for breaks or shorts between the copper tracks. Repair these as necessary. That done, make sure the holes are the correct size for each component siliconchip.com.au Fig.5: install the parts on the PC board as shown here. Inductor L1 is secured using cable ties. Fig.6: the full-size etching pattern for the PC board. and check that the PC board clips neatly into the integral side pillars in the box. The component overlay for the PC board is shown in Fig.5. First, insert and solder the resistors, links and trimpot. You should check the resistor values with a digital multimeter. Make sure IC1 is mounted with the orientation shown. The two electrolytic capacitors are mounted on their side to allow clearance in the box; make sure they are mounted with the correct polarity. LED1 is mounted with cranked leads so that it can poke through a hole in the side of the case. Again, take care with its polarity. There are four diodes on the PC board, including the zeners and TVS. Take care to ensure that all polarised parts (ie, the IC, diodes and electrolytic capacitors) are correctly oriented when building the PC board. Make sure you insert the correct ones in each position and with the correct orientation. Once they are in, insert and solder in the two PC stakes followed by slide switch S1. The latter is mounted so that the top of its body is 10mm above the PC board surface. Inductor L1 is wound on a powdered iron toroid with 0.5mm enamelled copper wire. Wind on 75 turns in two layers spaced evenly around the core. The wire ends must be scraped clean of enamel and tinned, before soldering. Alternatively, if the wire is coated with red enamel, this can normally be melted off with the tip of your soldering iron. The toroid is secured to the PC board with two cable ties. These Table 1: Resistor Colour Codes o o o o o o siliconchip.com.au No.   1   1   1   1   3 Value 1kW 560W 470W 10W 1W 4-Band Code (1%) brown black red brown green blue brown brown yellow violet brown brown brown black black brown brown black gold gold pass through holes in the PC board. Fig.7 shows the drilling details for the case. You have to drill holes for the DC socket and LED in one end, the switch at the top and the USB socket in the other end of the box. Mark these out and drill and file as necessary. Testing Initially wind VR1 fully anticlockwise. That done, set your multimeter to read DC volts and connect it between terminals TP1 and GND. Apply power to the input, switch on and adjust VR1 so that the voltage is 5V. This can generally be set to within Table 2: Capacitor Codes Value μF Code EIA Code IEC Code 100nF 0.1µF   104 100nF 470pF   NA   471 470p 5-Band Code (1%) brown black black brown brown green blue black black brown yellow violet black black brown brown black black gold brown NA February 2006  39 Par t s Lis t 1 PC board, code 14102061, 79 x 47mm 1 UB5 transparent blue plastic case, 83 x 54 x 31mm (Jaycar HB-6004 or equivalent) 1 12V DC plugpack fitted with a 2.5mm DC plug and rated at 350mA minimum 1 fused cigarette lighter socket lead with 2.5mm DC plug 1 SPDT slider switch (S1) (DSE P7602 or equivalent) 1 USB PC-mount “A” socket 1 PC-mount 2.5mm DC socket 1 powdered iron toroidal core measuring 14.8 x 8 x 6.35mm (Neosid 17-732-22, Jaycar LO-1242 or equivalent) 1 2m length of 0.5mm enamelled copper wire 1 50mm length of 0.7mm tinned copper wire 1 M3 x 12mm countersunk screw 1 M3 tapped x 12mm Nylon spacer 2 100mm cable ties 2 PC stakes 1 1kW horizontal trimpot (VR1) Fig.7: here are the drilling details for the plastic case. The square cutouts are made by drilling small holes around the inside perimeter, knocking out the centre pieces and filing to shape. Semiconductors 1 MC34063 switchmode controller (IC1) 1 1N5819 1A Schottky diode (D1) 1 1N5404 3A diode (D2) 1 P6KE27A 600W transient voltage suppression diode (27V) (TVS1) 1 5.1V 1W zener diode (ZD2) 1 3mm green LED (LED1) Capacitors 1 1000mF 16V low-ESR PC electrolytic 1 470mF 25V low-ESR PC electrolytic 1 100nF MKT polyester 1 470pF miniature ceramic Resistors (0.25W, 1%) 1 1kW 1 10W 1/2W 1 560W 3 1W 1/2W 10% 1 470W 20mV of 5V (ie, 4.98V to 5.02V) using the trimpot. Check that LED1 lights. If it doesn’t, check that it is the right way around. If there is still no power indication, use a multimeter to check for voltage at 40  Silicon Chip The PC board is clipped upside down into the bottom of the case and is secured using an M3 tapped Nylon spacer. This spacer ensures that the board doesn’t move when the slide switch is operated. pin 6 of IC1 and for a similar voltage at pins 1, 7 & 8. If there is no voltage here, perhaps the DC socket plug has the wrong polarity. The plug should have the positive to the centre hole and the negative to the outer case. When testing is complete, the PC board can be clipped into the case, making sure the LED protrudes from its hole in the side of the case. The section of PC board directly below the switch will need supporting so it is not pushed out of position when the slide switch is operated. We used an M3 tapped Nylon spacer in the side of the case to support the PC board and this is secured using an M3 screw. To do this hold the spacer tightly against the PC board directly below the switch and mark out the position of the hole for the screw. The transparent box makes positioning of this hole easy. Now drill out the hole and secure the spacer. Finally, fit the lid and insert the rubber feet into the screw holes. SC Footnote: iPod is a trademark of Apple Computer, Inc. siliconchip.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.bitscope.com Do-It-Yourself SERVICING So you would like to service electronic gear for yourself and your friends. Provided you have some basic test equipment such as a multimeter and oscilloscope, there is a surprising range of electronic equipment than can be repaired, provided you have the time and persistence to do it. This article gives some useful hints and tips. B y D AV I D R E I D E LECTRONICS IS A BLACK art to the uninitiated. They marvel at all those colourful little components and wonder how on earth we “experts” can navigate that secret world armed only with a schematic diagram – which to them is somewhat akin to a magician’s grimoire written in a long-dead language. That is why, upon seeing that you own a soldering iron and multimeter, your next-door neighbour may disappear briefly, only to return with his TV, DVD player, lawnmower or quite possibly, his wife’s pacemaker. “I don’t suppose you’d mind having a look . . .” You either decline and explain that it’s not really your field and that it should be seen to by an expert or you spend a couple of hours poking around inside, after which you say “look, it’s not really my field and it should be seen to by an expert”. In reality though, many fault-finding techniques are really just variations on common sense. You might be surprised at just how many repairs you can successfully complete. Play it safe Electrolytic capacitors degrade with age and heat. Inspect them carefully for signs of leakage and bulges in the case (especially the top). 42  Silicon Chip Get a portable Residual Current Device circuit breaker and “don’t leave home without it”. Never assume that you don’t need one or assume that it will magically protect you from every eventuality. It won’t. Never dismantle any unit with the 240VAC mains still connected. It is too easy to inadvertently touch exposed circuitry with the metal lid or drop a screw inside. Similarly, never power up a dismantled unit unless you are absolutely certain of the voltage distribution inside. Some manufacturers physically isolate mains and low-voltage circuitry siliconchip.com.au but it is common to find a single PC board with everything mounted on it, including the mains transformer. Tape exposed mains connections and never make assumptions. Treat every power supply as if every component were live, as there are many supplies where this is the case. If you do not find a decent-sized mains transformer in the unit, be especially suspicious, as you will probably be dealing with a switchmode power supply. In the case of colour television sets, they frequently have a live chassis. This means that it is not safe to touch any part of the electronics, including anything that looks like an earth, while the set is operating. If you feel uncertain as to the nature of a power supply, limit yourself to passive tests and measurements with the power off. Watch very carefully for high-voltage electrolytic capacitors. These are common in switchmode power supplies and 300V of DC can easily blow the tip off your favourite screwdriver! Finally, don’t work alone but ask for children to be removed from your vicinity, as they can be a dangerous distraction. Video heads are very brittle, and can be snapped by a cotton bud. Use a clean, flat piece of card moistened with alcohol. Initial observations Many faults are intermittent or become intermittent as soon as a technician enters the room, so keep your screwdriver holstered while you determine what the symptoms are. Check every function on the unit, as many faults have multiple symptoms which collectively point directly at the faulty circuit. Consider a DVD player, for example In spite of the owner’s claim that it “isn’t working”, a thorough check may reveal that the disc tray opens and closes, that the display is illuminated and that it seems to be spinning up and playing. As it turns out, most of it works and the actual fault is that there is no audio. When you dismantle the unit, you may find that the fault is gone but because you have done some preliminary work, you will have an idea where to look and it will later come as no great surprise if you discover a muting fault or a hairline fracture of the PC board next to the line output sockets. You repair the crack, hand the unit back and all that remains is to congratulate yourself on how terribly clever you are. siliconchip.com.au Don’t be tempted into thinking that you can adjust the fault out of a unit by playing with trimpots. It’s highly unlikely and can render many appliances inoperable. Sometimes, this initial analysis can save you the grief of attempting a dead-end repair. You have a friend who wants his beloved tape deck repaired. The fault is similar: no sound. However, you noticed that the meters are showing a signal on playback, so you very cleverly grab some headphones. Yes, there is audio. However, the speed is all over the place, one of the meter lamps is gone and the heads have a groove in which you could park a bicycle. Can you get the parts required? How badly does he want it fixed? Is he willing to pay what it’s likely to cost? If you are serious about saving time, see if you can get the brand and model number of the unit and hit the web. More and more schematics are finding their way online and there are some very specific fault FAQs on various products. Even if you can’t find something on the exact model, February 2006  43 Switchmode power supplies are potentially lethal. Some of the parts operate at 240V AC mains potential and that can include heatsinks. Never work on a switchmode supply with power applied unless you are an expert and know exactly what you are doing. something similar will often yield useful clues. Look, listen & sniff Many faults can be found by simple observation, so have a careful look around before you start exploring with your meter. You might find a plug that isn’t seated properly in its socket or a solder splash bridging two tracks on a PC board. Either way, the fault could rectify itself while you are attempting to fix it. In many cases, components actually look faulty; transistors that have cracked open, swollen or ruptured electrolytic capacitors or obviously overheated resistors. In the case of the latter, do not touch the resistor until you have had a chance to measure it. They have a nasty tendency to disintegrate at the slightest touch, leaving you with no idea of the original value. And you you’d be surprised how many technicians will take the back off a TV, take one sniff and mutter “caps”. Poor connections Poor connections are responsible for a huge proportion of faults. These come in a multitude of forms: dry solder joints, plugs and sockets (dirty or badly crimped, including edge connectors and IDC plugs), switches, 44  Silicon Chip board fractures and dirty pots. This brings us to the question of contact cleaning. There are dozens of contact sprays around and they all excel in their specific applications. However, they can cause trouble when used inappropriately. The only type of spray that can be used with confidence in most circuits is one designed for cleaning television tuner contacts or a plain isopropanol spray. Don’t fill your VCR with something designed for auto electrical systems. There are two cases where contact cleaners of any type should be used with caution: slide potentiometers and conductive rubber switches. In the case of the pots, contact cleaners can wash the lubricants out along with the dirt, causing them to stick and bind. Try to drop a tiny amount directly onto the carbon tracks. This often cures them. The rubber switches can be hard to recognise, but they are so common that it is better not to clean any switch unless you are reasonably sure that it has metallic contacts. I have had three memorable experiences involving sprays. Once, I was using a common furniture polish to restore an electronic organ. As I wiped the rag across the faces of the tab switches, the red lettering, which was embossed into the faces of the switches, disappeared! On another oc- casion, also with an electronic organ, a customer decided to try spraying the key contacts himself. However, he also liberally sprayed the plastic keys, chilling them to the point where they became brittle and snapped under tension! Finally, a totally predictable near disaster was caused by yours truly. My wife had been complaining of some intermittent fault in the washing machine. I wasn’t in the mood for any serious fault-finding, so I removed the top cover and soaked the beast with my favourite contact cleaner. I leaned up close to observe the results of my handiwork and hit the ‘go’ button. The ‘explosion’ that ensued was worthy of Francis Ford Coppola. I was unharmed and considered myself fortunate to have learned my lesson in an outdoor laundry, rather than in a customer’s living room! The ubiquitous dry joint Ubiquitous: u-bi’kwi-tus. (adj). Existing or being everywhere; omnipresent. Although common, dry joints (DJs) can be hard to locate as many perfectly sound joints look dry and often a crook joint looks fine. Fortunately, some components form DJs more frequently than others so you can usually save time by looking at the most likely culprits first: ie, any components that are physically large, conduct high currents or get hot. These three factors usually go hand in hand. The expansion and contraction associated with heating and cooling can fatigue joints, as can the vibrations from improperly secured large components. Consequently, the areas that are worth inspecting are power supplies, amplifier output transistors and drivers, servo motor drive transistors, TV line output transistors and so forth. Technically speaking, the best way to rework a DJ is to completely remove the old solder, clean the joint and then resolder it. In the real world, most of the time you will get away with reheating the old joint and adding a little fresh solder. If the joint doesn’t look right when you are through, you can always go back and do it the hard way. While we’re on the subject of soldering, one of the greatest causes of damaged PC boards is the act of removing an IC from a double-sided board. Unless you have a good vacuum siliconchip.com.au Sometimes it’s easier to remove a part by cutting its pins rather than desoldering it and it’s usually easier on the PC board tracks as well. One the part is out, you can desolder and remove the individual pins. desoldering station, the safest way is to carefully cut the component’s pins off one by one and then desolder them individually. Surface-mounted components are a different matter entirely. I’ve seen boards destroyed by salesmen who were demonstrating hot-air SMD rework stations. Many components are glued to the board, so it can be a challenge to remove even a 3-legged device. If you are desperate to have a go anyway, find a wrecked board and get some practice. You need an ultrafine tip, fine gauge solder and a very narrow probe that will allow you to lift individual legs clear of the board. Use a magnifier to make certain that all the legs are clear and then attempt to rotate the component on the board, rather than pulling it off. The glue is very strong but usually quite brittle. Pulling on the part might lift tracks but twisting it will often make it come away with very little force. All of the above presupposes that you have found a dry joint to resolder. If you cannot locate it visually, a little freeze spray often helps. Gentle tapping of components or the PC board with a (non-conducting) screwdriver often helps to localise the fault to a particular area. If all else fails, you can always try tracing out the fault. solder mask from the tracks and polish the copper at the same time. Tin the tracks, using an absolute minimum of solder and tack down the finest tinned copper wire you can get your hands on, such as 3A fuse wire. spot. If gently flexing the PC board seems to have an effect on the fault, then you may well be looking for a fracture. In this case, try removing the board completely and looking at it with a bright light behind it. Many boards are translucent to some degree and frequently, when backlit, the extent of the fracture will show up clearly. Again, large components are more likely to have fractures beneath them. Look closely around any mounting holes and any components which protrude into the “outside world”, such as volume controls, input and output sockets, etc. The repair of fractures is an art in itself and a shoddy job can introduce more problems than it cures. Modern equipment often has very fine tracks, narrowly spaced. The trick is to get the tracks really clean on both sides of the fracture. An ink eraser will remove the Component failure Even without a schematic, it is possible to pin-point many component failures, once you know where to look. Those same components which I mentioned as being prone to DJs are also the most likely to fail. The most reliable electronic appliances are those with little mechanical complexity and low power consumption. Hifi tuners and equalisers are generally more reliable than amplifiers, VCRs and DVD players. To begin with, don’t get too theoretical with the problem. Check the components which seem to have some bearing on the problem, starting with Fractured PCBs are remarkably common. Backlighting helps determine the extent of the crack. Board fractures Board fractures can be difficult to siliconchip.com.au February 2006  45 Warning labels are there for a purpose. Reading them is good for the soul, among other things. easily-tested components like output transistors and rectifier diodes. Desolder at least two legs of any transistor before measuring it. Any low value resistor is worth measuring. Often these are used as fuses in low voltage rails. Electrolytic and tantalum capacitors are also worth a look. These are often used to provide localised filtering of power supplies and can present real problems when they go short circuit. A short circuit on a 5V rail can be a nightmare in a digital circuit, but always look at the bypass caps before you start removing LSI chips. Most capacitors have 38 fewer legs to desolder! You can often determine what voltages should be present in a circuit without needing a schematic if Use a quality photographic blower-brush to clean the lens of a CD or DVD player. you have a degree of familiarity with the components involved. 3-terminal regulators are wonderful devices - they have their voltages printed on them. Integrated circuit families usually work off predictable rails, so a quick peek at pin 14 of most TTL ICs will often save time. Look for other old standards, such as LM741s, 555 timers, etc. Even if you have no idea what an IC does, it should usually have some sort of rail on one of the pins! Because much consumer equipment tends to be under-engineered, you often find that filter electros in power supplies are working very close to their rated voltages, so that 4700mF 63V cap in the power supply is not likely to be filtering the 5V rail. Transistors usually fail either open or short-circuit, so don’t worry about beta, hfe and all that other stuff unless you want to make a career of one repair. Diodes frequently go leaky and this is easily checked with a multimeter but make sure you are measuring leakage and not the resistance between your fingers. Resistors tend to go open-circuit and mostly these will be either very low or fairly high in value; less than 1kW or more than 100kW. This may sound like a very simple approach and may lead you to think that there is not much science involved in electronic repair. However, the really hard repairs can present such a challenge that a busy technician won’t have the time to worry about style on the easy ones. Dead shorts PC boards with surface-mount components are easily damaged during rework due to the small pad sizes. Note that most components are physically glued to the board as well as being soldered. 46  Silicon Chip A short circuit on a power supply rail can be one of the most difficult faults to find. Imagine a shorted bypass capacitor on a 5V rail on a good-sized logic board. In this case, practically every single component will be connected directly to the rail and any one of them could be the culprit. The real trick is not be overwhelmed by the magnitude of the task. First, disconnect every single item which is not soldered in - plugs and sockets, edge connectors, socketed ICs, etc. Check the resistance to ground after each removal. Next, desolder the “easy” components; large electros, regulators, transistors and so on. If you have access to a schematic, use logic (the intellectual type, not the electronic kind!). If your short circuit measures only a few ohms, then a transistor which has a 1kW emitter resistor siliconchip.com.au is highly unlikely to be the cause of the fault. However, if the same transistor had a 10mF capacitor across that 1kW resistor, then it would be conceivable for the capacitor to have developed an internal short, which in turn, could cause the transistor to go shorted. Thirty seconds taken to establish that a component could not possibly be the cause of the fault can save a lot of fruitless soldering. There is another approach which is a little unorthodox and if you decide to try it, you should be aware of the possible side effects. It involves attempting to ‘smoke it out’. By applying a power source to the rail (at no more than the rail’s rated voltage and preferably somewhat less) at a reasonably high current, it is often possible to heat the component enough to cause it to smoke or at least enough to make it hot. However, you should know that you could be forcing the board tracks to carry considerably more than their rated current. In most cases, I am reluctant to use more than 500-odd milliamps. As long as you do not exceed the rated voltage of that particular rail, the other components on that rail should be safe enough, even if the short should actually burn itself out. Of course, this assumes that you have access to a current-limited supply. If you cannot set the current separately from the voltage, give this technique a big miss. You will need to use your own judgment on this one, as it does involve potential risk to the PC board. Know your test gear I am continually surprised to see experienced technicians making fundamental mistakes in taking measurements. Because we mainly use high impedance digital meters these days, many of us tend to be blissfully ignorant of the bad old, “20kW/V” days and usually, this is a blessing. However, a 10-megohm input impedance is still a long way from being an open-circuit and loading effects can happen. Similarly, few crystal oscillators function properly, if at all, unless your oscilloscope probe is set to the X10 position and even then, they might not run. Nevertheless, I saw a very senior Technical Officer employed by a major manufacturer who was unaware of the loading effect. A typical multimeter will have poor frequency response on its AC volts siliconchip.com.au Do basic safety checks before and after every repair. Is there earth continuity? Is the appliance lead damaged? Is the polarity correct? This mains lead has obvious damage and must be replaced. ranges. However, if you have access to a meter with a good AC bandwidth, you can use it to trace an audio signal through an amplifier. To fix or not to fix It’s a sad fact that many appliances today are not economically repairable. DVD players are essentially throwaway items, VCRs aren’t far behind and even TVs are cheaper than ever before in real terms. If you get a sense of personal satisfaction from being able to get something going again or if you are fixing your own appliances, then it is probably worthwhile spending a few hours tinkering. However, be careful not to get into a vicious circle in doing repairs for friends. The scenario can go like this: you agree to look at something. A week goes by and you still haven’t got around to taking the covers off. The guilt kicks in, so you spend a while and get some idea of the fault. You order a part and a week later you fit it. And it still doesn’t work. With every day that goes by, you will feel more pressure to complete the repair, although the chances of you being able to fix it are decreasing at the same time. The trick is to be able to cut your losses and cut them early. Final checks There’s one important aspect to repairing an appliance which is easily overlooked. You must be certain that you have not overlooked a fault which might render it unsafe or worse, introduced one. For a non-professional, this is primarily a moral responsibility. Although there is an Australian Standard (AS/NZS 3760:2001) which details the tests required after repair of any appliance, it is unrealistic to expect full compliance from someone who is performing a “homer” for a mate. Nevertheless, basic tests can (and should) be performed which go some of the way towards keeping your friends and family intact: Inspect the power lead for any damage. • Check the wiring of the plugtop for correct polarity and anchoring of the cable. • Check the strain-relief where the cable enters the appliance. • Check that external fuses are of the correct rating. • Ensure that the resistance of the earth connection from the power plug to any exposed metal surface is less than 1W. • Measure the resistance from the Active pin to Earth and from the Neutral pin to Earth. Both should measure open circuit. Finally, note that these tests are not a substitute for a proper high-current earth-bond test, nor for a high-voltage leakage test, but they will give you an indication of gross conditions and a warm and fuzzy feeling when you hand the appliance back. SC February 2006  47 SERVICEMAN'S LOG Metz TVs & Car Engine Management This month, for a change, I describe some really nice Metz LCD TV sets and take a look at an unusual degaussing circuit. There’s also a look at the problems car engine management systems can create. Don’t lose your keys – on some models, it can cost you heaps! Some of the “golden moments” of my career are when I am invited to a trade seminar. More often than not, these are judged afterwards by how good the food, drink and snacks were. Occasionally, however, the lecture content can eclipse the hospitality. Recently, I had the good fortune to attend a technical seminar by Metz. Now before I hear you say “Metz who?”, Metz is a small German family company that has been producing TVs since 1951. Its products are marketed locally by Audio Products Group Pty Ltd through 50 dealers around Australia. In fact, I had attended another course held by them in 1999, with the same German lecturer who has a real sense of humour! What makes this all the more amazing is that Metz is one of only about five TV manufacturers left in Europe and the only one besides Loewe left in Germany. So how does a small company like Metz survive while much larger competitors go to the wall? I can only speculate that their small size makes overheads low. In addition, they have a relatively small but up-market, high-quality product range and the company is customer and service orientated. Metz LCD-TFT TV sets The really interesting part of the lecture was the brand new Metzdesigned LCD-TFT TVs. These are 32-inch (81cm) and 37-inch (94cm) high-definition units with Philips/LG display panels (seventh generation – I think). LCD panels have really have improved out of sight in recent years. 48  Silicon Chip First, the scare about pixel dropout (1 pixel = 1R, 1G and 1B liquid crystal) is no longer really the issue it was just a few years ago. The standard nowadays is zero white pixels and a maximum of four whole dark pixels at least 100mm apart from each other, anything else being unacceptable In fact, you would be very hard pressed to find any missing pixels and if they don’t fail in the first year, it is unlikely they will ever fail (unlike plasma screens). The Metz sets have a 5-year warranty but the life of the display is expected to be 50,000 hours or 20 years! The displays are backlit using 20 horizontal fluoro tubes emitting up to 500 candlelight per square metre (CRT = 450, PDP = 600). These have a life of 60,000 hours and you can really feel the heat on the front screen. The elements in an LCD are essentially viscous light switches that turn the light off. The much quoted response time is now down to 8ms “Grey to Grey” (GTG), as opposed to “Black to White” which is even quicker. By contrast, a CRT TV has a response of 10ms, the same as a plasma screen. In operation, the liquid crystal rotates 360°, which maintains its viscosity and stability and increases its Items Covered This Month • • • Metz LCD TV sets Metz 600plus series TV receiver LG RT-42PZ45V plasma display panel (RF-03FA chassis) lifespan. And because grey is the hardest to achieve (ie, where the crystal is at 45°, 135°, 225° or 315°), the set uses an overdrive circuit to accelerate the response time. Normally, it requires just 2V to rotate the crystal but for grey, Metz initially uses 5V which then drops to the usual 2V figure. The contrast range on current LG plasma displays (PDP) is now advertised at 10,000:1 (previously, they were only 1000 to 1). However, this is irrelevant, as the eye cannot discern better than 600:1 and Metz sets are 800:1. The dynamic range of 1600:1 is also improved by varying the back lights. This also helps to improve the resolution which is currently 1080i/720p (pixels per line) or a maximum of 1366 x 768 in 16:9 widescreen format. No interlacing LCD TV sets do not require interlacing and in fact normal TV pictures have to be de-interlaced (for motion), digitised 8-10 bit and vectored into 100Hz sloping contour steps for contrast and resolution. The sets are also fitted with auto-contrast (this varies with lighting conditions) and the screens can be viewed at angles of up to 176° in both the horizontal and vertical directions without degradation. The Milos 32S set we were shown performed spectacularly well as a computer monitor and is fitted with an SD (standard definition) tuner and an MPEG decoder with a second SD tuner to get true PIP (picture-inpicture). The set comes with a comb filter, noise reduction, HiText and Teletext as standard. It has a range of inputs: three SCART (one extra high definition, particularly for recording), an HDMI (High Definition Multimedia Interface) with HDCP (High Definition Digital Copy Protection), VGA and DVI-I/D (Digital Video Interface). The digital inputs go directly to the SCALER board that drives the LCD. There are also DVD component and AV inputs, plus many other features which I haven’t mentioned (eg, prosiliconchip.com.au Fig.1: the automatic degaussing circuit in the Metz 600plus series. It uses an extra winding on the chopper transformer and unlike other sets, operates each time the set is switched from standby to full on. gressive scan to T & A RS232C HiFi Component which isn’t applicable for Australia). The set also has 20W audio output power, SPDIF (Digital Sound Input), SRS-WOW (which increases the spatial effect) and a bass loudness control. And in a Dolby 5:1 surround system, the set’s own speakers can be used as the centre channel. The set has only been in production about three months and the power supply presented a technological challenge for Metz. They initially chose a Panasonic design which was then redesigned it to suit the rest of the set. The power supply is the only board that can be repaired to component level and is a fully-wired chassis with no surface-mounted components. It fully complies to the EU standard for power factor correction. This switchmode design operates at 50kHz using a Viper IC and has multiple power rails (D) that are always on and others (DS) that are switchable. It is fully regulated and can work with or without a load and features full protection and fast muting. The remaining five plug-in boards are available only on an exchange basis. They are for analog video signal processing (EA), digital signal processing (FS), sound output (NF) and for the tuner TH/DS options. There’s lots more I could go on about this great set and I am working on its one and only problem – the $6000 I need to own it! However, in the oversiliconchip.com.au all scheme of things, that’s still pretty competitive pricing. You can check out more at www.audioproducts.com.au and www.metz.de/en. 600plus series We also brushed up on the 600plus series of CRT TV chassis, covering the last five years of faults. These sets are so reliable I have seen only a few of them for repair, which is not good for the bottom line – at least, from my point of view. One of the features Metz has is an automatic degaussing circuit that operates whenever switching from standby to full on. This circuit relies on an extra winding on the chopper transformer (T1705) – see Fig.1. In the “standby burst” mode, the voltage developed is insufficient for zener diode D1706 to conduct. However, when the set changes to “full on” mode, the voltage rises and the zener conducts and turns an SCR (Ty1710) on. As shown, the SCR is connected between the positive (anode) and negative (cathode) terminals of a bridge rectifier (D1710). In addition, one side February 2006  49 Serviceman’s Log – continued of the AC mains is fed via a 2.5A fuse to one side of the bridge, while the other side goes to the PTC side of the degaussing coil. In operation, the bridge rectifier doesn’t actually rectify anything – rather, it’s there to direct the AC mains through the SCR and into the PTC and degaussing coil circuitry. The circuit draws a maximum of 1.5A at 240V. However, when one of the diodes fails, it gives a weird purity picture effect of concentric coloured rings that you would normally attribute to the PTC (Positive Temperature Coefficient) resistors. If the set is dead with no standby LED, check the following four resistors: R1706, R1710, R1701 and R1702 (1MW). These supply the start-up voltage for the IC controller but can go high in value, causing pin 11 to drop below the 1.3V starting threshold. If the main chopper FET (Tr1710) goes short circuit, be sure to also check R1705 as it will inevitably be open circuit. In addition, the control IC on 50  Silicon Chip board AN will have to be changed because 300V will have been applied – via the shorted FET – to its control output on pin 13, thus destroying it. When you have finished repairing it, always check D1811 (the main B+ = 135V rectifying diode), as well as C1811 across it. The D25 rail should also be checked for shorts before switching on. One interesting fault is when you get a small picture (or even a dead set). In that case, check the D138 rail. If it’s low, check zener diode ZD1786, which is critical. If the accompanying transistor does not switch off completely, then the primary goes into burst mode. The collector of Tr1870 must be at 0V. For a “no-sound” fault, check that D1845 isn’t leaky before checking the sound output IC. The fast mute circuit is +4.5V and not negative. Obscure fault One rather obscure fault that has been tracked down by Metz engineers concerns no sound and intermittent no digital tuner. What’s happening here is that when the set “boots up” from cold, the microprocessor intermittently doesn’t recognise the DVB and sound boards. However, if you subsequently switch the set off and then on again, it will work perfectly. What happens on switch-on is that the microprocessor looks for all the built-in modules (just like plug and play in an ordinary PC). However, if the supply voltage to the micro is slow in coming on, it doesn’t always pick up these modules. This delay is caused by capacitor C1880 going low in value. Replacing it and fitting a 15kW resistor in parallel with R1882 fixes this problem. Another problem concerns the 693 chassis. If the line output transistor fails and/or the picture jitters when cold, check C1210 and C1203. In common with other Metz sets, this set has a very sensible way of troubleshooting the line output stage – one that I haven’t seen since 1976. When you have line output transistors instantly failing for no apparent reason, there is a service link plug bridge that disconnects the +138V rail and allows you to connect the +25V rail instead. The D25 rail will let the circuit still work (at a reduced amplitude), allowing you to scope the waveforms without destroying any further devices. When the flyback transformer arcs over or fails, you can expect problems other than a failed line output transistor. You should also check the east-west modulator diodes D1218 and Tr1505, as well as C1261 in the protection circuit. Sometimes even the I2C data bus line can be damaged. These should normally be at +4.5V DC on earlier models and +4.0V on later models. Dry joints are unusual, as the sets are double soldered during manufacture – once with a solder bath and later, the hot spots by hand. The beam limiting is similar to the Philips system, using the aquadag of the CRT at between 3V and 8V. The set’s protection system also produces error codes using a flashing LED sequence. If the protection circuit is suspected, it can be disabled by removing D1305 – but switch on the service bridge first. The vertical output stage is pretty conventional, with C1417, C1422 and C1405 occasionally causing lack of height and lines across the picture. Finally there are some odd “no-picture” faults on the CRT drive circuits. Change TR5567, TR5560, D5560, D5561 and D5563 to cure these. If there is CRT spot persistence, then R5569 is probably high. In summary, the Metz seminar was well worthwhile. And the food was good too! Replacing a plasma panel I recently replaced my first plasma display panel (PDP) in a standarddefinition LG RT-42PZ45V (RF-03FA chassis) – although, admittedly under supervision! The problem with the panel was vertical white lines. It really requires two people to do this and you also need a good 240V electric screwdriver. First, two people are needed to lift and place the 106cm panel down on a padded bench and siliconchip.com.au remove the stand. That done, you use the electric screwdriver to remove about 50 screws that hold the back on, followed by the boards plus the framework after they have been unplugged. You don’t have to be an Einstein to do this – just methodical and with an eye to detail. It’s also important to remember what was removed from where and in what order – eg, the special conductive duct tape and the plugs and sockets underneath – and you have to be careful with the display nipple. Once the old panel has been removed, it’s important to blow out any dust on the front screen before fitting the new one. Then, after the boards and plugs and sockets have been refitted, the voltages must be read and compared to the labels on the new display. With the set on a 100% full white heat run pattern, “Va” must be checked at CN803 for the same voltage as written on the label of the new panel (ie, within ±0.5V) and if necessary, corrected using VR351. Similarly, “Vs on” CN805 is corrected with VR551. Any variations must be recorded on the label for future reference. Similarly, for the Vx and Vy voltages, you have to check the centre of the driver board for +20V and check that the output voltage is at +190V. When you are happy with all this, the next thing is to upgrade the software if necessary (the current version siliconchip.com.au is V.5.07). This is done using the RS232 null modem (pins 2 & 3 crossed) and the flash software downloaded from the LG website. It’s just a matter of following the instructions that come with the software and after the process has completed, you have to perform a factory reset before the settings take effect. That done, the back has to be screwed on tight to prevent rattles and the set then left on a full white heat run for four hours. Finally, by using the service remote control again, the small picture corrections have to be made to suit. Nope, TV servicing ain’t what it used to be! The next story is from my mate who works in the automotive repair industry. It looks at the problems that can be created by engine management systems – especially if you lose your keys. I’ll let him tell it in his own words. Engine management systems When it comes to automotive elec­ tronics, there is such a thing as overdesign! Early attempts at electronic engine management date back to the late 1960s. The first commercially available (read successful) system was the Bosch D-Jetronic EFI unit (read ECU) which was fitted to the VW Type 3 TL/E fastback. It was also later seen on some Volvos, Mercedes Benz and Jaguar cars. This unit featured an analog control unit that was about the same size and weight as the Sydney phone book. It controlled just the fuel delivery, using information from various sensors on the engine. The “D” in D-Jetronic comes from the German word “Druck” (pressure), which means it was basically measuring engine load by looking at the manifold air pressure (vacuum), via a primitive form of MAP sensor. Later L-Jetronic systems (L= Luft, meaning air), measured actual air flow into the engine to monitor load. The only other information utilised was the engine temperature (or more correctly, coolant temperature), the throttle position and the RPM, which governed the delivery pulse rate. The system was very straightforward – all the injectors (or fuel delivery solenoids) were pulsed simultaneously once every second engine revolution and their pulse width was varied according to the engine’s temperature (more fuel when cold) the load (more fuel with more demand). The fuel pressure was regulated at a constant rate, with the only variables affecting fuel delivery being the injectors’ pulse width and rate. It was all quite simple and very effective but remember that this system controlled just the fuel and nothing else. Despite that, “driveability” was good (better than using a carburettor) and there were also improvements in fuel economy and importantly for February 2006  51 Serviceman’s Log – continued our future, exhaust emissions. I’ll get down off my soapbox now. Modern day engine management systems are a far cry from the era of the D-Jetronic. The reason they’re now called “engine management systems” is that they control more than just fuel delivery. Instead, they are responsible for the entire fuel system, including pump switching and pressure monitoring, the ignition system with 3D mapping for advance, electric cooling fans, turbo waste-gate control (if turbocharged), air conditioning, cruise control, ABS, traction and air-bags. In addition, the engine management system provides the necessary information for automatic transmission shifting and controls the dashboard displays. Many units now control the matching automatic gearbox, because so much of the data is common to both the engine and the “box”. Other common features include interfacing with 4WD systems and immobilisers, etc. Most of these systems are now digital in their programming, which makes updating and remapping an easy chore. Correspondingly, all of this has led to huge gains in driveability, performance, economy and emissions. The main problem is that many systems are unnecessarily overcomplicated. For example, many immobiliser systems need “re-booting” with proprietary equipment (read 52  Silicon Chip dedicated scanner) after a simple battery swap and more than one vehicle has ended up on a tow truck because the immobiliser didn’t communicate with the engine’s ECU via the car’s “CAN-BUS” data link circuit. What’s more, if you have an ECU failure, you can’t simply swap to another unit without getting the same scanning equipment to make sure the system “handshakes”. Some 2000 onwards systems even have the ECU uniquely coded to the VIN (vehicle identication number) of that vehicle, making unit substitution impossible. The only method of repair is to purchase a new genuine “blank” ECU, sometimes at a price of many thousands of dollars, and have it reprogrammed. You then have to have it handshake with the anti-theft system, using the now very necessary scanner. In case you’re wondering, the VIN is either embedded in the immobiliser module or, in cars like the Commodore, the body control module (BCM). We sometimes look at componentlevel repairs on older cars’ ECUs, with many failures involving leaky electrolytic capacitors or blown driver transistors. With this type of repair, if you see enough of the same unit, a jig can be made up to fire up the unit on the bench for testing. Later model ECUs with mating immobilisers also require that the anti-theft module be jigged-up, along with its “aerial” and “transponder” key – otherwise “no-go”. At a basic workshop level, where component swapping is sometimes the only method of diagnosis (in the absence of test gear), not being able to swap late-model ECUs virtually puts that workshop out of business. Losing a car’s keys can also create big problems with some models. In most cases, if the owner loses one of their car keys, they can easily have a new transponder-style key made by the dealer. This is done by using the second car key to enter the “immobilised” system, after which a new transponder key can be programmed. However, if both keys are lost, the system cannot be initiated and a new anti-theft module is often required. The worst case scenario is when a uniquely-dedicated engine ECU and anti-theft module are required, as well as new transponders. This, of course, necessitates towing the vehicle to your local dealer, after which you have to purchase the above list of parts and then pay for all the necessary programming to go with them – not to mention the installation. We have seen figures as high as $9000.00 for this procedure on some imports! In other cases, losing the keys, although still inconvenient, is not such a tragedy. Some manufacturers have a master scanner that can interrogate the ECU and any other relevant modules and then program new keys from there. Another common “failure” is when the owner gets a new spare key “cut” to keep in their wallet (or, OK then, handbag) for the day when keys are lost. Any attempt at starting the car will ultimately result in disappointment, because the new spare key does not have the necessary coded transponder in its head (to disable the immobiliser). Owners are easily confused here, because the transponder key-head does not have any buttons, as normally seen on central-locking remote control style key-heads. Instead, it is quite often nothing more than a black plastic case with all the parts hidden inside. So a plain metal key-head can only be used for opening the doors and the boot – it certainly won’t start the car. It makes me wonder how much simpler life would be if we were still SC using good ol’ D-Jetronic! siliconchip.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.jaycar.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.jaycar.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.jaycar.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.jaycar.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.jaycar.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.jaycar.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.jaycar.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. 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SUBSCRIBERS QUALIFY FOR 10% DISCOUNT ON ALL SILICON CHIP PRODUCTS* * except subscriptions/renewals Qty Item Price Item Description Subscribe to SILICON CHIP on-line at: www.siliconchip.com.au Both printed and on-line versions available Total TO PLACE YOUR ORDER siliconchip.com.au P&P if extra Total Price BUY MOR 10 OR ISSU E BACK ES A 1 0 & G ET DISC % OUN T $A Phone (02) 9939 3295 9am-5pm Mon-Fri Please have your credit card details ready OR Fax this form to (02) 9939 2648 with your credit card details 24 hours 7 days a week OR Mail this form, with your cheque/money order, to: Silicon Chip Publications Pty Ltd, PO Box 139, Collaroy, NSW, February 2006  61 Australia 2097 02/06 By MICHAEL JEFFERY PICAXE-Powered Thermostat & Temperature Display As demonstrated in our recent “PICAXE in Schools” series, the PICAXE-08M is a useful little chip when it comes to learning about microcontrollers. You might think that it has limited uses outside the classroom but here’s a project that proves otherwise – a simple but accurate 3-digit temperature display that can act as a thermostat. miliar to many PICAXE experimenters. The sensor can be mounted directly on the board or via short flying leads tailored to suit the application. For those interested in experimenting with 7-segment displays, this project can also be connected to the Schools Experimenter (see SILICON CHIP, May 2005) using an optional header. Power for the project can come from a three or 4-cell battery pack or better still, a regulated 5V DC supply. B Three variants RIEFLY, THIS PROJECT SHOWS the current temperature on a LED display using an absolute minimum of parts and with very good accuracy. A temperature set-point can also be entered, enabling control of external 62  Silicon Chip devices for rudimentary heating or cooling applications via a single digital output. Temperature measurement is realised with a DS18B20 digital temperature sensor IC, a device that will be fa- First up, we must mention that the author is not releasing the BASIC code for this project. Instead, you can purchase pre-programmed PICAXE-08M chips (and PC boards) for a reasonable siliconchip.com.au Fig.1: here are the complete circuit details. A DS18B20 serves as the temperature sensor (IC2) and this drives pin 4 (P3) of a PICAXE-08M microcontroller (IC1). IC1 in turn clocks three 4026B decade counters/counters (IC3-IC6) which then drive the 7-segment LED displays. price. Three distinct versions of the code have been created to cater for a variety of needs. There are two thermostatic versions, identified as “heating” and “cooling”, and a “temperature only” version. Both thermostatic versions display the temperature of the DS18B20 sensor from 1°C to 124°C and allow entry of a user-selected setpoint. Above the programmed setpoint, the “cooling” version produces a logic high (+5V) on the digital output, whereas for the “heating” version, a logic high is produced while the temperature is below the setpoint. The “temperature only” version is just that; it displays the temperature of the DS18B20 sensor, ranging from -55°C to +125°C, but has no thermosiliconchip.com.au static functions. The digital reading from the DS18B20 is accurate to ±0.5°C from -10°C to +85°C, so the displayed reading will be accurate to 1°C. The on-board LED is used to indicate negative temperature readings. Pressing S1 switches the display to read in degrees Fahrenheit, with a range of 32°F-125°F. Note: a simplified version of the “temperature only” BASIC program (named tempdisplay.bas) is available for download from our website for those that wish to experiment with their own code. How it works Looking first at the LED display portion of the circuit (Fig.1), each display is driven by a 4026 decade counter/7-segment decoder. A 4026’s counter advances by one for each highgoing pulse on its “CLK” input (pin 1) and the result is decoded to drive the necessary segment output lines (A-G). In this simple design, the 4026 segment outputs directly drive the anodes of the LEDs in the common-cathode 7-segment displays. With a 5V supply, the impedance of the MOS outputs is such that it limits LED current to only a few milliamps; current-limiting resistors are not required. After each count of 10, the “Carry out” output (pin 5) goes high, and this is used to clock the succeeding stage in the chain. So with three stages cascaded together, the maximum count is “999”. Naturally, the display is arranged so that the count progresses February 2006  63 to the CD4026) is available from STMicroelectronics at www.st.com. Power supply To avoid damaging the PICAXE, it’s positive supply (+V) must never exceed 5.5V. A diode (D1) in series with the board’s positive input provides polarity protection and drops about 0.6V, so the board can to be powered from a 4-cell battery pack if desired. However, we recommend the use of a 3-cell pack or regulated 5V supply, in which case the diode should be replaced with a wire link. Take great care with supply polarity if the diode is omitted! Experimenter’s ideas Fig.2: here’s how to locate all of the parts. Take care with the orientation of the ICs, diode and LED. Note that LED1 is installed for the heating and cooling versions, whereas LED2 and link LK1 are installed for the “temperature only” version. See text for other variations. from right to left, so the rightmost digit is the least significant. The count can be reset to zero at any time by pulsing the 4026’s “Reset” input. To provide a brief positivegoing pulse, all Reset inputs connect to output 0 (pin 7) of the PICAXE via a 100nF capacitor. Note how the piezo sounder shares output 0 of the PICAXE with the 4026 CLK inputs. The BASIC program Fig.3: the on-board PICAXE chip can be removed and the project connected to the Schools Experimenter board for those that wish to write their own programs. As shown here, an 8-way header can be installed for the hook-up. A header socket and a short length of ribbon cable will also be required. Note how pin 4 has been cut short and connected to the track below via a 100nF capacitor. 64  Silicon Chip prevents piezo “beeps” from affecting the display count but the reverse does not apply; when the count is incremented, audible noise emanates from the sounder. If this proves to be a problem, a switch could be used to disable the piezo sounder. As mentioned previously, temperature sensing is performed by a DS18B20 from Maxim/Dallas. This unique device provides accurate, direct-to-digital temperature sensing and requires only one data line for interfacing. Maxim/Dallas refer to this as their “1-Wire” interface and it allows the entire device to be squeezed into a tiny 3-pin TO-92 style package. The PICAXE-08M’s BASIC language includes support for the DS18B20 and can read its temperature over the 1-Wire bus using the readtemp and readtemp12 commands. The DS18B20’s native measurement range is from -55°C to +125°C (–67°F to +257°F). Each chip has a unique 64-bit ID code stored in an onboard ROM and includes features such as 9 to 12-bit Centigrade measurements, alarm functions and non-volatile user-programmable upper and lower trigger points. Need to know more? Well, technical data on the DS18B20 can be downloaded from the Maxim/Dallas website at www.maxim-ic.com, whereas data for the HCF4026 (a direct equivalent As an option, an 8-way header can be installed on the board for connection to the header socket (H1) on the Schools Experimenter (see SILICON CHIP, May 2005). In this case, a PICAXE micro must not be installed on the board, as the display and sensor are accessed from the experimenter board instead. As mentioned in the construction section below, a 100nF capacitor must be fitted in series with input 0 from the header in order to be able to reset the 4026 counters. If you’re feeling adventurous and need more than three digits, then the left and right sides of the PC board can be sliced off along rows of holes next to the left and right sides of IC5 and IC3. This allows multiple boards to be stacked end-to-end, thus achieving uniform digit spacing. Of course, you’d need to do this before installing any parts on the board! Construction Construction is very straightforward and should only take a few minutes once the wire links are in place. The links can be fashioned from 0.7mm tinned copper wire or similar and should be installed first (see Fig.2). Next, install all of the resistors and fit socket strips for the three displays (DISP1 – DISP3) utilising 6 x 5-pin sections. These can be cut down from longer 32 or 40-way strips. Conventional 8 and 16-way IC sockets are used for IC1 and IC3-IC5.Now install all the remaining components, noting the orientation of the flat side of the pushbutton switch (S1). The diode (D1) need only be installed if you’ll be using a 4-cell battery pack, otherwise fit a wire link in its place. siliconchip.com.au Where To Buy Parts Par t s Lis t Blank PC boards and pre-programmed PICAXE-08M microcontrollers for this project are available from Michael Jeffery, Clinch Electronic Systems, 329 Hughes Lane, Eurobin, Vic 3739. Website: http://porepunkahps.vic. edu.au/home/jef01/display.htm 1 3-digit PC board (see panel) 1 pre-programmed PICAXE-08M micro (IC1) (see panel) 1 DS18B20 temperature sensor (IC2) (available from www. microzed.com.au) 3 CD4026B decade counter/7segment decoders (IC3-IC5) 3 0.5-inch common-cathode LED displays, FND500 or similar 1 1N4004 diode (D1) 1 PC-mount pushbutton switch 1 piezo transducer 1 32-way IC socket strip (Jaycar PI-6470) 1 8-pin IC socket 3 16-pin IC sockets 1 100mm x 0.7mm wire for links 4 100mF 50V monolithic ceramic capacitors 1 22kW 0.25W 5% resistor 2 10kW 0.25W 5% resistors 1 4.7kW 0.25W 5% resistor Please note that only Australian orders will be accepted and payment must be made either by cheque or by money order. Add $4.95 to all orders for postage and packing. Current prices (including GST) are: (1) Three-digit blank PC board: $12.00 plus p&p (2) Two-digit blank PC board (not shown in this article): $10.00 plus p&p (3) PICAXE-08M pre-programmed with “heating”, “cooling” or “temperature only” version of the software (please specify version): $5.70 plus p&p Fit a LED in location “LED1” for the thermostatic variants of the project, taking care with the orientation of the flat (cathode) side. This LED is connected to output 1 of the PICAXE via a 330W resistor and will illuminate when the temperature is above or below the programmed setpoint, depending on the version of the software. However, for the “temperature only” version, this output is used to indicate negative temperature readings, so you should install the LED in location “LED2” instead. This gives a slightly more aesthetic display, as LED2 is aligned with the three digits. In this case, a link is also required in location LK1. Alternatively, the “g” segment of DISP3 can be used to display a “-“ sign for negative readings and the LEDs can be omitted. To do this, cut the track joining pads A and B (above DISP3) and install wire links in locations LK1 & LK2. If desired, the temperature sensor (IC2) can also be located on-board, in which case it can be mounted using a 3-way socket strip. If you’ll be using the board with the Schools Experimenter, an 8-way rightangle header (eg, Altronics P-5518) can be installed for CON1. Note that the header is not required for normal (stand-alone) operation! Before installing the header, cut the end of pin 4 off so that it doesn’t quite pass through the PC board. The idea is to isolate the pin from the pad underneath, while leaving a few millimetres protruding from the rear of the plastic housing. After installing the header, solder a 100nF capacitor between the cut-off pin and the track that goes to pin 15 of IC3 (see Fig.3). Setup & use immediately after the current temperature disappears from the display. Upon pressing the switch, a single beep will be heard and the display will show “000” as before. When the programmed setpoint is “tripped”, the current temperature will be displayed, followed by four quick beeps and then the set-point temperature. This repeats continuously until the temperature moves above or below the set-point. To reiterate, the “cooling” version produces a logic high (+5V) on output 1 (pin 6) of the PICAXE for any temperature above the set-point. This function is reversed for the “heating” version; any temperature below the setpoint will produce a logic high on output 1. The LED is also connected to output 1 and will illuminate when the output goes high. Spare pads are provided on the board to allow this output to be wired to external switching circuitry SC of your own invention. No setup is required for the “temperature only” version. For the thermostatic (heating/cooling) versions, the setpoint temperature must be programmed after power is applied, as follows. At power up, the display will first show “000”, then the current temperature for about five seconds, followed by three short beeps and then “088”. This sequence is repeated continuously to warn of a previous power disruption. If the switch is pressed when “000” appears, a single beep will be heard and the unit waits for 20 seconds for the set-point temperature to be entered. Each press of the switch represents one setpoint degree. Once the value has been entered and after 20 seconds have expired, three beeps will be heard and the set-point will be displayed back for verification. From this point on, set-point changes can be made by pressing the switch Table 1: Resistor Colour Codes o o o o siliconchip.com.au No. 1 2 1 Value 100kW 10kW 4.7kW 4-Band Code (1%) brown black yellow brown brown black orange brown yellow violet red brown 5-Band Code (1%) brown black black orange brown brown black black red brown yellow violet black brown brown February 2006  65 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. Morse code identification unit Here’s a low-cost programmable Morse code identifier unit for use in amateur repeater stations/beacons. It utilises a PIC microcontroller, a discrete filter and a common op amp to generate an audio output for the CW tones. Up to 64 bytes (meaning 64 dits, dahs or spaces) can be stored in the PIC’s non-volatile memory. Most of the work is performed by IC1 (PIC16F84A) which runs at 4MHz. Port A is configured as an input, whereas Port B is configured as an output with all pins initially set low. The program continually monitors the RA0 (pin 17) input, which is normally held high by a 22kW resistor tied to +5V. A 10nF capacitor and 1kW resistor connected to this pin suppress RF interference from the outside world and provide some protection for the PIC’s input port. When RA0 is pulled low (via pin 3 of CON1), the program sets RB0 to a high state, which switches on 66  Silicon Chip transistor Q1 and relay RLY1. Diode D1 suppresses back-EMF generated voltage spikes. The PIC program then reads the data stored in EEPROM and translates it into a dit, a dah, or a space. Each byte of data is encoded as follows: 00 is a dit, 01 is a dah, and 02 is a space. A data value greater than 02 signals the end of the data block, causing the micro to write a low to RB0 to switch off the relay. The program then loops back to the beginning to wait for the next low on the TRIGGER input. The CW tones are output on RB1 as a square wave. To remove undesirable harmonics, a low-pass filter comprised of three 1kW resistors and 100nF capacitors converts the square wave into a reasonable quality sinewave. The resultant signal is buffered and amplified by an LM741 op amp (IC2). IC2 is configured as an inverting amplifier, so its voltage gain is set by the 10kW input and 22kW feedback resistors. This gives a gain of 2.2 and about a 1V p-p signal at the output with the wiper of VR1 set to maximum. It is possible to increase this level by replacing the 22kW resistor with a larger value, to a maximum of about 82kW. Exceeding this value will result in the output signal being clipped and therefore distorted. Power can be provided by a 12V DC unregulated source, which directly supplies the op amp and relay circuit. A 7805 3-terminal regulator brings this down to +5V to power the PIC microcontroller. Source code The complete program for the PIC micro appears in the accompanying listing and is self-explanatory. It is written in PICBASIC and therefore must be compiled into “HEX” file format before being programmed into the micro’s FLASH and EEPROM. The author compiled the code using Microcode Studio, although any PICBASIC compatible compiler would be suitable. Check out the commercial compilers at www.donsiliconchip.com.au Jame sC ;******************************************************************************************************** is this m utler on ;* Morseident.bas Version 2.0 01/06/2005 winner th’s ;******************************************************************************************************** of a TRISA = %11111 TRISB = %00000000 A VAR byte D VAR BYTE LET PORTB = 0 'set PORT A as inputs 'set PORT B as outputs Peak At las Instrum Test ent REAL VALUE AT eeprom 0,[02,02,00,00,00,01,02,01,00,01,02,00,00,01,01,01,02,01,02,00,00,02,01,01,02,02] :standby IF PORTA.0 = 1 then standby 'wait for button press on PIN 0, port A :transmit HIGH PORTB.0 gosub vk2tim LOW PORTB.0 GOTO standby :dit SOUND PORTB.1,[120,05] PAUSE 100 return :dah SOUND PORTB.1,[120,20] PAUSE 100 return :space PAUSE 200 return :vk2tim for a = 0 to 63 step 1 read a,d IF d = 00 then gosub dit IF D = 01 then gosub dah IF d = 02 then gosub space NEXT a Return Silicon Chip Binders $12.95 PLUS P & P 'close TX relay ‘open TX relay 'DIT 'DAH These binders will protect your copies of S ILICON CHIP. They feature heavy-board covers & are made from a dis­ tinctive 2-tone green vinyl. They hold 12 issues & will look great on your bookshelf. 'SPACE H 80mm internal width 'read CW information from EEPROM H SILICON CHIP logo printed in gold-coloured lettering on spine & cover tronics.com.au or search the ’net for various free or limited editions. The “eeprom” line in the listing contains the actual message data and this should be changed to suit your installation. Up to 64 dits, dahs or spaces can be crammed into a H Buy five and get them postage free! Price: $A12.95 plus $A7 p&p per order. Available only in Aust. PIC16F84A, while a PIC16F628A will hold a further 64. If you use the code as the basis of your own design, please include a credit to the author. James Cutler, VK2TIM, Werrington, NSW. Silicon Chip Publications PO Box 139 Collaroy Beach 2097 Fax (02) 9979 6503 or phone (02) 9979 5644 & quote your credit card number. 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 now 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, siliconchip.com.au with the compliments of Peak Electronic Design Ltd 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 silchip<at>siliconchip.com.au or post it to PO Box 139, Collaroy, NSW 2097. February 2006  67 Circuit Notebook – Continued Automatic soldering iron controller After leaving my soldering iron running all night a couple of times, I developed this simple circuit to automatically switch it off when nobody is around. A PICAXE micro (IC1) monitors the output of a PIR sensor that is “watching” the workshop and as long as movement is detected, the soldering iron remains powered up. However, if no movement is detected for 15 minutes, the iron is switched off via RLY1, which controls the 240VAC mains active line to the iron via its normally-open contacts. In case the operator is still in the area, the piezo transducer sounds an alarm 30 seconds before the time-out period. To operate initially, simply press the “ON/OFF” switch (S1), which is monitored on input 3 (pin 4) of the micro. The micro then generates a “beep” and starts a 15-minute timer (see program listing). Whenever input 1 (pin 6) of the micro goes low within the timing period, the timer is restarted. A variety of sensors could be used to trigger input 1 and restart the timer. Active-low devices are wired via diode D2, which prevents anything higher than +5V being applied to the PICAXE input. Active-high devices are handled by transistor Q1, which acts to invert the signal before applying it to the same input. The power supply is the standard bridge rectifier (BR1), filter capacitor and 3-terminal regulator (REG1) combination, providing +5V to power the circuit. Make sure that the relay contacts are rated for 250VAC operation and exercise the usual care with all mains wiring. Jeff Monegal, North Maclean, Qld. ($50) The Latest From SILICON CHIP Completely NEW projects – the result of two years research & development • • • • Learn how engine management systems work Build projects to control nitrous, fuel injection and turbo boost systems 160 PAGES 23 CHAPTE RS From the publishers of Switch devices on and off on the basis of signal frequency, temperature and voltage Build test instruments to check fuel injector duty cycle, fuel mixture and brake and coolant temperatures Mail order prices: Aust. $A22.50 (incl. GST & P&P); Overseas $A26.00 via airmail. Order by phoning (02) 9979 5644 & quoting your credit card number; or fax the details to (02) 9979 6503; or mail your order with cheque or credit card details to Silicon Chip Publications, PO Box 139, Collaroy, NSW 2097. 68  Silicon Chip Intelligent turbo timer I SBN 095852294 - 4 9 780958 522946 $19.80 (inc GST) NZ $22.00 (inc GST) TURBO BOOST & nitrous fuel controllers How engine management works siliconchip.com.au ;************************************************************************************** ; Automatic Soldering Iron Controller – PICAXE-08 Vers 1.00 12 June 2005 ;************************************************************************************** symbol symbol symbol symbol iron = 2 pir = pin1 timer1 = w0 timer2 = b9 'soldering iron control relay on this pin 'PIR (or other) people detector on this pin low iron start: if pin3 = 0 then pressed pause 50 goto start pressed: pause 50 if pin3 = 0 then yes_pressed goto start yes_pressed: high iron sound 4,(100,15,85,20) timer1 = 0 time_loop: if pir = 0 then clr_timer pause 500 timer1 = timer1 + 1 if timer1 > 1800 then time_out if pin3 = 0 then but_press goto time_loop clr_timer: timer1 = 0 timer2 = 0 goto time_loop 'debounce the button WHERE can you buy SILICON CHIP You can get your copy of SILICON CHIP every month from your newsagent: in most it’s on sale on the last Wednesday of the month prior to cover date. You can ask your newsagent to reserve your copy for you. If they do not have SILICON CHIP or it has run out, ask them to contact Network Distribution Company in your state. SILICON CHIP is also on sale in all 'system has now been turned on by operator 'so turn the soldering iron on stores . . . again, you can ask the store manager to reserve a copy for you. '1800 equals about 15 minutes 'reset timer 1 'reset timer 2 Or, to be sure that you never miss an issue and save money into the bargain, why not take out a subscription? The annual cost is just $83 within Australia or $89 (by airmail) to New Zealand. Subscribers also get further discounts on books, and other products we sell. A NOTE TO time_out: timer2 = 0 cont_lp: if pin3 = 0 then oper_can ‘button press cancels time out if pir = 0 then clr_timer 'the people detector has activated to_lp: if timer2 > 23 then times_up sound 4,(50,10,40,30) pause 1000 timer2 = timer2 + 1 goto cont_lp times_up: low iron pause 100 goto start oper_can: pause 50 if pin3 = 0 then tmr_reset goto to_lp SILICON CHIP SUBSCRIBERS 'this number equals a time of about 30s Your magazine address sheet shows when your current subscription expires. 'time has run out so switch off the iron Check it out to see how many you still have. If your magazine has not turned up by the first week of the month, contact us at silchip<at>siliconchip.com.au 'debounce the button Select your microcontroller kit and get started... From $295* tmr_reset: sound 4,(90,15,65,20) goto clr_timer but_press: pause 50 if pin3 = 1 then time_loop low iron switch_off: pause 50 if pin3 = 1 then start goto switch_off siliconchip.com.au 'switch off the soldering iron RCM3400 Fax a copy of this ad and receive a 5% discount on your order! Feature rich, compiler, editor & debugger with royalty free TCP/IP stack • Prices exclude GST and delivery charges. 'wait until the button is released... '...before restarting the program Tel: + 61 2 9906 6988 Fax: + 61 2 9906 7145 www.dominion.net.au 4007 February 2006  69 Circuit Notebook – Continued Improved speed alarm sensor The electromagnetic induction sensor described with the Speed Alarm (SILICON CHIP, Nov. & Dec. 1999) works well on rear-wheel drive vehicles but can be problematic on some front-wheel drive models. In rear-wheel driven vehicles, the tail shaft typically rotates about 2.5 times faster than the wheels and does not move up and down much relative to the chassis at the gearbox end. This makes it easy to mount a pick-up coil in a position that will maintain a reasonably constant distance from the rotating magnets. Unfortunately, the small drive shaft diameter and its slower rotational speed in front-wheel driven vehicles make it difficult to get an adequate signal from the sensor. In addition, readily accessible points on the drive shaft usually have large movements relative to any practical attachment point for the pick-up coil. For use as a 50km/h warning around local suburban streets, I found that the sensor could be dispensed with and an input from the ignition points (suitably attenuated) used instead. To make this arrangement work, a microswitch was fitted to the gear lever so that the unit operated only when in fourth gear. This worked well but when I switched to a vehicle with auto­mat­ic transmission, the marked difference between engine and road speeds 70  Silicon Chip meant reverting to a driveshaft sens­or. My design for an improved version was made as follows: First, extract eight small cylindrical magnets (6mm dia. x 4mm long) from a “Magnetix”™ toy, available from K-Mart. These magnets are very strong for their size and are set flush (all with the same polarity) in holes round the flat face of a 60mm dia. x 20mm thick wooden disc, which also has a central hole to match the driveshaft’s diameter. Two holes are drilled through parallel to the faces to accept 4-5mm screws and the disc is then sawn through at right angles to these holes, so that the disc can be clamped around the drive shaft. A proportional Hall-effect sensor (UGN3503U) is potted with epoxy inside a piece of brass tube with a flat brass shim soldered to one end. Before potting, its three leads are shortened and soldered to flying leads, so that the solder joints will be buried in the epoxy. The flat (active) surface of the sensor must be positioned against the shim. The completed sensor assembly is held on a wooden arm, which is a running fit on the shaft. This is again split, so that it can be mounted next to the magnet disc. The arm is long enough to rest against part of the front suspension so that it cannot rotate forwards and a light spring stops it from going too far back when in reverse. This method ensures that the sensor is always at the correct distance (about 3mm) from the magnet disc. A plastic collar is wired to the shaft to keep the disc and arm close together. The idea of a wooden bearing on a steel shaft may seem a touch medieval but well-oiled wood is an excellent bearing surface and the load here is very small. The photos show the disc and sensor arm separately and mounted side by side on a short dummy axle. All three leads from the UGN3503U must be cabled back to the speed alarm box, with the supply and ground pins of the sensor connected to the +5V and ground rails at any convenient point on the alarm’s PC boards. The output of the sensor goes to the inverting input of comparator IC2a via the existing 1kW resistor. With no magnet nearby, its output sits at 2.5V and goes up or down (depending on polarity) by about 0.5V as the magnets pass by. As the bias voltage on the noninverting input of IC2a also sits at 2.5V, it will need to be altered to get a reliable signal at the comparator’s output. This can be achieved by replacing one of the 2.2kW resistors (connected to the anode of D3) with a 1.8kW resistor; the polarity of the magnets determines which of the two 2.2kW resistors needs to be replaced. One major advantage of using a Hall-effect sensor over the original induction sensor is that its output pulse amplitude does not depend on how fast the magnets pass the sensor. Robin Stokes, Armidale, NSW. ($40) siliconchip.com.au siliconchip.com.au February 2006  71 WHAT? If you’d been off the planet for the last five years and considered a snake’s pit of cables linking computers and peripherals as normal, then today’s wireless connectivity could come as quite a surprise. C onsumers hate cables – and many Y2K era PCs had over a dozen of them. Although obviously wire and connector free, wireless linking traditionally involves tradeoffs between power, range and speed. Thus low power modules like the 433MHz units we’ve recently featured have fair range but only slow data speeds, while faster rates (900MHz cellular, etc) come with higher power demands, not easily met by batteries. by Stan Swan Much higher frequencies, such as the license-free 2.4GHz slot, offer greater bandwidth so more data can be squeezed into the same signal spectrum. However microwaves are very line of sight, so ranges may be greatly reduced. Phew – it’s all compromises... Acting in a similar manner to line- of-sight microwaves, infrared data remained the only easy wireless technique five years ago, although its need for clear links meant IR could never punch data pathways through walls, filing cabinets . . . or even paper. To overcome this limitation, WiFi (IEEE802.11x) – which itself has undergone three recent revamps (a,b,g with “n” due this year) – and Bluetooth (IEEE802.15.1) evolved. Bluetooth, although initially a sleeper, now features in almost all new Larger-than-life pics of MaxStream’s XBee (1mW) and XBee Pro (100mW) ZigBee devices. Expect prices to be in the $20-$30 range when they start arriving! 72  Silicon Chip siliconchip.com.au Name WiFi IEEE title Speed Range Power Hardware Cost Typical use IEEE802.11g to 54Mbps 300m Modest PC or AP Modest PC WLAN Bluetooth IEEE802.15.1-2 1-2Mbps 10m Low Camera/ Low cell phone Consumer PAN (to 8 devices) ZigBee IEEE802.15.4 250kbps 30m Very low Microcontroller Very low Low duty cycle (255 devices) Comparison between WiFi, Bluetooth and now ZigBee wireless systems. As you can see, WiFi is still king of the roost when it comes to range but ZigBee offers many advantages over Bluetooth – range included. Consume PAN (Bluetooth use) stands for Personal Area Network. cellular phones and such consumer peripherals as headsets, photo printers and PDAs. The Bluetooth title incidentally honours tenth-century Viking King Harald of Denmark, famed for feasting on blueberries until his teeth apparently were stained blue. His administration skills however were even more legendary, since for a period (no doubt in their blueberry off season) he managed to unify the war-mongering provinces of Scandinavia to work together (maybe raiding neighbouring blueberry patches!), much in the way that today’s Bluetooth seamlessly links cameras, PCs, headsets, and cell phones etc. You may groan with the nearbewildering rate of progress and worry about security and 2.4GHz “RF smog” but now there’s a further offering. ZigBee! In an attempt to simplify wireless data communications, yet another approach has recently emerged and is showing considerable industry support and promise. Formally based on IEEE 802.15.4, it’s better known as ZigBee. No, ZigBee is not just a whacky marketing title dreamt up over a 4-hour liquid lunch. Instead, it honours the energy-efficient zigzag “waggle dance” of honey bees, which directs worker bees to nectar sources. It was first studied by Austrian zoologist Karl von Frish in 1943. Available at 915MHz and 2.4Ghz (with the lower 915MHz being just 20kbps), ZigBee has several power ratings, with just 1mW the most common. It’s somewhat of a Bluetooth “lite” since, although it has similar crossroom range, it’s slower but far more energy efficient. Remember that tradesiliconchip.com.au off above between range, speed and power? ZigBee is further able to be implemented with simpler electronics and (in time) may be so cheap that even light switches could have it inbuilt, leading to more flexible and cheaper control layouts. Yes, wireless light switches! Given the obscene costs now associated with 240VAC fittings, mains cabling, conduit and redecorating (not to mention the difficulty of relocation), this may be a very welcome development indeed. The table above is a brief feature summary of these three main wireless data technologies. All are on the globally license-free (and increasingly “noisy”) 2.4GHz band. Power demands of ZigBee devices are so tiny that low duty-cycle applications may average current drains of only microamps, allowing batteries to last years – approximating their shelf life. Marketing is already playing on this benefit, with “Five years off a few AAs” noted! Solar powering from scavenged room light may even be feasible. A more dramatic feature however relates to the relaying of data to a specified address on the 255-device ZigBee network. This conjures up visions of your door keys relaying “Hi family, I’m home” details to the beer fridge, via perhaps a network of ZigBee devices in light switches and ad-hoc networked sensors throughout the house. Unlike the simplex and error-prone nature of 433MHz units, handshaking for data reliability is supported too. This makes more professional applications attractive, suiting drive-by utility monitoring and on-demand telemetry, etc. Although only ratified late 2004, many makers already offer modules, typified by the postage-stamp-sized “XBee” from US firm MaxStream (www.maxstream.net). These come as either a 1mW or a more powerful and sensitive longrange 100mW “XBee Pro” and allow easy RS-232 or USB connections to suit microcontroller interfacing. Both look very “user friendly”, with Hayes-style “AT” command radio modem features, although the low Picaxe serial data rates (typically just 2.4kbps) may rather “waste” the 250kbps Xbee horsepower. Since high-gain 2.4GHz antennas are compact and very easy to organise (see www.usbwifi.orcon.net.nz), lineof-sight control ranges to a kilometre should be feasible with even the 1mW version All manner of exotic applications arise with this new technique, the least of which could be ZigBee-fitted and powered solar garden lamps, all “chatting” across the neighbourhood and winking mesmerising messages together while exchanging wireless data about their owners’ lifestyles. They’ll probably be all the rage by next Christmas… SC References: Get used to the ZigBee logo . . . you’re going to see a lot more of it shortly! References are conveniently hosted at www.picaxe.orcon.net.nz/zigbee.htm February 2006  73 ADDING INFRARED TO YOUR In the December issue we had our first look at the Viper robot from Microbric – a new concept in project building that can turn a beginner into an expert in seconds! Now we’re going to start adding more functionality to the Viper by giving it some infrared control capability O ne of the difficulties new or would-be electronics enthusiasts Part 2 – by have is the (perceived?) difficulty of soldering, component identification and actual construction. While those more experienced in the art would say “just get in and learn it!” there is arguably nothing more disconcerting to a beginner than building a project and finding it doesn’t work, or work as intended, often due to a simple error that, with just a little bit more knowledge, would be easy to spot and fix. Many’s the project that has been thrown into a cupboard (or even bin!) for this reason. That was one of the stumbling blocks that Microbric wanted to avoid. And with their unique “bric” concept, they’ve succeeded very well! Soldering has been completely eliminated. If you can fasten a nut on a screw, you can build with Microbric. Component identification has been eliminated, again due to brics. Now it’s modular – some modules contain individual components, others a complete circuit element. But when you connect them together, they simply work! And the parts are reusable – you can dismantle and rebuild as many times as you like. With Microbric, you can build complex electronic devices with little or no prior electronics knowledge. You will learn as you go – that’s another one of the strong points. And that 74  Silicon Chip knowledge is not limited to electronics – other concepts will be covered along the way such as mechanics, programming and even designing your own projects. Incidentally, if you missed our Microbric introduction in December, we strongly suggest you read that before reading on. It covers the concepts and the fundamentals which are necessary background to building more complex robots (Back issues are available for $8.80 each including p&p). Ross Tester Minimum hardware requirements Before we get down to the nitty gritty, we should cover what you need in the way of a computer. Virtually anything from PII 233 up (Pentium II, 233MHz) will be fine. It would be hard to imagine one of those machines not running Windows 98, Me or XP – but that’s what is required. You’ll need a minimum 32MB of RAM (again, hard to imagine anything less) and at least 120MB of free hard disk space. As far as sound and graphics are concerned, any Windows-compatible sound card will be fine and 800 x 600SVGA with 4MB RAM will be required. As the manual comes on a CD, a CD-ROM (minimum 8x) is essential. The one area you might have problems with is an RS232C port. That’s required for data transfer to and from the Viper and regrettably, many modern computers don’t have one, using USB ports instead (here’s where older computers siliconchip.com.au will come into their own!). If your computer doesn’t have RS232C, a USB-to-RS232C converter/adaptor may be the answer (they’re cheap enough!) But note that we have NOT tried programming the Viper using this method so cannot guarantee it. The Viper kit When you open up the Viper kit (Dick Smith Electronics, K-1800, $199.00) you might think that you’ve been shortchanged because only about half the box is populated with bits. That’s deliberate – the kit contains all you need to put together the Infrared Controlled Viper with: • A motherboard (contains the microcontroller “brains” of the robot along with batteries and programming port • Two micromotor modules (each houses a high quality motor and metal gearbox plus the electronics to run them) along with two wheels; • The infrared receiver module (receives the output from the infrared remote controller, also included); • A buzzer, (plays notes and beeps; even has a volume control) • Two LED modules (with driver circuitry built in); • A button (to start and stop your program); • A switch sets the different modes of operation in your program input); • A bump sensor (detects obstacles in the robot’s path) • Plus an RS232 cable, software on CD-ROM and screw driver • And, of course, the connecting pieces to allow you to put it all together. The blank areas in the box are for supplementary or expansion kits, available separately, which you can then keep with the the main Viper kit. These includes Wheel Packs, Line Tracker modules, Sumo (robot wars) modules and even advanced projects such as the Spiderbot and Dragster. Giving the Viper Infrared Control We’re assuming that you have built the Microbric Viper (as per December 2005 issue) and have had a lot of fun playing with it. Now that fun is going to be magnified a whole lot because adding infrared control opens up whole new horizons. The infrared transmitter When you look at the hand-held infrared transmitter, you’ll probably think that it is just about the same as all of those infrareds you already have for the TV, VCR, DVD, set-top box, home theatre system, air conditioner . . . and you wouldn’t be far wrong. Most infrared remote controls work in very similar ways. They simply impress a digital code of pulses onto an infrared beam. Needless to say, because it’s infrared, you cannot see the beam. But most video cameras can, especially the cheaper ones such as webcams and security cams because, for the most part, they don’t have any filtering to “keep out” infrared. But even many stock-standard camcorders can “see” infared. If you aim the camera at someone holding the infrared remote across a room, then get them to push buttons, you’re likely to see a continuous bright white light in the viewfinder (assuming it’s working as a camera, not siliconchip.com.au a video player!). Connect to a TV set or monitor for a better view. Incidentally, this is a good way to check that the infrared remote control (for anything!) is working before you change the batteries. Many a perfectly good battery has been thrown out when it has been something else that hasn’t worked (eg, the loose nut on the keyboard . . .). It’s all in the timing The particular remote control supplied uses the 12bit Sony InfraRed Control (SIRCS) protocol – if you want to, you’ll find plenty more information about this protocol on the web (Google SIRCS). Each of the buttons on the remote control puts out a slightly different digital code. These codes are in the form of pulses which are far too fast for us to see, even when looking at them via a camera. Pressing different buttons results in very small differences between each pulse train. The receiver which we are about to fit to the Viper detects this pulse train, regardless of which button is pressed and translates it into language (actually electrical levels) the microprocessor can not only understand, but act upon and send the appropriate command. So it is actually the microprocessor which works out which button is pressed, not the receiver itself. One button might tell the microprocessor to apply power to both motors equally and move the Viper forward. Another button, for example, might be interpreted as applying power to one motor and applying reverse power to the other motor – which, fairly obviously, will turn the Viper in the direction of the wheel rotating backwards. Naturally, not all the buttons on the remote control will do anything (at least, not at the moment). Later on, as you become more adept at BASIC ATOM programming, you might be able to put some of the other buttons to use to get your Viper to do some really kinky things! But let’s get back to the task in hand: getting the Viper to work with the infrared remote. Modifying your Viper First of all, attach the Infrared Receiver module to Pin 6 on the Microbric motherboard. That’s the simplest part! In order to use the remote control with the microcontroller, you will need to follow a sequence of steps to preset the remote to work with the microcontroller. a. Put two AAA batteries into the remote control unit. b. Simultaneously hold down the S button (in the middle of the arrows) and the B button on the remote (a red light will go on in the top left hand corner of the remote. February 2006  75 c. Press the number sequence 0 1 3 on the remote buttons. d. Press the red power button on the remote. e. The remote is now configured to work with your microcontroller. Note that buttons A, C, D, E, F and G are for setting the remote control into different modes which are not required for this project. Avoid pressing these buttons as this will inadvertently set your remote into another mode. You can always return to the ‘B’ mode by pressing the B button. Entering the BASIC program Open a new file on your computer and call it IRProgram.bas You could type in the program as listed but it is fairly long and complex, so the chances are you will make a mistake. And one mistake could stop your project from working. It’s much simpler (and safer!) to load this program from the supplied CD (phew! Saves a lot of typing!). Save it (File/Save As…) to a location on you hard drive before programming it into the microcontroller. In this program you will be using the PULSIN command. This is a command that tells the microcontroller to wait for a pulse signal. You will note that it specifies the Pin for the input and then states what to do in the 0 state and the 1 state. Some things to note about the program: • This program will accept a signal from the remote control, analyse it, and then, according to the binary 16 bit number received, will either run the motor forwards, backwards, turn the LED on or play a tune. • The ‘pulse’ sequence is necessary to check all the possible incoming combinations. It is tedious to type in, but gives this program its flexibility to use multiple buttons to drive it. • Each of the buttons on your remote control has a specific 16 bit binary number (referred to as a 16 bit ‘word’). You can see four of them represented in the TESTIRDATA subroutine. The 16 bit numbers for each of the buttons on your remote control are written in the table below. You can use them to program 14 separate functions. SC Flowchart for infrared control of the Viper. When the signal is received by the infrared receiver and passed on to the microcontroller, it is looking for one of the valid codes from the table below. Remote Control Button 16 bit Button 1 button 0 0 0 0 2 button 1 0 0 0 3 button 0 1 0 0 4 button 1 1 0 0 5 button 0 0 1 0 6 button 1 0 1 0 7 button 0 1 1 0 8 button 1 1 1 0 9 button 0 0 0 1 0 button 1 0 0 1 button 1 1 0 0 button 0 1 0 0 button 0 0 0 0 button 1 0 0 0 76  Silicon Chip ‘words’ 0 0 0 0 0 0 0 0 0 0 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 siliconchip.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.microbric.com SILICON CHIP MIDI DRUM KIT by JOHN CLARKE PART 4 – the software . . . and driving it! Operating the MIDI Drum Kit via a computer requires software to be installed. In this final article we shall describe this final aspect of the MIDI Drum Kit. A S MENTIONED in earlier parts, ever we recommend using Rave first program) is the only software you will if you want to use the MIDI unless you are already well versed in need to install if you are connecting Drum Kit with a computer, as disusing the others. Rave for Windows to the computer using the sound card tinct from a MIDI instrument with is available as a free download from input via a games port. In this case, its own synthesiser, you will need to the ’net. make sure the Port settings on the MIDI install sequencer software and perThis software (or another sequencer Drum Kit are <MIDI PORTS>. haps a serial port driver Many sequencers are a lit(with the option to install tle daunting when you start a USB driver). them up due to their hugely The sequencer software complex control features. provides the means to send a The Rave sequencer is ideal MIDI signal to the computer for first-time users to get the and to drive the sound card’s MIDI Drum Kit up and runsynthesiser. ning. It is easy to use with There are many sethe MIDI Drum Kit. quencers available on the If you want added feamarket; we have tested tures then you must use a the MIDI Drum Kit using commercial sequencer. Propellerhead’s Reason, The Computer Muzys the Computer Muzys CM CM Studio, for example, Studio, Tracktion and is available on the CD Rave. supplied with “Computer Rave is, by far, the easMusic” magazine from iest-to-operate sequencer. Future Publishing in the While there are many sequencers available, Rave is the Of course you can use other UK. (www.computermusic. one we recommend for beginners and novice users. It’s by sequencer software, howco.uk). Check it out at your far the easiest to operate. 78  Silicon Chip siliconchip.com.au news­agent. The software requires a 500MHz PC or Mac . Reason can be found at www. propellerheads.se and the Tracktion sequencer is found at www.rawmaterialsoftware.com or at www.mackie. com/traktion this is not set to block programs from being installed. To check the settings in Windows XP, select Start/control panel/hardware/driver signing. Click on the Warn only button, if not already selected. Screen saver and power management What, no games port? Few computers these days have a games port. If you are in this position, you can connect via a serial port, or failing this using a USB port via a USB adaptor. USB connection is the most finicky way of operating the MIDI Drum Kit and if you have a serial port it is recommended to use it rather than via USB. For USB use, there are two options. Firstly, you can use a serial-to-USB converter and use it in conjunction with the MIDI serial driver. Software to set up a USB-to-virtual serial port driver will be required and this is normally supplied with the Serial to USB converter. (See the separate breakout panel for the USB installation). For this option, the Port settings on the MIDI Drum Kit will need to be set to <SERIAL PORT>. Alternatively, if you use a MIDI-toUSB converter (available from music shops or on the ’net) then you only need to install the sequencer software and the MIDI-to-USB driver. In this case, make sure the Port settings on the MIDI Drum Kit are <MIDI PORTS>. The MIDI-to-USB converter connects directly into the MIDI outlet on the Drum Kit. Installation of the software for this will be included with the converter when you buy it. We will only describe setting up the Serial-to-USB converter since this is the cheapest option. Checking computer settings When installing any programs or drivers, you need to be logged on to your computer as an administrator. Before installing the sequencer software, it is best to check the settings in your computer to make sure that the sound card is set up correctly for MIDI. For Windows XP select Start/control panel. If it is set in the ‘category view’ mode, switch to ‘classic view’. Now select sounds, speech and audio devices/audio/midi music playback. In the MIDI music playback, select an MPU-401 compatible synthesiser siliconchip.com.au When running the sequencer software, be sure to turn off any screen savers and any power-down energy management set for your computer. You can check these settings in the Control Panel and look for the Display options. If you are playing your Drum Kit and the screen saver starts or energy management shuts down a system, expect some huge latency in the sound output. Rave installation (eg, Microsoft GS Wavetable SW synth). Also make sure volume is up for the synthesiser. Do this by selecting volume in the MIDI music playback box and checking settings for the SW Synth. This is similar for Windows 98. In this case, select Start/Settings/ Control Panel/Multimedia/. In the multimedia properties select MIDI and an MPU-401 compatible synthesiser for internal synthesis. (eg, ESFM Synthesis (220)) Also check that the volume control level for the synthesiser is up (double click the speakers icon on the taskbar). Driver signing Later versions of Windows include driver signing. You need to check that The Rave sequencer program is available from the website (http:// www.files1.sonicspot.com/rave/rave. zip). The zip file is 647kb and can be unzipped in the normal way. The software was written to run on Windows 3.1 and so unless your computer is very old, it should run on just about any computer using Windows. We have tested the software on Windows 98, Windows Me and Windows XP. The only problem we have experienced is during installation, where error messages are shown because the DOS help file is not installed on the computer. This is just a software glitch that only occurs because the software was written for Windows 3.1. This operating system relied on having DOS installed. Once the Rave software is installed, the error messages do not affect the operation of the Rave sequencer. Download and save the rave.zip file from the location shown above to a directory (or folder) called C:\ rave (or similar) and unzip in the normal way. To use the wizard it is usually only a matter of double clicking onto the rave.zip file and following the prompts to unzip to the rave folder. If you are using Windows 3.1, then use Pkunzip to extract the zipped files. When the file is unzipped, double click on the setup.exe file. This will install the software to the C:\rave folder. During installation the computer may ask if you want to run this software with an unknown publisher. In this February 2006  79 case click on the Run tab. As mentioned, if you are using a current version of Windows that does not include DOS, there will be an error message saying could not open the file c:\dos\doshelp.hlp. Click on ignore. A similar DOS shell error will also be shown. Again, click on ignore. Click on close after the general protection fault error is shown. The three screens below show the error messages: nome/Bars Count In is set to at least 1 (if this is set to zero you will not be able to record) Recording Check in the Options/Output Assignments. The settings should show the MIDI Mapper. When installation is complete, navigate to the folder c:\rave. Single click onto rave.exe (c:/rave/rave.exe) then to “File” and then select create shortcut from the list of options. Drag the shortcut to the desktop (this does not apply with Windows 3.1). Also copy the midiout.drv file (found in the c:/rave folder to the c:\windows\ system folder. Serial or USB operation If you are connecting to the serial or USB port, you will need to install the requisite drivers now. Details are in the separate serial port driver section and Serial-to-USB section. Do not forget that if you are using the Serial-to- USB converter, the MIDI serial driver will also be required. For a MIDI to USB driver install as per the instructions supplied with the unit. Setting up Rave Once you’ve started Rave in the normal way, select “Options” and the “midi thru” box to bring up a tick against the MIDI Thru. The sound card synthesiser will not produce any sounds unless this box is ticked. Check that the Options/Metro80  Silicon Chip double check that “MIDI Thru” is ticked in the Rave/Options settings and that you have selected the correct port in the settings menu on the MIDI Drum Kit. You should also check the settings mentioned in the MIDI serial driver section and the Serial-to-USB sections. You will need to add in (check the Add New box) the assignment 10 that is mapped in channel 10 as shown in the set output assignment box. Click OK to place this into the output assignment selections list. Playing the MIDI Drum Kit You are finally ready to play the MIDI Drum Kit. Connect the serial, USB or games port lead between the MIDI Drum Kit and the computer, switch on the MIDI Drum Kit and check that you can play the instrument and hear it through the soundcard output using headphones or loudspeakers. If you cannot hear anything, make sure the volume is turned up on the computer and that the sound works on other mediums such as the CD player. If the CD player works and sound still cannot be heard with the Drum Kit, To record, select File/new. Save as ‘yourfilename’.blk. The following track details will be displayed. Where the Output is shown, change the number to 10 otherwise the drum sounds will just be instrument notes. This channel selection also applies to the Computer Muzys and Tracktion sequencers. Click onto the REC(ord) button to begin recording. The tape transport position marker will start to count up after a second or so and you are now recording. The play, fast wind and stop buttons operate the same as any tape or video recorder, so you can stop, rewind and play the composition. Selecting File/save saves the recorded composition. You can multi-track record if you want to. This lays down another recording alongside the original recording, leaving the original intact. So you can playback with more than one track, as if there is more than one Drum Kit playing or you can record another instrument such as a keyboard to accompany the Drum Kit track. To multi-track record, left-click the mouse pointer in the track name block (eg where “Silicon Chip 2” is positioned in the screen grab below) to select the second track. These are initially set with an unnamed label but they can siliconchip.com.au be renamed by right clicking on the word, using the backspace to delete the word and rewriting your required name. The selected track can then be recorded as a separate track with the original recording. Up to 32 tracks can be recorded. In the right hand blocks, there is the option to change the patch (instrument), the volume, pan and quantisation. The easiest way to understand the changes is to play with them! Latency Latency is the delay between when the MIDI signal is sent to the sequencer and when the sound is heard. The Rave sequencer does not have a facility to adjust latency but most other sequencer programs do have. Note that latency is sound-card dependent. The Realtek sound card in our test computer could only provide a latency of 32ms minimum when used with Propellerhead’s Reason. Setting for a shorter latency caused sound break-up. The other commercial sequencers we tested did not provide a suitable reduction in the latency. Ideally, a sound card that supports ASIO (Audio Stream Input Output) should be used to allow adjustment for minimal latency. With Computer Muzys select System/Audio Hardware. Note that if the latency does not appear to change regardless of the setting, it is probably due to the sound card. It may not be ideally suited for direct MIDI input with low latency. Try to update the driver from the manufacturer’s web site. If this does not help, use a sound card that supports ASIO drivers. When setting the latency for other sequencers you usually select Edit\ Preferences\ then select the audio section and change the sound card driver. The slowest sound card driver is the MME type while the ASIO types are the fastest. If your sound card does not support the ASIO driver then select a Direct Sound driver. The latency figure is usually shown as each driver is selected. Also the buffer size must be adjusted so that it is at a minimum but not so small that the sound for the drums becomes broken up. Macintosh Computers The Tracktion sequencer has a direct latency adjustment as shown that is found under the settings selection. Select a low latency that also works without affecting the sound. Then select the Driver Type as either a Direct Sound or ASIO driver if the output device supports it. Select the Device Setup tab to alter the latency and use the right or left mouse button to increase or decrease the value respectively. The drum sounds will become broken up if this latency is set too small in value. Just increase the latency until the drums sounds are correct and the latency is at a minimum. Latency proble siliconchip.com.au Note that any of the settings made on the MIDI Drum Kit such as the patch, volume and pan will not be implemented if the changes are made when the sequencer is not running. Switch the Drum Kit power on and off if you need the new settings to be activated. Also, you may need to adjust the Repeat and Threshold settings on the MIDI Drum Kit to allow the pads to be played at as fast a rate as possible and to prevent one sensor pad from triggering another. Details on these adjustments can be found in the first article. This is a basic rundown on how to use the software, sufficient to enable you to play and record plus do some multi-tracking if required. We hope you enjoy using your MIDI Drum Kit. This screen shot shows the set up for operating the MIDI Drum Kit. To enable sound you must select channel 10, the enable end to end tab and the e-to-e box. Although we have not tried it, Mac users should be able to use the MIDI Drum Kit by using a Mac version MIDI sequencer – for example the ComputerMuzys CM studio, Tracktion and Reason. There are at least two options when making the connections between the MIDI Drum Kit and the MAC. You may need to visit a music shop and purchase a cable or converter. The simplest option is to use a MIDI-to-printer-port cable. The Mac already has MIDI drivers installed for this connection but it is only useful if you have a printer port. For USB connection you will require a USB to MIDI converter such as the Yamaha UX96. This converts from the MIDI outlet on the MIDI Drum Kit to USB format. The driver supplied with the converter will need to be installed. A well-versed-in-MIDI music shop salesperson should­be able to supply you with the necessary software and hardware. February 2006  81 Installing the MIDI Drum Kit The serial driver is commercial software, written by Yamaha Corporation for their MIDI musical instruments. It supports Windows 95, 98, Me, NT, 2000 and XP. The driver automatically detects your operating system and installs one of two versions best suited for your computer. Both files are contained in a file called cbxdrv201w.zip. This is a 971kb file and is designed for use with a COM1 or COM3 port. When using with a serial port connection, make sure that you have a free COM1 to COM4 communications port on your computer before installing the driver. If you are already using a COM port (eg, for a serial mouse and external modem), you may have to free up one of these ports so you can use the MIDI Drum Kit with this serial port driver. In general, the modem connection could be used or if you only have one serial port, use this and connect your serial mouse to a USB port using commonly available USBto-serial converters (or buy a USB mouse). When used in conjunction with a USB-to-serial converter, the COM port numbers apply to the virtual serial port created with the USB-to-serial driver software (see its installation in the separate section). The Yamaha serial driver file can be obtained from www. yamaha.co.uk/xg/download/tools/cbxdrv201w.zip. Save the file to a directory (or folder) called c:\midicbx (or similar) and unzip in the usual way. A readme file will be unzipped to one of the folders (c:\ midicbx\cbxdrv201w\setupdir\009\readme.txt) and this describes in detail how to set-up the driver for the various Windows operating system versions. In abbreviated form, double click on the setup.exe (found in the setup folder) file and follow the prompts. When the “select COM ports” dialog shows, check the COM port that you are going to use. The selection is dependent upon how many serial ports you have and which one you are going to use for the MIDI Drum Kit connection. Note that if you are connecting via USB, then select a COM port number that does not correspond to a serial port that is already installed. Click on the Next button and the MIDI output ports dialog will be shown. For our purposes select the “Use single MIDI” output port. Click on Next and that completes 82  Silicon Chip the installation. This dialog box will be displayed. Normally it reminds the user to select the PC-2 position on the Yamaha MIDI unit’s ‘TO HOST’ select switch but for our MIDI Drum Kit, it reminds us to select the serial port setting on the Drum Kit. Restart the computer to finalise the installation. Correct installation can be seen in the sounds and audio devices properties box. For Windows XP, select Start/Control Panel, then switch to Classic View if set in the Category View mode. Now select Sounds, Speech and Audio Devices/Audio/ MIDI music playback. In the MIDI music playback, select the down arrow to check if Yamaha CBX A Driver is installed. Do not select this driver – we are just looking to see if it is there, so keep the original SW Synth setting. Once installed, you can change settings and disable the driver without uninstalling it. To do this, select Start/Control Panel and doubleclick on the Yamaha CBX driver icon. When you double-click on the Yamaha CBX Driver Icon, the CBX Driver Setup box will be displayed. You can select the COM port (again) and enable or disable the driver. The greyed out selections cannot be used. When using this driver with Rave, you can see if it is connected correctly by selecting Options/Synchronisation. If correct, the Yamaha CBX Driver will be displayed in the Synchronisation input port box. Removing the Yamaha CBX Driver Navigate to the c:\midicbx folder and double-click setup.exe. The Setup dialog will appear. Follow the prompts to remove the driver. Restart the computer to complete the removal. USB Operation (via serial to USB converter) When connecting the MIDI Drum Kit using a USB port, you siliconchip.com.au serial driver will need a USB-to-serial (DB9) converter. A suitable device is available from Jaycar Electronics (Cat. XC-4835). This unit converts the serial signal from the MIDI Drum Kit’s serial port output to a USB signal. The software supplied with this converter then produces a virtual serial port on the computer, which can be read by the Yamaha MIDI serial port driver that is already installed. Both the virtual serial port and the MIDI serial port driver must be set to the same COM port number. Note that if you have a serial port on your computer, it is preferable not to select the same COM port number for the virtual port. To install the USB-to-serial converter and the software, plug in the USB unit. The computer will alert that new hardware has been installed. In Windows XP, the Add New Hardware Wizard will start up and assist in setting up the USB converter. When prompted, insert the CD ROM and select the ‘USB to serial cable’\WN DRIVER\98-2009-2K20021 folder. Click next to install. If you have problems with this method, disconnect the USB-toserial converter, wait say ten seconds and reconnect. When the new hardware has been detected and the “add new hardware” wizard opens, select the install from a list or specific location, then click onto next. Select ‘Don’t search I will choose the driver to install’. Click onto next. Click on ‘Have disk’ then browse to the CD ROM\ WN Driver\98-2009-2K20021\serspl.inf. Click onto open, then OK and next. A warning may appear to say that the software is not logo tested for compatibility with Windows. Click on the ‘Continue Anyway’ button. Uninstalling or reinstalling Make sure the USB-to-serial driver is plugged into the computer and select Start/Control Panel/system. In the system properties select hardware/device manager/ ports (COM & LPT). Select the ‘Prolific USB-serial-bridge’. Double- click on this then select Driver/uninstall and OK when it prompts you to uninstall. You can reinstall using this method by selecting the update driver button and going to the folder on the CD ROM as before. To change the COM port setting on the USB-to-serial converter, select Start/Control Panel/system. In the system properties select Hardware/Device Manager/Ports (COM & LPT). Select the ‘Prolific USB-serial-bridge’. Double-click on this then select port settings/advanced. Select the COM port number from the drop down menu. Note that the port number must match the port number selected for the Yamaha MIDI serial port driver. You can only select the ports that the Yamaha MIDI serial port driver allows. In our case, as shown in the Yamaha CBX driver setup, this is COM1 or COM3. Notes on the USB connection 1. You can connect the USB-to-serial converter to the MIDI Drum Kit in one of two ways. First, you can use a DB9 extension cable. The cable connects to the MIDI Drum Kit serial outlet and the socket end connects to the USB-to-serial converter. Plug the USB end into the computer. Alternatively, if you only require a short connection, the USB converter can be directly connected to the MIDI Drum siliconchip.com.au Kit serial outlet. In this case, the retaining screws on the MIDI Drum Kit serial outlet will need to be removed. A 1.8m USB 2.0 A-to-A extension cable can be used to make the computer connection. 2. If you plug the USB-to-serial converter into a different USB port on the computer, you will need to install the driver for that USB port. It’s better to always plug into the original USB port where the driver was installed. 3. Avoid plugging the USB-to-serial unit into the computer while the MIDI Drum Kit is switched on, or the computer may sometimes decide the device is a mouse or similar “human interface device” rather than the USB converter. If this happens, you will need to reinstall the USB to serial converter software as detailed above or click onto the driver ‘roll-back’ button instead of the ‘reinstall button’. This last option reverts the driver to the previous USB-to-serial driver and installation is quicker as you do not need the CD ROM. 4. If you see this panel when starting Rave, it means that the MIDI Drum Kit will not (at present) work with the USB converter. The panel indicates that the virtual port data is corrupted. It could be that the Serialto-USB converter is not connected, or simply that the USB converter has to be reset. Alternatively, the COM ports selected for the Yamaha serial driver and the USB to serial driver may not be the same number. In the first two cases, click on the ‘No’ button and then OK on the copyright panel when Rave starts. Exit from Rave in the normal way. Unplug the USB connection and wait for the disconnect confirmation, then reconnect it and start Rave again. The wave device-warning panel should not appear this time. 5. If you switch off the MIDI Drum Kit while you are within Rave, then the only way to have the MIDI Drum Kit play again is to exit from Rave and then restart it. Similarly in Computer Muzys, you may receive this error when starting. In this case exit from the program, disconnect the USB connection and reconnect it. Restart the program. The Computer Muzys MIDI port is set using the System/ MIDI Hardware selection and the MIDI Hardware set-up panel will be shown. Make sure you also select channel 10 for MIDI In by right clicking on the input box and selecting channel 10 from the pull-down menu. SC February 2006  83 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/ Building the ULTIMATE When we ran out of space last month, we were just about to start installing the electronics. So let’s get that finished and start blasting the neighbours . . . B elow the speaker “box” is the space for the electronics assembly. Inserted from the rear, it consists of (a) the amplifier; (b) the preamplifier; (c) the master volume control; (d) the amplifier power supply (including transformer, fuse and on/off switch); (e) the notebook computer power supply; and (f) the USB hard disk drive (or maybe even two – there is plenty of room). These are all mounted on a 2mm aluminimum plate measuring 435 x 350mm, with the longer edge bent up 90° at the 50mm mark. A 125mm cutout is made in the middle which allows the heatsink to mount on the outer (vertical) surface and the amplifier PC board on its 10mm standoffs on the horizontal plate. Refer to our photographs and diagrams to see the layout. In general, the “noisy” bits – the transformer and computer supply – are kept well away from the amplifier input. The amplifier itself mounts with its heatsink on the outside of the bent-up section and is secured to it with two 3mm screws (we tapped the heatsink for convenience). Two screws from the underside mate with the 9mm tapped standoffs holding the amplifier firmly in place. By the way, we’re assuming you have built the amplifier module and set it up as per the instructions (including setting the quiescent current with resistors), so we are not going to re-invent wheels here! Similarly, the ±40V and ±15V power supply: it’s pretty-much self-explanatory and we don’t envisage anyone having any problems putting this together. Fairly obviously, you need to have this completed to set the amplifier quiescent current! By the way, the -15V supply is not used. We know it’s a waste of a few cents worth of components but if you got them in a kit, you might as well put them in anyway. You never know – one of these days you might need a ±15V supply! With only the mains transformer connected, confirm that you do indeed have +40V, 0V & -40V and +15V, 0V & -15V at the appropriate terminals. The Ultimate Jukebox in block diagram form. The green blocks are pre-existing SILICON CHIP projects, with the obvious exception of the notebook computer and its peripherals and the commercial speaker crossover. Note that the PreCHAMP is slightly modified from the published design – this is fully explained in the text. 88  Silicon Chip siliconchip.com.au JUKEBOX Part 3 by Ross Tester Better to find a power supply error now than have the power amplifier tell you in spectactular fashion! The preamplifier This really is a very simple preamp. Follow the instructions with your PreCHAMP kit but make the following changes: the 100kW resistor in the voltage divider in the base of Q1 should be increased to 120kW and Q1’s 100W emitter resistor should be increased to 560W. If for some reason you find you do need more gain, this resistor could be decreased to, say, 330W. Before use we’d suggest that you measure a couple of voltages to be sure, to be sure. First, with nothing connected except power (+15V and 0V from the power supply board), measure the DC voltage across the output terminals. It might first of all indicate a small voltage but quickly settle down to close to zero (anything up to a few tens of millivolts). Second, check the voltage at the input terminals: again, it should be next to nothing (anything higher than this The output from the computer headphone socket is stereo – two 5.6kW resistors sum this to mono and prevent interraction between channels. We used 1/8W types – but 1/4W should also (just!) fit inside the plug. Make sure neither short to each other nor to earth! siliconchip.com.au February 2006  89 Apart from the speakers, crossover and computer, everything mounts on an aluminium chassis or “tray” with a 50mm vertical lip on one edge. It’s shown here without the safety cover over the mains wiring. Compare this picture with the drawing at right. Yes, there are a couple of minor differences (eg, the earth wire is routed slightly differently)! indicates a fault which could damage your notebook computer). Finally, measure the voltage between Q2’s collector and 0V (eg, across the 2.2kW resistor). It should be pretty close to half the supply voltage (our supply voltage was 15.2V and we measured 7.8V). With these checks all OK, you can be pretty confident your preamp is working fine! plate with “U” brackets made from the piece we cut out of the top aluminium plate – so both were already carpet covered (and hence wouldn’t damage the units underneath). Finally, along the front “lip” is mounted an IEC connector with integral mains fuse and the on/off switch (illuminated type), with their heatshrink-insulated wiring connecting to Putting it all together Refer to both the photographs and the diagram opposite. The power supply mounts on its standoffs immediately behind the amplifier board, with the toroidal transformer alongside. Behind the power supply is mounted the notebook supply (in case we want to use the notebook outside the jukebox in the future, we bought a spare supply for the jukebox on eBay for $25). The supply, along with the USB hard disk, is held onto the aluminium base90  Silicon Chip Here’s the “PreCHAMP” preamplifier from our July ’94 issue – an oldie but a goodie! The green text and components show the altered/added components from the original. They’re basically to throttle the gain somewhat and also allow the circuit to run from a higher voltage (15V vs 12V originally). siliconchip.com.au The complete “electronics” section of the Ultimate Jukebox, which fits into an L-shaped chassis or tray in its own compartment underneath the speaker “box”. Not shown on this diagram (for clarity) are the lengths of heatshrink tubing which protect all the 240V AC connections (they are clearly visible in the photo). To be doubly sure, the entire area (IEC socket, switch and terminal block) is then protected with U-shaped aluminium cover which prevents any possible contact with mains wiring. Remember, this area is open to the back of the jukebox so you cannot be too careful. siliconchip.com.au February 2006  91 the transformer via a mains terminal block, insulated from the aluminium underneath by sitting it on a piece of blank PC board (just in case of a stray strand of wire!). There is a good reason for using a IEC connector instead of a captive mains cord: safety. We didn’t like the idea of a flailing mains cord when the jukebox is being transported so we made it removable. On the opposite side of the lip is mounted a 10kW pot which becomes a master volume control (volume is set on screen but this is effectively an over-ride to ensure noisy parties can be limited by the host as people keep on turning up the on-screen control). Take care with the mains wiring, especially the earth wiring – follow our diagrams to the letter and remember to cover all mains connections (eg, to the IEC socket and mains switch) with heatshrink tubing! When everything is completed, some form of mechanical barrier needs to be fitted covering the mains connector, on/ off switch and terminal block – ie, all the bitey bits. We haven’t shown this in either the diagram or the photographs because we wanted to make sure you could see everything underneath. Don’t you forget it, though! Connecting it all up We’ve already covered the output (speaker) wiring – all you need do is connect the crossover input to the amplifier output. The audio line coming down from the notebook computer headphone socket connects to the preamplifier input. Its output goes to the master volume pot. From the wiper of the pot, the audio line goes to the amplifier input. Back up the top (notebook) end, the audio line connects to the headphone socket via a 3.5mm stereo plug. This has two 5.6kW resistors (one per chan- The notebook computer sits in a “well” made from a U-shaped piece of 32mm craftwood. This depth suited this particular notebook perfectly; other notebooks might need a deeper or shallower well so the craftwood thickness would be adjusted to suit. When the jukebox is complete, a carpet-covered aluminium sheet screws over the top of the craftwood, hiding everything but the notebook screen and giving a place for the trackball to sit. nel) to sum the stereo signal into mono before sending it down to the preamp. These resistors also prevent any interaction between the channels. We used 1/8W resistors and were able to mount them inside the 3.5mm plug, with the solder connection between them and the shielded audio cable insulated with a length of heatshrink tube. Standard 1/4W types should fit – but they’ll be tight. USB cable & notebook supply A USB cable also comes up from below, connecting the USB hard disk to one of the computer USB ports. In our case, the hard disk cable wasn’t quite long enough to make it so we had to use a USB A-A extension cable. While this worked fine, we did find it introduced some computer noise into the system when the wick was wound up (on no signal). Still, for a jukebox, it would hardly be noticed (if at all). The computer power supply also has its output coming up through the same holes as the USB cable. In this case, it was long enough. Finally, the trackball or mouse connects to the appropriate socket: if it’s a serial device, it will need to go into a serial socket (if you have one) or via a USB-to-serial converter to a USB port. If it’s a USB trackball, it plugs (of course) straight into the USB port. Testing it all out First testing should be done without the notebook connected (ie, no music source). Turn the system on for a smoke test and if none escapes, try the “blurt” test – turn the master volume control up a little (not a lot!) and touch your finger to the tip of the 3.5mm audio plug. You should be rewarded with a nice, healthy “blurt”. Turn the master volume back down (otherwise you’re going to get a real crack and thump from the speaker) and plug in the 3.5mm plug. Most PC operating systems include some sample music which you can play to prove that everything is OK. Or you could play a CD. Running “Ultimate Jukebox” By now, we’ll assume you have downloaded at least the trial version of Ultimate Jukebox software (see last month) and have become conversant with it. If so, it’s just a matter of turning on the system, loading the music you want on your hard disk(s) from CD, download, etc, and then telling The tray for the electronics and the notebook cover plate start out the same size but require cutouts – and the tray needs a 90° bend to support the heatsink and house the power input socket, switch and master volume control. The cutout in the notebook cover plate depends on the specific notebook computer you use. Don’t throw any scraps away – they’re handy for brackets to hold the notebook power supply and USB hard disks, along with the mains area safety cover. 92  Silicon Chip siliconchip.com.au The view underneath shows the two castors along with the timber “foot” (camouflaged a bit by the carpet!). Speaker corner protectors are also added – for protection! Ultimate Jukebox to add it to the playlist. When you’ve done this, you can select the tracks you want to hear and include them in your playlists, or choose random, etc. The software is very powerful once you get to know it – and you’ll only learn how to do all this by playing with it, so play away! Just remember that when you disconnect the notebook or turn it off, you should turn down the master volume control first. The beeps and other noises that the PC makes as you do anything can be downright disconcerting at high level! Making it lively! If you saw the Ultimate Jukebox photo in Part 2 (last month) you would have to say that yes, it looks impressive but no, it doesn’t look too “partyish”. As we mentioned right at the start of this series, “real” jukeboxes of the past always had lots of chrome and flashing lights! The chrome is a bit of a tall order but the flashing lights we could handle easily! But which way to go? We thought about including some form of “Discolight” controller and including some coloured lights behind translucent panels. We also gave that idea away as overkill! What we did in the end is simplicity itself: we (very carefully!) attach ed a whole swag of ropelight to the edges of our jukebox using some fine panel pins. The ropelight we used came from Jaycar Electronics (Cat. SL-2820 <at> $34.95). At 10m long, it is arguably siliconchip.com.au Here’s our towel-rail “handle” – it makes moving the jukebox that much easier. It’s both stronger and cheaper than individual handles. too long for this application. But you can’t shorten it, so we were stuck with what we had. We wound it around and around, up and down – and then connected it to the mains terminal block on the amplifier tray. It comes with its own little controller which allows you to set a variety of patterns, so we arranged things to make this accessible (alongside the notebook computer) for the punters to play with! Driving it from iPODs, etc We’ve already been asked several times: can the Ultimate Jukebox be driven from, say, an iPOD or other personal audio devices? The answer is a resounding yes! Just in case you haven’t twigged, if you don’t want to use a notebook computer, the modified 3.5mm plug can also be used with just about any other audio device with a headphone socket. Because we have added a preamp, anything that normally drives Jaycar’s SL2820 Ropelight is 10m long, 240V operated and has a variety of light patterns (set by the black box). headphones should drive the jukebox perfectly. We think you will be pretty surprised by the grunt the Ultimate Jukebox delivers. Despite having “only” a nominal 50W amplifier, when you team that up with the sensitive speaker specified you will have more than enough power to rock your socks off! Given that the sensitivity of typical “hifi” speakers is in the 88-90dB range and the woofer we chose is some 97dB, we’re already starting at least 6dB higher – so the 50W amplifier will perform as well as a 200W amplifier. And also given the fact that the SC480 has a “music power” of 77W into 8W, it’s that much better again. It’s finished . . . I think Well, it’s finished as far as the jukebox itself is concerned. It does exactly what I wanted it to – and does it very well! And it sounds really great! But the first time we used the Ultimate Jukebox was at a surf club Christmas Party and it was when I was dragging the PA amplifier out that I realised the jukebox could have been just that much better had I included a PA function. Nothing particularly elaborate – provision for a microphone with its own preamp/mixer, possibly with a wireless microphone á lá the PortaPAL PA System (SILICON CHIP February 2003). It would also add significantly to its usefulness for weddings, parties, etc. So guess what I’m going to work on next? SC February 2006  93 Salvage It! BY JULIAN EDGAR Making an adjustable loud screamer This month we’re re-visiting our old friend, the 12V phone charger. As shown in April 2005, it’s easy to give these chargers an adjustable output voltage. However, it’s also easy to make them perform a completely different function – and here we use two to make a loud screamer. I N ADDITION TO a couple of 12V car phone chargers, you’ll also need a speaker for this project. You can use any salvaged wide-range speaker but in keeping with a mobile-phone theme, we used a boxed speaker from a hands-free car phone system. You can often pick these up at the same time as phone chargers. Cost? Well at garage sales and the like, expect to pay only a few dollars for the lot. But what can you do with these bits and pieces? One answer is to make a very loud pulsing screamer. The components In this system, the two phone chargers perform different functions. The first is modified to produce a pulsing output voltage, which in turn powers the second charger. The second charger is modified to produce the audio output tone which is fed to the speaker. And the speaker? Well, it makes the loud noises! The modifications to the charger boards are very easy and it takes only a few minutes to get the screamer up and running. In addition to the chargers and the speaker, you’ll also need a selection of capacitors. You’ll only end up using two of them but having a range available makes it easy to get the sounds you want. Building it The first step is to modify one of the chargers to produce the pulsing output. Begin by removing the PC board from its cigarette lighter plug enclosure, then remove the output filter capacitor. This is the electrolytic capacitor that’s usually located near to the output leads (a typical value is 680mF). Just desolder it and place it in your parts drawer – you never know when it might come in handy for some other project. The next step is to replace the timing capacitor. It’s dead easy to find – it’s the smallest disc-shaped capacitor on the PC board and typically has a value of 100nF. Carefully desolder Fig.1: the pulsing screamer uses two slightly modified 12V phone chargers and a speaker. The first charger pulses the second charger which in turn produces the audio frequency that’s reproduced by the speaker. 94  Silicon Chip this capacitor and temporarily replace it with a 100mF electrolytic capacitor (this can be tacked to the track side of the board). Note that electrolytic capacitors are polarised, so be sure to connect the negative lead of this capacitor to the ground track of the PC board. You might have to do some track tracing to make sure you get this right. Charger 2 The next step is to modify the other charger so that it will produce the sound (ie, an audio tone). As before, start by removing the output filter capacitor and placing it in your parts drawer. That done, remove the timing capacitor and temporarily replace it with a capacitor of around 1mF. Next, connect the outputs of the “Pulsing” charger to the power supply inputs of the “Tone” charger, making sure that the polarity of the connections is correct – see Fig.2. You can then connect the speaker to the “Tone” charger’s output terminals. Testing and Tuning Now for the smoke test – connect 12V power to the “Pulsing” charger and listen. It’s likely that the sound will not be quite as you want it – it may be too low in pitch and pulsing too slowly, for example (or vice versa). That’s easily fixed. To speed up the pulsing, decrease the value of the timing capacitor in the “Pulsing” charger. Similarly, to increase the pitch (frequency) of the sound, decrease the value of the capacitor in the “Tome” charger. By making some simple capacitor changes, it’s possible to have anything from a deep, slowly pulsing foghorn to an ultra-piercing, frantically pulsing screamer - and everything in between! When you’re happy with the sound, siliconchip.com.au Rat It Before You Chuck It! The pulsing screamer is easily made from two modified car phone chargers and a speaker. In this case, we used a (brand new) speaker from a hands-free kit which we picked up at a garage sale but any wide-range speaker is suitable. properly solder the selected capacitors in place. Now run the system for a while (you might want to wrap the speaker in a pillow!) and check the temperature of the two ICs. They are likely to be warm but they shouldn’t be too hot to touch. If they are, install a 5W 5W resistor in series with the 12V supply to the system. This will drop the audio output but the ICs will run cooler. Incidentally, when testing, always power the system using the voltage that will be used in the final application. This is because the pitch and pulsing frequency will vary with supply voltage. Note that depending on the value of the capacitors used, the circuit will work down to about 4V. Making it louder If you want to increase the loudness Whenever you throw away an old TV (or VCR or washing machine or dishwasher or printer) do you always think that surely there must be some good salvageable components inside? Well, this column is for you! (And it’s also for people without a lot of dough.) Each month we’ll use bits and pieces sourced from discards, sometimes in mini-projects and other times as an ideas smorgasbord. And you can contribute as well. If you have a use for specific parts which can easily be salvaged from goods commonly being thrown away, we’d love to hear from you. Perhaps you use the pressure switch from a washing machine to control a pump. Or maybe you salvage the high-quality bearings from VCR heads. Or perhaps you’ve found how the guts of a cassette player can be easily turned into a metal detector. (Well, we made the last one up but you get the idea . . .) If you have some practical ideas, write in and tell us! of the output, solder a bridging wire across the inductor on each PC board (the inductor is placed near to the output and is simply a coil of wire). A second bridging link should also be installed across the output diode on each board (see Fig.2). The prototype was configured to produce a very loud 200ms burst of 300Hz sound at 1-second intervals – so it was configured more as a “growler” than a “screamer”! This involved using a supply voltage of 12.0V, a 470mF capacitor in the “Pulsing” charger and a 47mF capacitor in the “Tone” charger. In addition, the inductors and output diodes were bridged on both chargers, as described above. Housing your screamer Fig.2: here is a typical circuit for a 12V phone charger. The primary modification is to alter the value of the timing capacitor to dramatically lower the frequency at which the charger is operating. Shorting the output inductor and output diode increases the output level. siliconchip.com.au Many hands-free speakers use boxes that are held together with screws, allowing the enclosure to be easily opened. If that’s the case, the two modified chargers can be insulated (eg, by being wrapped in electrical tape) and then placed inside the enclosure, one each side of the speaker basket. Alternatively, the chargers can be SC housed in a separate case. February 2006  95 PRODUCT SHOWCASE VAF speakers make true-to-life sound by keeping their cool Australian speaker manufacturer VAF Research has introduced technology which is claimed to significantly reduce distortion in its loudspeakers. VAF Founder and CEO, Philip Vafiadis said that by cooling both the woofer and tweeter voice coils of the new Generation 4 DC-Series loudspeakers, they have dramatically reduced thermal compression. “When current passes through a wire” he said, “it gets warmer. Woofer and tweeter voice coils are no exception. The warmer they get, the higher their electrical resistance becomes and the greater the difference in quality between quiet and loud sounds.” Radial VentingTM around every DC-Series woofer voice coil allows cooling air to be pumped in and out on every single movement. This cooling effect results in less temperature difference in the voice coil when driven with low or high level dynamic signals for a far more consistent and true to life sound. VAF claim that the bass is so linear and dynamic in their new range leading DC-X, they can be used without subwoofers even in home theatre systems. Heatsinks fitted to every DCSeries tweeter also ensure these tweeters keep their cool. The result of this woofer and tweeter combination is very low distortion and freedom from compression across the entire audio spectrum. Available in Black Oak, Jarrah or Oak finishes, VAF’s DCSeries comprises four models from Contact: $899 to $2499 per VAF Research pair including a 52-54 North Terrace, Kent Town SA 5067 powerful centre Tel: (08) 8363 9996 Fax: (08) 8363 9997 Website: www.vaf.com.au speaker. Want to make your own Diesel fuel? We don’t have to tell you that fuel costs are always on the rise. Even diesel, once half the price of petrol, now consistently sells for at least 10c/litre more than petrol. But there are lower cost alternatives! One increasingly popular solution is to look at alternative fuel sources including LPG, Electricity, Hydro-technology and a new source called ‘Biodiesel’ – a clean burning alternative fuel, produced from domestic, renewable resources. Biodiesel contains no petroleum but it can be blended at any level with petroleum diesel to create a biodiesel blend. It can be used in compression-ignition (diesel) engines with little or no modifications. Biodiesel is simple to use, biodegradable, nontoxic and essentially free of sulphur and aromatics. Jaycar Electronics have available a comprehensive guide to Biodiesel, which takes you through everything from starting your oil collection service to testing and using your fuel on the road. With the simple methods spelt out in this book, you can produce fuel for a diesel engine from vegetable oil – even used ‘fish and chip’ oil. “Simple Biodiesel”, by Robert Contact: Sharman, is avail- Jaycar Electronics able from all Jaycar PO Box 6424, Silverwater NSW 1811. Electronics stores Tel: 1800 022 888 Fax: (02) 9741 8500 Website: www.jaycar.com.au for $29.95 SILICON CHIP WebLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK We supply Radiometrix VHF & UHF OEM radio SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC for WEBLINK SCdata WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK modules wireless comms, control and Our website is updated daily, with over SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK monitoring. We also stock lowSC cost easy toSC WEBLINK 5,500 productsSC available through our SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK WEBLINK SC WEBLINK WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK WEBLINK WEBLINK SC ordering WEBLINKfacility. SC WEBLINK SC WEBLINK use Bluetooth modules and theSC new rfBASICSC WEBLINK SC secure online SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK programmable radio modules as well as other Features include semiconductor data SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK RF accesssories. SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SCreleases, WEBLINKsoftware SC WEBLINK SC WEBLINK sheets, media SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK Radiometrix - Engineers preferred choice for downloads, and much more SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK VHF UHF LowSCPower Radio SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC&WEBLINK WEBLINK SCModules WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK Tel: 1800 022 888 Tel: 1800 022 888 SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK WEBLINK SC WEBLINK SC6331 WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK Tel: SC (03) 6331 6789 Fax: (03) 1243SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK ilicon hip SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK Want your product or service featured both here and on the SILICON CHIP website for the one low price? Contact Phil Benedictus or Lawrence Smith on (02) 9211 9792 for all the details! 96  S C RF Modules Australia JAYCAR JAYCAR ELECTRONICS ELECTRONICS WebLINK: www.rfmodules.com.au WebLINK: WebLINK: www.jaycar.com.au www.jaycar.com.au siliconchip.com.au SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC “Uncompromised Performance Oscilloscopes” Tektronix claim their new DPO7000 Digital Phosphor Oscilloscopes (DPOs) eliminates the trade-offs found in all other oscilloscopes between sample rate, record length and waveform capture rate. Design engineers are increasingly working with embedded systems that present a variety of challenges in serial data, power design, video and other applications. In addition, faster signaling speeds are becoming more prominent in mainstream applica- tions. To meet the needs brought about by increasing speed and complexity, engineers need greater real-time signal acquisition and instrument intelligence for design validation, debugging and compliance. This requires the fast sampling rates, long record length (deep memory), fast waveform capture and analysis capabilities uniquely available in the DPO7000. Ranging from 500MHz to 2.5GHz, the new DPO7000 models are ideal for engineers and technicians wanting to more efficiently debug their devices, reduce time to market, obtain higher quality products and lower development costs. Contact: NewTek Instruments Pty Ltd 3 Byfield St, North Ryde NSW 2113 Tel: (02) 9888 0100 Fax: (02) 9888 0125 Website: www.newtekinstruments.com New Linux VI tools from NI National Instruments has released its newest Virtual Instrumentation tools for Linux operating systems, including NI-DAQmx 8 driver software and new instrument drivers for modular instruments. These innovative products not only triple the number of NI devices for the Linux OS but also make it even easier for the growing number of global Linux OS users to take advantage of the benefits of virtual instrumentation, including increased productivity and lower system costs. The new products build on the NI LabVIEW 8 graphical development platform, NI’s powerful flagship software that is now fully supported on the Linux OS. Virtual Instrumentation combines the easy-to-integrate NI LabVIEW software with open, cost-effective measurement and control hardware. With the release of NI- DAQmx 8 driver software, Linux OS users now can use ANSI C or LabVIEW 8 to develop distributed systems using more than 200 NI devices for PCI, PCI Express and PXI, including data acquisition, signal conditioning, dynamic signal acquisition and switching hardware. Additional new NI instrument drivers for Linux OS deliver the flexibility and power of virtual instrumentation to more specialized modular instruments, such as digital multimeters, high-speed digitisers, arbitrary waveform generators and instrument control devices. Contact: National Instruments (Australia) PO Box 382, North Ryde NSW 2113 Tel: 1800 300 800 Fax: (02) 8572 5290 Website: www.ni.com TOROIDAL POWER Manufactured in Australia Comprehensive data available Harbuch Electronics Pty Ltd 9/40 Leighton Pl. HORNSBY 2077 Ph (02) 9476-5854 Fx (02) 9476-3231 Computer video 150m over twisted pair! M i c r o g r a m ’s VE120L and 120R Video Extender uses a local transmitter connected by Cat. 5 STP cable to extend the distance between the PC and a remote monitor up to 150m. A local monitor can also be connected to the transmitter. It can handle VGA, SVGA and MultiSync with VGA resolution is up to 1600 x 1200 <at>100Hz. Input and output are by 15 pin HDB 8P8C jacks and the two boxes measure 119 x 86 x 58mm. Recommended retail price is $399 for the pair. (Cat 3441-13) Contact: Microgram Computers 1/14 Bon Mace Cl, Berkeley Vale 2261 Tel: (02) 4389 8444 Fax: (02) 4389 8388 Website: www.microgram.com.au C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SCFor WEBLINK SC WEBLINK WEBLINK WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK everything in radioSCcontrol forSC aircraft, JED designs and manufactures a range of We specialise in providing a range of C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK boats and planes, We also carry single board computers (based on Low Power Radio solutions for OEM’s to SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SCmodel WEBLINK SC WEBLINK SCetc. WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SCWilke WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SCan WEBLINK SC WEBLINK SC WEBLINK WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK WEBLINK SC WEBLINK SC WEBLINK extensive range of model flight SC control Tiger and Atmel AVR), as well SC as WEBLINK LCD incorporate in theirSC wireless technology C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK GPS, altitude and speed, SC WEBLINK displays and analog digitalSC I/OWEBLINK for basedSC products. The range C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SCmodules WEBLINKincluding SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SCand WEBLINK SC WEBLINK WEBLINK SCinnovative WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SCinterfaces, WEBLINK SC WEBLINK SC groundstation WEBLINK SC WEBLINK SC WEBLINK WEBLINK SC WEBLINK SC WEBLINK WEBLINK SCMK WEBLINK SC WEBLINK autopilot and PCs andSC controllers. JED also makes a PC SC WEBLINK includes SC products from Consultants, the SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK controllers. More info on our website! PROMSCprogrammer RS232/RS485 world-renowned specialist manufacturer. C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK WEBLINK SCand WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK converters. C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK Tel:(07) 4639 1100 Fax: (07)4639 1275 SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK Tel:(07)SC 4934 0413 SC Fax: (07) 4934 0311 SC WEBLINK Tel/Fax: (02)SC 9533 3517SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK WEBLINK WEBLINK WEBLINK SC WEBLINK Tel: (03) 9762 3588 Fax: (03) 9762 5499 C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SCebruary WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK siliconchip.com.au Silvertone Silvertone Electronics Electronics Jed Microprocessors Pty Ltd TeleLink Communications WebLINK: www.silvertone.com.au WebLINK: silvertone.com.au WebLINK: jedmicro.com.au WebLINK: telelink.com.au F 2006  97 SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC Vintage Radio By RODNEY CHAMPNESS, VK3UG Brian Lackie’s Wireless Museum Many people are enthusiastic about vintage radios and some amass a huge collection but few people go on to turn their collection into a museum. But that’s just what Brian Lackie of Urunga, NSW did, after collecting vintage radios over many decades. B RIAN LACKIE has been a collector of early radio paraphernalia since his early working days. He became interested in radio when he was in high school in the 1950s, although he wasn’t able to pursue this interest until after he had finished his schooling. A correspondence course run by the Australian Radio College in Sydney helped Brian gain his amateur radio operator’s ticket (VK2DLM) in 1970. He became a builder after leaving school and did radio service in his spare time. He often worked in the country, particularly in farming areas. He was often offered an old radio or two and remembers once being given five Atwater Kent receivers. Collectors were considered a bit odd in those days. However, he accepted these offerings and gradually the lower floor of his home became filled with multitudinous old radios – obsolete, unloved and faulty; radios that others didn’t want. At that stage, Brian didn’t have any particular direction in his collection; he just collected because he liked old radios and felt he needed to save and preserve these pieces of our history. He believed that he was the only one with this interest and as collectors of old radios were considered “a bit odd”, he didn’t advertise his interest widely. Then he went to an amateur radio field day and met another collector, Lou Albert of Newcastle. Lou invited Brian to come and see his collection and having seen it, Brian was hooked. He has enthusiastically collected, restored and retained any item of radio history he could obtain since that day. But like most collectors, he didn’t display his “treasures” to advantage. Sets were stacked everywhere, on top of each other, jammed tight – there was no room to even walk around the sets. As well as radios, he collected publications, leaflets, servicing equipment, components, valves, electronic novelties and advertising signs – in fact, anything that appeared to have anything to do with our radio heritage. Establishing the museum This view shows some of Brian’s early horn and cone speakers. They date from around 1924 for the horn speakers to around 1928 for the moving-iron balanced-armature type cone speakers. 98  Silicon Chip Brian could see that he couldn’t share his passion for our radio history if he couldn’t show people what he was so passionate about. So around 20 years ago he believed he should move towards establishing a museum containing the most significant items within his collection of many hundreds of sets. Time was a problem but planning went ahead and work started on a completely separate building on his property in 2001. The building took about six months to bring up to the fitting-out stage. It siliconchip.com.au All types of vintage radios are on display, ranging from very early (and very collectable) sets to later sets. Some of these early radios are now quite rare. had to have provision for display as well as a workshop area for restoration work. Facilities were provided to operate the equipment, like an aerial/ antenna system, an earth leakage protection circuit and for imported radios, a 115V AC supply using a 240V to 115V 17A power transformer purchased for the princely sum of $10. Like most projects it took longer than expected. It was officially opened by Lou Albert on the 17th March, 2002. Touring the museum An inspection of Brian’s museum can take hours, because there is just so much to see. He has an encyclope- dic knowledge of our radio heritage so you only have to ask to learn a lot about individual items or the general philosophy of radio development. Only recently, he obtained a large number of newspaper cuttings from the era around 1910 concerning Father Shaw and his radio works. They seem to paint a different picture of some of the things that happened in radio/ wireless at that time to what we have seen in some publications. A David Jones single valve regenerative receiver, circa 1924. It has three basket-weave, moveable coils and sold for fifteen pounds ten shillings – a large sum of money in those days. siliconchip.com.au February 2006  99 Also in Brian’s museum is this early PMG sign which dates from around 1900. There are many books on various aspects of vintage radio in the museum that can be consulted to check that information gleaned from various sources is correct. As with most subjects, it pays to get as many publications as practical, so that various statements can be tested for accuracy. Interesting signs Some readers will remember the enamelled signs that were made early last century to advertise various products. For example, one of the photos in this article shows a typical advertising sign (circa 1900) that was used at post offices. In those times, trunk line telephone calls were booked in advance – there were no STD phone calls then. This enamelled HMV sign dates from around 1925 and is still in quite good condition. It may have taken the telephonist an hour or two to be able to connect you to the person you wanted to speak to in the next state and it cost a fortune compared to phone calls today. Telegrams were also a fairly quick method (for the era) of getting a message to people interstate. The message was handed in at the post office counter and then sent by Morse code to a post office near where the recipient lived, where it was typed up and then delivered by a delivery boy. Another interesting sign is a goodquality example produced for His Master’s Voice (HMV) around 1925. People tended to know organisations by their signs and HMV was always known as a quality producer of radio and record playing equipment. There was a lot more brand loyalty in those days. Radio gear A beautiful display of polished horns and slightly later speakers can be seen on a high shelf. They date from around 1924 for the horn speakers to around 1928 for the moving-iron balanced-armature type cone speakers. Another photo shows an early Stromberg Carlson 9-valve TRF Model 633 coffin style receiver from 1927 with its floor standing cone speaker (not complete) in the background. On top of the receiver is a Browns horn speaker on the left and a Ferranti on the right, with a more modern air-cooled transmitter Fig.1: the Loewe 3NF envelope contained three triodes, four resistors and two capacitors. Right: the Loewe 3NF triple-triode valve, circa 1926. It’s probably one of the first integrated circuits ever made! 100  Silicon Chip siliconchip.com.au Silicon Chip Binders REAL VALUE AT $12.95 PLUS P & P The museum features a good collection of early receiving and transmitting valves, all displayed in a large glass cabinet. These binders will protect your copies of S ILICON CHIP. They feature heavy-board covers & are made from a dis­ tinctive 2-tone green vinyl. They hold 12 issues & will look great on your bookshelf. H 80mm internal width H SILICON CHIP logo printed in gold-coloured lettering on spine & cover H Buy five and get them postage free! Price: $A12.95 plus $A7 p&p per order. Available only in Aust. Silicon Chip Publications PO Box 139 Collaroy Beach 2097 Or fax (02) 9979 6503; or ring (02) 9979 5644 & quote your credit card number. This rare set is a Stromberg Carlson 9-valve TRF Model 633, circa 1927. Its floorstanding cone speaker (not complete) is in the background. valve alongside them. The receiver even has a meter so that the filament voltage can be checked. Also on display is a 1924 “David Jones” one-valve regenerative receiver. The price was fifteen pounds ten shillings, a large sum of money in those days. It has three basket-weave, movable coils which could be moved in relationship to each other to obtain best signal input and regeneration control. It was a very simple set and featured very neat wiring using square siliconchip.com.au Use this handy form Enclosed is my cheque/money order for $________ or please debit my busbar. Listeners in those days didn’t get much for their money. There are a variety of other sets on display, from an early cathedral style wooden cabinet set to several coffin cabinet styles, several AWA “Empire State” receivers from the 1930s, and many Bakelite and wooden cabinet sets from the 1940s and early 1950s. Brian has tended to keep the older sets on the lower shelves in the museum, with later and smaller sets on the higher shelves. Quite a number  Bankcard  Visa    Mastercard Card No: _________________________________ Card Expiry Date ____/____ Signature ________________________ Name ____________________________ Address__________________________ __________________ P/code_______ February 2006  101 A selection of very early vintage radios and small kitchen (mantel) receivers. of these sets have not been restored. It does take a long time to restore hundreds of sets. One of the sets still awaiting restoration and display is Brian’s favourite, a rare Traeger 36/40 Flying Doctor Radio. A glass case houses Brian’s collection of early receiving valves and a few transmitting valves. Note the blue coloured Arcturus valves. Supposedly the colour somehow magically improved the valve’s performance and life! Valve design and manufacture advanced considerably from the time of the valves in the display. One extremely interesting valve in the museum collection is a 1926 Loewe 3NF triple-triode, complete with four resistors and two capacitors all within the one rather large envelope, which measures 160mm in height and 45mm in diameter. This would have been a glass-blower’s work of art. Perhaps this triple-triode valve with its components could be considered one of the first integrated circuits ever made. The supply to the valve consists of filament current of 0.3A at 4V and a high tension (HT) supply of 135V. You may wonder why were three valves built into the one envelope when the valves of that time were not particularly reliable. The reason was that the German government of the time taxed radios on the number of valves used in them. One valve envelope attracted a third of the tax that three valve envelopes did. Information on this and other Loewe valves is contained in the book Saga of the Vacuum Tube by Gerald F. J. Tyne, published Howard W. Sams & Co. Inc, USA. A receiver of the 1920s using this valve would have required very little extra circuitry to make a complete receiver – see Fig.1. In fact, other than the power supply, an input tuned circuit and a pair of headphones were all that was needed as far as the electronics were concerned. If the plate of the first valve had come out to a terminal on the valve base it would have been possible to use regeneration and thus achieve even better sensitivity from the receiver. Summary Like any museum, nothing remains completely static as new items become museum pieces. I had a fascinating and instructive time being shown through the museum, seeing equipment and parts of our radio heritage I didn’t know about. Brian Lackie’s Wireless Museum is at 60 Yellow Rock Road, Urunga NSW. Phone (02) 6655 6135. It is open most days from 9.00 AM to 4.00 PM. Admission is free, to foster interest in SC vintage radio. Photo Gallery: Peter Pan BKM (1948) Manufactured in 1948 by Eclipse Radio, South Melbourne, the Peter Pan BKM was a 4-valve reflex superheterodyne broadcast-band receiver housed in a modern (for the time) bakelite cabinet. The unit pictured here is housed in an “amber” cabinet, which was one of the less common colours used for these radios. The valve line-up was as follows: 6A8-G frequency changer; 6B8-G reflexed IF amplifier/first audio amplifier/ detector/AVC rectifier; 6V6-GT audio output; and 5Y3-GT rectifier. Photo: Historical Radio Society of Australia, Inc. 102  Silicon Chip siliconchip.com.au Custom-made Lithium Ion, NiCd and NiMH battery packs Smart Chargers www.batterybook.com (08) 9240 5000 High-capacity 280mAh rechargeable 9V 2400mAh NiMH AA cells siliconchip.com.au High-quality single cell chargers with independent channels. Charge any combination of NiCd & NiMH AA and AAA cells High-capacity 9Ah rechargeable D February 2006  103 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 silchip<at>siliconchip.com.au SCART connectors and A/V inputs I recently bought my young son his own TV. This fits into his entertainment unit to stop him messing around with the cables at the rear. The problem is that this set does not have audio/video inputs. It does have a SCART connector and I have been told that if I use an adaptor, the TV will switch itself onto the appropriate A/V channel when it receives a video signal. I tried this on all three A/V inputs but to no avail. I have also been told that I need to send one of the SCART connector inputs high with a +5V feed but no-one will tell me which one and I am not about to guess. Can you tell me which cable in the SCART connector needs to be pulled high to get the thing to switch to the appropriate A/V input? (D. S., via email). • With some TV sets fitted with SCART sockets for AV input, it is necessary to pull pin 16 of the socket up to +5V via a 220W resistor before the set will recognise that video is being fed in. If you are feeding in composite video from a video game console, you may also have to pull pin 8 down to ground via a 10kW resistor, to make the set recognise that the video is in composite form. 18V version of charger circuit I found an article on a cordless drill auto-charger in “Circuit Notebook” of your July 2005 edition. I would like to build the circuit but my cordless drill is 18V with a plugpack of 24V <at> 400mA. Can the 12V circuit be adapted to cater for an 18V charger? (F. N., via email). • Yes, the circuit could easily be adapted for use with an 18V charger. To do this, upgrade the 470mF 25V filter capacitor to a 35V rating. Also, swap the 1kW current limiting resistor in series with LED1 to 2.2kW. The division ratio of the resistive string connected to the A/D input of the PICAXE will also need to be Balancing The Unbalanced Most of SILICON CHIP’s audio projects are designed for hifi systems and hence are “unbalanced” (ie, signal and shield). By contrast, most professional PA systems use balanced lines (signal+, signal-, shield) because of their superior noise rejection, especially for long cable runs. I am wondering if there is any way to convert balanced signals to unbalanced signals to use on projects such as the subwoofer crossover (EA, September 1994) or for the many amplifiers recently published? Would this be possible with a transformer or a differential op amp, or is there a better way? If you could convert a balanced signal to unbalanced, it would be 104  Silicon Chip possible to take advantage of the noise rejection of a balanced line for a long cable run and provide an unbalanced input to take advantage of the cheap and useful projects available. (A. W., via email). • We published a PC board with balanced and unbalanced stages in the December 1989 issue. These stages used LM833 op amps and were originally intended for the Studio Series third-octave and half octave graphic equalisers published in the same year. They can be used wherever you need balanced-tounbalanced or unbalanced-tobalanc­ed conversions. The PC board is coded 01112891 and can be obtained from RCS Radio Pty Ltd. Phone (02) 9738 0330. altered. Try replacing the paralleled 15kW and 82kW resistors with a single 30kW resistor. This larger value ensures that the input voltage rating of the PICAXE port pin is not exceeded in normal use. Some minor changes must also be made to the BASIC program to reflect the changes to the voltage divider and battery pack. This involves changing the threshold values described in the comments within the BASIC program. Note that the above changes assume that the open-circuit plugpack voltage doesn’t exceed 35V, as this is the maximum rating input of the 7805 regulator. Basketball Scoreboard display problem I have recently completed the construction of the Jaycar Basketball Scoreboard Kit and there are a few questions that I would like to pose. First, there is flicker on the scoreboard LEDs. Is this due to the multiplexing at 40Hz? There is also a problem when hooking up the second Fouls board. With only Fouls board1 connected, the number of fouls increment singularly ie, 1, 2, 3, etc. With Fouls board1 and Fouls board2 connected, the Fouls board2 display increments both digits at the same time, ie, 11, 22, 33, 44, etc while Fouls board1 operates normally. With Fouls board2 connected alone, it operates normally. Any suggestions on this problem? (M. S., via email). • The small amount of flickering on the Scoreboard displays is due to the 40Hz multiplexing. This was done deliberately, as it increases the apparent brightness of the displays. It’s not easy to suggest what might be causing your strange fault with digits responding together on Foul board 2 but only when both foul display boards are connected. It sounds like some sort of short-circuit or poor connection on one of the 16-way IDC siliconchip.com.au cable connectors, or a dry joint or short in the digit driver section of the Fouls display board. Apparently, it’s a fault that is causing both digits of the Fouls 2 board to be gated on together, rather than separately (as they should be), so you should look for anything that can cause these digits to be gated on at the same time. This means looking for faults on the Fouls 2 display board itself, on the 16-way cable and its connectors, or at the 26-way connector on the controller board. Earthing a turntable I am restoring an old turntable which has a contact switch linked to the tonearm cradle. When the arm is removed from its cradle, the contacts are closed, sending 240VAC to the motor. My problem is that this causes a loud thump through the audio output. I understand that suppressor capacitors may solve this problem but what values should I use and where should I place them? The power cord into the unit has no Earth lead so there’s no direct earth connection from the player, although the unit has a Ground connection that can be connected to the dedicated GND connection on the back of the amplifier. I’m fairly sure that the player’s audio circuitry is isolated on the chassis from the power circuit. Could it be causing the problem via the amplifier instead? (P. S., Lane Cove, NSW). • Use a .01mF or .022mF 250VAC metallised polypropylene capacitor across the switch contacts. The turntable chassis should be earthed, ideally via its own 3-core power flex but you need to make sure that the cartridge output leads are fully isolated from the mains earth otherwise you will get severe hum from the resulting earth loop. Demister car radio antenna Does SILICON CHIP have a project for an antenna amplifier for a car radio? I’ve managed to zap the amplifier in my car’s system and thought making one would be pretty cheap compared to spare part prices. My car is a Nissan 200SX and the amplifier sits above the rear passenger’s head, close to the aerial which is siliconchip.com.au Smoking an Output Filter At 80kHz I recently built the SC480 power amplifier, as featured in the January & February 2003 issues of SILICON CHIP, and have been testing it on the bench. I am viewing the results on an isolated scope and using a function generator for the input source at 1.6V amplitude (3.2V peak-to-peak) and all is well up to 60kHz input. However, when I increase the input frequency to about 80kHz, the 6.8W 1W output resistor starts to smoke! Is this a result of the load being resistive and not running it through a speaker system or something else? Will using a 2W resistor resolve this issue? Second question: why doesn’t SILICON CHIP use Australian Standards for schematic symbols (ie, resistors, capacitors, fuses, etc)? (S. S., via email). • We are not surprised that 6.8W resistor is smoking. The amplifier was never intended to be tested at full power at such a high frequency. If you have a look at the output filter and consider its behaviour at very high frequencies, it is no wonder the 6.8W resistor is smoking. At 80kHz, the 150nF capacitor has an impedance of 13W while the 6.8mH choke now has an impedance just over 3.4W. So instead of the 6.8W resistor in the rear window. (K. M., Bathurst, NSW). • We published a rear window demister car radio antenna adaptor in the December 1988 issue of SILICON CHIP. This is not an amplifier but an interface circuit to allow the demister array to pick up RF signal and direct it to the car radio. Ballast required for UV steriliser I run a business in water filtration and have bought a UV steriliser light from an importer. While the light fitting is good, the ballast transformer is rubbish and actually smokes and gets very hot. Inside the plastic box, it appears to be a transformer. The mains Active being effectively short-circuited by the 6.8mH inductor (as it is at normal audio frequencies), it is being subject to about 30% of the amplifier’s output signal. At full power, this amounts to about four or five watts across a resistor with a 1W rating. Even going to a 2W resistor would not improve matters much. In fact, none of our amplifiers are intended to deliver their rated power above 20kHz, even though their frequency response at 1W may be 60kHz or more. Testing at high power at such high frequencies will not only burn out the 6.8W resistor but may also cause the output transistors and their drivers to overheat. The output filter would have to be changed and so would the output stages and the heatsinking, in order to make the amplifier reliably deliver high power at 50kHz or more. Unless you have a specific need to operate the amplifier supersonically, we recommend you don’t do it. We don’t use Australian Standards drawing symbols because as far as we are concerned, they are not as easy to follow as our own symbol library. Our drawing symbols are also more in line with those used on the circuits of most consumer electronics equipment. connects to one side of the transformer and the other side goes to the light fitting. The Neutral is connected directly to the other side of the light fitting. The label on the ballast reads: UV Lamp Ballast; Input AC 240V/50Hz; Amps 147mA; Output AC 44V, 6 watts. The label on the light reads: UV output 253.7nm; Lamp current 0.162A, 6 watts. I would like to use something smaller, electronic (switchmode?), encapsulated, that can be connected inside a junction box (not running hot). As it is used in hire equipment, and has to run continuously all year, approval for use in Australia would be good. (N. J., Mackay, Qld). • The ballast is not a transformer; it is a choke (inductor) and only has two terminals, as you have noted. There is February 2006  105 Fuel Mixture Kit Displays Awry I put the Fuel Mixture kit together and found it does not function. The directions state to check the voltage on pins 4 & 14 of IC1 for 5V before installing the chip. This was present. There was 5V present on another two or three pins as well. I put the two circuit boards together and applied power and grounded the sensor wire. This produced a momentary reading of “14.” on the two left LEDs. After a second, the reading is a partial 0. I say partial because the centre LED shows an incomplete zero. The right LED (the one that would be tenths of a volt) does not light up and the LED bar does not light up at all. I have R1 installed for bar mode, and did not install R2 or R3, as no electronic equivalent that we know of but it might be possible to substitute a fluorescent light ballast (say an 18W unit), as these are designed for continuous use. You would need to make sure you obtain the correct voltage across the lamp, otherwise it will be damaged. Bridging the Mighty Midget amplifier module Is the Mighty Midget amplifier module (March 2002) bridgeable? The article talks about the bridging of the internal power device but there is nothing on whether two modules can be bridged. (T. O., via email). • Since the two outputs of the TDA­1562Q are themselves bridged and both swing in anti-phase with each other, it’s not possible to bridge to another TDA1562Q. If you did connect one speaker between two modules, the remaining two outputs would be swinging in “mid-air” doing nothing? Using Luxeons in the Spacewriter Could you suggest modifications to the Spacewriter described in your May 1996 issue to allow it to drive seven 1W Luxeon LEDs? (A. C., via email). • The Spacewriter could drive 1W 106  Silicon Chip this was for unleaded use using A/F ratio. Last, the brightness of the LEDs does not change when I cover the photocell. I realise this is hard to troubleshoot and there are as many possible problems as there are solder connections. However, if there is something you can suggest, I would be most appreciative. (J. M., via email). • We suspect that transistors Q2 and Q5 are the incorrect types. Q2 is a BC327 and Q5 a BC337. This would prevent the third display from working and the brightness adjustment from working. Check the pin connections to DISP2. Perhaps there is a bad solder joint on one of the pins. LEDs, with the following modifications: (1). Change the power supply regulator to a 7805, fitted with a heatsink. (2). Change the 9V battery to six C or D cells (in order to supply 1A). (3). Remove the 10W series resistor from the 5V supply to the LEDs and change each 15W LED series resistor to 4.7W 1W. (4). Change transistors Q1-Q7 to logic level Mosfets (eg, ZT-2271 from Jaycar; STP30NE06L) (5). Increase the 10mF supply decoupling capacitor for the LED supply to 1000mF 16V. (6). Thicken the relevant PC tracks with solder to cope with the higher LED currents. Courtesy light delays immobiliser I recently purchased the Courtesy Light Delay kit (described in the June 2004 issue) and fitted it to my 2005 Nissan Patrol. It works very well although I did modify the installation by connecting the bridge rectifier to the accessories switch rather than to the parking lights. This means that the lights go out instantly when you start the car rather than having to switch on the lights. The issue I now have is that the remote central locking system/immobi- liser monitors the courtesy light circuit and if it detects that one of the doors is open, it will not arm the system. The courtesy light kit puts a voltage back into the courtesy light circuit which is interpreted by the immobiliser that one of the doors is open. So I have to wait for the lights to go out before it will lock the doors, which means that I have to stand next to the car or lock it manually. Do you have a suggestions as to how the overcome this situation as I quite enjoy having a delay on the interior lights? (A. C., via email). • You could use a separate door switch for the immobiliser “door closed” detector or set the courtesy delay to a shorter time so you do not need to wait so long before leaving the car. Jacob’s Ladder cannot climb I built the Jacob’s Ladder project from the September 1995 issue and have a few questions about it. I had it running on a power supply and everything was fine until someone “juiced” it up way over 12V. The 10W resistor got a bit black and the thing still works but it’s not going up the ladder much now; it tries but it mostly burns out at the start. Might the 555 timer chip be dead? I can’t see anything else on the board that looks damaged. (M. S., Penrith, NSW). • The 10W resistor was burnt because it would have had to supply excess current into the 16V zener diode (ZD4) when the supply voltage was increased. This resistor should be replaced, along with ZD4. It is also possible that the 75V zener diodes have been damaged and they are now reducing the maximum coil voltage. The remaining parts should be OK. Inverter for car fridge I would like to know if the output of the CFL inverter described in the September 2004 issue can be reduced to 240V DC. The reason for this is that I would like to see if I could use it for a fridge in my camper, mainly while driving long distances. The fridge does not hum so this tells me it’s a heater (evaporative) type and 240V DC would not affect the circuit siliconchip.com.au in the fridge. I can’t quote the output power of the fridge to see if the inverter can handle the load, because it has no plate that I can see. Also, how much load will this have on the car battery if it is continuously being charged by the alternator while driving. (M. B., via email). • You can reduce the output to 240V by increasing the 6.8kW resistor to 11kW. We don’t know how much your fridge would draw at 240V but would guess between 50W and 100W. This would not be a problem when your car is being driven. Battery indicator for R/C aircraft We have a problem in finding a low voltage indicator circuit for flying radio-controlled aircraft. We need a device in the aircraft to indicate that the onboard battery is at full charge (5.6V) and when the voltage falls to about 5.2V. Below 5.2V, the battery can sustain flight but not the operator’s ability to control the craft, even at fairly close range. As the aircraft can cost anything up to $1500, we do not want to see it nose-dive or fly into the sunset! (J. G., Cudal, NSW). • We have published two low battery indicators in Circuit Notebook, in June and November 2003. The June 2003 circuit may be more relevant. Electric brake control for a caravan I am looking for an electric brake controller circuit for a small caravan. I built a similar circuit for a model train controller for my kids a few years ago and it worked very well but unfortu- Notes & Errata Studio Series Stereo Preamplifier (October 2005): the parts list erroneously shows transistors Q1-Q5 as BC337 types, instead of BC327. The circuit and overlay diagrams are correct. Portable PIC Programmer (September 2003): a few constructors have reported problems programming newer devices such as the PIC16F88. This problem can be resolved by using an alternative programming package called “WinPIC”, available for free download from http:// people.freenet.de/dl4yhf/winpicpr. html (includes comprehensive doc­ umentation). Choose an interface type of “COM84 programmer for nately, I have lost the circuit. It used a variable pulse width control with a 555 IC and a diode (for 360° control). I completed much of the control box a few years ago, with a pendulum and magnet sweeping over 10 reed switches, and mounted a 2N3055 on the diecast box to control the 6A <at> 12V the brakes draw. (N. W., via email). • Check out the pulse width modulation generator in the Duty Cycle Meter project as published in our “Performance Electronics for Cars” handbook. A very similar PWM controller is also included in the Nitrous Fuel Controller in the same book. This lastmentioned project includes a Mosfet to drive a solenoid load and may be ideal for the brake control. serial port” for compatibility with the Portable PIC Programmer. This setting can be found on the “Interface” tab. Although experienced users may be able to get the original programming software (IC-Prog) and WinPIC to co-exist on the same PC, this is not recommended. To uninstall ICProg, go to Settings -> Options and choose the “Misc” tab. Remove the tick in the “Enable NT/2000/XP” and click OK. A dialog box will then appear asking “Do you also want to remove this driver?” Click on the “Yes” button, then click OK at the bottom of the window. You can then close IC-Prog and delete all of the associated files from your IC-Prog folder. The PWM adjustment is made with a potentiometer that could be used to swing in response to braking. A kit for the Nitrous Fuel Controller is available from Jaycar. Accuracy of speed sensors How accurate are the speed sensors on 2000 Detroit Diesel in large trucks? (T. S., Troutville, VA, USA). • We assume you are talking about road speed. It would be better than 5% but it will depend on the rolling tyre diameter and this will decrease significantly with tyre wear. Speedo accuracy is typically much worse, SC usually high by 10% or more. 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 February 2006  107 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. by Douglas Self 2nd Edition 2006 $69.00* 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, 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. 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. 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. 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. See Review Feb 2004 SWITCHING POWER SUPPLIES A-Z PROGRAMMING 32-bit MICROCONTROLLERS IN C By Luci di Jasio (2008) $79.00* PRACTICAL GUIDE TO SATELLITE TV See Review March 2010 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. 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. PRACTICAL RF HANDBOOK 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 by Carl Vogel. Published 2009. $40.00* by Ian Hickman. 4th edition 2007 $61.00* Alternative fuel expert Carl Vogel gives you a hands-on guide with A guide to RF design for engineers, technicians, students and enthusiasts. the latest technical information and easy-to-follow instructions Covers key topics in RF: analog design principles, transmission lines, for building a two-wheeled electric vehicle – from a streamlined couplers, transformers, amplifiers, oscillators, modulation, transmitters and scooter to a full-sized motorcycle. 384 pages in soft cover. receivers, propagation and antennas. 279 pages in paperback. *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 To Place Your Order: INTERNET (24/7) PAYPAL (24/7) eMAIL (24/7) www.siliconchip. com.au/Shop/Books Use your PayPal account silicon<at>siliconchip.com.au silicon<at>siliconchip.com.au with order & credit card details FAX (24/7) MAIL (24/7) Your order and card details to Your order to PO Box 139 Collaroy NSW 2097 (02) 9939 2648 with all details PHONE – (9-5, Mon-Fri) Call (02) 9939 3295 with with order & credit card details You can also order and pay for books by cheque/money order (Mail Only). Make cheques payable to Silicon Chip Publications. 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. by Douglas Self 2nd Edition 2006 $69.00* 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, 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. 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. 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. 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. See Review Feb 2004 SWITCHING POWER SUPPLIES A-Z PROGRAMMING 32-bit MICROCONTROLLERS IN C By Luci di Jasio (2008) $79.00* PRACTICAL GUIDE TO SATELLITE TV See Review March 2010 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. 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. PRACTICAL RF HANDBOOK 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 by Carl Vogel. Published 2009. $40.00* by Ian Hickman. 4th edition 2007 $61.00* Alternative fuel expert Carl Vogel gives you a hands-on guide with A guide to RF design for engineers, technicians, students and enthusiasts. the latest technical information and easy-to-follow instructions Covers key topics in RF: analog design principles, transmission lines, for building a two-wheeled electric vehicle – from a streamlined couplers, transformers, amplifiers, oscillators, modulation, transmitters and scooter to a full-sized motorcycle. 384 pages in soft cover. receivers, propagation and antennas. 279 pages in paperback. *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 To Place Your Order: INTERNET (24/7) PAYPAL (24/7) eMAIL (24/7) www.siliconchip. com.au/Shop/Books Use your PayPal account silicon<at>siliconchip.com.au silicon<at>siliconchip.com.au with order & credit card details FAX (24/7) MAIL (24/7) Your order and card details to Your order to PO Box 139 Collaroy NSW 2097 (02) 9939 2648 with all details PHONE – (9-5, Mon-Fri) Call (02) 9939 3295 with with order & credit card details You can also order and pay for books by cheque/money order (Mail Only). Make cheques payable to Silicon Chip Publications. ALL TITLES SUBJECT TO AVAILABILITY. PRICES VALID FOR MONTH OF MAGAZINE ISSUE ONLY. ALL PRICES INCLUDE GST MARKET CENTRE Cash in your surplus gear. Advertise it here in Silicon Chip. FOR SALE SUPERBRIGHT LEDS from just 15 cents each, including new wide angle range! 12 volt LED lightbars, great for solar/camping. Nixie tubes and nixie clock kits. Lots of other stuff, and always more items being added. New webshop now online! 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 USB KITS: Gas Sensors (CO, LPG, Alcohol), GPIB Interface, Thermostat Tester, LCD Module Interface, Stepper Motor Controller, PIO Interface, DTMF CLASSIFIED ADVERTISING RATES Advertising rates for this page: Classified ads: $22.00 (incl. GST) for up to 20 words plus 66 cents for each additional word. Display ads: $36.00 (incl. GST) per column centimetre (max. 10cm). Closing date: five weeks prior to month of sale. To run your classified ad, print it clearly in the space below or on a separate sheet of paper, fill out the form & send it with your cheque or credit card details to: Silicon Chip Classifieds, PO Box 139, Collaroy, NSW 2097. Alternatively, fax the details to (02) 9979 6503 or send an email to silchip<at>siliconchip.com.au Taxation Invoice ABN 49 003 205 490 _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ Enclosed is my cheque/money order for $­__________ or please debit my o Bankcard   o Visa Card   o Master Card Card No. Signature­­­­­­­­­­­­__________________________ Card expiry date______/______ Name _____________________________________________________ Street _____________________________________________________ Suburb/town ___________________________ Postcode______________ Phone:_____________ Fax:_____________ Email:__________________ 110  Silicon Chip Transceiver, Thermometer, DDS HF Generator, Compass, 4 Channel Volt­meter, I/O Relay Card, USB via Lab­VIEW. Also available: Digital Oscillo­ scope, Temperature Loggers, VHF Receivers and USB ActiveX (and USBDOS.exe file) to control our kits from your own application. www.ar.com. au/~softmark MORE CONTROL SOLUTIONS for you! N1500LC Load Cell Panel Meter: New Low Cost, Great Accuracy, Fully programmable Indicator with 4-20mA and 2 relay output. USB to RS422/RS485 converter: With 1500V Isolation, RTS or Auto Data Flow control. Heaps of other features. Temperature and Humidity Sensors: Great accuracy 4-20mA output. Wall and Duct mounting available. Signal Conditioners non isolated and isolated: Convert thermocouples, RTDs to 4-20mA or 0-10V Fully programmable. Stepper Motors: We have a selection of Stepper motors for hobby and high torque CNC applications DC Motors: for both hobby and high torque applications. DC, Stepper and Servo Motor controller kits. Labjack Ethernet/USB Data Acquisition Module: features 14 16-bit analog inputs, 23 digital I/O, 2 analog outputs and 2 high speed counter. Free software, Labview driver and ActiveX component. Counter and Timers: 7-digit and 10year battery operated. Multi-FunctionTimer and CyclicTimer/ Pulse Generator. Serial and Parallel Port relay controller cards. Pump and Trip Alarm Controller card. Duty-Standby operation. PIC MicroProgrammers serial and USB port operated. 2, 4 & 8 Relay Cards suitable for TTL and Open Collector Outputs Switch Mode, Battery Chargers and DC-DC converters. Full details and credit card ordering available at www.oceancontrols.com. au Helping to put you in control. siliconchip.com.au CLEVERSCOPE USB OSCILLOSCOPES 100MSa/s 10bits each channel 4M samples per input 100MHz bandwidth 8 digital inputs Sig-gen option Spectrum analyser Windows 98/Me/NT/2k/XP More Stable DVB-T healing HSDT 821 GRANTRONICS PTY LTD Laceys.tv www.grantronics.com.au 42 Brunel Rd Seaford VIC 3198 Tel (03) 9776 9222 web:www.laceys.tv also Sydney, CoffsHarbour, Ulverstone PO Box 275, Wentworthville. 2145. Ph: 02 9896 7150 ™ Satellite TV Reception Best high end DIY audio kits on the planet! www.aksaonline.com Importer Direct Sale International satellite TV reception in your home is now affordable. Send for your free info pack containing equipment catalog, satellite lists, etc or call for appointment to view. We can display all satellites from 76.5° to 180°. AV-COMM P/L, 24/9 Powells Rd, Brookvale, NSW 2100. Tel: 02 9939 4377 or 9939 4378. Fax: 9939 4376; www.avcomm.com.au Foam surrounds,voice coils,cones and more Original parts for Dynaudio,Tannoy and others Expert speaker repairs – 20 years experience Australian agents for products Trade welcome – email for your user ID Phone (03) 9647 7000 speakerbits.com.au S-Video . . . Video . . . Audio . . . VGA distribution amps, splitters, standards converters, tbc’s, switchers, cables, etc, & price list: www.questronix.com.au ImageCraft C Compilers: 32-bit Wind­ows IDE and compiler. For AVR, 68HC­ 08, 68HC11, 68HC12, 68HC16. from $330.00 Atmel Flash CPU Programmer: Handles the 89Cx051, 89C5x, 89Sxx in both DIP and PLCC44 and some AVR’s, most 8-pin EEPROMS. Includes socket for serial ISP cable. $220, $11 p&p. SOIC adaptors: 20 pin $132.00, 14 pin $126.50, 8 pin $121.00. Full details on web-site. Credit cards accepted. GRANTRONICS PTY LTD, PO Box 275, Wentworthville 2145. (02) 9896 7150 or http://www.grantronics. com.au siliconchip.com.au You have the Circuit - We can Package it? Printed Circuit Boards New American technology, polycrystalline solar panels, super long service life, high-efficiency output, compact and light, just 34 x 36cm and 1.58kg. Full weather-proof aluminium frame and tempered glass. Rated 10W, 12V, 0.82A; can charge 12V battery in virtually any climate. Brand new, limited stock. $159. Free post delivery. Ausino Pty Ltd, 129 Mcewan Rd, Heidelberg West, Vic 3081. Tel: (03) 9459 6011; Email: ausino99<at>optusnet.com.au 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 WEATHER STATIONS: windspeed & direction, inside temperature, outside temperature and windchill. Records highs and lows with time and date as they Call Mike for PCB Layout Prototyping, Small Runs and Production Runs Product & Panel Labelling - Call Martin for Full Colour on Clear, White, Brushed Aluminium, or Gold Label. Mi Mar Resources FACTORY 3 / 26 STAFFORD STREET HUNTINGDALE 3166 Tel: (03) 9 562 7030 Fax: (03) 9 562 7040 e-mail: pcbs<at>alphalink.com.au occur. Optional rainfall and PC interface. Used by government departments, farmers, pilots and weather enthusiasts. Other models with barometric pressure, humidity, dew point, solar radiation, UV, leaf wetness, etc. Just phone, fax or write for our FREE catalog and price list. Eco Watch: phone (03) 9761 7040; fax (03) 9761 7050; Unit 5, 17 Southfork Drive, Kilsyth, Victoria 3137. ABN 63 006 399 480. Circuit & Design 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. Provided your idea is workable & original, we’ll publish it in Circuit Notebook & you’ll make some money. We pay up to $60 for a good circuit or you could win some test gear. send your idea to: Silicon Chip Publications, PO Box 139, Collaroy, NSW 2097. February 2006  111 Do You Eat, Breathe and Sleep TECHNOLOGY? Opportunities for full-time and part-time positions all over Australia & New Zealand Jaycar Electronics is a rapidly growing, Australian owned, international retailer with more than 39 stores in Australia and New Zealand. Our aggressive expansion programme has resulted in the need for dedicated individuals to join our team to assist us in achieving our goals. We pride ourselves on the technical knowledge of our staff. Do you think that the following statements describe you? Please put a tick in the boxes that do: Knowledge of electronics, particularly at component level. Assemble projects or kits yourself for car, computer, audio, etc. Have empathy with others who have the same interest as you. May have worked in some retail already (not obligatory). Have energy, enthusiasm and a personality that enjoys helping people. Appreciates an opportunity for future advancement. Have an eye for detail. Select your microcontroller kit and get started... Fax a copy of From $295* this ad and receive a 5% discount on your order! Why not do something you love and get paid for it? Please write or email us with your details, along with your C.V. and any qualifications you may have. We pay a competitive salary, sales commissions and have great benefits like a liberal staff purchase policy. Send to: Retail Operations Manager - Jaycar Electronics Pty Ltd P.O. Box 6424 Silverwater NSW 1811 Email: jobs<at>jaycar.com.au Jaycar Electronics is an equal opportunity employer and actively promotes staff from within the organisation. Advertising Index 555 Electronics.............................71 Altronics................................. 84-87 Amateur Scientist CDs...............IBC Aspen Amplifiers........................111 Ausino Pty Ltd............................111 Av-Comm...................................111 BitScope Designs.........................41 Conference Plus...........................15 Dick Smith Electronics........... 20-25    Digital Graphics............................71 Dominion Electronics............69,112 Eco Watch..................................111 Elexol...........................................17 Furzy Electronics........................112 RCM3400 Grantronics.................................111 Feature rich, compiler, editor & debugger with royalty free TCP/IP stack Harbuch Electronics.....................97 • Prices exclude GST and delivery charges. Tel: + 61 2 9906 6988 Fax: + 61 2 9906 7145 www.dominion.net.au 4007  Instant PCBs..............................112      TAIG MACHINERY Micro Mini Lathes and Mills From $489.00 Jaycar ..................IFC,53-60,97,112 JED Microprocessors................5,97 Laceys TV..................................111 Microbric......................................77 Microgram Computers....................3 MicroZed Computers....................51 MiMar Resources.......................111 Ocean Controls..........................110 Quest Electronics..................97,112 TOROIDAL POWER TRANSFORMER DESIGN SOFTWARE. Windows based. Three winding each with four taps. Save and print out designs and winding instructions. Specify temperature rise, ambient temp, max core and copper loss, impedance, core size, flux density and core material data. $149.00 with instructions. wb914370<at>bigpond.net.au ANNOUNCEMENTS CENTRAL COAST FIELD DAY: Sunday 19th Feb. Don’t miss Australia’s biggest Amateur Radio exhibition and sale of new and used radio and communications equipment at Wyong Race Course, just 1 hour north from Sydney. Gates open 8.30am. Special Field Day bargains from traders and tons of disposals gear in the flea market. Exhibits by clubs and groups with interests ranging from 112  Silicon Chip Stepper motors: 200 oz in $89.00, 330 oz in $110.00 Digital verniers: 150mm $55.00, 200mm $65.00 59 Gilmore Crescent (02) 6281 5660 Garran ACT 2605 0412269707 Radio Parts..............................OBC RCS Radio.................................111 RF Modules..................................97 RF Probes..................................101 SC Perform. Elect. For Cars.........68 Silicon Chip Bookshop....... 108-109 Silicon Chip Subscriptions...........61 Silvertone Electronics................111 vintage radio, packet radio, scanning, amateur TV and satellite www.ccarc. org.au (Ph (02) 4340 2500). KIT ASSEMBLY NEVILLE WALKER KIT ASSEMBLY & REPAIR: • Australia wide service • Small production runs • Specialist “one-off” applications Phone Neville Walker (07) 3857 2752 Email: flashdog<at>optusnet.com.au Siomar Batteries........................103 Speakerbits................................111 Taig Machinery...........................112 Telelink..................................97,103 ____________________________ PC Boards Printed circuit boards for SILICON CHIP projects are made by: RCS Radio Pty Ltd. Phone (02) 9738 0330. Fax (02) 9738 0334. siliconchip.com.au