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SILICON CHIP APRIL 2007 PRINT POST APPROVED - PP255003/01272 8 $ 50* NZ $ 9 90 GOVT TO BAN INCANDESCENT LAMPS? They’re dreamin! INC GST INC GST FR Jaycar EEE! le 2007 Ca ctronics talog* *(Aust only) A Jacob’s Ladder display TO siliconchip.com.au LD: Motor Speed Controller I U B “Dual Core” Picaxes! April 2007  1 SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.jaycar.com.au Contents Vol.20, No.4; April 2007 SILICON CHIP www.siliconchip.com.au Features 10 The Proposed Ban On Incandescent Lamps Who flicked the switch to stupid? Banning incandescent lamps and using CFLs instead might seem like a good idea but there are serious ramifications. Here’s a look at the pros and cons – by Leo Simpson 22 Review: SPLat CC16 OEM Controller New credit-card sized controller costs less than $100 and boasts 16 digital input/output (I/O) lines – by Peter Smith Pro jects To Build Those Naughty Incandescent Lamps – Page 10. 26 High-Power Reversible DC Motor Speed Controller Simple design can operate from 12V or 24V batteries at currents up to 40A and can be controlled using a single potentiometer or an RC 1-2ms pulse train – by Leo Simpson & Branko Justic 32 Build A Jacob’s Ladder It sizzles, it sparks, it crackles, it’s fascinating and it’s electrifying. And it’s easy to build – by Leo Simpson 38 GPS-Based Frequency Reference; Pt.2 It’s based on a Garmin GPS receiver module and gives very accurate 1MHz & 10MHz reference frequencies. Here’s how to build and adjust it – by Jim Rowe High-Power Reversible DC Motor Speed Controller – Page 26. 66 Programmable Ignition System For Cars; Pt.2 There are six versions to build; you choose the one suit your car’s ignition pick-up system Here’s how to build the various modules – by John Clarke Build a Jacob’s Ladder – Page 32. 86 Dual PICAXE Infrared Data Communication Want to transmit data using infrared signals? No problem . . . just use two PICAXES – by Stan Swan Special Columns 57 Serviceman’s Log Sorting out customer A/V installations – by the TV Serviceman 62 Circuit Notebook (1) Optical Water Level Switch; (2) 12V SLA Battery Capacity Tester; (3) Rotary Encoder Interface; (4) Simple Circuit For Measuring High-Q Inductors; (5) Stage Microphone Muting Circuit 90 Vintage Radio How to build a super crystal set – by Rodney Champness Departments   2   4 79 80 Publisher’s Letter Mailbag Order Form Product Showcase siliconchip.com.au 96 Ask Silicon Chip 99 Notes & Errata 102 Market Centre Building The Programmable Ignition System – Page 66. April 2007  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 Photography Ross Tester Reader Services Ann Morris Advertising Enquiries Glyn Smith Phone (02) 9939 3295 Mobile 0431 792 293 glyn<at>siliconchip.com.au Regular Contributors Brendan Akhurst Rodney Champness, VK3UG Kevin Poulter Mike Sheriff, B.Sc, VK2YFK Stan Swan SILICON CHIP is published 12 times a year by Silicon Chip Publications Pty Ltd. ACN 003 205 490. ABN 49 003 205 490 All material 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: $89.50 per year in Australia. For overseas rates, see the subscription page in this issue. Editorial office: Unit 1, 234 Harbord Rd, Brookvale, NSW 2100. Postal address: PO Box 139, Collaroy Beach, NSW 2097. Phone (02) 9939 3295. Fax (02) 9939 2648. E-mail: silicon<at>siliconchip.com.au ISSN 1030-2662 * Recommended and maximum price only. 2  Silicon Chip Publisher’s Letter Banning incandescent lamps will have negligible effect on greenhouse gases It is about time some logic was brought to bear on this hysteria about global warming. Even if it is really happening (yes, yes the glaciers are melting but they have been doing so for hundreds of years) and even if some of the warming is caused by human activity, we need to take a measured response. If we assume that a good portion of the current global warming is caused by human activity, what are the major contributors to it? They would seem to be land clearing, coal mining and coal burning and oil consumption in all its forms (mainly for transport). As far as fossil fuel consumption is concerned, transport and power generation would be the major uses. So if we decide that we must reduce fossil fuel use, we should be looking to more efficient transportation and more efficient power generation as well as increasing renewable energy sources such as solar, wind and hydro electricity. And of course, there is nuclear power generation. We will also want to make major reductions on the consumption side but this is much harder. So the Federal government’s recent announcement of a proposed ban on incandescents seems like desperately wanting to be seen to be “doing something” (see the press release on page 11 of this issue, from Malcolm Turnbull, Minister for the Environment and Water Resources). By the government’s own figures, quoted in the press release, its overall effect on Australian greenhouse gas emissions will be tiny, estimated at 800,000 tonnes per annum from 2008 to 2012. Well whoopee. As a proportion of domestic power consumption, lighting is quite small. If we halve the power used by domestic lighting, it will have very little effect on our overall power bills and by extension, on greenhouse gas emissions. For those that don’t already know, the major power use in homes is for heating, cooling and cooking. Any reduction in domestic power use due the proposed ban on incandescent lamps will be easily swamped by the increasing take-up of air-conditioning and plasma TVs. Another factor to be considered is that most domestic lighting use is at night. That might seem blindingly obvious but the government apparently has not recognised why it might be important. The reason it is important is that most power usage at night is merely using the “spinning reserve” of our base-load power stations. You could switch all the lights off (if that was possible) and the base load power stations would still be spinning away, using just as much coal. Just as this issue went to press there came the news that Europe was likely to adopt the same measure to ban incandescent lamps. They gave credit to Australia for coming up with the idea. Normally the European community is quite capable of coming up with all sorts of measures to restrict trade, economic activity and freedom but now they are about to adopt a stupid idea from Australia. Wonderful. I wonder how Italian lighting companies will like the idea. Why should I be concerned about Italy in all of this? It turns out that most of Australia’s domestic light fittings (apart from fluorescent battens) come from either Italy or China. That is why we have ended up using such a diverse range of incandescent lamps, including all those Edison screw lamps. Much of that trade is going to be disrupted, isn’t it? Many Australian lighting retailers will also find the going pretty difficult too, unless they can quickly source a whole range of new light fittings which are compatible with compact fluorescent lamps. That’s just another of Malcolm’s unforeseen ramifications. If governments really want to reduce greenhouse gas emissions they will need to do a lot more hard thinking and develop some real strategies to achieve it. Leo Simpson siliconchip.com.au They have arrived Off grid power for measurement, transportation, security and telecommunications industries Independent operation for weeks 5 litre and 10 litre fuel cartridges are available. For example, an off-grid video camera will operate for up to 8 weeks on a single 10 litre fuel cartridge. Fuel Cells Generate electricity without combustion, without sunlight or wind, without pollution Fuel cells are small, lightweight and portable, quiet, have no major moving parts and require no maintenance. They have an expected operational live exceeding 8000 hours of run time. Technical data Model 600 1200 Charging capacity 600Wh/day 50Ah/day 1200Wh/day1600Wh/day 100Ah/day 130Ah/day Nominal Voltage * 12V 12V 12V Nominal Power 25W 50W 65W Nominal Current 2.1A 4.2A 5.4A Fuel consumption Weight Dimensions Batteries 1600 1.1 litres per kWh. 1.3 litres per 100Ah 7.3kg 7.5kg 7.6kg (L x W x H) 435mm x 200mm x 276mm 40 to 200AH recommended * 24V available on request 100% availability Maintenance free and absolutely reliable. Even under extreme climate conditions it ensures 100% availability of your equipment. This is a decisive advantage, especially in hard-to-reach areas or with critical applications such as observation posts. Fully automatic Automatic charge control, continuously monitors battery status as it powers your electrical equipment. If the battery’s voltage sinks below the level pre-programmed by the user, the fuel cell activates, charges the battery, and then automatically shuts itself off. And it does so without any user intervention. Remote Control Each fuel cell can be connected by an interface adapter to any RS232 interface and serviced/monitored using a cellphone, laptop or PC from the office. Theft Proof Solar cells need to be placed out in the open where it is difficult to protect them against theft and vandalism. The compact fuel cell can be integrated into any standard cabinet or box. More Power With the control interface you can operate up to 5 fuel cells in parallel, giving you a capacity of up to 8000Wh per day. ar.com Contact: Siomar Battery Industries Ph: (08) 9302 5444 Email: mark<at>Asiom2007  3 siliconchip.com.au pril MAILBAG Letters and emails should contain complete name, address and daytime phone number. Letters to the Editor are submitted on the condition that Silicon Chip Publications Pty Ltd may edit and has the right to reproduce in electronic form and communicate these letters. This also applies to submissions to “Ask SILICON CHIP” and “Circuit Notebook”. Headphone amplifier solution for serious hearing loss With respect to the item on serious hearing loss on page 101 of the February 2007 issue, I too have a serious hearing loss problem with, effectively, one ear useless and the other cutting off quite sharply at around 5kHz. Combined with severe tinnitus, this leaves me straining to hear dialog from the TV, particularly female voices. Some moons ago I purchased a Super Ear kit (“Electronics Australia”, May 1998) from Jaycar (Cat KA-1809). This has proved to be a boon which provides more than adequate audio HF boost, enabling me to enjoy TV programs with satisfactory resolution of all AF frequencies within the normal speech band. I would recommend this kit to your reader, W. B. Ernie Blankley, Brisbane, Qld. Help with B&W picture tubes I just could not help but smile Excellence in Education Technology Awards May I express my appreciation to Leo Simpson and the team who produce this excellent magazine every month. The articles are varied and I think there is a good balance between general interest, cutting edge, practical projects and vintage radio. I know there has been some negative comment about valves but I really marvel at what the radio engineers achieved with them before the semiconductor revolution. That’s one reason why I appreciate the Vintage Radio section. My introduction to radio and electronics goes back to 1954, when I built a one-valve set, a “Radio & Hobbies” project of that year. While I have taken a big detour into agriculture for about 30 years, I have 4  Silicon Chip when I read the introduction to the Servicemen’s Column in December 2006: “Imagine watching a TV that’s now 50 years old”. I was doing that very thing some two hours earlier on my AWA 21-inch 204T (with the deluxe chassis). So I don’t find it unusual. Mine gets a work out at least once a week with either DVDs, tapes or my younger kids who watch ABC cartoons. The reason I am writing is the intriguing mention of Stephen Appleby and the replacement Thomas picture tube. I was led to believe that Thomas Picture Tubes in Riverwood, Sydney closed down in the late 1980s and the remaining stock of monochrome picture tubes went to the tip. I have a few pre-1960 television sets which I work at restoring. They take an excessive amount of time and mostly are nearly impossible to get 100% perfect. Unfortunately, my only source of replacement picture tubes and certain other bits is from council clean ups and the problem is that scroungers hunting come back to really enjoy this hobby in “retirement” and am back again building SILICON CHIP projects and vintage radio restoration. Hopefully, I can encourage some young person to take up similar or more challenging projects. I was particularly pleased to see the article on Page 57 of the February 2007 issue, concerning the “Excellence in Education Technology Awards” to two HSC students, Matt McDonald and Lauren Capel. The choice of these two winners shows the learning value of widely differing electronics projects chosen by these two young people and the encouragement in this field by Leo Simpson and the SILICON CHIP staff. Congratulations! Richard Wood, Loxton, SA. around for scrap metal rip the backs off these old sets, smash the neck off the picture tube and take the copper deflection yoke. My question is: can anyone help? Are there any SILICON CHIP readers who have an ancient TV covered in junk in their garage or rotting under their house which is destined to become council clean-up landfill in the Sydney area or surrounds? I don’t seem to be able to beat the scrap guys and would love to get to it first. I’ve almost got enough 21-inch 90° and 70° tubes (though extras would be welcome) but really need a couple of 17-inch 70° or even 90° types. These have longish necks of about 37mm in diameter with a large multi-pin Bakelite plug. These are physically quite different to the more common shorter 110° types used from around 1959 until the end of black and white TV. If anyone could help I would be most appreciative. Thanks for all the Vintage Radio columns and the recent historical articles. Please keep them coming. Owen Kemp, Phone (02) 9524 0746 ake90071<at>bigpond.net.au Comment: there must be quite a few old colour sets which are about to be disposed of, as well. Anyone wanting to restore old colour sets would be wise to act now and collect as many as possible before they all go to council clean-ups. Ultrasonic Eavesdropper and ANABAT I got to the end of the Ultrasonic Eavesdropper article in the August 2006 issue to find that you only talked about it being used as a direct listening device. Why not connect it to a computer running ANABAT software? This siliconchip.com.au Radio broadcasts for the blind at sporting events Recently, I was listening to the cricket on ABC radio when an idea came to me. They were interviewing a fellow who (I think) is the boss of Blind and Visually Impaired Cricket in Australia. He’s blind himself and was talking about his love of going to regular cricket matches but he lamented that it’s rare for a match to be broadcast on the radio. His point was that while he gets the atmosphere from being at the game, it’s the ABC radio commentary that takes a blind person to the game. This got me thinking that there must be hundreds of thousands of visually impaired people around Australia who would love to attend sporting and other events but need more than the normal PA system to tell them what’s happening. They need the information they aren’t able to read, can’t see and which most of us take for granted. would make the project more useful and of wider practical value. ANABAT displays the call patterns of bats and identifies them and was apparently designed for bat census taking. To find out more, got to www.titley. com.au/tanabat.htm Pete Hutton, Glen Waverley, Vic. Comment: thanks for your reference to the ANABAT system. We had not heard of it. However, we doubt that our Eavesdropper circuit would be compatible with ANABAT software because their system uses different frequency division ratios and uses a zero crossing method to derive a digital version of the signal for software analysis. Microwave oven transformer can be rewound I like your magazine in most cases, however the recent article on what to throw away from a microwave oven (SILICON CHIP, December 2006) really got me. You said to chuck the transformer! That’s the most useful part of the whole thing. You cut out the high voltage secondary and rewind it with siliconchip.com.au I wonder how hard it would be to set up a national system of local broadcasting for visually impaired people (and anyone else who would appreciate it). I guess it could be AM or FM but FM is probably as good as any because of the capture effect. If possible, find a standard, single frequency in the broadcast band so that anyone, anywhere in the country would know where to listen. The “broadcasts” would be done by volunteers. It would have to be coordinated so you don’t have a double up at any one event but this should be easy to do via a central body (website). The gear would be relatively inexpensive to produce and I guess the ERP could be limited to legal levels. Once such a service takes off, there’s no reason why it couldn’t be extended to places such as shopping malls, tourist attractions and so on. Paul Zucker, via email. thicker wire and you have the basis for heavy-duty battery charger. Any low voltage can be obtained, depending on the number of secondary turns. I know you don’t like telling dummies to play mains games but this is an exception, surely! Lester Hendershot, via email. Comment: you are correct, of course. However, we would not recommend this to anyone not experienced in rewinding mains power transformers. Hospital electronics requires technical backup (1) Your January 2007 Publisher’s Letter prompted me to write. It is rare that anybody notices much in a hospital other than the front line doctors and nurses. I don’t mean to detract from the great work they do, however as a Biomedical Engineer, recently retired after 30 years in a major public hospital, it is heartening to see our work being noticed (even if it is by “one of us” so to speak). Biomedical (or clinical) engineers and technicians look after the vast array of equipment used for patient care in modern hospitals. Inventories Atmel’s AVR, from JED in Australia JED has designed a range of single board computers and modules as a way of using the AVR without SMT board design 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. AVR573 Single Board Computer 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 $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 April 2007  5 Mailbag: continued Microcontroller projects not lightweight I note that in the February 2007 Mailbag pages of SILICON CHIP, Ian Farquar lists the Programmable Christmas Star as an example of the sort of “lightweight” project that he would prefer to see less of. More than 100 constructors would perhaps disagree, several of whom have provided very positive feedback. I don’t claim that the Christmas Star was in the class of those complex projects of yore that Ian praised. But what’s not apparent is that the PIC assembler source code ran to more than 1000 lines – a very far cry from the 20 lines of PICaxe code that Ian mentioned. And it took months to write (albeit part-time). And that ties in with the point I was making my letter that you also printed in February. Much of the true complexity of microcontroller-based electronics is hidden in the (quite run into many thousands of items and tens of millions of dollars in value. Most of the equipment is electronic based but many items, such as patient ventilators and dialysis machines, are mechanically complex. The work is exacting and interesting. Much of the equipment is used for life support or making patient treatment decisions. Routine and breakdown maintenance must be carried out with great care and a clinical understanding of the purpose of the equipment is essential for troubleshooting. The complexity of modern computer-driven equipment, particularly in the operating theatre and intensive care, often requires technical staff to support the nurses and doctors using the equipment. This may be in the form of training or troubleshooting, or working alongside the clinicians in the ICUs and theatres. I suppose the greatest reward in the job is knowing the value of the work you are doing – contributing to patient care – and I would encourage qualified technicians and engineers to consider a career in this field. Just contact the 6  Silicon Chip extensive) firmware. You rightly give the Digital Volume Control as a counter-example of a project requiring a lot of development. Yet it looks deceptively simple – “essentially a 2-chip solution”, as the project description puts it. Again, a low parts count does not necessarily imply a lack of developmental complexity. I say keep up the good work! David Meiklejohn, via email. Comment: you make a very good point about microcontroller projects. For example, the software for the Programmable Ignition project currently featured in SILICON CHIP is the most complex we have developed to date. The final assembler line tally totals some 6020 lines required to perform all the functions and features required of the programmable ignition. It took many months to write and debug and represents a substantial investment in R&D. Biomedical (or Clinical) Engineering Department of a major hospital. Good committed staff are in demand! John Symonds, Sydney. NSW. Hospital electronics requires technical backup (2) It was great to hear of Leo Simpson’s appreciation of the vast array of “biomedical” or “electromedical” equipment on his recent visit to hospital. I am a Biomedical Engineer and look after the service, repair and mainten­ ance of all the biomedical equipment you described in your article. I work with a small team of engineers that look after Eastern Health, a network of hospitals in the Eastern suburbs of Melbourne – see www.easternhealth. org.au. The “drip machine” is known as an infusion pump. They are commonly used for the controlled delivery of fluids and drugs to patients. There are other pumps know as PCA (Patient Controlled Anaesthesia) pumps which have a hand control that allow the patient to request a “shot” of morphine or pethadine when they are in pain. All these devices have a vast array of hardware and software safeguards that prevent over delivery of drugs and protect the patient in case of failure. The vast array of biomedical equipment that was used during Leo’s time at hospital would not work as well if it were not for the team of biomedical engineers servicing and maintaining the equipment in the background. Most biomedical equipment requires annual service to check electrical safety and calibration and to replace commonly worn parts. Simon Cowley, Ringwood East, Vic. Nuclear power reactors could be greatly improved I enjoyed reading the “Publisher’s Letter in the February 2007 issue of SILICON CHIP. I would like to comment in the following way. I am not necessarily a promoter of nuclear energy as the best way to minimise global warming. In some cases (China) it is worth consideration. But if one is to examine its prospects, the best implementations of this technology should be considered. I refer to an article in Scientific American for December 2005: “Smarter Use of Nuclear Waste” by William H. Hannum, Gerald E. Marsh and George S. Stanford. This article described the advanced liquid metal reactor (ALMR) cycle as in advanced fast neutron integrated reactors. This technology has been demonstrated successfully in a prototype reactor prior to 1994. The main points are: (1) For a given equal energy output, this reactor produces less than 1% of the radioactive waste that a conventional reactor produces. (2) The radioactive waste that this reactor produces is less radioactive in 200 years than the waste from a conventional reactor would be in 100,000 years. (3) This reactor can be fuelled with the radioactive waste from conventional reactors and/or decommissioned nuclear weapons. (4) Reprocessing of fuel rods takes place in the same building complex that the reactor is in. (5) This reactor is “passive safe”. While operating, its cooling system can be siliconchip.com.au turned off and it will not melt down. (6) Because of the high efficiency of this reactor, known uranium ore reserves would serve our energy needs for many thousands of years. G. Calhoun, via email. Comment: AMLR sounds very attractive but it may be many years before commercial designs exist. This is especially the case since research into the prototype IFR (Integral Fast Reactor) which incorporated the AMLR concept, was discontinued by the US government in 1994, only three years before completion. This was a seriously misguided decision, similar to the US move to kill off their electric car industry just a few years ago. Plugpack mayhem The Mailbag letters by Ross Herbert and Graeme Dennes in the October and December 2006 issues of SILICON CHIP respectively raised issues with plugpacks. It seems that the plugpack situation is very untidy if not bordering on mayhem. Perhaps one could stand back and take a broader view. Our houses are supplied with alternating current. AC power is approp­ riate for efficient transfer of bulk electrical power over long distances and for meeting the needs of high power domestic devices such as electric ovens, toasters, air conditioners, etc but not so appropriate for modern domestic electronics. In the last 30 years or so, domestic and office electronic equipment has trended towards lower power and internal DC voltages, as witnessed by the variety of voltages output by plugpacks. Laptop computers are a special case that require from 15-18V DC at up to 8A! A solution to managing this changed load type could be to install properly engineered DC distribution systems in homes and businesses. This DC system would not replace the current 240VAC system but be installed in addition. Appropriately designed electronic equipment would simply use a cable to plug in to the DC system with no plugpack or internal AC section required! An appropriate distribution voltage might be 24V DC (or a combination of 12V and 24V) to match current battery technology. siliconchip.com.au In simple form, the DC distribution system could be fed directly from the AC system through rectifiers. However, real benefits accrue if the DC system is coupled with a system containing substantial energy storage (most likely a lead/acid battery bank under current technology). The battery bank would act as a power supply buffer and AC system power spikes and brownouts would not be such a hazard to sensitive equipment. There are further gains if the energy is derived from a non-polluting source such as a solar array. Solar systems would match a DC distribution system beautifully and are now well developed. A typical domestic solar system providing 13kWh/day out of a total daily load of 25kWh/day has been reported in the media. Advances are being made in areas such as solar cells efficiency and highintensity LED lighting. Once the DC distribution system became established, it is likely more loads would switch to DC; eg, house lighting. Mass production would tend to lower installation costs with time and development of such systems would be directly transferable to developing countries where AC supplies are problematic. Implementing a DC distribution system would not require particularly novel or new technology but would require development of standards and hardware. Additionally, manufacturers would need to be encouraged to modify their designs to accommodate standard voltages. So maybe there is a solution to plugpack mayhem, which may also provide significant greenhouse gas savings, but implementing such a concept is more of a political challenge than it is a technical issue. Bruce Fischer, Giralang, ACT. Information on Geiger counters In the February 2007 issue of SILICON CHIP, I saw the request from B. B. for information about a Ratec brand Geiger Counter. I can help! As a geophysicist working in min­ eral exploration, I’m familiar with the now outdated Geiger counters (also known as ratemeters) once used for We apologise that Agilent’s new DMM is not available... ...in yellow! Introducing the new U1252A DMM from Agilent Technologies, the world leader in Test & Measurement. The U1252A comes with... - Dual simultaneous measurements - 4.5 digit resolution on both displays - 0.025% Basic DCV accuracy; True RMS AC measurements - Dual temperature; Capacitance 10nF to 100mF - 20MHz Frequency Counter; Maths Functions - Programmable square-wave generator - Rechargeable battery, backlit LCD display - Free PC connectivity software for data-logging (optional cable required) - Built tough and reliable - Calibration certificate included - 3 year Australian warranty ...and at a very affordable price! Model U1251A Model U1252A $586 + GST $641 + GST Download product brochures, view online demos, and purchase online at www.measurement.net.au. Agilent’s new handhelds are distributed Australia-wide by Measurement Innovation. Tel: 1300 726 550 www.measurement.net.au info<at>measurement.net.au April 2007  7 Mailbag: continued Car Speedos can be wrong while odometer is correct I read with interest Jack Chomley’s letter in the February 2007 issue regarding his speedo experience. In 1995 I purchased a 1991 Volvo 240 wagon, which comes fitted with a VDO speedo with electronic pickup, a stepper motor odometer and a 270° needle analog speedo display. I soon realised there was a cal­ ibration problem, even though I have all standard equipment and tyres. I made many tests; using speedometer check zones, advisory radar install­ ations and lots of kilometre peg and stopwatch observations during long distance cruising trips in places like the North­ern Territory. What is amazing is that when I read Jack’s article, I felt like he had stolen my data, as my results were identical to his! My odometer is correct to within 100m over 10km, while my speedo indicates 108-109km/h for an actual road speed of 100km/h. An indicated 100km/h gives an actual road speed of 92km/h. My (less than ideal) solution uranium exploration. I don’t actually have a circuit for the Ratec instrument mentioned but I do have several old geophysics texts (1940-50s) that describe the technology and provide circuits for battery-valve instruments. These show that the Geiger tube needs about 400V DC for operation. Also, the well-known book “Fortunes in Minerals” by Ion Idriess (1951) (available from most antiquarian book dealers) gives a detailed description on using the Geiger counter and provides the circuit for the instrument built by the Australian Bureau of Mineral Resources. In particular, one other I have – “Prospecting and Mining for Uranium in Australia – Notes for the Guidance of Prospectors”, published in September 1954 by the Australian Atomic Energy Commission and Department of Nat­ ional Development, gives quite detailed instructions for building 2-valve and 3-valve portable instruments. Again, 8  Silicon Chip was to fit a VDO Speed Alert unit calibrated to the correct reading and rely on it rather than the speedo when cruising. However, it is still inconvenient having to mentally convert every time I look down at the speedo. I also noted Jack’s mention of the relaxing of the accuracy requirements of the Australian Design Rules. Meanwhile, our technically illiterate legislators and law interpreters keep trying to reduce the allowable tolerances for radar speed checks to less than the tolerance of the equipment fitted to our cars. Dave Heap, Armidale, NSW. Comment: we suspect that this big discrepancy between odometer and speedometer has been present in cars for a very long time. After all, there is a specific requirement about odometer accuracy yet car reviewers have been complaining about optimistic speedos for decades. It will probably require the successful challenging of speed fines because of inaccurate speedos before the situation changes. 400V seems to be the voltage needed for the Geiger tube. In addition, it lists all the commercially built instruments available in Australia in April 1954 and the Ratec instrument is mentioned (with the approximate purchase price of 70.00 pounds) from Medical Equipment Services Pty Ltd, 79 Collins St, Melbourne. A search of the internet shows that this company still exists in Melbourne as a supplier of medical electronics: http://www.mesaustralia.com.au/ Maybe B. B. could contact them directly for information about his Raytec 115F Geiger-Muller counter. For further information, I would recommend that B. B. visit the library of his State Mines Department and look for other (Australian or State) government publications of that era concerning uranium exploration, as they too are likely to have further information about these instruments, and may even describe the Ratec instrument. In particular, try the library at Geoscience Australia (previously Bureau o f Mineral Resources until 1990, then called Australian Geological Survey Organisation – AGSO, now Geoscience Australia) in Canberra – the biggest earth science library in Australia. Stephen Mudge, Nedlands, WA. Comment: thanks for that information. We liked your mention of Ion Idriess. He was a great Australian writer whose works have long disappeared from library shelves. Bike Computer Ampere Hour Meter I was very interested to see Stan Swan’s article about using cheap bike computer plus a PICAXE micro as a DC ampere-hour meter (SILICON CHIP, February 2007) as I had been wanting such a device for my electric powerassisted bicycle. Generally, I ride for exercise but have a number of large hills near my home and these are difficult at my age. My solution was to purchase an electric conversion kit for my 26-inch bike. It is a 200W hub motor mounted in the front wheel with a 24V NiMh battery and speed controller. My problem is knowing if I have enough battery capacity left to get up my hill at home after a long ride. I was able to use Stan’s circuit but with a 0.01W resistor in place of the 1W resistor in the battery negative line to measure the current. The resistor was made from about 35mm of heavy nichrome wire from my junk box and carries a maximum current of 20A. The low value of resistor was chosen to minimise voltage drop to the motor. I found I needed to set the bike computer for a 500mm diameter wheel to get a high enough pulse rate to measure low currents. Only one line of the program had to be modified for calibration. By trial and error w2=2500/w1 came out right compared to a digital multimeter. The bike computer speedo indicates amps and the distance then shows ampere-hours directly. This was my first venture using a PICAXE which I found easy to use and understand. Bevan Walls, Saratoga, NSW. siliconchip.com.au SURPLUS ELECTRONIC COMPONENTS #35697 500V 16A Triac (Pk-10) Device: BT139-500 Volts: 500V Amps: 16A IGT: 35mA (min) Package: TO-220 #35680 Low Dropout Pos. Regulator Desc.: LM2931AT-5.0 Function: Low Dropout Pos. Voltage Regulator Rating: +5V $1.00 ea #10326 Package: TO-220 $5.00 Per Pack of 10 60V 2A NPN Darlington (Pk-10) Device: TIP110 Pd: 50W Package: TO-220 #35624 Device: BSR50 Polarity:NPN Ptot:.8 Package: TO-92 Per Pack of 10 $3.00 40V 0.6A PNP Transistor (Pk-100) Device: 2SC5508-T2 Polarity:NPN $6.00 Vceo:3.3V Per Pack of 100 Ic:35mA Pt: 115mW #35300 Package: 4P Mini Mold 65V 100mA 250mW Transistor(Pk-100) $2.00 Per Pack of 100 #35717 100nF 50V Y5V 20% SMD 1206 (Pk-100) Desc: SMD CAPACITOR Tol: 20% $2.00 Per Pack of 100 Low Noise Precision Op Amp Device:OP27EZ #35651 Function:Low Noise Precision Op Amp Vos:10V Package:DIP-8 $1.00 * For Data See Web ** * Just Shake for Power * No batteries needed * Size: 165 x 32 (dia)mm * Super bright LED * Transparent ABS body $3.50 #35715 #35280 Desc.: Steel construction modular connector crimping tool. Double as a handy cutter or splicer. Suits 6 position 4 or 6 contact modular plugs. PCB Mom. Push Switches(pk marked 0-9) Marked with numbers (0,1,2,3,4,5,6,7,8,9) = 1 set Type: SPST N/O Momentay Pitch: 2.54mm (0.1”) Size: 19 x 19mm Heigth: 10.5mm $2.00 PK #35698 #13474 $3.00 $3.00 Miniature 3VDC SMD Relay (Pk-5) White This unit is moulded from high grade thermo setting resin.The pins are adequately plated and have deep solder terminals, sufficient for several hard wiring points per pin. Sturdy flange mount is meant for fitting above the chassis. #35654 $3.00 3 Way Plugable Euro-Style Terminal (Pk-10) $3.00 Type: 3 Way Stackable Per Pack of 10 Rating:300VAC 10A Spacing: 5mm Inc.3 Way PCB Strip #35707 63A 240VAC Mini Din Circuit Breaker Device:V87382 Function:Circuit Breaker Rating:240VAC 63A Mounting:Mini Din Manu:TERASAKI Device:1591CBK Description:Plastic Enclosure Colour:Black Size(LBHmm):120x80x38 Manu:HAMMOND ** For PDF see web ** #35009 8-Pin Valve Socket $1.00 Flame Retardent ABS Cabinet $2.00 80-1-5 2200mF 80V 85° Radial Electrolytic Cap. Value: 2200mF Volts: 80V Type: Radial Size: 25.5(D) x 42(L)mm Temp: 85° Lead Spacing: 12.5mmsc. Solder #29258 With LED indicator Mid/High range for 3 way systems Impedance: 8 ohm Power: 18 Watts #35685 Arista: LA5 Length: 5ft $12.00 #35716 Counts every time power is switched Rating: 230VAC <at> 3700 Ohm Size: 35 x 40 x 67mm $3.00 Made in Japan #35684 Device:UD2-3NUN-L Contacts:1A <at>30VDC 3A <at>125AC Coil Volts: 3VDC Action: DPDT $4.00 Coil Res.: 64.3 Ohm Per Pack of 5 Manuf: NEC * For Data See Web *** #35709 #35303 5-Pin Mini SMD USB Type B Recept. (Pk-10) Contacts: Phosphor Bronze Current Rating: 0.5A Contact Resisitance: 50m Ohm max Size: 8 x 4 x 9mm * Data Sheet Available $5.00 #30544 Per Pack of 10 32.768KHz Crystal (Pk-10) Freq.: 32.768K Package: HC-38U Lead spacing. 1mm $5.00 Rockby Electronics Pty Ltd ABN# 3991 7350 807 ACN# 006 829 821 Battery Free Small Hand Powered Torch 6P6C Modular Crimping Tool STD. 0.9mm Soder Wick. NPN 2GHz SMD RF Transistor (Pk-100) #32131 0.75mm 1.0mm 1.25mm 1.5mm Dual Attenuator #26720 Device: PN2907A $4.00 Polarity:PNP Per Pack of 100 Ptot:0.4W Package: TO-92 #35692 Device:BC856B Polarity:PNP Case: SOT-23 * RoHS Compliant #35713 #35714 5-Digit 230V AC Counter $3.00 Per Pack of 10 $8.00 Device:PAR45025P Value:2.5mF Volts:400/450VAC Class C/Class D Connection: 6.3mm Tab Mount. End Bolt (M8 Stud) Size(LDmm):58.5 x 30 $2.00 Manuf:Lifasa 100V 6A PNP Transistor (Pk-10) Device: TIP42C Ptot:65W Package: TO-220 #35625 Single Sided DVD-R Size:4.7GB $3.50 10 per Spindle Manuf: EMTEC #35683 2.5mF 400VAC Class C Motor Start Cap Per Pack of 10 350MHz 60V 2A Darl. Transistor (Pk-10) ROCKBY ICS ELECTRON Weight: 500gm Type: 63/37 Flux RMA: 2% Manuf. AIM Made in CANADA #35710 #35712 $5.00 4.7GB 4x Speed Blank DVD-R (Pk-10) Solder (500gm) ROCKBY ICS ELECTRON Device: MHW6181 Vin: +70dBmV Freq: 40MHz-550MHz Gp: 18.2dB Package: 714-04 $8.00 ea Vcc: 28Vdc Manuf.: MOTOROLA $3.00 #26005 Per Pack of 10 For a Free Monthly Mailer Please Contact Us Mail Orders To: Showroom & Pick-up Orders: P.O Box 1189 Huntingdale 56 Renver Rd. Clayton Victoria 3166 Victoria 3168 Ph: (03) 9562 8559 Fax: (03) 9562 8772 ROCKBY ICS ELECTRON ROCKBY ICS ELECTRON 40MHz-550MHz CATV Amplifier Internet: Web Address: www.rockby.com.au Email: salesdept<at>rockby.com.au * Stock is subject to prior sale Y And Y On-Line Ordering And OtherProducts ProductsSee See Website: B KB Kwww.rockby.com.au C ForFor On-line Ordering Other Web www.rockby.com.au CSite: O RO ROur S IC N O ONICS R R ELECT ELECT The proposed ban on incandescent lamps . . . What will it mean? In February 2007, Malcolm Turnbull, Federal Minister for the Environment and Water Resources, announced that incandescent light bulbs would be phased out and replaced by more efficient lights such as the compact fluorescent light. Superficially, it seems like a good idea but closer examination shows that there would be substantial drawbacks. T here is no denying that Malcolm Turnbull is a very clever man. He was the co-founder of Ozemail, a successful barrister and merchant banker and now a prominent member of Federal parliament. But that does not make him infallible and particularly not with regard to decisions involving electrical and electronic equipment. We think he has been badly advised. Yes, incandescent light bulbs are inefficient when compared to fluorescent lights and other forms of lighting. As a corollary of that, they pump out a lot of heat for the amount of light that they produce. And yes, typical compact fluorescent light (CFL) bulbs produce about five times the light output of 10  Silicon Chip an equivalent incandescent bulb. Under ideal conditions, they can also last somewhere between four and 10 times longer than incandescent lamps and therefore can lead to substantial energy savings. The trouble is, ideal conditions do not occur very often in household use. For a start, depending on ambient temperature, a CFL takes about 10 to 15 minutes to reach full brilliance. So while they come on as soon as you throw the switch, their initial light output can be quite weak and can have a tendency to flicker as well. If you install a CFL in a toilet or bathroom you may find that they are seldom on long By LEO SIMPSON enough to get to full brilliance. Some very ambitious claims are made for life on CFLs. For example, a GE 15W unit in our office at the time of writing claims 8000 hours on the packet while a range of CFLs made by Mirabella claims 15000 hours. In our experience, these are very ambitious figures and are probably longer than you could expect from a typical 36W fluorescent tube. After all, at 10 hours a day, 15,000 hours is equivalent to an operating life of over four years. Not only that, by the time 15,000 hours rolled around, a typical 36W tube would be a pale tube indeed. CFLs certainly do not last as long as conventional fluorescent tubes and the reduction in light output is siliconchip.com.au proportionately greater as they age. A 15W CFL may be equivalent to a 75W incandescent when new but after several thousand hours its light output will be quite weak, if indeed it has survived for that long. In fact, the only practical applications for CFLs are where they are in use every day for several hours at a time. If you operate them under those conditions, particularly where they are used in applications such as stair wells and external lighting for home units (ie, on for long periods at a time), they can easily last for around 8000 hours or more. But if you use them in other domestic applications, their life can be shortened drastically, to the point where they often do not last as long as the much-maligned incandescent. The reason they don’t last well where they are used for frequent short periods is that they simply don’t work well with short start/stop cycles. The tube phosphor becomes blackened and the tube becomes much harder to start or the complex electronic driver circuit simply fails. As you can see from the description in the separate panel, a CFL circuit may use up to 30 components and these are highly stressed, operate at high temperatures and are subject to severe temperature cycling if frequently switched on and off. Other drawbacks If you take a look at the packet for any CFL, you should see warnings about suitability. Specifically, they are not suitable for use with electronic dimmers. In fact, they don’t work at all with dimmers. Any warranty will be void if they have been used with a dimmer. Nor are they suitable for use with any electronic switch or remote control, sensor lights or with timers. The last two are significant because that is an acknowledgement by the manufacturers that CFLs do not last well when switched on or off frequently or at short time intervals. Heat, cold and vibration CFLs cannot be used in any application where they get hot. They need plenty of air circulation around them. They cannot be used in recessed light fittings or in table lamp fittings where they are closely confined or poorly ventilated. That rules out a siliconchip.com.au T11/07 20 February 2007 World first! Australia slashes greenh ouse gases from ineffic ient lighting In a world first move, the Australian Government is taking action to phase light bulbs. out ineffic ient The step, announced tod ay at Double Bay Public School by Minister for the and Water Resources, Ma Environment lcolm Turnbull MP, should reduce Australia’s greenh emissions by 4 million ton ouse gas nes by 2012. The reduction in emissions will increase as the phase out progresses and the ann reduction between 2008-2 ual average 012 is estimated at around 800,000 tonnes. However, the annual cut in emissions by 2015 will have soared to an esti mated 4 million tonnes per Household lighting costs annum. can be reduced by up to 66 per cent. “The most effective and immediate way we can red uce greenhouse gas emissi using energy more efficien ons is by tly,” Mr Turnbull said. “Electric lighting is a vita l part of our lives; global ly it generates emissions cent of those from all the equal to 70 per world’s passenger vehicle s.” “But it is still very ineffic ient. We have been using incandescent light bulbs and up to 90 per cent of for 125 years the energy each light bul b uses is wasted, mainly as heat.” “A normal light bulb is too hot to hold – that heat is wasted and globally represe of tonnes of CO2 that nee nts millions dn’t have been emitted into the atmosphere if we had efficient forms of lighting used more .” “These more efficient ligh ts, such as the compact fluo rescent light bulb, use aro cent of the electricity to und 20 per produce the same amoun t of light.” “A compact fluorescent light bulb can last betwee n 4 and 10 times longer incandescent light bulb, than the average which can lead to major savings in household ene rgy costs.” “While they may be more expensive to buy up fron t, they can pay for themse power bills within a yea lves in lower r.” In Australia, lighting cur rently represents around 12 per cent of greenhous from households, and aro e gas emissions und 25 per cent of emissi ons from the commercia l sector. Working with its state and territory counterparts, the Australian Government phase out all inefficient will gradually light bulbs and is aiming for full enforcement of new standards legislation by lighting 2009 to 2010. Special nee ds areas, such as medical oven lights, will be taken lighting and into consideration. The Government will also work with the world’s larg est manufacturers of ligh including China, to broade t bulbs, n the benefits beyond Au stralia. “The International Energy Agency has estimated tha t if all countries made the to compact fluorescent ligh global switch ts that by 2030, annually it would save energy equ more than 5 years of Au ivalent to stralia’s current electricity consumption,” Mr Turnbu ll said. “The climate change cha llenge is a global one. I encourage other countries Australia’s lead and make to follow the switch to more energy efficient products like com fluorescent light bulbs.” pact lot of lamp fittings, including oysters (ceiling) and those which include a glass tube within another glass housing. Nor can they be used in ovens, microwave ovens or refrigerators. Why not refrigerators? Because CFLs and standard fluorescent lamps, for that matter, will not work in the cold; they simply refuse to start. And since CFLs have lots of internal electronic components they don’t like vibration either. That means that they should not be used inside garage door openers, vacuum cleaners or combined light/exhaust fans in bathrooms. There is also a substantial environApril 2007  11 Typical CFL lamps as used already in thousands of homes, offices and public buildings around Australia (indeed, around the world). The manufacturers make some incredible claims for long life and brightness – which we find just a little difficult to substantiate. mental drawback: mercury. All fluorescent tubes contain a small amount of mercury and CFLs are no different. The mercury is there because that is what sustains the electrical discharge in the tube once it is fired. When the tube fires, the mercury is vapourised by the high voltage across the ends of the tube and the resulting electrical discharge produces intense ultraviolet light. This irradiates the white phosphor coating on the inside of the tube and it “fluoresces” to produce visible light. The amount of mercury inside a CFL is small, typically 4 to 5mg. While it is inside the tube, it is perfectly safe. But once the tube is broken or crushed, as will ultimately happen, the mercury will be released into the environment. With millions of CFLs likely to be disposed of every year, that amounts to a lot of mercury going into the environment. Electrical interference CFLs can cause two forms of interference, electrical and infrared. Part of 12  Silicon Chip the electrical interference is inherent in any fluorescent or vapour discharge tube. The high voltage discharge radiates interference over a wide frequency range, up to 10MHz or more and can interfere with radio reception on the broadcast and shortwave bands. The interference from conventional fluorescent tubes is modulated at 100Hz, giving a rough buzzing sound in an AM broadcast radio. But interference from a typical CFL is worse because it is modulated by the high frequency inverter used to drive the tube. So whereas a fluorescent tube might cause a buzzing sound on weak stations in the broadcast band, CFLs can completely obliterate reception in rural areas. While the discharge inside fluorescents and CFLs is mainly ultraviolet, they also produce heat (infrared) and this is also modulated by twice the driving frequency. So a typical fluorescent light produces heat (you can easily feel it) modulated at 100Hz. A CFL also produces heat (they get quite hot) modulated by twice the inverter frequency. This modulation can typi- cally be at around 20-30kHz but can be in the slightly higher frequency range used by typical infrared remote controls. So if you have a CFL in the same room as your TV or hifi system, the infrared remote control may not work at all – its signal will be completely blanketed by the modulated infrared from the CFL. By the way, in some CFLs, you can actually hear the whistle from the inverter/electronic ballast. Whether this is a sub-harmonic or because the operating frequency is low is not clear but some people will find it objectionable. Huge range of incandescents So far this article must seem pretty negative concerning CFLs. We have harped on about short life, reliability, heat, cold, vibration, interference and so on. What other problem could there possibly be with a general changeover from incandescent lamps to CFLs? The biggest problem of all is simply the huge range of currently available incandescent lamps. In my own home I can count at least siliconchip.com.au They haven’t really thought this one through, have they? This photo by no means shows the full range of incandescent lamps currently in use (eg, how about all the high intensity halogen floodlights out there) – but the only incandescent lamps that CFLs can now replace are the standard-sized BC and ES general lighting types. 10 different styles of incandescent bulb. In addition to the standard-sized bayonet cap (BS) and Edison screw (ES) bulbs, there are fancy round, candle and twisted candle, in miniature BC and ES, as well standard bases, large round (100mm and larger), double-ended lamps for lighting bathroom mirrors and cabinets, miniature incandescents for sewing machines and so on. Then there are 100W and 150W ES reflector lamps used in outdoor security lights. Where does it all end? Most of these “non-standard” incandescent lamps will never be duplicated in CFL, particularly the smaller ones. If you want to see the scope of the problem, just visit your local lighting retailer or a branch of Bunnings. The range of available lamps is astounding. Even if CFLs can fit in place of incandescents in many light fittings, they may still not be suitable because of their longer form factor – they may simple poke out of a fitting rather than be fully housed. Some light fittings do not suit CFLs because of their different light output siliconchip.com.au distribution. For example, most CFLs have little light output on their longitudinal axis. With the best will in the world, we cannot see too many people being happy with a 24-lamp chandelier fitted out with CFLs! And what about 240VAC doubleended halogen lamps used in higherpowered exterior lighting used around homes and commercial buildings? In truth, we do not yet know the scope of this proposed ban or phaseout of incandescent lamps because the announcement released by Malcolm Turnbull (reproduced elsewhere in this article) is quite general in tone, with no specific details or timetable. But if the aim is to phase out inefficient incandescent lamps, what about 12V halogens used in such large numbers in modern homes? These are a real drain on Australia’s electricity grid, both in homes and retail showrooms where their numbers are so great that they substantially increase the air-conditioning load. Mind you, if 12V halogens were to be banned, a great many homes and shops would require substantial rewiring and all new lamp fittings, unless reasonably effective LED equivalents become readily available. Existing LED equivalents are expensive and not as bright as halogens. Ultimately, if the proposed ban is to be all encompassing, a large proportion of home-owners are going to be very unhappy when they realise the full implications. Finally, if you don’t accept our word on the above disadvantages and drawbacks of CFLs, just go to http://www. gelighting.com/na/business_lighting/faqs/cfl.htm This is a list of frequently asked questions (FAQs) on CFLs on General Electric’s Consumer & Industrial Lighting website. Note that GE do have a dimmable CFL available in the USA but we have not seen a version of it on sale in Australia. Will the whole idea of phasing out incandescents be quietly shelved after the next Federal election? We think that is a strong possibility. If not, you had better stock up on the more unusual incandescents in your home. April 2007  13 How CFLs work make up an oscillator or inverter. The fluorescent tube is driven via inductor L2 and winding N1 of the transformer. T1 also drives the gates of Q1 & Q2 via windings N2 & N3 which are connected in antiphase. Tube starting This photo shows the internal circuitry of a current model CFL used in a recent promotion by Sydney’s major electricity distributor, Energy Australia. The two Mosfets are tiny, in TO-92 encapsulation. The 4.7mF main DC filter capacitor can be clearly seen. It is this capacitor which is the component most at risk from high temperatures. The operation of a compact fluorescent lamp (CFL) is rather more complex than the simple resistive element of an incandescent lamp. The circuit above is for a typical compact CFL operating at 240VAC. Note that this is a general description of CFL circuit operation. Actual circuits vary widely from brand to brand and model to model but the broad principle of operation is much the same. It uses a bridge rectifier in series with a small inductor (L1) and 47W resistor together with diode D1 and capacitor C1, to develop around 340V DC. The rectifier in American CFLs (operating from 110V) uses a voltage doubler on the input instead of a bridge rectifier. The 340V DC is fed to the rest of the circuit which functions as an inverter and ballast. In effect, what happens is that the circuit operates in two separate modes, one to start the tube and the second mode for normal running. Two Mosfets (Q1 & Q2), transformer T1 and a number of associated components Taken with a short antenna in close proximity to CFLs, these scope screen shots demonstrate the RF interference modulation. In this scope shot, we see a 22kHz carrier modulated by 100Hz. The 22kHz is the inverter frequency of the CFL ballast circuit while the 100Hz is a product of the bridge rectifier and 50Hz 240VAC mains supply. 14  Silicon Chip When power is first applied, the 2.2nF capacitor connected to Diac 1 charges via the 560kW resistor. When the voltage reaches about 30V, the Diac fires (breaks down) and discharges the capacitor into the gate of Q2. Zener diode ZD2 protects the gate from over-voltage. Mosfet Q2 is now switched on and current flows from the positive supply via the 47nF capacitor, the fluorescent tube top filament, the 3.3nF capacitor, the second tube filament, inductor L2 and transformer T1’s N1 winding. This current flow in N1 then applies gate drive to Q1 via N2 and switches off gate drive to Q2 via N3 due to the antiphase connection of this winding. If oscillation doesn’t occur, the process starts all over again with the 2.2nF capacitor charging again to fire the Diac to turn on Q2. When oscillation does occur, Mosfets Q1 and Q2 rapidly switch on and off in alternate fashion. The frequency of operation is set by the combined inductance of L2 and the N1 winding, together with the 3.3nF capacitor across the tube. The startup circuit comprising the 2.2nF capacitor and the Diac is now prevented from operating by diode D2. This diode Here we see the same CFL waveform running at a higher timebase frequency to show its roughly sawtooth waveform. siliconchip.com.au 47nF 340V P-P D1 + A 240V AC N 47 ~ A K +340V 2.2nF ~ 330k 560k 100nF 100nF A The frequency of oscillation is now deter- A Q2 G S K 2.2nF L2 D 10 N3 ZD2 33 A mined by the prop­erties of the core used for transformer T1. As the current builds up in winding N1, the core begins to saturate. When this happens, the flux in the core stops changing and gate drive to Q1 or Q2 ceases. The flux now collapses to drive the opposite Mosfet and this process continues to maintain oscillation. The current through the tube is limited by the current at which T1’s core saturates and by L2’s inductance. The two 10W resistors, together with zener diodes ZD1 & ZD2, limit the gate drive to Q1 & Q2, while the 2.2nF capacitor The scope shot above, from another CFL, shows a 30.75kHz waveform modulated at 100Hz while the scope shot at right shows the same waveform at higher timebase speed (20ms/div) to show its sawtooth shape. siliconchip.com.au 3.3nF 33 DIAC1 A typical circuit for a 240V CFL. It incorporates a bridge rectifier to produce about 340V DC and an electronic ballast which is basically an inverter/oscillator. Normal running CFL ZD1 N1 L1 discharges the 2.2nF capacitor every time Q2 is switched on. The oscillator current now flows through the filaments of the fluorescent tube and allows the normal mercury discharge to take place. This means that the fluorescent tube will light up. When this happens, the 3.3nF capacitor is effectively shunted by the mercury discharge and the voltage across the tube is now about 100V peak. S K K C1 100nF 4.7 F Q1 G N2 D2 – T1 D 10 at the cathode of D2 forms a snubber network to suppress commutation in the opposing Mosfet at switch on. This considerably reduces the switching losses in each Mosfet. The 330kW resistor in parallel with this capacitor keeps diode D1 reverse biased at start-up. Finally, the 4.7nF capacitor in series with one of the tube filaments ensures that the tube is driven by AC. This prevents mercury migration to the tube ends which would cause blackening and shorten the tube life. SC None of these waveforms reveal the modulated broadband RF noise radiated by CFLs but this is easily demonstrated if you operate a standard AM broadcast band radio in close proximity to any CFL. April 2007  15 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 Introducing the SPLat CC16 . . . the world’s lowest cost “industry-ready” OEM controller! By PETER SMITH SPLat Controls, an Australian company that produces a range of home-grown industrialstrength controllers, recently added the credit-card sized ‘CC16’ to their line-up. This new controller sells for less than $100 yet includes many of the features of SPLat’s more sophisticated controllers. T HE CC16 BOASTS 16 digital input/output (I/O) lines. All inputs feature over-voltage protection and are designed to work with industrial style “NPN” type sensors. The outputs are capable of sinking up to 400mA and can directly drive solenoids, contactors and small stepper motors – so for many applications, no additional interfacing circuits are required. Like all SPLat controllers, the CC16 utilises a proprietary programming 22  Silicon Chip language. Unlike other controllers that use C, BASIC or ladder logic, the SPLat language was designed from the ground up for industrial control and is therefore exceptionally easy to use. While it is possible to create rudimentary programs in minutes using a subset of the SPLat language called “Fast-track”, much more sophisticated control functions can also be built that include maths, state machines, heuristics and look-up tables. A major selling point of the controller is its multi-tasking abilities, which are an integral part of the SPLat language. Up to 32 concurrent tasks coupled with an execution rate of about 15,000 high-level SPLat instructions per second provide enough scope for a wide variety of applications. Add to that the large program memory (approx. 12,000 instructions) and it’s hard to imagine a job that these little devices couldn’t tackle! SPLat’s claim that their programming language is the “easiest in the world” for embedded OEM applications piqued our curiosity. While it might be easy for an experienced programmer to use, how would someone with no programming experience fare? To learn more, we obtained a CC16DK Developer’s Kit which includes the CC16 controller, a CD-ROM with PC software and technical information, a siliconchip.com.au Fig.1: the CC16 features 16 digital input/ output (I/O) lines. Here’s the basic structure of a single I/O line, showing how one input and one output are connected together and brought out to a single point. Each output is capable of sinking up to 400mA, made possible by ULN2803A high-voltage Darlington driver ICs. When used as inputs, 330kW resistors divide the applied voltage by two. The 330kW series resistor also limits current flow in the micro’s internal protection diodes to provide overvoltage protection. A logic low is specified as 0-3V on an input and a logic high as 7-32V. For those interested, the complete schematic can be downloaded from www.splatco.com.au – look in “Outline drawings & other files” under the “Support” section. serial cable and five friction lock connectors for I/O and power hook-up. A power supply is not included in the kit but a plugpack or any DC supply that can provide 10-24V will work. Getting started The first step is to install the Windows-based development software, “SPLat/PC”. While we installed ours from the CD, it is also available for free download from www.splatco.com. au. The software provides a means of entering and testing your SPLat programs and includes a comprehensive help system. The serial cable mentioned earlier connects the CC16 to a free serial port on your PC, allowing SPLat/PC to communicate with the controller for debugging and programming. USB-to-serial adapters are available separately if your system lacks the necessary port. Once testing is complete, a couple of keystrokes see a “tokenised” version of your program uploaded to the flashbased memory in the CC16’s on-board microcontroller. The controller is then ready for use and can be disconnected from the PC. Note: for the technically curious, the microcontroller embedded in all SPLat controllers is factory programmed with run-time firmware that interprets and executes your tokenised program. This means that your program is not compiled to machine code; rather, it is converted to a “shorthand” language (and all comments stripped away) to conserve space in the micro’s Flash memory. SPLat provide free updates to the on-board firmware as new features siliconchip.com.au are implemented. A simple system called “reFlash” is used to apply the updates to all later model controllers, including the CC16. When SPLat/PC is first launched, a message appears encouraging you to follow a “mini-tutorial”. This tutorial describes the basics of the system and gives a rudimentary, hands-on programming example. Let’s look at a few of the simple examples given in the tutorial to get an idea of how the SPLat programming system works. Programming The Editor window opens immediately when SPLat/PC is started (see Fig.2). This window functions as a basic text editor, where you enter and edit your SPLat program. It also acts as the central control point for all other functions. From within this window, you can write your programs, test them and then download them to the CC16 controller. The program shown in Fig.2 makes use of SPLat’s simplified Fast-track instruction subset. It waits for input 0 to turn on (go to a logic “low” level) and then turns on output 5. It then waits for input 0 to turn off (go high) again before turning output 5 off and then looping back to the start. Having entered this simple program, we can then download it directly to the controller and check if it works as intended. However, unlike this ridiculously simple example, most real programs will have a few problems and will not operate as expected without “debugging”. This is where the real power of SPLat’s development environment comes in. We can step through our program one line at a time, get it to stop at any line we desire or run it uninterrupted to help track down any anomalies (Fig.3). To see the state of the outputs, it’s just a matter of opening the Input/ Output window from the toolbar (Fig.4). This window (Fig.5) gives a graphical representation of the state of each output line in the form of a graphical “LED”. The Input/Output window also includes a graphical “switch” for each input line, allowing the state of any input to be viewed and altered with just a mouse click – so it’s easy to simulate a real switch on any of the controller’s input lines. This enables you to test and debug your program without even having the real-word sensors or switches wired to the controller! Fig.2: SPLat/PC’s Editor window looks a lot like Windows Notepad and works in a similar fashion. Here we’ve typed in a very simple program (borrowed from the mini-tutorial) using just a few instructions from the Fast-Track instruction subset. The operation of the program is largely selfexplanatory (see text). April 2007  23 Fig.3: once you’ve entered your program, you can use the debugging functions on the Run menu to pause execution at a particular line or to step through one line at a time. This makes it much easier to track down bugs and is invaluable as a training aid. Fig.4: a whole host of other windowed functions can be opened from the Editor’s Window menu to assist in the development and debugging of a program. In this short review, we mention only the “Input/ Output” window (see Fig.5). A 64-pin MC9S08AW60 surface-mounted microcontroller IC (the small square black device) accounts for the vast majority of the CC16’s operation. All connections to the board are made via friction lock connectors on a 2.54mm pitch. The four 6-way connectors on the left side each carry four I/O lines, power and ground. The 3, 4 and 8-way connectors at the right and bottom sides provide for power input, serial communications and I/O expansion, respectively. As you’ve probably gathered by now, SPLat/PC simulates the entire operation of the controller; you don’t even need to have the CC16 connected to test your program! However, if it is connected, the controller acts as a “dumb” I/O device. This means that input/output instructions executed in SPLat/PC act indirectly on the controller’s port lines (albeit slower than in real time), allowing in-situ testing and debugging. Using just 14 instructions that make up Fast-track (see Table 1), we’ve no doubt that just about anyone could write a rudimentary SPLat program in short order. And once you’ve got those down pat (or if you’re already a programming expert), you’ll be able to build up your repertoire from some 24  Silicon Chip 400 instructions that make up the complete instruction set! Multi-tasking Multitasking is a common requirement in industrial automation, so it makes sense to build support for this right into the programming language. SPLat’s integrated multi-tasking capabilities are called “MultiTrack” and are almost as easy to use as Fast-track! Remember our programming example from Fig.2? Imagine for a moment that this simple section of code controls a bottle capper on an assembly line. What changes might be required to drive a multi-headed capper, where each head operates asynchronously? Believe it or not, the necessary program is barely more complicated than the original, once we’ve added a few MultiTrack instructions – see Fig.6. Moreover, the program is easily expanded to handle many more channels or other “simultaneous” tasks. Don’t be fooled by the simplicity of our example. MultiTrack can be used to build sophisticated routines with inter-task communication and multiple 24-bit timers, with the latter limited only be available memory space. MultiTrack also provides a useful framework for libraries of common functions. According to SPLat, sample library style programs will be available in the future for a range of common functions. Expansion If your application demands more than 16 I/O lines, the CC16 is easily expanded via its SPI-like serial bus. SPLat offers a range of compatible 8-bit and 16-bit expansion boards, one of which features eight heavyduty 20A relays and eight optically isolated inputs. Additionally, the CC16 supports the industry standard Modbus protocol and can act as a Modbus RTU slave. Presumably, this would function over the TTL level “Comms” interface, as the low-cost CC16 doesn’t include an RS232 interface. Check it out As mentioned earlier, SPLat/PC siliconchip.com.au Table 1: Fast-Track Instruction Set WaitOn i Wait for input i to turn on WaitOff i Wait for input i to turn off WaitOnT i,tttt Wait for input i to turn on, timeout after tttt x 10ms WaitOff i,tttt Wait for input i to turn off, timeout after tttt x 10ms GoTo line Go to line GoIfT line Go to line if the expected input did occur in the preceding WaitOnT or WaitOffT instruction GoIfF line Go to line if the preceding WaitOnT or WaitOffT timed out Pause tttt Pause the program tttt x 10ms On o Turn on output o Off o Turn off output o SetMem m,cc Set memory location m to value cc DecMGoIfNZ m,line Decrement memory location m, go to line if the result is not equal to zero GoIfInOn i,line Go to line if input i is on GoIfInOff i,line Go to line if input i is off simulates the controller in software, so you can use simple code examples to learn more about the system even without a controller attached. Note that as the same software drives all of SPLat’s controllers, you must first specify the controller that you wish to simulate. This is done via the File -> Configure -> Board Type menu in the Editor; simply choose “CC16” from the drop-down list. The on-line mini-tutorials (accessible from the Help menu) are definitely worth a look too – they’ll have you writing your own code in less than a couple of hours! SPLat/PC can be Fig.5: the Input/Output window indicates the status of all of the CC16’s output lines using graphical “LEDs” and inputs using graphical “slide switches”. Any input can be simulated as high or low by altering the respective switch position with a mouse click. Inputs can also be momentarily set (simulating a pushbutton switch) by simultaneously holding down the Shift key. downloaded from www.splatco.com. au. Special offer Until 31st May 2007, SPlat Controls are offering a very special deal for SILICON CHIP readers interested in purchasing the CC16 development kit. To find out more, check out this “special offer” web address: www. splat-sc.com. SPLat Controls design, manufacture and support their products in Australia. They are situated in Seaford, Victoria and can be contacted on (03) SC 9773 5082. Fig.6: multitasking is built into the CC16 and it allows separate “slices” of a program (in this case TaskA and TaskB) to run simultaneously and independently of one another. Essentially, SPLat’s simple multitasking instructions allow less experienced users to write more sophisticated programs. The CC16BB Breakout Board is a useful add-on device to have during development, as it provides convenient screw terminal connections for power and all I/O connections, plus indicator LEDs on all I/O lines and DIP switches for activating inputs. It simply plugs into the four I/O connectors on the CC16 board. siliconchip.com.au April 2007  25 High-Power Reversible DC Motor Speed Controller Words by Leo Simpson Design by Branko Justic* *Oatley Electronics This reversible DC motor speed controller uses a switchmode Mosfet bridge circuit that drives the motor. It can be controlled by a 1-2ms pulse train from a radio control system or by a single potentiometer to give forward/reverse throttle control. It can operate from 12V or 24V batteries at currents up to 20A with just four Mosfets in the bridge circuit. O VER THE YEARS, motor speed controls have always been popular and this one is a beauty. Its Mos­ fet bridge circuit can be used for speed control in an R/C system using standard 1-2ms pulse control or you can simply connect a 10kW (linear) potentiometer or joystick to give single-handed forward/reverse control. As such, it would be suitable for a golf buggy, electric wheelchair, go-kart or whatever motor control application you have in mind. The bridge driver circuit employs 80A N-channel Mosfets that have an on-resistance of just five milliohms 26  Silicon Chip (5mW) and are suitable for 10-30V operation. In practice, that will mean operation from 12V or 24V batteries. When tested with a loaded 24V motor at a continuous 10A the MOSFETs became just slightly warm. No additional heatsinking would be required for operation at 20A. This test was conducted with four MOSFETs in the output bridge but there is provision for another four MOSFETs to be paralleled with the existing ones in the output bridge driver. This would result in each of the paralleled MOSFETs having one quarter of the power dissipation when compared to the original single devices! In a 24V system, there would be no problem powering motors with a power rating of up to 1kW. The complete circuit of the Speed Control For DC Motors is shown in Fig.1. With a total of four op amps, four comparators and four Mosfets, it may look fairly complicated but we can break it down into two sections in order to understand how it works. Bridge circuit operation First, let’s have a look at the bridge output circuit which drives the motor. You first need to understand how a siliconchip.com.au This view shows the top side of the assembled PC board. Be careful not to get the two ICs mixed up and take care to ensure that all polarised parts (ICs, diodes, zener diodes & electrolytic capacitors) go in the right way around. The power Mosfets are mounted on the underside of the board (see below). The surface-mount Mosfets are soldered to the underside of the PC board while the external connections are run via crimped eyelet assemblies which are fastened in place using M3 machine screws and nuts. Mosfet bridge circuit drives the motor. Only two Mosfets turn on to drive the motor at any one time. The motor is connected to the terminals marked “Motor 1” and “Motor 2”. For example, to drive the motor in the forward direction, Q7 and Q6 would be “on” while Q5 & Q8 would be “off”. This would mean that current would flow from the positive rail VPOS (10-30V), through Q7, through the motor and then Q6 to the 0V (GND) rail. To drive the motor in the reverse direction, Q5 & Q8 would be “on” while Q7 and Q6 would be “off”. Both the above forward and reverse siliconchip.com.au conditions imply full speed operation with the respective Mosfets being turned on all the time. But this speed control is fully variable and the voltage to the motor is switched on and off rapidly at about 300Hz. For low speed, the turn-on pulses to the gates of the relevant Mosfets are quite short and for the high speeds they become progressively longer until at full speed the relevant gates are pulled high continuously. OK. So we know that only two Mosfets in the bridge circuit are turned on at any one time to drive the motor in forward or reverse but an extra wrinkle in this circuit is that all four Mosfet are N-channel devices. In order to switch on the top Mosfet (Q5 or Q7), we need a gate voltage which is about 8V higher than the main (motor) supply voltage (VPOS). How do we manage that? What we need first is a higher voltage supply to provide those high voltage gate signals Q5 & Q7. This is provided by op amp IC1b, complementary transistors Q3 & Q4 and the capacitors associated with D2-D7. Op amp IC1b is connected to operate as a square wave oscillator at a frequency of 4kHz. Its output is about 6V peak-peak. This is coupled to the April 2007  27 Fig.1: the circuit uses four Mosfets in a bridge configuration to drive the motor and these are pulse width modulated by sawtooth oscillator IC1a and comparators IC2a-IC2d. IC1c & IC1d provide an interface for a standard 1-2ms R/C control. IC1b, transistors Q3 & Q4 and diodes D2-D7 provide a high gate voltage for Mosfets Q5 & Q7. bases of transistors Q3 & Q4 which are connected as complementary emitter followers to provide a buffered output from the op amp. This combination produces an AC output voltage of 4.8V peak-peak. This AC output voltage is used to drive a Cockroft-Walton voltage multiplier made up of diodes D2-D7 and their associated 10mF capacitors. The DC output voltage from this multiplier is about 7-8V higher than the main supply voltage VPOS. The VPOS + 8V supply is coupled to the gates of Q5 & Q7 via 6.8kW resistors and these connect, in turn, to the outputs of comparators IC2a & IC2b. Note that this high voltage does not harm IC2 because it is an LM339 quad comparator with open-collector outputs. This means that its outputs 28  Silicon Chip are essentially the collectors of NPN transistors which can withstand any voltage up to +36V. In our circuit, the collector outputs of the four comparators are tied to VPOS + 8V via 6.8kW resistors for IC2a & IC2b and to VPOS via 4.7kW resistors for IC2c & IC2d. Switchmode operation For the following explanation, let’s assume that the 10kW potentiometer connected to terminals B, C, & D has its wiper initially centred. Op amp IC1a and its associated parts form an oscillator which produces a 300Hz sawtooth waveform of about 1.2V peak-peak. This sawtooth voltage is applied to the non-inverting input (pin 11) of IC2d and to the inverting input (pin 8) of IC2c. The 39kW, 15kW and 33kW resistors form a voltage divider from the regulated +8V supply in order to bias pin 10 of IC2d at +4.4V and pin 9 of IC2c at +3V. Since the swing of the sawtooth waveform is actually sitting between the upper and lower threshold voltages, both comparators (ie, IC2c & IC2d) have an output of 0V – ie, there is no pulse output from the comparators and the motor is stationary. Rotating the 10kW potentiometer so the voltage at its wiper is higher effectively raises the level of the sawtooth so that part of it intersects the 4.4V threshold for IC2d. This causes the output of IC2d to go high whenever the peaks of the sawtooth are above the +4.4V threshold. The output pulses from IC2d are buffered by IC2a. This means that gate pulses are delivered to Q6 & Q7 which siliconchip.com.au Table 1: Resistor Colour Codes o o o o o o o o o o o o o o o siliconchip.com.au No. 3 2 5 2 1 1 2 2 1 1 2 3 5 1 Value 1MW 220kW 120kW 68kW 39kW 33kW 15kW 12kW 10kW 8.2kW 6.8kW 4.7kW 2.2kW 220W 4-Band Code (1%) brown black green brown red red yellow brown brown red yellow brown blue grey orange brown orange white orange brown orange orange orange brown brown green orange brown brown red orange brown brown black orange brown grey red red brown blue grey red brown yellow violet red brown red red red brown red red brown brown 5-Band Code (1%) brown black black yellow brown red red black orange brown brown red black orange brown blue grey black red brown orange white black red brown orange orange black red brown brown green black red brown brown red black red brown brown black black red brown grey red black brown brown blue grey black brown brown yellow violet black brown brown red red black brown brown red red black black brown April 2007  29 Parts List 1 PC board coded OE-K243, 115 x 71mm 4 3mm screws 4 3mm nuts 8 3mm washers 2 14-pin IC Sockets 1 3-way 5mm screw terminal block 2 2-way 5mm screw terminal blocks 4 crimp eye terminals (for supply and motor connections) 1 10kW (lin) potentiometer 1 2kW trimpot (VR1) 1 100kW trimpot (VR2) Semiconductors 1 LM324 quad op amp (IC1) 1 LM339 quad comparator (IC2) 1 7808 8V voltage regulator (REG1) 1 C8050 NPN transistor (Q3) 1 C8550 PNP transistor (Q4) 1 1N4148 signal diode (D1) 6 1N5819 Schottky diodes (D2-D7) 4 18V 400mW zener diodes (ZD1-ZD4) 4 SDB85N03L N-channel surface-mount Mosfets (see text) Capacitors 4 100mF 35V electrolytic 6 10mF 35V electrolytic 2 1mF 16V electrolytic 1 4.7nF metallised polyester (greencap) 1 1nF metallised polyester (greencap) Resistors (0.25W, 1% or 5%) 3 1MW 2 12kW 2 220kW 1 10kW 5 120kW 1 8.2kW 2 68kW 2 6.8kW 1 39kW 3 4.7kW 1 33kW 5 2.2kW 2 15kW 1 220W Kit availability This project was produced by Oatley Electronics who own the design copyright. Kits (Cat. K243) can be purchased from Oatley Electronics Pty Ltd, PO Box 89, Oatley, NSW 2223. Phone: (02) 9584 3563 Fax: (02) 9584 3561 http://www.oatleyelectronics.com 30  Silicon Chip Fig.2: follow this parts layout diagram carefully when assembling the PC board. Eight surface-mount Mosfets are shown here but the “A” devices are all optional – see text. Note that Q3 and Q4 have different type numbers. drive the motor in one direction. Rotating the 10kW potentiometer in the opposite direction, so that the voltage at its wiper is lower, effectively lowers the level of the sawtooth so that part of it intersects the +3V threshold for IC2c. This causes the output of IC2c to go high whenever the troughs of the sawtooth are below the +3V threshold. The output pulses from IC2c are buffered by IC2b. This means that gate pulses are delivered to Q5 & Q8 which drive the motor in the other direction. The only part of the circuit which remains to be explained is that comprising op amps IC1c & IC1d and associated components. This takes the standard 1-2ms pulse from a radio control decoder and converts it to a varying DC level to control the sawtooth oscillator of IC1a. It does this in the following way. The pulse signal is first fed to IC1c which is connected as a comparator to buffer and “limit” the signal before it is fed to diode D1 and filtered by the 1mF capacitor. The resulting DC level represents the width of the input pulses. Short pulses give a low level while long pulses give a higher level. This is amplified and level-shifted by op amp IC1d and then fed to terminal A on the connector strip. This is linked to terminal C on the connector strip and fed via the 220kW resistor to IC1a to level-shift Table 2: Capacitor Codes Value 4.7nF 1nF mF code IEC Code    EIA Code .0047mF 4n7 472 .001mF 1n0 102 the sawtooth waveform and hence control motor speed and direction as described above. It is important to note that if you are using the 10kW potentiometer to control speed and direction, then terminals A & C must not be linked. Conversely, if you are using 1-2ms pulse control, then terminals A & C must be linked and the 10kW potentiometer must be omitted. Note that transistors Q1 & Q2 are missing from the circuit and PC board. These were present in an earlier prototype but have been designed out the circuit. Construction All the components of the Speed Control, with the exception of the 10kW potentiometer, are mounted on a PC board measuring 115 x 71mm. Assembly is best started with the SDB85N03L surface-mount Mosfets. Solder the legs of the Mosfets first and then solder the metal tag of each Mosfet to the PC board. A wooden clothes peg can be used to hold each Mosfet in place while it is soldered. Note that you will need a larger than normal siliconchip.com.au WARNING! Fig.3: here’s how to connect the speed pot and run the external wiring connections. The supply and motor connections are fastened to underside of the PC board (see photo). soldering iron to do this because most temperature-controlled irons will not have enough power to do the job. Make sure you place and solder each Mosfet in the correct location, so as to leave room for the additional Mosfets if they need to be fitted as well. With the Mosfets installed, you can then solder in all the smaller components. Make sure that the diodes, transistors, ICs and voltage regulator (REG1) are correctly located and oriented. Mistakes here can cause major damage if not discovered before power is applied. C O N T R O L S       The supply polarity is crucial. Reversed polarity may destroy the unit. In particular, note that Q3 and Q4 are different. Q3 is a C8050, while Q4 is a C8550. Don’t mix them up. Check each resistor’s value with your digital multimeter, before it is installed. Finally, make sure that you install each electrolytic capacitor with the correct polarity. nect a 12V battery or DC power supply. Do not connect the motor yet. Now check that +8V is present at the output of voltage regulator REG1 and on pin 4 of IC1. +12V should be present at pin 3 of IC2. That done, check that the voltage multiplier is working by measuring the voltage at the cathode end (white band) of diode D7. It should be about +20V or thereabouts. With the 10kW potentiometer centred (ie, for zero motor speed in either direction), the voltages at pins 1, 2, 13 & 14 of IC2 should all be low (ie, less than about 100mV) and similarly, the voltages at the Motor1 and Motor2 outputs should also be close to 0V. Now try rotating the 10kW pot in one direction and then other. You should find a proportional increase in the voltage at the Motor1 or Motor2 terminals. If all these checks are OK, you should be able to then connect the motor and control its speed. Note that as its speed is increased, the motor will produce a more or less musical tone. That is due to the 300Hz switching frequency. Next month, we will describe a companion interface board which provides a hand throttle control and has a toggle SC switch for motor direction. Testing When assembly is complete, check all your work very carefully. As noted above, any mistake in component placement or polarity may cause damage when the supply is connected. When everything checks OK, con- CC16: A professional, quality controller at an affordable price! Ready to use. No soldering, no extra circuitry required 16 industrial strength input/output points Easy to program Huge 25K program memory, 250 bytes RAM Floating point, multitasking, ModBus communications Expandable Ma de i nA us tra lia From $98 incl GST (OEM pack, board + connectors) Developer’s kit $148.50 includes programming cable & programming software -v alu ed wo rld - Save $56! Visit splat-sc.com for a special offer exclusive to SILICON CHIP readers siliconchip.com.au wi de April 2007  31 It sizzles!   It sparks!   It crackles!    It’s Build a Jaco High voltage displays have always been awe-inspiring. They not only look and sound spectacular – they even have a pungent smell, caused by the ozone which is generated by any high voltage discharge. One of the most fascinating high voltage displays is the Jacob’s Ladder, in which a series of sparks continually climb between two vertical wires. Warning! This Jacob’s Ladder display uses very high voltage which can give a nasty shock. Do not put your fingers anywhere near the display, the coil, nor any part of the circuit while ever power is applied. By Leo Simpson 32  Silicon iliconCChip hip At night it’s really spectacular: this photo of our new Jacob’s Ladder is a two-second time exposure. siliconchip.com.au siliconchip.com.au   Fascinating!   It’s electrifying! ob’s Ladder SO HOW DO YOU make an electric discharge spectacular they are also quite dangerous. climb a pair of wires? In practice, it is quite We got to thinking: how can we produce something just easy. The two vertical wires are spaced close as spectacular but not mains-powered? Our original Jacob’s together at the bottom and slightly splayed apart to increase Ladder circuit was based on a conventional 12V ignition the gap as the sparks rise. coil and we realised that today’s cars have very powerful So why do they rise at all? Surely the spark would always ignition systems. take the shortest route rather then extend itself as it travels So why not revise the circuit with a higher-powered coil upwards? out of a late model car? But the spark discharge is actually taking the shortest In practice, it turned out to be not quite so simple. While path, or rather, the easiest path from one electrode to the all current model cars use engine management and highother. Initially, the discharge does take energy ignition systems, they use the shortest path which is at the bota wide variety of ignition coil artom of the wires. But the continuous rangements. spark discharge is hot and heats up the Some use direct fire ignition air around it. This heated ionised air systems, with a coil right on top of rises, carrying the discharge up with it each spark plug. Others use a conuntil the gap between the two electrode ventional coil and distributor while wires is too large to maintain the spark. some others such as the Holden The discharge then starts at the bottom Commodore use three doubleagain and the cycle continues. ended coils to run a V6 motor. Back in September 1995 we proWe decided that the doubleduced a Jacob’s Ladder circuit which ended coil arrangement was probFig.1: this shows the spark has been popular ever since. But just ably the best for our purpose since plug firing arrangement for the Commodore V6 double-ended ignition coil. The two recently our attention was drawn to a it should have much higher voltage spark plugs are fired together (in series), so number of mains-powered discharge than a coil which only has to fire quite a high output voltage is needed. circuits on the internet. While quite one spark plug at a time. siliconchip.com.au April 2007  33 + F1 10A 0.47Ω FAST 5W D1 A T1 IGNITION COIL K JACOB'S LADDER 10Ω 1N4004 18k 12V BATTERY INPUT 7 470 µF 16V ZD5 16V 1W K 18k 2 6 A 8 4 VCC RES OUT DIS TRIG 3 2.2k Q1 BC327 B E CV 1W 5 B 1 ZD3 75V 5W 100nF ZD4 75V 5W – SC  2007 JACOB'S LADDER 555 DIODES (D1, ZD1-ZD5) A B K BAND BC327 8 4 1 E K ZD2 75V 5W E GND 330nF ZD1 75V 5W C C 150Ω IC1 555 THR Q2 MJH10012 BU941P A MJH10012 BU941P C B C C E Fig.2: the circuit uses a 555 timer (IC1) to pulse transistors Q1 & Q2 on and off at 75Hz. Q2 drives a Commodore V6 ignition coil and this delivers high voltage pulses to the Jacob’s Ladder wires. By way of explanation, the Commodore ignition coil has two high voltage terminals, each of which is connected to a spark plug. So when the coil fires, it drives two spark plugs in series; one will be on the power stroke while the other will be on the exhaust stroke and thus will be “wasted”. The arrangement is shown in Fig.1. The only drawback is that Commodore ignition coils come in an assembly of three, all attached to a common mounting plate. This assembly is quite expensive to buy, whether new or from a wrecker – you can expect to pay around $150 or more. Too much! However, you can purchase single ignition coils for a VN Commodore (the first with the 3.8-litre V6) and that is what we did. Even so, they typically cost around $50 although you might get one at lower cost from a wrecker. By the way, it may be possible to adapt other double-ended coils, such as from a Toyota V6 Camry or Avalon, but we have not tried them. main power transistor does not get too hot – it operates without a heatsink. IC1 is a 555 timer used to produce the short pulses. Note that we used a standard 555 timer here since it is more rugged than the CMOS (7555) version and less likely to be damaged by any high voltage transients which may be present on the PC board. IC1 is connected to oscillate at about 75Hz, as determined by the 330nF capacitor at pin 6 and the two associated 18kW resistors. The two resistors set the duty cycle of the pulse train delivered by pin 3 at about 66%. When pin 3 is high, transistor Q1 is held off and no base How it works Our Jacob’s Ladder circuit does not in fact produce a continuous discharge. Since it is based on an automotive ignition coil, it produces continuous individual sparks, at a rate of around 75 sparks/second. So you have a whole series of sparks which appear to be climbing up the wires. The result is noisy and smelly (from the ozone) and looks quite dangerous, as it indeed it could be, if you are unlucky enough to inadvertently touch the high voltage terminals of the coil. You’d get much the same belt as you would if you touched a spark plug top while the motor is running. The circuit itself comprises a 555 timer IC, two transistors, the ignition coil and several resistors, capacitors and diodes – see Fig.2. This revised circuit (compared with September 1995) has been modified to ensure that the high-energy coil is driven to a reasonably high current of around 5A peak while still maintaining a duty cycle which means that the 34  Silicon Chip This scope screen grab shows the circuit operation. The upper trace (yellow) is taken at the collector of Q1, showing the pulse waveform fed to the base of Q2. The lower trace (purple) shows the high voltage waveform produced at the collector of Q2 and therefore the voltage across the primary winding of the ignition coil. Note that it is limited to 328V peak-peak by the four 75V zener diodes. siliconchip.com.au Fig.3: the component overlay for the PC board. The photo below is an early prototype (in fact, using the same PC board as our original Jacob’s Ladder) – hence the TO3 transistor and some other circuit changes. However, it does give a good idea of how the Commodore coil is mounted in the new version. At the bottom of the page is a section of the reverse side of the board showing how connection is made to the primary of the ignition coil via spade lugs passing through the board. current flows in Q2. When pin 3 goes low, Q1 is switched on due to the base current flow through the 2.2kW resistor and Q1 switches on Q2 via its 150W base resistor. The coil now begins to charge via fuse F1 and the 0.47W 5W resistor. The instant pin 3 goes high again, Q2 switches off and the coil develops a high voltage and generates a spark across the gap. Q2 is an MJH10012 Darlington power transistor, specifically designed as a coil driver in automotive ignition systems. It has a 500V collector-emitter rating so it can withstand the high voltages developed across the coil’s primary winding. Depending on the spark gap, the coil’s peak primary voltage may only be about 300V or so, but if the gap is very large or the coil is operated without any EHT output lead, the secondary voltage can be excessive and there can be a flashover across the coil’s high voltage terminals. In practice, our scope measurements showed that this could siliconchip.com.au April 2007  35 produce a coil primary voltage well in excess of 400V, which leaves less safety margin than we would prefer for Q2. Accordingly, four 75V 5W zener diodes, ZD1-ZD4, are connected in series across Q2 to limit the primary voltage developed by the coil to about 300V, well within the transistor’s rating of 500V. Note that Q1 inverts the output signal from IC1 and therefore drives Q2 with a duty cycle of about 34%. As noted above, the duty cycle is set to provide sufficient “on” time for Q2, so that the coil current can build to a value of about 5A peak, ensuring hot, juicy sparks. By the way, the specified Commodore VN ignition coil has a very low primary resistance of about 350 milliohms so we have added the 0.47W 5W resistor into the collector circuit of Q2, to limit the primary current and reduce heat dissipation in the power transistor. Power for IC1 is provided by the 12V battery via a 10A fuse (F1), the 10W resistor and diode D1. A 470mF capacitor filters the supply to provide reliable triggering for the timer. Transient protection is provided with ZD5, a 16V zener diode. A 100nF capacitor at pin 5 filters the trigger point voltage to ensure that the timer does not false trigger. Diode D1 offers reverse polarity protection for IC1, while the fuse protects the battery from supplying excessive current should a fault occur. Note that you will need a heavy-duty power supply to run this circuit; ie, one capable of providing about 5A or more, with low output impedance. Alternatively, use a sealed lead acid battery rated at 7Ah or more. You will need to keep it charged up between short periods of use. Construction The circuit is constructed on a PC board coded 11104071 and measuring 170 x 76mm. This board, together with the ignition coil mounted on it, can be mounted on a suitable piece of timber or MDF. Fig.3 shows the assembly details for the PC board. Begin the assembly by installing and soldering in all the low profile components such as the IC, diodes and resistors. It is a good idea to double-check the resistor values using a digital multimeter before soldering them in position. Now solder in the capacitors, taking care to ensure that the 470mF electrolytic is oriented as shown. Take care to ensure that the semiconductors are correctly oriented as well. Pin 1 of the IC is adjacent to a notch in one end of the plastic body. Transistor Q2 should be push­ ed down onto the board as far as it will easily go before soldering its leads. Q2 is secured directly to the board (ie, with no insulating washer) using 3mm machine screws and nuts. As well as securing Q2 in place, these mounting screws and nuts also connect Q2’s collector (ie, the case) to a track 36  Silicon Chip on the PC board. To ensure reliable connections, use star washers under the screw heads and solder the nuts to their surrounding copper pads. Note that our circuit and the PC board overlay diagram show a BU941P or MJH10012 plastic TO-218 power transistor fitted instead of the MJ10112 TO-3 version shown in the photos of our prototype. This is because we built our prototype on the PC board for the September 1995 original version of our Jacob’s Ladder. If you have the original PC board (coded 11306951), you could adapt it to the circuit shown here but you will need to have four 75V zener diodes connected in series rather than the three zeners used in the 1995 design. The 150W 1W and 0.47W 5W resistors are mounted about 6mm above the PC board to improve heat dissipation – they do get warm. The fuse clips can now be installed. Note that these each have a little lug at one end to retain the fuse after it has been installed. These lugs must go to the outside ends; otherwise you will not be able to fit the fuse. The ignition coil is secured to the PC board using two 25mm long M4 screws, with nuts and lockwashers. The connections to its primary winding are made underneath the PC board, through holes, using crimped spade connectors. The specified type is red with a 5mm wide spade section. To do this, cut two 50mm lengths of heavy-duty hookup wire with a wire size up to 1mm in diameter. Strip both ends of each wire and crimp a spade connector to one end of each – these go into the underside of the ignition coil via 8mm clearance holes on the underside of the PC board. The other ends of the wires are soldered to their respective points on the top of the PC board – see Fig.3. Then fit the twin-lead battery cable (red to positive, black to negative). The other end of this cable is fitted with large (30A) battery clips. Now you are ready to test the circuit. Testing Before you apply power, you must provide a temporary spark gap for the igniThe two tion coil, otherwise it may lengths of PVC tube be damaged by an internal shown here discharge. The gap can be do a great made quite simply with job of moving a paper clip. Push it over the spark one of the high voltage up the wires, terminals and then posiaway from tion it so that any spark the soldered can jump about 20mm terminals. There across to the other high was just one tiny voltage terminal. problem: after prolonged use Now for the smoke they started to test. As soon as you catch on fire . . . connect the power, so we are not there should be a recommending they continuous stream be used! of sparks across the siliconchip.com.au temporary spark gap. Do not attempt to touch the coil (nor anything else!) while power is applied because it can give you a nasty shock! If everything works OK, disconnect the battery leads and mount the whole PC board assembly on a suitable piece of timber or MDF (medium density fibreboard). We mounted our prototype using four woodscrews and some plastic spacers. We made our Jacob’s Ladder spark gap with two 30cm lengths of springy steel wire. These were attached to the high voltage terminals of the ignition coil by soldering each to bare spark plug connectors. These connectors are not particularly easy to find these days but we tracked them down at a specialist auto parts supplier. Your local auto electrician could be another possibility. If you cannot find any, perhaps you could “rat” some old spark plug leads and extract the connectors. Being designed for crimping, they may also not be easy to solder to – we managed by filing the surface of the connectors to a bright surface and then immediately soldering the wires on with a large (100W) hot soldering iron (normal 30W-ish hobby electronics irons don’t stand a chance!). Note that the two wires should be as straight as possible without any kinks but are slightly splayed apart to make the spark discharge run smoothly up the wires. Any slight kinks will mean that the sparks will not progress smoothly up the ladder but will tend to “stick” at the kinks. So keep the wires as straight as possible and splay them apart very slightly so that the gap at the top is no more than about 20mm. Coat-hanger wire would probably work just as well, bearing in mind that it can be difficult to get coat-hanger wire absolutely straight. Don’t use electrical conduit We originally placed a 50mm length of 20mm electrical conduit over both high voltage terminals of the coil (as seen in the photographs). This stopped any tendency for the spark to jump between any slight bumps or protuberances on the spark plug connectors and made the sparks climb up the wires much more smoothly. Unfortunately, though, after a prolonged period of use, these got carbonised and started to catch fire. Well, it seemed like a good idea at the time. If you find the sparks jump between the terminals and do not rise up the wires, try using proper spark plug insulating sc boots. DO NOT use electrical conduit. PARTS LIST – JACOB’S LADDER 1 PC board, code 11104071, 170 x 76mm 1 VN Commodore V6 12V ignition coil (see text) 2 3AG PC mount fuse clips 1 10A 3AG fuse 2 red 5mm crimp spade terminals 2 25mm M4 screws, nuts and star washers 1 red battery clip 1 black battery clip 2 bare spark plug connectors (see text) 2 spark plug insulating boots (if required – see text) 2m length of twin red/black automotive wire 2 300mm lengths of 1mm steel or copper wire 1 timber or MDF baseboard 1 12V DC 5A power supply or SLA battery (see text) Semiconductors 1 555 timer (IC1) 1 BC327 PNP transistor (Q1) 1 MJH10012, BU941P 500V NPN TO-218 Darlington transistor (Q2) 1 1N4004 1A diode (D1) 4 75V 3W or 5W zener diodes (ZD1-ZD4) 1 16V 1W zener diode (ZD5) Capacitors 1 470mF 16V PC electrolytic 1 330nF MKT polyester 1 100nF MKT polyester Resistors (0.25W 1%) 2 18kW 1 2.2kW 1 150W 1W 1 0.47W 5W wirewound 1 10W Fig.4: actual size artwork for the PC board. The corner mounting holes and the two ignition coil mounting holes should be drilled at 5mm while the three clearance holes for the coil primary wires should be drilled at 8mm. siliconchip.com.au April 2007  37 GPS-Based Frequency Reference Pt.2: By JIM ROWE Last month, we published the circuit for our new GPS-Based Frequency Reference and described how it works. This month, we show you how to build and adjust it. B uilding the GPS-Based Frequency Reference is quite straightforward, since all the parts are mounted on two PC boards: a main board coded 04103071 (143 x 123mm) and a smaller display board coded 04103072 (145 x 58mm). All wiring between the two boards is via a short 16-way ribbon cable, fitted with an IDC line socket at each end (to link CON6 & CON9). Everything fits snugly inside an ABS plastic instrument case measuring 158 x 155 x 65mm, the display board mounting vertically at the front. As you can see from the diagrams and photos, the main board has a small rectangular extension at front right for the 10MHz and 1MHz output connectors (CON1 and CON2), while the display board has a matching rectangular cutout to fit around these connectors. 38  Silicon Chip In addition, the display board has a small cutout at upper left, to provide clearance for the interconnecting cable between the two boards. When the case is assembled, output connectors CON1 and CON2 are accessible via the front panel, while the remaining connectors are all accessible via the rear panel. The LCD and status LEDs are also at the front, along with the three main control pushbutton switches (S1-S3). The GPS receiver initialisation button (S4) is operated via a small access hole in the front panel, along with a similar access hole for adjusting the display contrast (via trimpot VR2). Main board assembly Fig.6 shows the parts layout on the main board. Begin by installing the wire links, then install PC stakes at test points TP1-TP3 and the adjacent TPG and GND terminals. Follow these parts with the resistors, diodes and the MKT and ceramic capacitors. Table 1 shows the resistor colour codes but you should also check them using a DMM, as some colours can be difficult to read. Note that the 10kW and 20kW resistors in the resistor ladder DAC (just to the left of IC12) are mounted in inverted-V fashion, to fit them all in. Table 2 shows the capacitor codes. Take care to ensure that the diodes are all correctly oriented and be sure to use the correct type at each location. Next, fit the IC sockets if you’re using them (they’re recommended for this project). The IDC header pin connectors CON6 & CON7 can then go in, followed by BNC connectors CON1CON4, power input connector CON5 and RCA connector CON8. The finned heatsink for regulator REG1 is next on the list. Make sure it’s seated all the way down on the PC board before soldering its mounting pins to the board pads. siliconchip.com.au Regulator REG1 is mounted vertically against the heatsink and is attached to it using an M3 x 6mm machine screw (this goes into a tapped hole in the heatsink). Apply a thin smear of heatsink compound to both the back of the regulator and the heatsink surface before screwing them together, to ensure a good thermal bond. Tighten the mounting screw firmly, then solder the regulator’s leads to its board pads. The remaining smaller parts can now all be installed. These include trimpot VR1, trimcap VC2 and quartz crystals X1 and X2. CON4 CON3 CON8 ERROR PULSE (INVERTED) 1Hz GPS 12V DC IN + 1k 68Ω 33k 680Ω 100nF IC13 LM358 CON7 (GPSRX) 1M 10 µF VC1 15pF NPO 180Ω 22pF 1M NPO IC3 74HC04 + IC7 74HC4046 100nF 10k 4.7pF NPO VC2 3-10pF 100nF TP3 50kHz IC6 74HC73 100Ω IC5 74HC160 100nF PIC16F628A 100Ω 100nF IC1 + 4.7 µF IC4 74HC160 MAIN BOARD Fig.6(a): follow this parts layout diagram when building the main PC board and refer also to the detail drawing (Fig.7) when installing the parts for the mini oven (under the film canister). The Garmin GPS 15L mounts on spacers above ICs 9 & 12 (see Fig.8) CON1 10MHz OUT CON2 1MHz OUT Fig.6(b): assemble the display PC board as shown here. Switches S1-S3 must be mounted with their flat sides as shown, while LEDs 1-3 should sit 11mm above the board surface. Note also that the 10mF capacitor must be mounted flat against the board (see photo). siliconchip.com.au 180Ω 74HC374 IC12 7002 C 100nF 1nF 3.3k 16 15 4148 33k 33pF BB119 35mm FILM CANISTER (SHORTENED) 33pF 10MHz X2 100nF TO DISPLAY PCB 2 1 1 2 9 10 1k 4148 April 2007  39 GND TP1 6.8k D4 D2 FINNED TO-220 IC10 LM335Z OXDSPG HEATSINK 17030140 Q1 A DRAOB BD136 X1 CON6 100pF D3 CABLE TIES TO HOLD DOWN CANISTER 2.0k 2.2nF 4148 IC14 74HC04 5k IC11 74HC14 1k 100nF VR1 IC2 LM311 TPG TP2 7805 REG1 3.3k + ANTENNA CONN 100pF 47k 10 µF 100nF 33Ω FINNED TO-220 HEATSINK 100nF 100Ω 100Ω 100nF IC8 74HC161 20k D6 D7 2.2k 4.7k GARMIN GPS15L Rx 20k 20k 20k 20k 20k 20k 20k 20k 10k 10k 10k 10k 10k 10k 10k D5 1000 µF 10 µF 10 µF + 1N4004 D1 1M 74HC161 1M 1M IC9 CON5 Making the mini oven The first step in making the oven is to fit the second finned heatsink. Before doing this however, it needs to have a chamfer cut along both inner edges of the two centre fins, to clear the small flange around the bottom of the crystal can – see Fig.7. Basically, you need to remove enough material so that the outer fins rest on the top of the PC board. A small rotary “hobby grinder” can be used to make these chamfers or you could use a small dental burr or milling cutter. After cutting the chamfers, apply a small smear of heatsink compound to both sides of the crystal can and to both sides of the centre slot in the heatsink. This ensures a good thermal bond between the two when the heatsink is fitted. It’s now just a matter of slipping the heatsink into position over the crystal and soldering its mounting pins to the board pads. Mini-oven heater transistor Q1 is in a TO-126 package. As shown, it’s fas- ERROR VOLTS This is the fully-assembled main PC board but with both the Garmin GPS 15L receiver and the oven cover (ie, the film canister) removed so that the components under them are visible. Make sure that all polarised parts are correctly oriented. tened to the end of the oven heatsink, again using an M3 x 6mm machine screw. Smear both the transistor and heatsink mating surfaces with heatsink compound before slipping the transistor into position. Take care with the orientation of Q1 – its metal surface goes towards the heatsink. Don’t forget to solder its leads to the board after tightening its mounting screw. The LM335Z temperature sensor (IC10) is next on the list – see Figs.6 & 7. It’s in a plastic T0-92 package and slips easily into place between the heatsink fins. Before doing this though, give it a generous coating on both sides with heatsink compound. That done, slide it down between the heatsink fins so that its body sits about 6mm above the PC board before soldering its leads to the board. Assuming you’ve already fitted varicap VC1, its 15pF series capacitor and the 47kW isolating resistor, the inside of the mini oven is now complete. All that remains is to fit its outer casing. This casing is made from a 33mmdiameter plastic film canister (you can get one from a photo processing store) and lined with expanded polystyrene foam sheet about 3mm thick. It’s built as follows: (1) Shorten the canister to about 32mm long, using a pair of scissors or a sharp knife. (2) Cut a 31mm diameter disc from the expanded polystyrene foam sheet and push it right down to the bottom of the canister. (3) Cut another piece of the foam into a 28 x 70mm strip and make a series of shallow cuts across the strip on one side, so that it can be rolled lengthwise Fig.7: this detail drawing and the photo at left show how the mini-oven is built. Not shown here is heater transistor Q1 which is fastened to the back of the heatsink. 40  Silicon Chip siliconchip.com.au A 16-way IDC cable (see Fig.9) is used to connect the display board to the main board. Take care to ensure that the three LEDs are correctly oriented and that their bodies sit 11mm above the PC board. The 10mF capacitor must be mounted with its body flat against the PC board as shown. into a tubular shape. Fit this inside the canister to form the wall lining. Having lined the canister, the next step is to “up-end” it and lower it down over the mini-oven components on the PC board. Note, however, that you may have to cut a small “pocket” in one side of the foam liner to clear the 15pF capacitor. Finally, a long plastic cable tie (or two shorter cable ties in series) can be threaded through the adjacent 3mm holes in the PC board and tightened to Table 2: Capacitor Codes hold the canister down. The mini-oven assembly is now complete. Value 100nF 2.2nF 1nF 100pF 33pF 22pF 15pF 4.7pF Installing the ICs The next step in the assembly is to install all the ICs. If you’ve previously installed IC sockets, then it’s just a matter of plugging the ICs in, taking care to ensure they are all correctly oriented. Be sure to use the correct device at each location. Note that most of the ICs are CMOS devices and are easily damaged by mF code 0.1mF .0022mF .001mF NA NA NA NA NA EIA Code    IEC Code   104 100n    222      2n2   102   1n0   101 100p    33   33p    22   22p    15   15p      4.7   4p7 Table 1: Resistor Colour Codes o o o o o o o o o o o o o o o o o o o o siliconchip.com.au No. 5 1 1 2 1 9 10 1 1 2 1 1 3 1 3 2 4 1 1 Value 1MW 68kW 47kW 33kW 22kW 20kW 10kW 6.8kW 4.7kW 3.3kW 2.2kW 2kW 1kW 680W 330W 180W 100W 68W 33W 4-Band Code (1%) brown black green brown blue grey orange brown yellow violet orange brown orange orange orange brown red red orange brown red black orange brown brown black orange brown blue grey red brown yellow violet red brown orange orange red brown red red red brown red black red brown brown black red brown blue grey brown brown orange orange brown brown brown grey brown brown brown black brown brown blue grey black brown orange orange black brown 5-Band Code (1%) brown black black yellow brown blue grey black red brown yellow violet black red brown orange orange black red brown red red black red brown red black black red brown brown black black red brown blue grey black brown brown yellow violet black brown brown orange orange black brown brown red red black brown brown red black black brown brown brown black black brown brown blue grey black black brown orange orange black black brown brown grey black black brown brown black black black brown blue grey black gold brown orange orange black gold brown April 2007  41 Fig.8 (above): the mounting details for the Garmin GPS 15L receiver module. Fig.9 (right): this diagram how to fit the 10-way IDC line socket to the Garmin GPS 15L’s cable. It also shows how to make the 16-way IDC ribbon cable. electrostatic discharge. It’s really just a matter of taking a couple of precautions: (1) avoid touching the IC pins; and (2) earth yourself while you’re removing them from their packaging and plugging them in (eg, by periodically touching an earthed metal object or by using a wrist strap). Installing the GPS module Fig.8 shows the mounting details for the Garmin GPS 15L receiver module. This mounts above the main board, behind the mini-oven assembly and above IC9, IC12, the resistors in the ladder DAC and sundry other parts. As shown in Fig.8, the module is mounted on three M3 x 15mm tapped spacers and secured using three M2 x 25mm machine screws, together with six M2 nuts, six M2 flat washers and six M2 lockwashers. Note that the GPS 15L module has a very small female MCX connector for the active antenna lead on one of the Fig.10: the LCD module is secured to the display board using M2 x 10mm screws, nuts & flat washers. 42  Silicon Chip longer sides and an ultra-miniature 8-way SIL “flex” connector on one end for all other connections. The module is mounted over the main PC board with its antenna connector facing towards the front and the flex connector end on the right (near CON7). Once the receiver module has been mounted, shorten all eight wires on the special interconnecting cable supplied with it (ie, with the tiny 8-way flex connector at one end) to about 60mm long. Don’t bare their ends though, because they need to be fitted to a 10-way IDC line socket to mate with CON7. Although IDC sockets are intended for use with ribbon cable, they can also be used with separate light-duty hookup wires of the type used to make the receiver module’s cable. The idea is to partly assemble the socket first and then feed the end of each wire through from one side, passing it over the teeth of its connector pin and out the other side. Fig.9 shows where each wire goes on the connector. Once all eight wires have been fitted, the two halves of the connector are squeezed together firmly in a small vyce, to make the insulation displacement connections. Finally, the top part of the socket can be fitted if you wish and a small cable tie or two used to keep the wires together. The completed cable can now be connected between the GPS module’s connector and CON7. wire links (four under the LCD module), then install the resistors, trimpot VR2 and the transistors Q2-Q4. Follow these with CON9, the 14-way (7 x 2) pin header for the LCD module, switches S1-S4 and the 10mF electrolytic capacitor. The latter must lie flat against the PC board – see photo. Take care when installing switches S1-S3. Each switch must be seated all the way down on the PC board with its flat side to the left. The next step is to fit the three LEDs (LED1-LED3). These must be installed with their bodies exactly 11mm above the board, so that they later protrude through matching holes in the front panel. A cardboard spacer cut to 11mm is the easiest way to do this – just push each LED down onto the spacer and solder its leads. All that’s left now is the LCD module. Fig.10 shows the mounting details. Install the four M2 x 10mm screws first and secure them using M2 nuts. That done, place an M2 flat washer on top of each nut, then mount the LCD module is position, making sure it mates correctly with the header pins. The module can now be secured in position using four M2 washers, four lockwashers and four M2 nuts. That done, the header pins can be carefully soldered to the pads on the top of the LCD module. Display board assembly You now need to make up a small ribbon cable assembly to connect the two PC boards together. This is made Fig.6(b) shows the display board assembly. Begin by installing the nine Interconnecting cable siliconchip.com.au Fig.11: these diagrams show the drilling details for the front and rear panels. using a 95mm length of 16-way IDC ribbon cable, fitted with a 16-way IDC line socket at each end – see Fig.9. Note that the two sockets both face in the same direction. Note also that you can’t fit the usual top cover to the socket at the display board end, because there isn’t enough space for it to clear the front panel. In fact, you may even need to file about 0.5mm from the top of the line socket to provide enough clearance. You now need to prepare the front and rear panels of the case by drilling and cutting the various holes. These are all shown in the panel cutting diagram – see Fig.11. The 12.5mm dia­ meter hole in the upper centre of the rear panel is used for mounting a BNC female-female panel adaptor. This is used to bring out the GPS receiver module’s antenna lead. Once the panels have been drilled, they can be dressed by attaching the front panel artworks (the relevant file can be downloaded from the SILICON CHIP website and printed out on a siliconchip.com.au colour printer). These artworks are attached using double-sided adhesive tape. Once attached, they can be protected by covering them with clear selfadhesive film (eg, wide sticky tape). Case assembly Now for the final assembly. The first step is to loosely fit the front and rear panels to the main board. That’s done by removing the nuts and lockwashers from BNC connectors CON1-CON4, then fitting the panels in place over these connectors and refitting the nuts and lockwashers. Don’t tighten the nuts at this stage though. Instead, leave them loose so that the panels can be adjusted. Having attached the panels, you can now lower the entire assembly into the bottom half of the case, sliding the front and rear panels into their matching case slots as you go. Similarly, the display PC board slides into the third board slot from the front. The main board is then secured to the integral moulded support pillars using the four small self-tapping screws supplied with the case. The next step is to fit the cable that connects the GPS receiver module to CON7 on the main board. That done, fit the 16-way IDC cable between and CON6 on the main board and CON9 on the display board. Construction can now be completed by fitting the BNC-BNC adaptor to the rear panel and connecting the internal MCX-BNC antenna cable between this adapter and the GPS receiver module. That done, tighten the nuts on the front and rear panel BNC connectors. Setup & adjustment Before doing anything else, you need to install your active GPS antenna. This must be mounted outside and as high as possible, so that it gets an unobstructed “view” of the sky. A good position should be on the top of your TV antenna mast but you may decide on somewhere else because of the need to keep the cable length as short as possible. April 2007  43 What The PIC Firmware Does The main part of this project is the hardware circuitry which effectively locks the phase of the main 10MHz crystal oscillator to the very accurate 1Hz pulses from the GPS receiver module, as explained in the text. However, since the GPS receiver module also provides strings of useful GPS-derived data every second, along with the 1Hz pulses, we use a PIC micro to “catch” these strings of data and allow selected data items to be viewed on the LCD. The GPS data stream is sent in ASCII sentences at 4800bps, or 480 characters per second. The main part of the firmware program in the PIC simply scans front panel pushbuttons S1-S4 and if none of the buttons is pressed, it simply waits until a character arrives from the GPS receiver and is “caught” by the hardware USART module in the PIC. When this happens, the PIC then jumps into an interrupt servicing routine and after making sure there This view shows the completed assembly ready for installation in the case, again with the oven cover and the Garmin GPS 15L module removed. 44  Silicon Chip weren’t any errors, it reads the received character from the USART and then inspects it to see if it has any special significance – such as the start or end of a sentence. If it isn’t one of these special characters, it simply saves the character in the next available address in a buffer area in its data RAM. However, if the character is a “start of sentence” character, it doesn’t save it. Instead it simply resets the PIC’s “pointer” to the RAM buffer, so that following characters in the sentence will be saved from the start of the buffer. On the other hand, if the character is an “end of sentence” character, it jumps to a separate part of the interrupt routine which analyses or “parses” the sentence in the RAM buffer to identify which kind of a sentence it is. It then saves the wanted data in that sentence into specific RAM addresses where they can be displayed later. As well as scanning the push­ buttons, the main part of the project simply displays some of this received GPS information on the LCD – ie, the UTC time and date, plus the GPX receiver’s fix status and the PLL lock status. However, if you press S1, S2 or S3, the program switches to one of three alternative display modes, which allow some of the other GPS information to be displayed – the latitude and longitude, the antenna height above mean sea level, the number of GPS satellites currently in view and so on. Each of these alternative display modes only lasts for about 20 seconds, after which the program switches back to the main time and date display. Finally, press switch S4, the program displays a message to advise that it is sending initialisation commands to the GPS receiver (and does just that). It then switches back to the main display again. The receiver end of the antenna is fitted with a BNC plug, to mate with the “outside” section of the rear panel BNC adaptor. Be sure to fit this plug without introducing any short circuits, because this cable carries DC power up to the active antenna (via the GPS receiver module), as well as carrying the GPS signals down to the receiver. A short circuit could damage the GPS module. Once the antenna is in place, apply power via the DC input socket (CON5). LED2 (PLL Lock) on the front panel should begin glowing almost immediately and you should also be able to measure +5V on the wire link just to the right of IDC header CON6 (relative to the TPG ground pin to the left of REG1). The LCD should also spring to life, although it will probably be showing mainly zeroes for the first 10-20 seconds. After this time, the GPS receiver module should have found a “fix” and the display should change to show the current UTC time and date, plus a “1” in the upper righthand siliconchip.com.au The main PC board is secured to integral spacers on the base of the case, while the display board slides into one of the case slots. Note that the front and rear panels must be attached to the BNC sockets on the main board before mount ing it in the case. corner to show the fix status. LED3 on the front panel should also begin to blink once per second, showing the GPS 1Hz pulses, while LED1 should also begin glowing continuously to show the fix status. LED2 may now either be off or it may begin to flash, because the PLL may not be able to lock the phase of the 10MHz crystal oscillator with the 1Hz GPS pulses as yet. The Garmin GPS 15L receiver module is mounted on spacers attached to the main board (see Fig.8). It sits above ICs 9 & 12 and is connected to the main board via the 10-way IDC line socket. Adjusting the mini-oven The next step is to check the status of the mini oven’s temperature control. First, measure the voltage at TP1 relasiliconchip.com.au April 2007  45 This view shows the fully-assembled unit, with both the Garmin receiver and the oven cover in place. Note the internal antenna connection from the Garmin GPS 15L receiver’s socket to the BNC-to-BNC adapter on the rear panel (see also picture on facing page). Monitoring Its Performance If you’re using your frequency reference in a normal workshop/home lab environment, there’s probably no need to monitor its performance any further than glancing at its front panel displays from time to time – to confirm that its GPS fix and PLL lock status are both OK. However, if you need to monitor its performance in more detail, this can be done fairly easily using the DC error voltage fed out via CON8 on the rear panel. There is a direct relationship between this error voltage and the instantaneous phase error in the frequency reference’s PLL. In fact, each 19.53mV of this error voltage corresponds to 100ns of phase error, so if you have the PLL stabilised at an average phase error of 10ms, the error voltage will have an average value of 1.953V. And as the phase error jitters up and down in 100ns increments, the instantaneous error voltage will similarly vary up and down in 19.53mV increments. This means that if you monitor the DC error voltage continuously using a DMM and link the DMM to a PC running a data-logging program, you can record the frequency reference’s PLL performance over a suitable period of time. You can then plot the mean value and standard deviation of its phase lock error. This will give you a much better idea of its medium and long-term accuracy, as well as the short-term error tolerance. 46  Silicon Chip tive to ground pin TPG; this should measure very close to +3.15V. You should find a similar voltage on TP2 (within a couple of tens of millivolts). This is the voltage across temperature sensor IC10 and reflects the temperature inside the mini oven (3.15V = 315K = 42°C). If the voltage on TP2 is outside the range 3.14-3.16V, try adjusting trimpot VR1 in one direction or the other until the voltage drifts back inside this range. Don’t adjust the trimpot setting in large jumps though, because the temperature changes quite slowly following each adjustment. Adjusting the PLL When you are satisfied that the voltage at TP2 is stabilising inside the correct range, you are ready to turn your attention to setting up the 10MHz crystal oscillator and the PLL. For this, siliconchip.com.au The rear panel carries BNC sockets for the antenna (top, centre) and for the GPS 1Hz and phase error pulse outputs (bottom left). It also carries an RCA socket for the phase error voltage and provides access to the DC power socket. you will need to use an oscilloscope and a frequency counter. The input of the scope should be connected to CON4 on the rear panel of the frequency reference, where it will be able to monitor the PLL’s phase error pulses (inverted). By contrast, the counter’s input should be connected to CON1 on the front panel, where it can measure the 10MHz output signal. Before you start the setting up, see what frequency reading you are getting on the counter. It should already be quite close to 10.000000MHz, although the exact reading will depend on the calibration of the counter’s own timebase. Now look at the pulse waveform on the scope. What you should see is a negative-going rectangular pulse of 5V peak-to-peak, with a width somewhere between 0ms and 20ms. It may not be fixed in width, though – in fact, if the siliconchip.com.au PLL isn’t in lock as yet, it may be cyclically varying up or down in width within the 0-20ms range. At this stage, try adjusting trimcap VC2, which you’ll find just to the front right of the mini oven. Adjust it using a small insulated alignment tool and change its setting by only a very small amount in one direction or the other. As you do, watch the pulse waveform on the scope. If it was cycling back and forth in width, this cycling will slow down if you’re adjusting the trimmer capacitor in the right direction. Conversely, if it speeds up, turn VC2 back the other way until it does slow down. If it wasn’t cycling to begin with but does so when you adjust VC2, the same applies – turn it back the other way. The objective is to carefully adjust VC2 until the error pulse width stops cycling and remains fairly steady at a width of about 10ms. This setting corresponds to the PLL being locked close to the centre of its lock range. By the way, don’t be worried if the pulse width still varies up and down randomly in steps of 100ns (0.1ms). This is normal and is due to propagation jitter on the GPS signals, noise, dither in the PLL as a result of drift in the “about-10MHz” clock oscillator, and so on. Once you have achieved this stable pulse setting, check the reading on the frequency counter. It should now be reading very close to 10.000000MHz. If you get a reading very close to this, any error you see is almost certainly due to the calibration of the counter’s timebase. The only proviso here is if the counter reading is stable but very close to a frequency that’s 200Hz away from 10.000000MHz (ie, 9.999800MHz or April 2007  47 Fig.12: these full-size artworks can be copied and used to make the front and rear panels, or you can download the relevant file from the SILICON CHIP website and print it out on a colour printer. 10.000200MHz). In this case, it means that the PLL is locking quite nicely but to one of those other frequencies. So if you do get a reading very close to these “200Hz-away” frequencies, you’ll need to try adjusting VC2 again until the PLL locks at the correct frequency. If you can’t achieve this by adjusting VC2, you will have to replace the 4.7pF NPO capacitor located just behind VC2 with a lower or higher value – depending on which frequency your PLL had been locking at. For example, if it was locking at 9.000800MHz and VC2 couldn’t bring it up to 10.000000MHz, replace the 4.7pF capacitor with a 2.2pF capacitor. Alternatively, if it was locking at 10.000200MHz and VC2 couldn’t bring it down to 10.000000MHz, use a 6.8pF capacitor. When your scope shows a reasonably stable phase error pulse (with a width close to 10ms) and the counter 48  Silicon Chip displays a reading that’s very close to 10.000000MHz, your GPS-Based Frequency Reference should be set up and ready for use. LED1 (GPS FIX) and LED2 (PLL LOCK) should now both be glowing steadily, while LED3 should continue to blink reassuringly once per second. Similarly the LCD should normally show UTC time and GPS fix status (Fx1) on the top line and UTC date and PLL lock status (PLL: L) on the lower line. Additional information Additional GPS information is available on the LCD for about 20 seconds if you press one of the three frontpanel buttons. For example, pressing S1 (LOCATION) will display the exact latitude and longitude of your external GPS antenna, while pressing S2 (ANTENNA) will display the antenna’s height in metres above mean sea level plus the number of GPS satellites currently in view. Pressing S3 (SAT INFO) displays the identification number of the main four satellites in current view, plus the signal-to-noise ratio of their signals in dB – giving you a good idea of the current GPS “fix” quality. If your LCD readout isn’t very clear, try adjusting its contrast control pot using a small screwdriver through the hole in the lower centre of the front panel. This should give you an easyto-read display. Normally, you shouldn’t need to initialise the GPS receiver module using switch S4 (accessible via the second small hole in the front panel). However, by all means try doing this if you are unable to set up your frequency reference as described above. At the very most, this initialising should only be necessary once, because the GPS module normally saves its configuration data in non-volatile flash memory, where it’s read whenSC ever the power is applied. siliconchip.com.au 675+ NEW PRODUCTS Oscillating Blue 2 Line Message Display Kit of the Month Jacobs Ladder High Voltage Display Kit Mk II OBD II LCD Scan Tool If you have a late model car, it will probably have an OBD (On-Board Diagnostics) connector. If it was manufactured after 1996, it will support the OBD II protocols. This OBD II Scan Tool supports the CAN (Controller Area Network) protocol and can be used to diagnose prior to repair and to verify a repair after service. Cat. QP-2294 00 $ 129. Can be used to check the VIN number on late model cars! 3 Watt 38 Channel UHF CB Radio with Scrambler Up to 10km transmission range. Maximum output is 3 watts with 1W battery saver mode. All 38 legal channels are utilised as well as CTCSS sub channel calling, automatic muting, and scrambling. Supplied with a high gain (168mm) antenna. SMA connector allows the use of external antennas. See our full range of Cat. DC-1060 CB radios 00 $ in-store... Refer: Silicon Chip April 2007 With this kit and the purchase of a 12V VN Commodore ignition coil (available from auto stores and parts recyclers), create an awesome rising ladder of noisy sparks that emit the recognizable smell of Ozone. This improved circuit is suited to modern high power ignition coils and will deliver a spectacular visual display that appears dangerous as indeed it is. Kit includes PCB, pre-cut wire and all electronic components. • 12V automotive ignition coil not included • 12V car battery, 7Ah SLA or Cat. KC-5445 95 $ >5Amp DC power supply required 39. Recharge your cordless drill on a building site or your rechargeable RC models when you don't have mains power or a generator. 169. Quad Processor with 2 CMOS Colour Cameras & Remote Control Add a monitor and you have a complete surveillance system. With 2 colour IR cameras, this processor turns any standard TV or monitor into a mulitplexer. It can display a single camera view, or combinations of different camera views including one or two picture-in-picture, or Cat. QV-3095 00 $ automatic sequencing. 349. FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 69. Solar Charger & Power Bank Charge your phone, MP3 player and other digital devices wherever you are. The solar charger can be charged either by the sun, USB port or mains power. Depending on your method, charging will be ready in less than 12 hrs. • Li-ion rechargeable battery Cat. MB-3588 • Output voltage/current 95 $ 5.5V/500mA • Suits most phone types Motorola, Nokia, Samsung, Sony Ericsson, Siemens • Folded size: 120(L) x 17(W) x 62(H)mm Multi-Function Clock with Dual Projector • Automatic battery voltage detection • Manual charge current adjustment • Discharge button Cat. MB-3630 • LED charge status indication 95 $ • Reverse polarity, short-circuit 59. and overload protection • Includes 900mm cigarette lighter lead, 1800mm extension lead with alligator clips, 1.8m battery charging lead with 2 pin adaptor, 2 pin Utilux type connector for RC battery packs and a 2 pin lead with alligator clips NEW STORE IPSWICH QLD Opening this Month Phone (07) 3282 5800 160 Brisbane Road BERGIN ST 19. Cat. XC-0197 95 $ 69. 12V Ni-Cd/Ni-MH Charger Countdown Timer Use it for projects, parking, exercising or studying. It's water resistant, has a memory setting for frequently used values and the buzzer alerts you to when your time is up. • Countdown range 99 hours 99 minutes 99 seconds Cat. XC-0271 • Batteries included 95 $ • 88(W) x 130(H) x 22(D)mm This ultra modern message display clock uses a fast oscillating arm with 16 LEDs to make messages and clock functions appear to be floating in mid-air. You can program 5 messages with a total of 400 characters and have them appear on 5 different dates. • 200(W) x 200(H) x 70(D)mm • Plugpack included 19. HDMI Four Channel HDTV Input Selector This four input HDMI selector routes HD video and audio signals from the selected input to the HDMI output. The switcher also supports optical and coaxial audio inputs which are switched in unison with the HDMI . Cat. AC-1694 00 $ 199. Shopping Centre Better. More Technical INTERNET> www.jaycar.com.au Projects the time and the temperature on your wall or ceiling. The LCD constantly displays time, temperature, day and date while the alarm and snooze option finish off this neat little unit. • 140(L) x 34(W) x 90(H)mm Cat. XC-0219 95 $ • Requires 2 x AA batteries (not inc) or 3V DC adaptor (not included) 1 2.4GHz Wireless Audio & Video Sender SAVE $10 Watch cable TV all over the house. This audio video sender is even more compact and features 4 frequency channels complete with phase-locked-loop (PLL) technology to prevent signal drift and provide assured picture and sound quality. Pack includes a transmitter, receiver, AV leads, power supplies and instruction manual. • Additional receivers sold Was $69.95 separately AR-1843 $39.95 Cat. AR-1842 • Also available with IR remote 95 $ control extender AR-1844 $69.95 59. MP3 Player to Cassette Adaptor Plug in your media card with your music files, load it into the cassette deck in your car stereo and control the music with the remote unit - it provides track selection, volume control and a choice of five EQ settings. You can also plug in your head-phones and use it as a stand-alone MP3 player or connect to your PC. • Built-in 3.7V 250mAh battery Cat. AR-1764 • Supports SD, mini SD & MMC 95 $ cards 69. Car Amplifier 4 x 100WRMS Power output exceeds 100WRMS power per channel or 300WRMS in bridged mode at 4 ohms, making it ideal for a one amplifier system powering both full range speakers and a subwoofer. • 4 x 130WRMS <at> 4 ohms • 4 x 190WRMS <at> 2 ohms • 2 x 380WRMS <at> 4 ohms NEW FOR ‘07 Diversity Type Microphones Wireless Microphone UHF Dual Channel Includes Two Microphones This wireless microphone system features two separate channels, one for each mic. Output is either via separate balanced XLR socket, one for each channel, or via an unbalanced line with the two channels mixed. The system includes 2 microphones & batteries, receiver unit, 14VDC plugpack Cat. AM-4078 and 1 metre 6.5mm mono plug 00 $ to 6.5mm mono plug lead. 199. Wireless Microphone PLL UHF 32 Channel Diversity Receiver Cat. AA-0426 95 $ 299. Kevlar Coaxial Speakers This range of coaxial speakers offer high performance and great looks. They have a large super tweeter and their Kevlar cones take them into a realm of their own. 4" Kevlar - 2 Way CS-2320 $99.95 • 40WRMS • 86.5dB sensitivity 5" Kevlar Coaxials CS-2322 $109.95 • 50WRMS power • 89.5dB sensitivity 6.5" Kevlar Coaxials CS-2324 $119.95 • 75WRMS power handling • 91dB sensitivity 6" x 9" Kevlar Coaxial CS-2328 $139.95 • 80WRMS power • 93.5dB sensitivity Suitable for professional and stage use, this UHF wireless microphone system features 16 user - selectable channels on each microphone input to provide interference-free transmission. It also has phase locked loop (PLL) Cat. AM-4079 00 $ circuitry for frequency stability. Shortwave AM, FM, PLL Receiver PLL (phase locked loop) enables a radio to 'lock on' to a signal with great precision. A PLL shortwave front end locks on to that distant station and sucks it in. It features 9 presettable stations, a cool blue LED backlight, auto scan, full clock functions, headphone output jack and LED stereo indicator. • Power: External supply: 240VAC or 4 x D batteries (not included) - use SB-2418 Pkt 2 $4.75) • Size: 180(H) x Cat. AR-1746 $ 95 300(W) x 85(D)mm 99. MPEG-4 Media Player with Remote Control Boasting composite, S-Video, component and RGB video output with stereo and digital (SPDIF) audio output, it is compatible with almost any home theatre system. With up to 500GB of hard drive storage (IDE HDD not supplied), you can keep a large library of movies and music on the device to entertain for days. PC connection is made easy with the USB 2.0 interface and supplied USB cable. The unit features a cool blue LCD and backlit control panel and is supplied with a slim line remote control that allows for full playback Cat. XC-4866 functions, zoom and slideshow 00 $ control. The included stand allows for vertical mounting. 2 Better. More Technical Suitable for both analogue and digital free-to-air TV reception, this distribution amplifier is suitable for MATV applications. Housed in a fully screened diecast aluminium case, it features single or combined VHF/UHF inputs, separate VHF/UHF gain controls and -30dB test point. Mounting bracket and 12V plugpack included. Cat. LT-3288 95 $ 47. 2 x 100WRMS Stereo Amplifier with Remote Control A no-nonsense stereo amplifier that will form the heart of an impressive entertainment system. Rated at a generous 100WRMS per channel, this two-channel amplifier features a microphone input and quality screwdown speaker Cat. AA-0470 terminals. 00 $ 199. Includes Two Mics 399. See our full range of award winning amplifiers in our catalogue Kingray VHF/UHF Distribution Amplifier' 199. Composite Video to VGA Converter This neat device converts all region video signals into a noninterlaced VGA signal for monitors. With features such as, an on screen display and a SAVE slim line remote control, this converter $10 box is user friendly and easily connected to your PC, video source & video game Cat. XC-4872 consoles without any $ 95 Was $99.95 software installation. 89. Amplified Stereo Speakers 3 Wa y - 5 0 WR M S Each speaker tower consists of a screened 8.5" subwoofer, 3.5" mid range speaker and 1.5" tweeter in a ported, magnetically screened enclosure. The integrated amplifier makes for plug and play and features two microphone inputs with volume control, treble, bass and master volume control, an echo adjustment tuning knob and an independent power switch. Sold as a pair. • Output power: 2 x 25WRMS Cat. AR-1898 • 630(H) x 295(W) x 160(D)mm 95 $ • 240VAC operated 149. FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 INTERNET> www.jaycar.com.au 2 Channel USB Oscilloscope At last! A genuinely affordable computer connect oscilloscope. Using the Plug 'n Play USB technology and providing full optical isolation from the computer, this oscilloscope is easy to setup and use, as well as providing protection for the computer. The software (again developed in Europe) is a fully featured chart recorder, function generator, logic generator, logic analyser, and spectrum analyser all in one easy to Cat. QC-1930 use package. See website for 00 $ specifications. 299. 29. 400A Stainless Steel Battery Clamps This pair of heavy-duty battery clamps are ideal for making up jumper leads and for use with our inverters. All metal parts are made from 316 marine grade stainless steel, so they can be taken and used anywhere without the risk of corrosion. Cat. HM-3086 95 $ 19. Use this remote in conjunction with any of the below receivers and control up to 4 devices, it has a Cat. MS-6134 range of 50m (approx). 95 $ 24. Receivers to Suit These modules work with remote control unit MS-6134 to control devices. 240VAC: Switches incandescent lights or other 240VAC mains Cat. MS-6138 appliances. 95 $ 6. 29. 12V:Rated for 12V AC or DC. Cat. MS-6139 95 $ 29. Weatherproof Receiver 240V Similar to MS-6139, except housed in a weatherproof IP44 rated enclosure and rated for 6A at 240V. Operates on Cat. MS-6136 95 $ 433.92MHz in conjunction with MS-6134. IP64 Electrical Tester Merit Plugs and Sockets are the new standard in automotive power, replacing the old 12V cigarette lighter sockets. They have been used in some European bikes and cars for several years and are ideal when size and reliability of connection are important. Spring Flip Cover Socket PS-2092 Plug PP-2090 Plug with Cigarette Lighter Adaptor PP-2094 In-line Socket with Cover PS-2096 Improved Model for 2007 $8.95 $4.95 $5.50 $5.95 Non-Contact AC Voltage Tester with Torch 79. FOR INFORMATION AND ORDERING INTERNET> www.jaycar.com.au Was $39.95 Cat. TS-1660 $ 95 29. Low Cost Gas Soldering Iron This butane gas soldering iron features adjustable tip temperature and a foldout stand. Remove the soldering tip and you have a flame torch. Improved Model for 2007 Cat. TS-1111 95 $ 19. IP67 Rated USB Connectors for Harsh Environments IP67 Rated D-Sub Connectors for Harsh Environments Dwell Tacho DMM 39. SAVE $10 Industrial USB connectors encased in a robust housing with an IP67 waterproof seal. A Female PS-0782 $16.95 A Male Lead PP-0784 $13.95 A Female Lead PS-0786 $13.95 CAP PP-0788 $8.95 39. Designed with DIY car enthusiast in mind, this unit has standard meter functions and features a 3.5 digit LCD with auto zero adjustment, low battery warning and auto power off. Includes dwell angle and RPM (x1, x10) for 4, 5, 6 and 8 cylinder engines. Probes, holster and battery included. Cat. QM-1440 95 $ Was $49.95 19. Ideal for brazing, silver soldering, jewellery work, heat shrinking, and a whole lot more. It has a 1300°C adjustable flame and includes a stand. • Dimensions 150(H), base 69 x 69mm The ability to analyse and store information on your home or notebook computer makes this meter ideal for laboratory or fieldwork. Cat. QM-1538 Was SAVE 95 $ $49.95 $10 This clever device will allow you to use an ordinary IDE or SATA disk drive on a USB-2 interface. The adaptor can be powered from the existing computer power supply or from the supplied mains adaptor. The adaptor has plug and play support for Windows ME, 2000, and XP. • Win98 supported via downloaded Cat. XC-4833 software 95 $ • Interface cables included Cat. TD-2081 95 $ Piezo Ignition Butane Gas Torch Merit Plugs and Sockets Auto Range DMM USB to IDE and SATA Hard Drive Adaptor This carbon composite digital caliper is ideal for general use and situations where the cost of our precision stainless steel tool isn't justified. The digital display is calibrated in imperial and metric units with a corresponding vernier scale etched onto the caliper slide. Excellent value for money. SUPER PRICE! 17. 49. Budget 150mm Digital Vernier Calipers 39. About the size of a marking pen, this non-contact tester detects AC voltages from 100 - 600V. It can be used for detecting live Cat. QP-2271 mains in outlets, powerboards or 95 $ insulated wiring. It also has an LED torch and a handy pocket clip. This unit will indicate the nearest voltage up to 690V AC and DC with polarity indication. It will also check for low impedance, continuity, do a single pole phase test and show rotary field indication. An LED light is included for use in poor light and the probes are IP64 rated. • Requires 2 x AAA batteries (included) • Voltage test works Cat. QP-2286 without batteries 95 $ TELEPHONE> 1800 022 888 Get the hole spacing for your resistors and diodes perfect every time. This handy forming tool provides uniform hole spacing from 10 to 38mm. Suitable for production assembly, education and training. The tool is double sided with one side for use with DO47 outline diodes (eg 1N914) and 1W zener diodes; the other side being suitable for 1/5W resistors, DO41 outline Cat. TH-1810 diodes (eg 1N4004). An incredibly 95 $ handy tool! Remote Control For RF Devices 44 Piece 12 Volt Grinder Kit SAVE Attachments include a $5 6-piece diamond burr set, various shaped grinding stones, a sanding drum set, buffing wheels, etc. and is See all our Drills housed in an attractive in our latest aluminium case with a Catalogue transparent cover. The drill is 12VDC operated and is fitted with a Was $34.95 1.2m cord that is terminated with a Cat. TD-2450 DC power plug. A 240VAC mains $ 95 adaptor is included. Component Lead Forming Tool Control Appliances with the Push of a Button Robust and housed in an industrial case they are waterproof and are rated at 5A. SAVE $10 25 pin male 9 pin male 25 pin female 9 pin female PP-1216 PP-1226 PS-1210 PP-1220 Better. More Technical $13.95 $15.95 $13.95 $15.95 3 Colour CCD Camera - Pro Style Delivers a flickerless digital colour image via a Sony CCD image sensor. Suitable for high-end surveillance installations, the flickerless ability makes it ideal for See our applications that demand a high catalogue for quality, stable, no compromise lenses to suit picture. Also features a high sensitivity microphone plus auto iris lens controller. Cat. QC-3309 $ 00 149. Infrared Security Spotlight The long-range beam has a range of 30 metres and will switch on automatically as darkness falls or ordinary lights are turned off. Higher power spotlight also available Cat. QC-3652 QC-3655 $199 $ 95 79. Aspherical Vari-focal Lens for Day / Night Cameras This high-grade aspherical lens is constructed from ED (extra-low dispersion) glass elements for greatly enhanced low light Cat. QC-3353 performance and 00 $ improved picture quality. 149. Solar Power Spotlights They have bright LEDs and a built-in solar panel to charge the internal batteries during the day. Mounting hardward supplied 11 LED Solar Powered Garden Spotlight • 11 LEDs • 10 hours Illumination • Automatic daylight shut-off Cat. SL-2714 95 $ 49. Economy Car Alarm The alarm SAVE has many $10 of the advanced features you would normally only expect to find on more Was $99.00 expensive systems. We have called this our budget alarm, but Cat. LA-9000 00 $ it is still feature-packed and will provide thorough protection for your precious vehicle. 89. 2.4GHz Wireless Digital CCD Colour Camera This camera has a 420TV line resolution, 27 IR LEDs for night viewing and includes a mounting bracket and power supply. Use these cameras with any of our 2.4GHz wireless receivers. Cat. QC-3564 Under eave mounting $ 00 recommended. Colour Video Doorphone with 4 Camera Inputs With this system up to 4 standard CCTV cameras can be utilised without the need for a second monitor. The supplied external CCD camera is cased in a tamper proof enclosure and features IR illumination for viewing in poor light conditions. The internal monitor has a contemporary black housing and a crystal clear 5" colour LCD which can also accommodate a door strike Cat. QC-3614 release (LA-5078 $44.95). 00 $ 599. Child or Pet Door Annunciator 249. RF Bug Detector Detect radio transmissions from bugging equipment operating between 50MHz to 3,000MHz (3GHz). It will alert you to them via a three stage LED indicator and beeping alarm. Requires 2 x AA batteries (not included) Cat. QC-3430 • 55(W) x 92(H) x 25(D)mm $ 95 Was $179.95 SAVE $10 169. 2 Channel Wireless Intercom This intercom plugs into your power point and sends audio signals to another room. It has a monitor function and additional units can be added for a multi-point intercom system. Cat. AI-5500 SAVE • Sold as a pair $10 $ 95 Was $74.95 Now you don't need eyes in the back of your head! Simply mount at any entrance and the alarm will sound for 30 seconds every time your child or pet passes through. You can know exactly where your little ones are without having the alarm go off every time an adult passes through as the sensors discriminate between adults, toddlers or pets. • Batteries not included • Unit measures 1 metre when assembled Cat. LA-5166 95 $ 49. 64. See our full range in our Catalogue 30 LED Solar Powered Garden Spotlight NEW FOR 2007 - Record & Capture Packages Multiplexing DVR with Weatherproof Colour IR Cameras DVR Camera Kit with Dome and IP56 Cameras View and record 4 video channels at once and network up to seven DVR units together. The 4 colour cameras have IR illuminators for night use and are weatherproof. Comes fitted with a 250GB HDD, but supports up to 400GB hard drives. The cameras are all powered from the DVR. The pack includes 4 colour IR cameras, DVR with 250GB HDD, power supply Cat. QV-3070 SAVE & cables. 00 $ The DVR is fitted with a 250GB hard drive, can accommodate up to 4 cameras with power derived from the DVR and will allow you to record and view up to 4 cameras simultaneously. Package includes the DVR with a dome and outdoor IR camera with bracket, mounting hardware, power supply, 14m camera connect cable, Cat. QV-3085 software, USB interface 00 $ lead and user manual. • 30 LEDs • 10 hrs Illumination Cat. SL-2716 • Automatic daylight $ 00 shut-off 129. Solar Powered Garage LED Light Ideal for garages, gazebos and greenhouses, the 360° adjustable solar panel will allow for custom positioning. It's waterproof, features a cord-switch to operate, and is simple to install. Pack includes solar panel and mounting bracket, 2.4m cable & rechargeable enclosed Ni-Cd battery. Cat. SL-2715 95 $ 39. 4 Was $1199 Better. More Technical $100 1099. 999. FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 INTERNET> www.jaycar.com.au Solar Powered 6 LED Torch The solar panel charges the internal battery keeping the 6 LEDs ready to use at any moment and will last for several hours. Ideal for camping or bushwalking keep it exposed to the sun during the day for a light filled night. • Solar panel measures 117(L) x 38(H)mm • Torch measures 153(L) x 56(H) x Cat. ST-3087 40(W)mm 95 $ 19. Solar Charge LED Keyring Torch This is an excellent keyring torch with a single, super-bright LED that produces more than enough light to find the key hole or even find you way up the driveway on a dark night. Cat. ST-3389 95 $ 9. Remote Controlled Solar Fountain The 350mm platform accommodates a150mm2 1.3 watt solar panel that charges a Ni-Cd battery pack. It can pump up to 500mm high and will run continuously for 45mins on a full charge. It features 2 white LEDS for effect at night and comes complete with a remote control to operate it from a distance of 15m. The lily shaped fountain is supplied with 2 spare pumps, remote control and batteries. The unit has a 1m 'out' or fridge sensor and will trigger an alarm when the fridge, freezer or incubator rises or falls below set temperatures. It has an 'in' temperature range of -10 to +50°C and an 'out' range of -50 to +70°C. Includes magnet for mounting Cat. QM-7209 and AAA battery. 95 $ • 67(W) x 39(H) x 15(D)mm 16. Rechargeable LED Work Light It has a strong magnetic mount, twisting handle and hanging hook. This robust unit has two lighting options, 1W LED for use as a torch, 30 LEDs for use as a Was $39.95 lamp and is supplied with Cat. ST-3024 SAVE mains and car chargers. 95 $ $4 • 360 x 45 x 55mm 35. Automotive Interior LED Up-grade Kit Its luminance is 2 to 3 times stronger and the LED lamp uses one-eighth to one-tenth of power as traditional light bulbs and can continuously light up for over 10,000 hours. Easy to follow Cat. ZD-0485 95 $ installation instructions are included. 29. With the same technology used in new luxury cars no other torch is capable More HID of such intensity Torches in-store! in such a small package. This 24W rechargeable torch has a burn time of over 100 minutes and is housed in a sturdy weatherproof aluminium casing. Supplied with car and mains Cat. ST-3362 chargers, lanyard and filters for 00 $ varying applications. 499. Keyring with Twin LED Torch and Laser Pointer The sturdy keychain has two high intensity LEDs and a laser pointer. Very handy and great for the worksite, lectures and presentations. • Size: 33(W) x 72(H) x 8(D)mm Cat. ST-3109 95 $ 14. Stainless Steel Travel Mug with Built-in Heater Has a built-in, thermostatically controlled heater and will maintain one of four selectable preset temperature settings ranging from room temp to very hot. Heats from 10 to 70°C • Includes 1.5m detachable 12V power lead with Cat. GH-1301 cigarette lighter 95 $ plug 29. We Have The Best Range of USB Gadgets USB Missile Launcher USB Retro Fan Cat. YH-5452 95 $ 69. New for '07 - Travel Gadgets Rechargeable Shaving Kit Stay groomed while you're travelling with this rechargeable shaver kit. Ultra-thin foil and floating cutter for a close Cat. GH-1516 shave. 95 $ • Mains charger included 29. Travel Shaver The razor is housed in a sturdy case that is easily removed to reveal the razor and a compact illuminated mirror. Great for planes, trains, and automobiles. • Cleaning brush and Cat. GH-1515 batteries included 95 $ • 62(W) x 103(H) x 25(D)mm 19. Rechargeable Travel Hair Straightener A rechargeable hair straightener, ideal for travel. Provides even heat and turns off automatically when folded into the holder. Cat. GH-1490 95 $ 29. Simply plug it into your computer's USB port to feel the gentle breeze. The 3 soft foam blades are encased in a metal cover and with four speeds you can control the airflow. • Fixed or oscillating modes • Base measures 100mm (Dia.) • Fan casing Cat. GH-1068 measures 95 $ 150mm (Dia.) Having a slow day at work or are there too many people bothering you? Missiles locked and loaded! Ready! Aim! Fire! Cat. GE-4072 • Pans 180° & 95 $ tilts 45° • Connects to PC via USB port • Realistic sound effects 49. 19. Solar Powered Calculator with 3 Port USB Hub Cool Mist Humidifier To help reduce the spreading of allergens and skin dehydration this elegant humidifier generates cool mist via safe, quiet ultrasonic waves. Add a few drops of essential oil to give a nice scent to the entire room. • Automatic shut-off Cat. YH-5462 95 $ • 60ml water tank capacity • Mains power supply included • Measures 90(Dia.) x 210(H)mm It features a standard calculator and connects to your laptop or workstation for use as an external numerical keypad. It also is a passive 3 port USB hub. Cat. XC-4846 95 $ 49. 39. All-In-One Memory Card Reader Exchange data between your PC and all the flash memory cards currently on the market. One simple solution, no need for different card readers for different electronic devices. FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 24W HID Rechargeable Torch Digital Thermometer for Fridge or Freezer INTERNET> www.jaycar.com.au Cat. XC-4856 95 $ 19. USB Pencil Sharpener Just plug this little beauty into your computer’s USB port, put the pencil into the hole for sharpening and voila! - the perfect point! Great for office & home use. • Flashing LED while in use • Batteries not included • Unit measures 75(L) x 65(W) Cat. GG-2269 x 72(H)mm 95 $ Better. More Technical 9. 5 5VDC 6A Switchmode Power Supply INVERTERS 50-watt power supply with regulated output. The output cable is terminated Cat. MP-3238 to a common 95 $ 2.5mm DC plug 12VDC to 230VAC Inverters Inverters are available from 150W to a massive 1500W. All have a LED power indicator, electrical isolation between the battery and secondary voltages for safety, and the higher power inverters feature fan assisted cooling. 24V inverters also available. 59. 13.8VDC 8.5A Switchmode Power Supply Suitable for high-current applications. Output is to a cigarette lighter socket. • Fan cooled. • 130(L) x 92(W) x 65(H)mm 1000VA Uninterruptible Power Supply 39. No more wasted AC outlets! Light, sleek and compact, these new switchmode regulated AC adaptors fit snugly side by side on a powerboard and feature high efficiency circuitry, a built-in EMI filter, short circuit protection, over current protection and thermal shutdown capability. MP-3144 5VDC 1Amp MP-3145 6VDC 800mA MP-3146 9VDC 550mA MP-3147 12VDC 500mA All models $17.95 each 65W BP Solar Panel If you are looking for a long life, premium solar panel with a 10 year warranty, you can't go past this latest addition to our solar panel range. The panel has an Cat. ZM-9067 00 $ array of 36 polycrystalline cells and will charge a 12V battery in virtually any climate. The modules are very strong See our full range and are designed to of Solar equipment in our 2007 withstand the impact of a Catalogue 25mm hail stone traveling at terminal velocity MI-5102 Cat No MI-5102 MI-5104 MI-5106 MI-5108 MI-5110 MI-5112 MI-5114 Power 150 Watt 300 Watt 400 Watt 600 Watt 800 Watt 1000 Watt 1500 Watt MI-5110 Was $48.95 $99.95 $159.95 $249.95 $299.95 $399.95 $599.95 Now $43.95 $79.95 $139.95 $229.95 $269.95 $359.95 $529.95 An extremely comprehensive coverage of the subject of photovoltaic devices. It covers everything from the characteristics of sunlight to the detailed operation of solar cells and specific purpose photovoltaic applications. Quite technical and detailed, this book is aimed at an engineering level understanding. Soft cover 313 pages with illustrations. 49. 12V 5A Battery Charging Regulator for Solar Panels Designed for efficiently charging 12V batteries using solar cells rated up to 5-amps. It is easy to wire-up, prevents battery discharge during low sunlight and indicates charging and full battery conditions using a yellow and green 3mm LED respectively. Cat. AA-0348 Ideal for charging 12V SLA 95 $ batteries and solar panels up to 60 watts. 29. 6 Designed to fit into your car's drink holder, this can-sized inverter alleviates the need for permanent mounting. Featuring a 150W output, this inverter is deceptively small Cat. MI-5121 but still has 95 $ plenty of grunt. 49. Rugged 16 Amp 12 Volt Car Battery Charger This fully automatic, switchmode, car battery charger utilises a four stage rapid charge design to optimise the life and performance of your car or GEL battery. Includes a top mounted carry handle Cat. MB-3620 and cable storage for the battery $ 00 leads and clamps. • Dimensions: 270(W) x 220(H) x 120(D)mm Charge that digital device, iPod®, PSP® or mobile phone anytime, anywhere. The pack is charged via USB and includes 7 output adaptor plugs to suit the most popular digital devices. • See website or in-store for compatible digital devices. 169. iPodTM not included Cat. MB-3300 95 $ 69. Mains Timer with LCD A switching contact rated at 30 amps! Featuring 8 on/off programmes across 16 combinations of days or blocks of days for unrivalled flexibility. The unit also has a one-touch 'summertime' button to convert to daylight saving time. Great for hydroponics, Was $29.95 security lighting Cat. MS-6110 and much more $ 95 23. Cat. BE-1533 95 $ Save $5.00 $20.00 $20.00 $20.00 $30.00 $40.00 $70.00 Battery Back-up Pack 599. Applied Photovoltaics 2nd Edition 199. Can Sized 150W 12VDC to 230VAC Inverter Cat. MP-3470 95 $ Ultra-Slim Switchmode Power Supplies Protect valuable computer systems from power failures, preventing data loss or corruption. The included software can be set up to save your data and close down your computer automatically if the power fails. The UPS is supplied with two 12V 7Ah Cat. MP-5202 SLA batteries, USB interface cable 00 $ and software. • 600VA UPS also available MP-5200 It has a built-in 17Ah battery to jump-start your car, a cigarette lighter outlet for use as a auxiliary power source test button with voltmeter and a work light. Recharging this power pack is via the supplied plugpack. • Extra long 850mm heavy-duty cables Cat. MB-3596 • 330(W) x 380(H) x 100(D)mm 95 $ 79. SAVE $6 4 Outlet Powerboard with 5 Metre Extension Cord This 4 outlet powerboard features an integrated cable reel which stores its 5m extension cord. Featuring surge protection and an on-board illuminated power switch it is portable, easy to store and can be rolled out at a moments notice. High End Jump Starter Power Pack with Light Cat. MS-4042 $ 95 29. Four Pack Ni-MH Rechargeable Batteries Modern digital devices require high current high drain performance cells. These high capacity batteries will provide the best in portable power. SB-1738 2500mAh AA $19.50 SB-1735 2400mAh AA $15.95 SB-1737 2000mAh AA $13.95 SB-1739 900mAh AAA $11.95 Solar Wireless Bell Box Siren & Strobe This siren/strobe combination includes an integrated solar panel to charge a 6V SLA battery and uses wireless RF technology to communicate with an ordinary alarm panel. Wireless receiver included. SLA battery available separately. Better. More Technical Cat. LA-5307 00 $ 199. FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 INTERNET> www.jaycar.com.au 7" Four Input In-Car TFT Colour Video Monitor This stylish monitor is an excellent choice for in-car applications from DVDs to game consoles or reversing cameras and GPS navigation systems etc. Can also be used with multiple cameras on larger vehicle and trucks. Supplied complete with mounting bracket, input and power leads, and infrared See our full range remote of In-car Monitors control. Cat. QM-3772 in our 2007 00 $ Catalogue 299. USB Bluetooth Hands-Free Stereo Earphones SAVE $50 This affordable computer connect weather station monitors indoor and outdoor temperature and humidity, rainfall, barometric pressure, wind speed & direction, Cat. XC-0291 wind chill, & dew point. 00 $ Was $399.00 349. Computer Connect Weather Station with Touch Screen Weather Station with Wireless Sensors and Doorbell Twin-Pack 38 Channel UHF Mini CB Radios The system consists of two wireless outdoor sensors, a wireless doorbell and an indoor receiver. The device will measure indoor and two outdoor temperatures, humidity, barometric change as well as the respective maximum/ minimum temperatures and humidity. The indoor receiver has a large LCD, which shows full clock and calendar functions, humidity, temperature readings, barometric change as well as an audio and visual annunciation when the doorbell is pressed. It also can be either desk Cat. XC-0336 (stand supplied) or wall mounted. 95 $ See website for specifications This pack of 2 mini UHF CB communicators can keep you clearly in touch up to 3km. They feature electronic volume control, monitor functions and an integrated blue LED torch. • Requires 3 x AAA batteries (not included) Cat. DC-1005 95 $ pr 49. 6.6 Mega Pixel Digital Video Camera Don't miss recording any action with this 6.6 mega pixel DV cam that literally fits in the palm of your hand. Extend the memory with the SD/MMC card slot and it features a 1.5" colour rotatable TFT screen. Records video, sound and still photos. Also has a MP3 player and PC camera functions. • Requires 4 x AA batteries (not included) Cat. QC-3234 $ 00 279. Weather Station with Wireless RF Sensor Forecast the weather accurately and easily with this contemporary slim line weather station. The internal unit can be either wall or desk mounted and features a large LCD with full clock and calendar functions, dual in/out temperature readings, humidity, barometric pressure and weather trend. Supplied with the unit is an external transmitter to measure Cat. XC-0335 95 $ outdoor temperature, pressure and humidity. 49. 10 Million Candle Power Spotlight 449. 99. SAVE $20 Wireless Weather Station with Computer Interface This affordable computer connect weather station features a touch screen and graphing software. It automatically monitors indoor and SAVE outdoor temperature and $50 humidity, rainfall, barometric pressure, wind speed & Cat. XC-0292 direction, wind chill, & dew point. $ 00 Was $499.00 Listen to your iPod® or MP3 player without missing a call from your mobile phone. This tiny device will allow you to answer, hang up and swap between your music source and mobile handset as Cat. XC-4894 well as adjusting 95 $ the volume. Was $299 C omp u t e r I n t e rf a c e Wea t h e r S t a t i o n s 99. Wireless Brake Light for Motorcycle Helmets Built into a lightweight, flexible strip that attaches to the back of your helmet with strong double-sided tape, the light incorporates six high intensity red LEDs and is triggered by a tiny wireless transmitter wired to the brake light on the bike. Can be removed when necessary without damage. Batteries included Cat. ST-3186 • 195(W) x 30(H) x 15(D)mm 95 $ Note: Helmet not included. 49. 63 LED Work Light with Tripod Stand The ultimate battery powered portable work light available. It features an adjustable head that can be pointed up or down to direct the light where you want it. Every home and car should have one of these beauties. Cat. ST-3126 • Mains and car chargers included 95 $ • Size 100(W) x 300(H) x 120(D)mm Features a super powerful 100W halogen globe, a switch for dim lighting, and twin fluorescent globes for reading or as a work light • Replacement Globe: SL-3223 $12.95 • 12V SLA battery and chargers supplied SAVE Was $79.95 TELEPHONE> 1800 022 888 INTERNET> www.jaycar.com.au 69. 0.5W Luxeon LED Lantern Generating an output of 30 lumens this tiny lantern is the perfect answer to a power outage or during a car breakdown at night, For extended lighting, you can switch the lamp to a weaker intensity. Running off 4 x AA batteries it can last as long as 25 hours of continuous illumination. Measures 193(H) x 88(W) x 88(D)mm Cat. ST-3034 Was $29.95 $ 24.95 SAVE $5 Stainless Steel Flexible BBQ Lamp This outdoor light is made from rust-resistant stainless steel and is battery powered. It is fitted with 25mm clamping jaws and 480mm gooseneck so that it can be attached to whatever is handy, be it table, fence or BBQ. • Runs on 4 x AA batteries, available separately. Cat. SL-2806 95 $ 29. Economy Headtorches They have a fully adjustable head strap and are light, compact, and very efficient on batteries and will never require replacement globes. Two models available: ST3286: 12 White LEDs 4 selectable settings: 4 LEDs, 8 LEDs, 12 LEDs and strobe. • Requires: 3 x AAA batteries (not included) 17 White LEDs Cat. ST-3286 3 selectable settings: 4 LEDS, 95 $ 17 LEDs and strobe • Requires: 3 x AAA batteries Cat. ST-3287 (not included) 95 $ 49. FOR INFORMATION AND ORDERING Cat. ST-3308 95 $ $10 Better. More Technical 9. 14. 7 IR Remote Control Extender MKII Kit Improved Model Refer: for 2007 Silicon Chip October 2006 Operate your DVD player or digital decoder using its remote control from another room. It picks up the signal from the remote control and sends it via a 2-wire cable to an infrared LED located close to the device. This improved model features fast data transfer, capable of transmitting Foxtel digital remote control signals using the Pace 400 series decoder. Kit supplied with case, screen-printed front panel, PCB with overlay and all electronic components. Cat. KC-5432 • Requires 9 VDC 95 $ power use MP-3146 $19.95 & 2 wire cable 24. YOUR LOCAL JAYCAR STORE Freecall Orders: Ph 1800 022 888 NEW SOUTH WALES Albury Ph (02) 6021 6788 Alexandria Ph (02) 9699 4699 Bankstown Ph (02) 9709 2822 Blacktown Ph (02) 9678 9669 Bondi Junction Ph (02) 9369 3899 Brookvale Ph (02) 9905 4130 Campbelltown Ph (02) 4620 7155 Erina Ph (02) 4365 3433 Gore Hill Ph (02) 9439 4799 Hornsby Ph (02) 9476 6221 Newcastle Ph (02) 4965 3799 Parramatta Ph (02) 9683 3377 Penrith Ph (02) 4721 8337 Silverwater Ph (02) 9741 8557 Sydney City Ph (02) 9267 1614 Taren Point Ph (02) 9531 7033 Tweed Heads Ph (07) 5524 6566 Wollongong Ph (02) 4226 7089 VICTORIA Coburg Ph (03) 9384 1811 Frankston Ph (03) 9781 4100 Geelong Ph (03) 5221 5800 Melbourne Ph (03) 9663 2030 Ringwood Ph (03) 9870 9053 Springvale Ph (03) 9547 1022 Sunshine Ph (03) 9310 8066 QUEENSLAND Aspley Ph (07) 3863 0099 Ipswich Ph (07) 3282 5800 Mermaid Beach Ph (07) 5526 6722 Townsville Ph (07) 4772 5022 Underwood Ph (07) 3841 4888 Woolloongabba Ph (07) 3393 0777 AUSTRALIAN CAPITAL TERRITORY Belconnen Ph (02) 6253 5700 Fyshwick Ph (02) 6239 1801 TASMANIA Hobart Ph (03) 6272 9955 SOUTH AUSTRALIA Adelaide Ph (08) 8231 7355 Clovelly Park Ph (08) 8276 6901 WESTERN AUSTRALIA Maddington Ph (08) 9493 4300 Northbridge Ph (08) 9328 8252 NORTHERN TERRITORY Darwin Ph (08) 8948 4043 NEW ZEALAND Christchurch Ph (03) 379 1662 Dunedin Ph (03) 471 7934 Glenfield Ph (09) 444 4628 Hamilton Ph (07) 846 0177 Manukau Ph (09) 263 6241 Newmarket Ph (09) 377 6421 Wellington Ph (04) 801 9005 Freecall Orders Ph 0800 452 9227 8 Speedo Corrector MkII Kit Refer: Silicon Chip December 2006 When you modify your gearbox, diff ratio or change to a large circumference tyre, it may result in an inaccurate speedometer. This kit Improved Model alters the speedometer for 2007 signal up or down from 0% to 99% of the original signal. With this improved Cat. KC-5435 model, the input setup selection 95 $ can be automatically selected and it also features an LED indicator to show when the input signal is being received. Kit supplied with PCB with overlay and all electronic components. • Recommended box UB5 use HB-6013 $3.15 49. 50MHz Frequency Meter Mk 2 Ref: Silicon Chip February 2007 This compact, low cost 50MHz Frequency Meter is invaluable for servicing and diagnostics. This upgraded version, has a prescaler switch which changes the units from MHz to GHz, kHz to MHz and Hz to kHz, and has 10kHz rounding to enable RC modellers to measure more accurately. Other features include: Improved Model • 8 digit reading (LCD) • Prescaler switch for 2007 • Autoranging Hz, kHz or MHz • 3 resolution modes including 10kHz rounding, 0.1Hz up to 150Hz, 1Hz up to 16MHz & 10Hz up to 16MHz • Powered by 5 x AA batteries Cat. KC-5440 or DC plugpack Kit includes PCB with overlay, 95 $ enclosure, LCD & all components. 69. Car Air Conditioner Controller Kit Refer: Silicon Chip January 2007 This kit stops the air conditioner in your car from taking engine power under acceleration. It will allow the compressor to run with low throttle even when the cabin temperature setting has been reached and will automatically switch the compressor off at idle. It also features an override switch, an LED function indicator. Kit supplied with PCB with overlay and all electronic components. Fuel Cut Defeater Kit There are 16 projects in total, ranging from devices for remapping fuel curves, to nitrous controllers, and more! The book includes all instructions, components lists, color pictures, and circuit layouts. There are also chapters on engine management, advanced systems and DIY modifications. Over 150 pages! Cat. BS-5080 80 $ All the projects are available in kit form. 19. USB Experimenter's Interface Kit Interface your computer to the real world. There are five digital and two variable gain analogue inputs. Eight digital and two analogue outputs are available. Supplied with all components, silk screened PCB, assembly manual, and software. 69. Outstanding Educational Kits Digital Multimeter Kit Learn everything there is to know about component recognition and basic electronics with this comprehensive kit. From test leads to solder, everything you need for the construction of this meter is included. All you'll need is a soldering iron! • 67(W) x 123(H) x 25(D)mm Cat. KG-9250 95 $ 19. Cat. KC-5437 $ 95 39. Refer: Silicon Chip December 2006 Cordless drills are fantastic and cheap, but really the batteries in them don't last with the simple charger supplied. This controller turns the cheap charger into a contractor grade intelligent charger. Suits Cat. KC-5436 both Ni-Cd and Ni-MH cells. Kit includes 95 $ PCB with overlay, case, all electronic 39. components. Variable Boost Kit for Turbochargers Refer: Silicon Chip February 2007 It's a very simple circuit with only a few components to modify the factory boost levels. It works by Combine these intercepting the boost signal from the car's two kits to get the engine management computer and modifying best dollar per the duty cycle of the solenoid signal. Kit kilowatt performance supplied in short form with Cat. KC-5438 increase on the PCB and overlay, and all 95 $ market specified electronic components. 19. With more than 675 NEW PRODUCTS make sure you take time out to check through our latest catalogue Better. More Technical Cat. KV-3600 95 $ Kit Powertool Battery Charger Controller Refer: Silicon Chip February 2007 This cheap and simple kit enables you to eliminate this factory fuel cut and go beyond the typical 1517PSI factory boost limit. The kit simply intercepts the MAP sensor signal, and trims the signal voltage above 3.9V to avoid the ECU cutting the fuel supply to the engine. Kit includes PCB with overlay and all specified Cat. KC-5439 electronics components. 95 $ • Recommended box UB5 use HB-6013 $3.15 19. High Performance Electronic Projects for Cars Book FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 Don't forget all our products are available 24/7 online at www.jaycar.com.au Prices valid until April 30th 2007 INTERNET> www.jaycar.com.au SERVICEMAN'S LOG Sorting out customer A/V installations It’s not always obvious how you use modern equipment, particularly when there’s a menudriven remote control involved. More and more of our work involves sorting out customer installations but first, here’s a story about a rear-projection TV I recently encountered. Most repairs are either repetitive or have simple solutions, although they aren’t always as simple as they once were (thanks to the increasing complexity of modern sets). Obviously, I cannot tell you all the stories about blown fuses or easily-diagnosed transistor failures, as you would fall asleep. As a result, I try to keep to the stories that are interesting (hopefully) or have a twist in them. A good example of the latter was the rear-projection TV that came in with a colour purity problem. A purity error refers to a spurious colour patch and in CRT sets, you adjust the yoke in and out and rotate the purity ring magnets so that the screen is filled with only one colour, as selected on a pattern generator. Normally, you do this in turn for Red, Green, Blue and finally, White. However, before proceeding, you first Items Covered This Month • Philips 43PP9251/79 rear projection TV (A10 PTV 2.0 chassis) • • NEC FS8002 TV set Philips 32PW8806/79R TV set (MG2.1E chassis) • Sanyo CP32WF2-00 TV set (EB7-A chassis) • Sony KV-ES29M31 TV set (AG3 chassis) • Teac PLH4220 SD/4942 plasma set siliconchip.com.au make sure that the set is degaussed and is correctly aligned to the Earth’s magnetic field. It must also be well away from all other sources of magnetism. The rear projection set in question was a 2003 Philips 43PP9251/79 using an A10 PTV 2.0 chassis and it had a colour patch in the bottom righthand corner. But how could this happen? The set uses three dedicated CRTs (red, green and blue) and there is no purity adjustment as none is necessary. This set had obviously had a hard life and came in with a dreadful picture. The convergence was shot and the picture quality was dull, the blue and green colour saturation both being particularly poor. Two new convergence ICs fixed the convergence problem after which a vain attempt was made to adjust the G2 screen voltages before it was realised that the CRTs themselves were to blame. You couldn’t actually see the problem until you removed the screen and mirror and looked into each lens. The blue and green in particular had algae growing in them and the fluid had turned a murky yellow. Basically, there are two ways to change the fluid – the “hard way” and the “easy way”. The former is what Philips recommends and this involves removing each CRT, disassembling the whole thing and removing the complete lens assembly. You then fit new gaskets after cleaning the screen face, pour in the new fluid and then reassemble them before doing major realignment. The easy way is to raise the corners of the cabinet until the CRT you are working on is dead level. You then undo four inverted star screws (a 6mm spintight will do) and remove just the lens. During this process, it is absolutely essential to pack lots of rags tightly around the CRT face and underneath it to prevent any liquid spillage from dropping onto the PC boards below. Usually, when you remove the lens assembly, the rear lens remains stuck to the CRT gasket, with the lens dome submerged in the liquid. This is fine because you can then concentrate on removing this final lens swiftly and cleanly, without causing any fluid to overflow. Next, using a pipette or syringe, you remove the remainder of the liquid before using Windex to clean off the caked algae and dirt stuck on the CRT screen. You then pour the new liquid in using a funnel, being careful not to overfill as subsequently replacing the lens would then cause it to overflow. With patience and care, you can do this quite easily and the beauty of it is there is no realignment necessary. Of course, when I did it, things took a slightly different turn – for the worse, of course. First, the red gun lens April 2007  57 Serviceman’s Log – continued This resulted in the set refusing to start and setting off a protection circuit which left the Standby LED flashing. When the job was completed, the picture wasn’t too bad, even though there was a bit of screen phosphor burn on each of the CRTs. It’s not obvious decided to stick to the lens assembly rather than to the CRT, so the liquid overflowed and somehow managed to miss the rags and fall directly onto the new convergence ICs. That meant removing the board and cleaning it very carefully. However, it still managed to ruin a PNP transistor which switched the -30V rail to the IC, causing all sorts of weird blue convergence errors. When the lens was refitted, the fluid again overflowed but I managed to clean up the excess without incident this time. I was pretty confident that all was OK until confronted with a purity error. It took a while to realise what was happening. When the set is level (ie, in its normal operating position), each CRT gun is angled – particularly the red and blue guns. And although I thought they were full of liquid, a slight air bubble was in fact appearing on the edges of the red and blue gun lenses in the normal position. This time I turned the whole cabinet over and aligned it until the filler nuts were uppermost. That done, I removed the nuts in turn and filled them right up. This was not quite as simple as it sounds, as one gun (the blue one) was for some reason 180° different from the other two. Fortunately, when the job had been completed, the purity error had been eliminated. Finally, the greyscale needed aligning but I ran into problems at one stage when I got the A2 adjustment wrong. It’s not always obvious how you use a lot of modern equipment. For example, some TVs and DVD players have very complex menu systems. And if a language like Chinese or Korean is already selected, then how do you figure out how to change it back to English? Recently, I had a Sharp LCD TV where the customer was unable to select the DVD input. When I arrived at his house, he demonstrated the problem. He picked up the remote, switched the set on and then pressed the DVD button. He then pointed to the screen which clearly showed a “DVD” window in the middle. But then nothing else happened – certainly nothing in the way of video or sound was coming from the DVD. Well of course I had never seen this particular TV before so I started by making sure that all the connections were kosher, which they were. My client became a little disconcerted when I hadn’t discovered the problem in the two minutes I had been there and became even more concerned when I wanted to see the instruction book. Obviously I didn’t know anything if I had to consult a “map”! Frankly, I’m a great believer in the old adage that when all else fails, read the book. If that fails, you get a guide to the instruction book from the manufacturer! The disturbing thing about most instruction books – like remotes – is Issues Getting Dog-Eared? Keep your copies of SILICON CHIP safe with these handy binders REAL VALUE AT $13.95 PLUS P & P Available Aust, only. Price: $A13.95 plus $7 p&p per order (includes GST). Just fill in and mail the handy order form in this issue; or fax (02) 9939 2648; or call (02) 9939 3295 and quote your credit card number. 58  Silicon Chip siliconchip.com.au that they are physically small, with hundreds of pages and a really poor index. Eventually, however, the penny dropped. The remote control unit was a type that could be programmed for other items or accessories. It could be made to operate a VCR, an amplifier or, in this case, a DVD player. So despite its prominence on the front of the remote, the DVD button wasn’t the button to press. Instead, there was another button next to it with a symbol showing an arrow pointing into a TV screen. This was the button to use, as it sequentially controlled the AV inputs into the set. Selecting DVD with this produced the desired picture and sound. OK, so that was fairly obvious. The next one I had concerned a guy who had a large NEC FS8002 CRT TV and when ever he selected DVD, the picture was in black and white though the sound was OK. Now I had originally installed this set and knew that it was OK the last time I had seen it (about a year ago). Subsequently, I had to go into hospital for an operation – no, not a lobotomy – and during this time, the customer called about something else. However, I didn’t know anything about this until I arrived to sort out his “black & white on DVD” problem. Apparently, he had called in another technician when he found out that I was in hospital – one who was much more “savvy” than I. This technician had flogged him a Digital Set Top Box (DSTB) and installed it, which was smart thinking money-wise – at least from the tech’s viewpoint. The only thing was that they could already get all the stations they wanted via Foxtel Digital, so they didn’t need the DSTB. Unfortunately, if my opposite number had left any instructions on how to use this, he hadn’t done it in writing and the elderly owner had no idea how to use it. Anyway, I studied the manual for his TV and checked all the connections. I also made sure that the input menu was set for AUTO or PAL but I was going nowhere. When you pressed the Input button on the remote, it sequentially cycled TV (free-to-air), AV1 = Foxtel and Combo, AV2 = DSTB, AV3 = not used and DVD. All gave CIRCUIT ! W E N WIZARD A revolutionary new system that combines circuit design, PCB design, simulation & CAD/ CAM in one complete package for your pc. IDEAL FOR SCHOOLS, HOBBYISTS, TAFE & BUSINESSES Circuit Wizard - Standard $202 inc GST & post in Aust. Circuit Wizard - Pro $390 inc GST & post in Aust. om: r f o m e d free cepts.com a d a o l n w con Do e v a w w www.ne ions click on To see the s between difference Standard onal vers & Professi ‘features’. And still available . . . These two great packages: PCB WIZARD 3 and LIVEWIRE! Standard edition – $115 ea inc GST and Pro edition – $286 (both post in Australia) Australia and New Zealand – for orders or more information, please contact 555Electronics, McLaren Vale, SA 5171 Tel (08) 8323 8442 email: bwigley<at>senet.com.au www.555electronics.com.au siliconchip.com.au April 2007  59 Serviceman’s Log – continued colour except the DVD input. So what was going on? It took a very long time for my brain to twig what was happening. In fact, there was nothing wrong at all. This TV set was just unusual and shared inputs AV1 and DVD. AV1 used the usual Yellow, Red and White leads (ie, composite video and left & right audio), while the DVD input required RGB signals (plus the left and right audio signals). To match his DVD player, all he had to do was select AV1 on his TV and change the combo from VHS to DVD (AV1). The only thing he shouldn’t do was select the DVD input on the TV. Weird, eh? Another schemozzle Last month, I was carrying on like a two-bob watch about error codes and this month I got embroiled in yet another schemozzle. It concerned a 2000 Philips 32PW8806/79R TV set (MG2.1E chassis) that was intermittently not starting. When I did manage to get it to go, I put it into the SAM mode (Service Alignment Mode) as soon as possible and checked out the error codes. These were 67 and 68 which refer to the +8V and +5V supplies respectively. However, when I cleared the error 60  Silicon Chip buffer and did a functional test, no further codes came up. The set then worked perfectly, even switching on and off correctly with the remote. It didn’t last long because the very next day, when switching it on from cold, the problem was back. After eventually getting it going, I went through the above procedure again. This time, I even measured the +5V and +8V rails as being spot on. Eventually someone whispered in my shell-like . . . “it’s the relays”. In fact, there are two 5V 10A IP relays (1002 and 1010), one for the degaussing and the other for switching the main +330V rail to the switchmode power supply. The quickest way to check the latter (it is unlikely that the former would be the cause, being the degaussing circuit) was to short out the relay switch contacts and then test it. Well, much to my surprise, that fixed the problem! To further confirm it, I swapped the two relays around and noticed that the purity was now slightly out (indicating that the degaussing was no longer working correctly). However, the original fault did not reoccur, so I ordered and fitted two new relays just to be sure. The relays are sealed units so you can’t see inside them but it’s almost certain that the contacts were worn in the unit that switched the +330V supply rail. It just goes to show you can’t always believe error codes. DOA Sanyo A wide-screen Sanyo CP32WF2-00 (EB7-A chassis) arrived on my bench DOA (dead on arrival). The power supply was blown. As usual, I replaced chopper transistor Q613 (2SC4429), driver transistor Q612 (2SC3807) and the main B+ (330V) feed resistor (R602, 1.8W 5W). This fixed the power supply but when the picture came on, the set would immediately close down. The B+ for the line output stage was spot on at +150V and the other supply rails looked OK too. As a result, I decided to check the protection circuits, starting at pin 11 of microprocessor IC801. This should have been at +5V but was in fact down to +4.5V. I followed the protection lines back to their diode detectors but could find no reason why this voltage was low, even when I disconnected them one at a time. I then tried asking Sanyo Technical Support and the technician there suggested that either crystal X801 and or X231 might be off frequency, so I changed them – to no avail. When I had disconnected the +200V rail protection, it took much longer for the set to close down. Thinking that this might be a clue, I subsequently spent a lot of time investigating this protection circuit before finally abandoning the theory. Next, I tried hooking pin 11 up to the +5V rail via a 100kW resistor. When this happened, the set came on and stayed on with a good picture and sound. It was then that I noticed that the +5V rail was now high at somewhere between +8V and +9V. I had actually measured it before and I promise you, it was then spot on 5.0V! This brought Q646 (2SC3807), the 5V regulator, to my attention. I removed this transistor and tested it but it looked OK, even with a Peak Transistor Analyser. However, a new transistor fixed the problem completely – the +5V rail was now correct (and stable) and the set stayed on. Interestingly, the protection rail is apparently measured by the CPU at pin 11 and triggers if it goes below 5V. Even a 0.5V drop is enough to turn the set off. It seems to me also that it measures it in relation to the +5V rail and not ground. Non-starting Sony I was invited by a colleague to assist in the repair of a 1999 Sony KVES29M31 employing an AG3 chassis. The set wouldn’t start, initially flashing the green LED four times and then red LED four times before reverting back to Standby. The Green LED denotes the number of times the set tried to start, while the Red LED indicates error code 6 which denotes horizontal deflection failure. The probable cause of this is that C6831 (8.2nF) across the line output transistor has gone open circuit. As a result, the horizontal output pulse is going too high and setting off the protection circuit. However, in this case, the capacitor measured fine but we still fitted a new one. We also checked the capacitors all around it. The service manual also siliconchip.com.au mentions connector CN6101 to the D1 board can also cause this symptom if it is disconnected. Next, we checked all the usual suspects around the line output stage and even changed the flyback transformer without result. We then began to realise that we didn’t really understand what we were doing and were just checking things in an ad-hoc manner. We started again and noted that at no time did we hear the EHT static, which suggested that contrary to the error code, the line output stage never really got going. We measured +135V to the line output and PIN OUT transistors and their drivers but only one was actually switched on. Q6805’s collector was very high, implying that there was no drive signal. We traced this back through CN116213 from the D Board to the A Board and then from CN1140/4101-4 to the E Board. The E Board is a small, almost inaccessible, vertical module with many surfacemount components. Without expensive extension leads, it would be impossible to scope the waveforms through it. Using an ohmmeter, we found that surface-mount transistor Q4808 (2SA1037) on this board – the horizontal pre-driver – was open circuit. We replaced this with a BC857 which is similar general-purpose transistor but despite our optimism, it didn’t fix the fault. By now, we had spent too much time on the problem, so we decided to fit a new E Board. That fixed the problem but it was disappointing that we didn’t find the precise cause of the fault. Dead Teac I was called out to a dead 2-year old Teac PLH4220 SD/4942 plasma set. This time, I remembered to bring my special large piece of cardboard with spaced sponges glued onto it. When I got there, the customer helped me lift this 106cm set and lay it face down on the sponges. I then used my electric screwdriver to undo the numerous screws in order to remove the back before checking the fuses using an ohmmeter. The important thing to remember here is to check the fuses outside their holders as there are diodes strapped across them on the PC board. I soon found that the fuse on siliconchip.com.au Professional AM-FM Monitor Receivers RMR-01 Complete Broadcast Studio Off-Air Monitor Receiver System with Composite Output, Audio Distribution and Alarms RRR-01 Versatile AM-FM Receiver 240 V AC and 12 V DC Operation Composite Output - Re-Broadcast - MATV Systems Tunnel Repeaters - Radio News Rooms - Pre Select up to 32 Mixed AM - FM Stations via RS-485 Control Optional Model PSS-01 Wired Controller Available Ideal AM Receiver for use in Remote Locations SMR-01 Scanning Monitor Receiver Monitoring of up to 8 Mixed Remote AM - FM Services - Failure Report by FAX For Details and Price, please contact us at ELAN Phone 08 9277 3500 AUDIO Fax 08 9478 2266 2 Steel Court. South Guildford email sales<at>elan.com.au www.elan.com.au Western Australia 6055 the Y SUS Board had failed, indicating further problems on this board. This set is basically a re-badged LG and the Y SUS, Z SUS and CONTROL boards are a matched set. As a result, no attempt should be made to repair these boards to component level. Fortunately, the replacement boards were surprisingly cheap and had been updated by the factory. I fitted them and checked the voltages before replacing the back and stand. And that was it – problem fixed. SC April 2007  61 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. Optical water level switch Here’s a novel approach to detecting water level. It uses a photodiode glued to the rear of a LED as the detecting element. The principle of operation can be demonstrated by observing the light from the rear of an ordinary red LED. When the tip is dipped in water, the light level emitted is significantly reduced. This circuit uses an infrared LED to reduce the effects of ambient light, although it will still need to be shielded from bright light. An infrared photodiode acts as the light detector. It is wired in series with a current-limiting resistor and is reverse-biased in dark conditions. When sufficient light strikes the photodiode, it begins to conduct, causing an increasing voltage at the non-inverting input (pin 3) of op amp IC1. The op amp is wired as a voltage comparator and has about 1.2V on its non-inverting input (pin 2), which is conveniently sourced from the anode of the LED. Until the tip of the LED is im- mersed in water, the photodiode is conducting, holding the voltage at pin 3 higher than pin 2. In this condition, the op amp’s output if driven towards the positive rail, switching on Q1 and energising the relay. When the water reaches the LED, photodiode conduction is reduced such that the voltage on pin 2 of the op amp is now higher than that on pin 3. As a result, its output swings towards ground, turning off Q1 and the relay. As mentioned, the diode is glued to the rear of the LED. A felt-tipped pen housing can be used to contain the probe assembly, allowing all electrical connections to be completely water-proofed. Phillip Foote, Dianella, WA. ($35) 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, with the compliments 62  Silicon Chip 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 silicon<at>siliconchip.com.au or post it to PO Box 139, Collaroy, NSW 2097. siliconchip.com.au 12V SLA battery capacity tester Here’s a relatively simple circuit that can be used to test the capacity of 12V SLA batteries. It’s powered from the battery under test and uses a standard 1.5V quartz clock to indicate discharge time. Circuit operation is initiated by pressing the “Start” switch (S1), which connects battery power to the circuit. Assuming that the battery voltage is above the programmed cut-off voltage, the output of op amp IC1a immediately swings high, switching on Q1 and pulling in relay RLY1. An alternative power path now exists via the relay contacts, so the circuit remains active when the Start switch is released. IC1a is wired as a voltage comparator with a 6.8V reference applied to its inverting input (pin 2). This is sourced from a simple shunt regulator formed by zener diode ZD1 and its 2.7kW series resistor. The voltage on IC1a’s non-inverting input (pin 3) is adjustable via trimpot VR1 and when this drops below the reference voltage, the outsiliconchip.com.au put (pin 1) swings low. This in turn switches off transistor Q1 and the relay, removing power from the circuit and terminating the discharge. Op amp IC1b operates as a voltage follower. It attempts to maintain the voltage at its inverting input (pin 6) – and hence the voltage across the 1W sense resistor – equal to the reference voltage on its non-inverting input (pin 5). In conjunction with Mosfet Q2, this configuration yields a constant-current sink. Toggle switch S2 allows selection of either a 0.5V or 1V reference voltage, corresponding to 500mA or 1A of discharge current, respectively. After initial construction, select the 1A range and adjust VR2 for precisely 1A of battery current, as measured on a DMM. In addition, VR1 should be set to the correct discharge end voltage for the selected discharge rate, as specified by the battery manufacturer. For example, a 12V 1.3Ah Panasonic VRLA battery would be discharged to a minimum of 9.8V on the 1A setting, which equates to a 0.77C discharge rate. The larger 7.2Ah Panasonic unit would be discharged to Cliff W is this m ylie onth’s winne Peak At r of a las Instrum Test ent a minimum of 10.5V on the 1A setting. The discharge time is read off the quartz clock, which is powered from the circuit rather than its usual internal 1.5V cell. A standard red LED acts as a simple shunt regulator for the clock, ensuring that no more than about 1.9V is applied to the 1.5V mechanism. The LED flashes each time the clock pulses, which is also a good indication that the system is operating. In use, the clock is first set to 12:00 and then the discharge current selected. It’s then just a matter of pressing Start, after which the battery will be discharged until the cut off voltage is reached. At this point, if a charger is connected, the battery will be recharged. The clock indicates the number of hours taken for the discharge at the set rate. Note that if testing high-capacity batteries, the discharge time may exceed 12 hours – keep an eye on the clock. Alternatively, the circuit could be modified to support higher discharge rates. Cliff Wylie, Camden, NSW. April 2007  63 Circuit Notebook – Continued Rotary encoder interface Many front-panel interfaces can benefit greatly from a rotary encoder or “jog wheel”, which in some cases can replace an entire array of switches and knobs. Unlike the rotary encoder interface in the May 2006 issue, this design uses a hardware-assisted approach and is well suited for use with microcontrollers that lack a sophisticated (or any) interrupt system, such as the PICAXE series. The two encoder signals “A” & “B” are first debounced with RC networks comprised of 4.7kW resistors and 100nF capacitors and 74HC14 Schmitt-trigger inverters (IC1a & IC1b). The direction of rotation is determined by “comparing” the phase of A & B with one half of a 74HC74 flipflop (IC2a), while the other half (IC2b) is used as a latch to capture the narrow pulses. The resultant pulse and direction and signals are interpreted by a PICAXE microcontroller. In use, the microcontroller program (ie, in the PICAXE) must poll the pulse input (from pin 9 of IC2b) until a high level is detected, indicating that the encoder is rotating. The direction input is then read and a program variable is incremented or decremented as required. Following this, the pulse output is momentarily driven low to reset the “pulse memory” flipflop (IC2b), ready for the next pulse. Note that depending on the type of encoder and the performance of the microcontroller, pulses might be missed if the encoder is rapidly rotated. This will likely be of no consequence if the design is used as part of a front-panel interface. A suitable encoder with a 6mm shaft and 10mm mounting bush is available from www.farnellinone. com.au, stock number 109-113. Keith Bolton, Hobart, Tas. ($35) may be 100mV or less. The series resistance of the tuned circuit is given by: r = R2 x VNULL/VIN when r << R2 and VIN and VNULL are the RF voltages at the input and the detector nodes. Typically, R1 = R2 = 100W so that at resonance the signal generator sees a 50W load. At resonance, the detector impedance has little effect as it is shunted by the low series resistance of the tuned circuit. Almost any highspeed diode can be used provided that its load resistance is sufficiently high. However, diodes with lower equivalent shunt resistances at zero bias (eg, Schottky and germanium) will work better with lower load resistances. A high input impedance DVM such as the HP/Agilent 34401A must be used to minimise loading. Also, care has to be taken to ensure that “spillback” from the DVM isn’t rectified by the diode detector, falsifying the reading. An RC filter can be used to significantly reduce the effects of noise injected by a DVM. Alternatively, an analog meter may be preferable as it produces very little noise. Bruce Griffiths. Hamilton, NZ. ($35) Measuring high-Q inductors A common approach used to measure an inductor is to connect it in a tuned circuit with a known value of capacitance. In conjunction with an RF signal generator and other measurement instruments, the Q factor and inductance are then readily obtainable. Unfortunately, loading effects of the test equipment can compromise measurement accuracy but this can be improved by adding a simple diode detector circuit. The diode detector monitors the RF voltage (VNULL) at the input to the series tuned circuit (L1 & C1). The signal generator is then tuned for a minimum RF voltage at this node, as measured at the detector output (VDET) with a high-impedance DVM. With a high-Q inductor the detector output voltage at null 64  Silicon Chip siliconchip.com.au Stage microphone muting circuit This simple pair of circuits addresses the problem of open microphones, which commonly pick up extraneous sounds and limit the gain of live sound systems before feedback. The circuits are designed so that their microphones are active only when the vocalists are standing on pressure mats. One version of the circuit is for mixers that supply phantom microphone power. Operation is very straightforward; JFET Q1 is used to short-circuit the balanced audio output from the microphone whenever the pressure mat switch is open. When the vocalist steps on the pressure mat, the switch closes and the gate voltage of Q1 goes negative with respect to its source. This causes the drain-source resistance to swing very high, removing the short circuit from the signal lines. The 470kW resistor and 1mF capacitor provide a gentle turn-on and turn-off characteristic (about two seconds) in order to reduce clicks and pops. A second version can be built for mixers that do not have a phantom supply. It adds a battery supply for biasing the JFET as well as DC blocking capacitors in series with the output lines. Note that while other JFETs can be substituted for the J111, be sure that their drain- source resistance is less than 100W to provide useful off-state attenuation. Robert Budniak, via email. ($40) Looking for real performance? NOT A REPRINT – Completely NEW projects – the 160 PAGES result of two years research & development • Learn how engine management systems work • Build projects to control nitrous, fuel injection and turbo Fro m the pu bli sh ers 23 CHAPTE RS of boost systems • Switch devices on and off on the basis of signal frequency, temperature and voltage Intelligen t turbo timer • Build test instruments to check fuel injector duty cycle, fuel mixture and brake and coolant temperatures • Speedo Corrector, Turbo Timer, Nitrous Fuel Controller & Digital Thermometer Projects I SBN 095 852 9 7809 5 294 - 4 8 5229 4 $19.80 (inc GST) TURBO B OOST & ni trous fuel 6 NZ $22.00 (inc GST) controllers How eng in managemene t works Mail order prices: Aust. $A22.50 (incl. GST & P&P); Overseas: $A26.00 via airmail. Order by phoning (02) 9939 3295 & quoting your credit card number; or fax the details to (02) 9939 2648; or mail your order with cheque or credit card details to Silicon Chip Publications, PO Box 139, Collaroy, NSW 2097. siliconchip.com.au April 2007  65 By JOHN CLARKE Programmable Ignition System For Cars; Pt.2 Six Versions To Build To Suit Your Car’s Trigger Input! This month, we describe the circuit for the LCD Hand Controller module and provide all the assembly details for the Programmable Ignition. There are six versions to build. L AST MONTH, we published the circuit details for the Programmable Ignition Timing Module and its companion Ignition Coil Driver Module and described their operation in some detail. The various input trigger circuits (points, reluctor, Hall sensor, optical, etc) were also described. LCD Hand Controller That just leaves the LCD Hand Controller Module. Its circuit is shown in Fig.7. It comprises an LCD module, a 4017 decade counter (IC1), a DB25 socket and several pushbutton switches. This unit connects to the main circuit via a standard DB25 RS-232 cable. Signals from the microcontroller 66  Silicon Chip in the Programmable Ignition Timing Module drive both the LCD module and IC1. IC1 has 10 outputs and each output independently goes high in sequence as it is clocked at its pin 14 input. A high at the reset (MR, pin 15) sets the “0” output at pin 3 high. Each output connects to a switch. When a switch is closed, it pulls pin 9 of the DB25 socket high whenever its corresponding output on IC1 is high. This allows the microcontroller (in the Ignition Timing Module) to recognise which switch is closed. The LCD is driven using data lines DB7-DB4. The display readings are entered via the data lines and are controlled via the EN and RS (Enable and Register Select) inputs. Note that the data lines and the EN & RS lines are all connected to ground via 330W resistors. These resistors allow the LCD module to be driven without the signals being corrupted by interference from the car’s ignition. Finally, trimpot VR1 is used to adjust the display contrast. Construction OK, that completes the circuit description. Let’s now build all the modules for the unit. As shown in the accompanying diagrams, the Programmable Ignition system is built on three PC boards – one for the Programmable Ignition Timing Module (code 05104071, 103 x 82mm); one for the Ignition Coil Driver Module (code 05104072, 40 x 39mm); and one for the LCD Hand Controller (code 05104073, 115 x 65mm). The Programmable Ignition Timing Module board is housed in a diecast aluminium case measuring 119 x 93 x 57mm, while the Ignition Coil Driver board goes into a much smaller diecast case measuring siliconchip.com.au Fig.7: the circuit for the LCD Hand Controller is quite simple. It uses 10 switches, an LCD module, a 4017 counter (IC1), a DB25 socket, a 10mF capacitor and a few resistors. Trimpot VR1 sets the display contrast. 51 x 51 x 32mm. The LCD Hand Controller board goes into a 120 x 70 x 30mm plastic case with a clear lid. Before installing any parts, check each PC board for etching defects by comparing it against a printout of its pattern (you can download the relevant board files from the SILICON CHIP website). Check also that all the holes have been drilled and that the hole sizes for the larger parts are correct. Ignition timing module There are six different component layouts for this board, one for each different trigger input. It’s just a matter of choosing the one that’s applicable to your car. For example, if your car has a reluctor distributor, follow the reluctor version overlay diagram – see Fig.10. Similarly, if it has a Hall effect or Lumenition pickup module, use the layout of Fig.11, etc. It’s not difficult to recognise the different sensor types. Reluctor dissiliconchip.com.au tributors have a coil and a magnetic ring that has as many points (or protrusions) as the number of engine cylinders. By contrast, Hall effect distributors include a metal vane that passes through a gap in the Hall sensor itself. Lumenition triggers are similar to Hall effect sensors and so the overlay diagrams for these trigger types are the same – see Fig.9. Start construction by installing PC stakes at the external wiring points, then solder in all the wire links. That done, install the resistors, using Table 1 as a guide to select the values. In addition, it’s also a good idea to check each resistor using a digital multimeter (DMM) to make sure you have the correct resistor for each position. Next, install the IC socket for the microcontroller, making sure that it’s oriented with its notch at the lefthand end, as shown. Don’t install the microcontroller (IC1) at this stage though – that step comes later. Diode D1 and TVS1 are next on the list. Note that D1 must be oriented as shown, while TVS1 can be installed either way around. Follow these with the transistor(s) and REG1, taking care to ensure that these parts are oriented correctly. Trimpot VR1 should now be installed if you are building the reluctor version (Fig.10). It should be oriented with its adjusting screw to the left. The link headers for LK1 and LK2 can be installed now. LK1 is a 3-way header while LK2 is a 2-way header. Place a jumper shunt over two of the three pins for LK1 and another jumper shunt onto both pins for LK2. Now for the capacitors. Several types are used on the board: ceramic, MKT and electrolytic. The ceramic capacitors are all shown on the overlays in yellow, so that you don’t get them confused with the MKT types. Be sure to orient each electrolytic capacitor with the polarity shown. Once the capacitors are all in, install the crystal (X1). Note that the crystal’s metal case is earthed using a short wire link. This link is soldered April 2007  67 Fig.8: this is the points version. Secure all wiring leads to the board using cable ties and cover the connections to the PC stakes with heatshrink tubing or silicone, to prevent them coming loose. Fig.9: the engine management trigger version requires no additional input conditioning circuitry. In this case, the ECU trigger signal goes straight to pin 6 of IC1 via a 2.2kW resistor. to the case and runs to a pad on the PC board between the two 22pF ceramic capacitors. Sensym pressure sensor If you are using the Sensym absolute pressure sensor (eg, if you car doesn’t 68  Silicon Chip already have a MAP sensor or you are not using a seconhand MAP sensor), then this can be installed now. Note the orientation notch on the sensor – this goes towards the righthand edge of the PC board. If you get the Sensym sensor’s orientation wrong, it will not be powered but no damage will result from doing this. Inductors Inductors L1 & L2 are next on the list. First, L2 is made by passing a 0.7mm tinned copper wire link siliconchip.com.au Fig.10: follow this parts layout diagram if your car’s distributor has a reluctor pickup. The Sensym pressure sensor is used only if there is no external MAP sensor (applies to all versions). Fig.11: this is the layout to follow if the distributor uses a Hall Effect device or a Lumenition module. Take care with component orientation during assembly. through three ferrite beads. A length of the 4mm heatshrink tubing is then slid over the three cores and shrunk down to hold everything in place, after which the assembly can be soldered to the board. Inductor L1 is much larger. It’s siliconchip.com.au made by winding 23 turns of 0.5mm enamelled copper wire through a 15 x 8 x 6.5mm powdered-iron toroidal core. These turns should be evenly spaced around the core, as shown on the overlays. That done, the wire ends are stripped of insulation and soldered to the PC pads. The toroid is then secured to t he board using two plastic cable ties. Finally, the DB25 socket can be installed in position. Before doing this though, two D-connector nut extenders must to be attached to the April 2007  69 Fig.12: build this version if your distributor has been fitted with a Crane optical pickup. Make sure that inductor L1 is firmly secured, to ensure reliability (all versions). Fig.13: the Piranha optical pickup version is almost identical to the Crane version but note the different locations for the 22kW and 120W resistors. PC board. These are simply passed through their two mounting holes and secured using spring washers and nuts on the underside of the board. In addition, the righthand extender is fitted with a Nylon washer to prevent the spring washer and nut from short70  Silicon Chip ing to nearby tracks. Don’t leave this washer out! By contrast, the lefthand extender makes contact with the ground track on the PC board, so that the shell of the socket is earthed when it is installed. That way, when the DB25 lead is connected, its shield will also be earthed. The DB25 socket can now be secured in place using a second set of nut extenders and its pins soldered to the PC pads. Note that you may need to cut down the extender threads so siliconchip.com.au Fig.14: these diagrams show the modifications required to invert the output from the Ignition Timing Module. the nuts sit flush with the socket’s mounting flange. Inverting the output In normal operation, the RB3 output from the Programmable Ignition Timer Module goes high in order to turn on transistor Q1 (via Q3 & Q2) in the Ignition Coil Driver. This in turn allows current to flow through the primary of the coil. Conversely, when RB3 goes low, Q1 switches off, the current through the coil is interrupted and the coil “fires” the relevant spark plug. So a low-going signal at the Ignition Timing Module’s output normally causes the Ignition Coil Driver to fire a plug via the coil. However, there may be some applications where the output from the Programmable Ignition Timing Module needs to be inverted; ie, so that a low output “charges” the coil and a high-going output causes the plug to fire. This may be the case if you connect the Programmable Ignition Timing Module to a different ignition coil driver. In this case, an inverted output can be provided using the tachometer driver transistor (Q4). The necessary changes to the circuit and to the PC board layout are shown in Fig.14. The only extra parts required are a 220W resistor and some tinned copper wire for the link. Housing Having completed the board assembly, the next step is to install it in its metal diecast case. Fig.15 shows the assembly details. The first step is to position the board inside the case and mark out its four mounting holes. That done, remove the PC board and drill the mounting holes to 3mm. Deburr each hole using an oversize drill bit, then secure a 6mm-long tapped spacer to each mounting point using an M3 x 15mm screw inserted from the outside of the case. You will also have to drill a hole in one end of the box to accept a cable gland for the various external leads (ie, +12V lead, trigger signal leads and signal output lead). An additional hole for a second cable gland will also be required if you are using an external MAP sensor (see Fig.15). Next, a 3mm hole must be drilled through the side of the box adjacent to the GND (0V) PC stake. This mounting hole is used to terminate an earth wire from the PC board via a crimped eyelet connector. A second wire terminated in an eyelet connector is also Table 2: Capacitor Codes Value 220nF 100nF 10nF 2.2nF 1nF 470pF 22pF mF code 0.22mF 0.1mF .01mF .0022mF .001mF    NA   NA IEC Code    EIA Code 220n 224 100n 104 10n 103 2n2 222 1n0 102 470p 471 22p 22 Table 1: Resistor Colour Codes o o o o o o o o o o o o o siliconchip.com.au No. 2 3 1 7 2 1 1 3 2 1 1 9 Value 100kW 47kW 22kW 10kW 2.2kW 1.8kW 1.2kW 1kW 470W 120W 100W 10W 4-Band Code (1%) brown black yellow brown yellow violet orange brown red red orange brown brown black orange brown red red red brown brown grey red brown brown red red brown brown black red brown yellow violet brown brown brown red brown brown brown black brown brown brown black black brown 5-Band Code (1%) brown black black orange brown yellow violet black red brown red red black red brown brown black black red brown red red black brown brown brown grey black brown brown brown red black brown brown brown black black brown brown yellow violet black black brown brown red black black brown brown black black black brown brown black black gold brown April 2007  71 Fig.15: this diagram shows the final assembly and external wiring details for the Ignition Timing Module. Note how the 0V (ground) rail on the PC board is connected to one side of the case, with a lead then run from this point to the vehicle’s chassis. Use cable ties to help secure the leads, both inside and outside the case. attached to the outside of the case to make the chassis connection, with the entire assembly secured using a M3 x 9mm screw, nut and star washer – see Fig.15. Another 3mm hole is drilled to allow the metal tab of regulator REG1 to be secured to the case using two M3 x 15mm tapped metal spacers. This arrangement serves a dual purpose: (1) it mechanically secures the regulator to prevent its from breaking; and (2) it provides heatsinking for the regulator tab. The two spacers are secured to REG1’s tab using an M3 x 20mm screw, while an M3 x 9mm screw secured the spacers to the side of the case. Note that star washers must be used under each screw head, to prevent the assembly from shaking loose. Hose adapter This view shows the assembled PC board for the Ignition Timing Module with the optional internal Sensym MAP sensor fitted (ie, when there is no existing external MAP sensor or you are not using a secondhand MAP sensor). Make sure that the unit is ruggedly built (ie, so that no leads can come adrift). 72  Silicon Chip If you are using the on-board Sensym pressure sensor, then a hose connection will be required from the sensor to a chassis-mount flange (or through-piece) on the side of the box. This piece serves as both an anchor siliconchip.com.au Manifold Pressure Sensor Options I N ORDER TO utilise the vacuum advance feature provided by the Pro­grammable Ignition System, some means of monitoring manifold pressure is required. There are several options available here. The simplest option is to use the MAP (manifold air pressure) sensor that’s already installed on your car (if it has one). This sensor would normally be used to detect manifold pressure for the car’s own Engine Management Unit, to control the timing. If your car does not have a MAP sensor, then you can easily obtain one to do the job. There are different sensors to suit normally aspirated engines and to suit turbocharged engines. Normally aspirated engines do not boost the air pressure for the fuel mixture and so a 1-bar (one atmosphere, 100kPa point and as a 3mm-to-5mm adapter. This is necessary because the sensor’s hose connection is 3mm in dia­ meter while a standard automotive vacuum tube requires (at least) a 5mm fitting to enable it to stay in place without air leaks. A 15mm round brass spacer is used as the adapter. The 3mm-diameter hose from the sensor is pushed inside the spacer at one end (ie, the end inside the case), while the external vacuum tube is fitted over the spacer at the other end (outside the case). Note that it will be necessary to enlarge the hole at one end of the spacer slightly to accept the 3mm (ID) hose. Silicone sealant can be used later, when fitting the hoses, to ensure that or 15psi) sensor is all that is required. These sensors measure the air pressure compared to a vacuum and output a voltage close to 4V for atmospheric pressures and close to 0V for a vacuum. Turbo engines boost the air pressure above atmospheric and consequently a 1-bar sensor is inadequate. This is because the output from a 1-bar sensor would not change for pressures above 1-bar. There is also a possibility that the sensor could be damaged if the pressure went too far beyond its rating. In this case, a 2-bar sensor should be adequate for most applications. However, if the boost is greater than 2-bar, a 3-bar sensor will be required instead. One option is to use an on-board Sensym sensor that covers from 0-1 bar or from 0-2 bar, as specified in the parts list. the connections are air-tight. Fig.16 shows how the adapter is fitted. First, a brass nut is soldered to one end of the adapter, after which the adapter is pushed through a 5mm hole in the side of the case. It is then clamped in position using a 20mm OD washer and a couple of M3 x 6mm machine screws that go into tapped holes in the washer (or you could use M2 x 10mm screws and nuts). Alternatively, you can do away with the adapter altogether and pack the inlet on the Sensym sensor out with several layers of heatshrink tubing so that the 5mm hose is a tight fit. That way, the 5mm (ID) vacuum hose that runs to the engine manifold can simply pass through a hole in the Fig.17: this is the parts layout for the Ignition Trigger Module. Note the different orientations for ZD1-ZD4. siliconchip.com.au This device is best used at temperatures ranging from 0-85°C and so the Programmable Ignition Timing Module should be mounted inside the cabin rather than in the engine bay. Alternatively, most automotive wreckers can sell you a MAP sensor quite cheaply. These are available from various models of Holden, Honda, Toyota, Subaru and others. Details of the Holden type 1-bar, 2-bar and 3-bar MAP sensors and the Motorola 2.5-bar MAP sensor are available at this web site: http://web.archive.org/ web/20050906201309/www.pgmfi.org/ twiki/bin/view/Library/MapSensor Typically, the 1-bar Holden sensors are designated with a 039, 460 or 883 code. 2-bar sensors have a 886, 012, 539 or 609 code and 3-bar sensors have a 749 code. The A, B and C labels refer to the positioning of the Ground, Signal and +5V terminals. Fig.16: a simple adapter made from a brass spacer can be used to connect the 3mm outlet on the Sensym pressure sensor to a standard 5mm vacuum hose. The metal tab of the Darlington transistor (Q1) must be insulated from the case using a TO-218 insulating washer and a Nylon screw and nut. April 2007  73 case and go straight to the Sensym pressure sensor. As before, silicone sealant can be used to ensure an airtight fit but be careful not to block the sensor inlet with the sealant. Once all the holes have been drilled in the case, the PC board can be fitted and the assembly completed as shown in Fig.15. Be sure to use automotive wiring for all external connections. These leads should all be secured using cable ties and the connections to the PC stakes covered with heatshrink tubing. This is necessary to prevent the leads from vibrating and coming adrift. Wiring the pressure sensor There are three options when it comes to wiring the pressure sensor: (1) If you are using an existing MAP sensor, connect the signal lead only. DO NOT connect the +5V and 0V supply leads (the sensor will already have supply connections). (2) If you are using an external (eg, secondhand) MAP sensor that you’ve added to the vehicle, then connect all three leads (ie, signal, +5V and 0V). (3) If you are using the on-board Sensym sensor, do not make any external connections (the second cable gland can be deleted). Ignition Coil Driver Fig.18: final assembly and external wiring details for the Ignition Coil Driver. After assembly, use a multi­meter (set to a low ohms range) to confirm that the metal tab of Darlington transistor Q1 is properly isolated – ie, it must not be shorted to the case. This is the view inside the Coil Driver Module. Note the use of a separate cable gland for the trigger input lead. As with the timing module, this unit must be ruggedly built to ensure reliability. 74  S 74    S ilicon iliconCC hip hip Fig.17 shows the assembly details for this small PC board. Begin by installing the wire link, then install the 1.2kW and 470W resistors. The 100W 5W resistor can then go in – it should be mounted all the way down onto the PC board, so that it cannot vibrate and break its leads. Zener diodes ZD1-ZD4 are next on the list. Be sure to orient them as shown (two face in one direction and two in the other, so take care here). Follow these with transistors Q2 & Q3 and the 1nF ceramic capacitor. Transistor Q1 is mounted on the underside of the PC board. This device is installed with its leads bent up through 90°, so that they go through matching holes in the PC board from the track side (ie, the metal tab of the device faces away from the board – see photo). Push the leads through their holes until the metal tab is exactly 6mm below the underside of the PC board, then lightly solder one of the leads. This will allow you to make any adjustsiliconchip.com.au Fig.19: the LCD Hand Controller PC board is easy to assemble. Install the three links first and note that the switches, IC and 10mF electrolytic capacitor are polarised. The LCD is connected via a 14-way DIL pin header. The PC board mounts inside the case on four M3 x 12mm spacers and is secured using M3 screws, nuts and flat washers – see Fig.19. Note how the 10mF capacitor is mounted on its side, so that it clears the front panel. ments as necessary before completing the soldering. Finally, complete the board assembly by installing PC stakes at the four external wiring points. Once completed, the Ignition Coil Driver PC board can be installed in its diecast case – see Fig.18. As shown, the board in mounted on the lid of the case on 6mm tapped spacers and secured using M3 x 15mm screws, nuts and star washers. Transistor Q1 (on the underside of the board) is fastened to the lid for heatsinking. The first step is to mark out all the mounting holes on the lid. Drill these holes to 3mm, then carefully deburr siliconchip.com.au them using an oversize drill. In particular, make sure that Q1’s mounting hole is perfectly smooth and free of any metal swarf that could puncture its insulating washer. Note too that Q1’s mounting hole should be chamfered (use an oversize drill bit). This is necessary to avoid sharp edges around the circumference of the hole, to prevent arcing through the insulating washer (due to the high voltages present on the transistor tab). Once the holes have been “cleaned up”, fit the four tapped spacers to the board mounting positions and secure them using the M3 x 15mm screws. That done, install transistor Q1’s Nylon mounting screw and insulating washer (see photo), then slip the board into position and secure it using M3 nuts and star washers. Don’t leave the star washers out – they are necessary to ensure that the nuts don’t shake loose due to vibration. Transistor Q1 can now be secured by installing its nut and tightening the Nylon screw (use a pair of needle-nose pliers to hold the nut in position while you “start” the screw). Finally, use your multimeter (set to a low ohms range) to confirm that Q1’s metal tab is indeed electrically isolated from April 2007  75 Programmable Ignition: Parts List Programmable Ignition Unit 1 PC board, code 05104071, 103 x 82mm 1 diecast aluminium case, 119 x 93 x 57mm 2 IP68 waterproof cable glands for 4-8mm cable 1 15 x 8 x 6.5mm powdered-iron toroid (Jaycar LO-1242 or equivalent) (L1) 3 5mm Ferrite beads (Jaycar LF1250 or equivalent) 1 20MHz crystal (X1) 1 SPDT toggle switch for map switching (optional) 1 18-pin DIL IC socket 1 DB25 female straight pin PC mount socket 4 D-connector nut extenders and two locking nuts and shake proof washers 1 2-way pin header 1 3-way pin header 2 jumper pin shorting links 2 crimp eyelets 4 6mm tapped Nylon standoffs 1 3mm Nylon washer 2 M3 tapped x 15mm brass standoffs 1 M3 x 20mm screw 4 M3 x 15mm screws 2 M3 x 9mm screws 8 M3 star washers 5 M3 nuts 10 PC stakes 1 60mm length of 4mm ID heatshrink tubing 4 100mm cable ties 1 2m length red automotive wire 1 2m length black automotive wire 1 2m length green automotive wire 1 2m length brown automotive wire 1 2m length yellow automotive wire 1 150mm length of 0.7mm tinned copper wire 1 600mm length of 0.5mm enamelled copper wire Semiconductors 1 PIC16F88-E/P microcontroller programmed with ignprgm.hex (IC1) 1 LM2940CT-5 low-dropout 5V regulator (REG1) 1 BC337 NPN transistor (Q4) 76  Silicon Chip 1 1N4004 1A diode (D1) 1 1W Transient Voltage Suppressor (TVS1) 13.6V standoff voltage (Jaycar ZR 1162 or equivalent) Capacitors 1 1000mF 16V PC electrolytic 3 100mF 16V PC electrolytics 1 10mF 16V PC electrolytic 1 220nF MKT polyester 3 100nF MKT polyester 1 10nF MKT polyester 1 10nF ceramic 1 1nF MKT polyester 2 1nF ceramic 2 22pF ceramic Resistors (0.25W 1 %) 2 100kW 1 1.8kW 2 47kW 1 1kW 3 10kW 1 470W 2 2.2kW 9 10W Points and ignition module version 1 100W 5W resistor Reluctor version 1 BC337 NPN transistor (Q5) 1 2.2nF MKT polyester capacitor 1 470pF ceramic capacitor 1 100kW top-adjust multi-turn trimpot (VR1) 1 47kW 0.25W 1 % resistor 2 10kW 0.25W 1 % resistors 1 1kW 0.25W 1 % resistor 1 PC stake Hall effect version 1 1kW 0.25W 1 % resistor 1 100W 0.25W 1 % resistor 2 PC stakes Optical pickup version 1 22kW 0.25W 1 % resistor 1 120W 0.25W 1 % resistor 2 PC stakes Manifold pressure sensor alternatives (see text) 1 ASDX015A24R Sensym (0-15PSI, 0-1bar) Absolute Pressure Transducer (RS Components Cat No. 2508593055) (Farnell Cat. No. 419-7586); or 1 ASDX030A24R Sensym (0-30PSI, 0-2bar) Abso- lute Pressure Transducer (RS Components Cat No. 2508593077); or 1 Manifold Absolute Pressure (MAP) sensor – available from an automotive wreckers. Map sensors are available from most Holden, Honda, Toyota and Subaru models and others that have an engine management computer. Try to obtain the wiring connector with the sensor. Miscellaneous Angle brackets for mounting units, automotive connectors, self-tapping screws etc. Programming Code Note: the programming code (ignprgm.hex) for the PIC16F88-E/P microprocessor featured in this project will not be released or be made available on our website. Authorised kit sellers will supply programmed microcontrollers as part of their kits. For people who do not wish to build the project from a kit, programmed micros will be available from SILICON CHIP for $25.00 including postage anywhere within Australia, or $30.00 by airmail elsewhere. Ignition Coil Driver 1 Ignition Coil Driver PC board, coded 05104072, 40 x 39mm 1 diecast aluminium box 50.8 x 50.8 x 31.8mm (Jaycar HB6050) 1 TO-218 insulating washer rated at 3kV 2 IP68 waterproof cable glands for 4-8mm cable 4 M3 tapped x 6mm Nylon standoffs 4 M3 x 15 screws 1 M3 x 10mm screw 1 M3 x 6mm Nylon screw 5 M3 nuts 6 3mm star washers 4 PC stakes 1 2m length red automotive wire 1 2m length black automotive wire 1 2m length green automotive wire 1 2m length brown automotive wire 1 60mm length of 0.7mm tinned copper wire siliconchip.com.au 1 40mm length of 4mm heatshrink tubing Semiconductors 1 MJH10012, BU941P TO-218 high-voltage Darlington transistor (Q1) 2 BC337 transistors (Q2,Q3) 4 75V 3W zener diodes (ZD1ZD4) Capacitors 1 1nF ceramic capacitor Resistors (0.25W 1%) 1 1.2kW 1 470W 1 100W 5W wirewound LCD Hand Controller 1 PC board, code 05104073, 115 x 65mm 1 front panel label (or screen printed lid) for case 1 plastic case, 120 x 70 x 30mm with clear lid (Jaycar HB 6082 or equivalent) 1 LCD module (Jaycar QP 5515 or backlit QP 5516) 5 white click action switches (S1,S2,S5,S7,S9) 4 black click action switches (S3,S4,S6,S8) 1 SPST micro tactile switch (S10) 1 4017 decade counter (IC1) 1 DIL 14-way pin header 1 DB25 PC mount right angle socket 1 DB25-pin male to DB25-pin male 1.8m RS-232 connecting lead (all pins connected) (Jaycar WC 7502) 4 12mm long M3 tapped plastic spacers 4 M3 x 6mm CSK screws 2 M3 x 6mm screws 2 M3 x 12mm plastic screws 2 2.5mm thick plastic washers 1 100mm length of 0.7mm tinned copper wire 1 10mF 16V PC electrolytic capacitor 2 10kW 0.25W 1% resistors 1 7-way, 8-way or 9-way 330W terminating resistor array (8-10 leads). Note: 6-resistors are used in the circuit and one end of each resistor connects to the pin 1 common 1 10kW horizontal trimpot (code 103) (VR1) siliconchip.com.au Fig.20: this cross-sectional diagram shows how the PC board for the LCD Hand Controller is mounted in the case. Note how the top edge of the LCD module is supported on two M3 flat washers. the case lid (you should get an opencircuit reading). The earth supply lead goes to a crimp eyelet and this is secured to the inside of the case using an M3 x 10mm screw, star washers and nut. This screw secures a similar eyelet and earth wire arrangement on the outside of the case (this wire goes to the vehicle chassis). As shown in Fig.18, the remaining wires exit via the cable glands. Cover these leads with heatshrink tubing at the exit points and note that the signal lead must pass through its own separate gland, while the ignition coil (-) lead and the +12V lead pass through a second gland. Note that, in addition to the heatshrink, these leads may require packing out with tubing so that they are tightly clamped by the glands. The signal lead must at all times be kept clear of the ignition coil (-) wire to prevent retriggering as the coil fires. Be sure to take it out through its own cable gland and route it well away from the ignition coil wire – see Fig.18. Hand Controller The Hand Controller assembly is shown in Fig.19. Start by installing the three wire links, including the one under the DB25 socket. That done, solder in the dual-in-line 14-pin header for the LCD module, taking care to avoid solder bridges between adjacent pins. The SIL resistor array is next. This will have a pin 1 indication at one end (usually a dot) and this end must go towards trimpot VR1. Note that all the top seven holes must be used, leaving some free adjacent to VR1 if the array does not have 10-pins. IC1 can now be installed, taking care to ensure it is correctly oriented. That done, install the two 10kW resistors, trimpot VR1 and switches S1-S9. Note that each of these switches must go in with its flat side to the left – see Fig.19. We used white and black switches as indicated on the overlay. S10 is a smaller pushbutton switch that will only fit with the correct orientation. The 10mF capacitor is next on the list. This must be mounted on its side to provide clearance when the lid is on (see photo). Take care with the polarity of this capacitor. The DB25 right-angle socket can now go in. Make sure it is seated flat against the board and take care to avoid solder bridges between the pins. Finally, the LCD module can be installed by pushing it down onto its 14-pin DIL header. Push it all the way down until it is correctly seated against the header, then solder the header pins to the top of the module’s PC board. Fig.20 shows how the PC board is mounted in its case. If you are building a kit, the case will be supplied pre-drilled and with a screen-printed front panel. If not, then holes will need to be drilled in the base of the case for the four board mounting holes and a cut-out made to accommodate the DB25 socket in the side of the case. In addition, the lid will require holes for the switches and a clearance slot for the DB25 socket. Note that S10’s hole should only be about 3mm in diameter – ie, just sufficient for a small probe to actuate the switch. If you already have an LCD Hand Controller as described in “Performance Electronics for Cars”, then this can also be used with some minor April 2007  77 Inverting The Firing Sense Of The Ignition Coil Driver modifications. That earlier circuit is identical to the one described here except that it didn’t include the six 330W terminating resistors. This means that all you have to do is add these six resistors between the relevant pins on the LCD module (pins 4, 6, 11, 12, 13 & 14) and ground. These will have to be mounted on the track side of the PC board. The ground connections are best made at pins 7-10 of the LCD module. Testing Fig.21: this modified Ignition Coil Driver circuit can be used to “fire” a plug when the input signal goes high. Fig.22: this is the modified parts layout. Use a 470W resistor for R1 for a 5V input signal and a 1.2kW resistor for a 12V input signal. T HE IGNITION COIL DRIVER can be used on its own for other applications; eg, as a replacement coil driver in an existing system. However, in some cases, it may be necessary to change the “trigger sense” of the circuit. The standard set-up has the coil “charging” when the input signal is high and then “firing” a plug on a negative edge input signal. To invert this level sense, transistor Q3 and the 1.2kW resistor are deleted and a link installed between the pads normally used for Q3’s base and collector leads. This effectively bypasses Q3 and the input now drives Q2 via a base resistor (R1) – see Fig.21. Fig.22 shows the revised parts layout for the PC board. Use a 470W resistor for R1 when it is driven by a 5V input signal and a 1.2kW resistor when driven from a 12V signal. With this arrangement, the coil “charges” when the input signal is low and “fires” a plug when the signal goes high. 78  Silicon Chip OK, now for the smoke test, starting with the Programmable Ignition Timing Module. First, apply +12V to the supply input and connect the case to the 0V rail. That done, use your multimeter to check that there is 5V (±0.1V) between pins 14 & 5 of IC1’s socket. If this is correct, switch off and install IC1, making sure it is correctly oriented. Next, connect the RS-232 DB25 lead between the Programmable Ignition Timing Module and the LCD Hand Controller and apply power. You should be greeted with some characters on the LCD. If there are none, or if the display is faint or the contrast is poor, adjust VR1 on the LCD Hand Controller board for best results. If there is still no display, recheck the parts placement on both PC board assemblies. Check also that the DB25 cable is correct – each pin should be connected through to the same socket pin on the opposite end of the lead. Assuming all is well, the display shown on the LCD will depend on the position of jumper shunt LK1. Remember that the Settings position will show the settings mode (used when changing parameters), while the Timing position will show the RPM and Load site values against the timing values. The initial timing values are all set to 0° advance. Check that you can change the values using the switches on the LCD Hand Controller. Converting your distributor Finally, note that if you have a distributor with points, you can convert it to a Hall effect pick-up instead, to make it maintenance-free. The details on how to do this were published in our January 2006 issue. That all for this instalment. Next month, we will describe how the unit SC is set up and installed in a car. siliconchip.com.au SILICON CHIP Order Form/Tax Invoice Silicon Chip Publications Pty Ltd ABN 49 003 205 490 www.siliconchip.com.au PRICE GUIDE: SUBSCRIPTIONS YOUR DETAILS (Note: all subscription prices include P&P). (Aust. prices include GST) Your Name________________________________________________________ (PLEASE PRINT) Organisation (if applicable)___________________________________________ Please state month to start. 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Card expiry date: Signature_____________________________ 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, April Australia 20972007  79 04/07 PRODUCT SHOWCASE Agilent U1252A True RMS digital multimeter Describing the Agilent U1252A as a digital multimeter is a little unfair, since it has many more features than the average DMM. Features like true RMS AC measurement, two measurement displays both with 5-digit resolution, inbuilt 20MHz frequency meter and capacitance measurement from 10nF to 100mF (millifarads) are seldom found on DMMs. Apart from those features, the Agilent U1252A includes a programmable square wave generator, something that we have not seen on any DMM. So here we have a DMM with an output. To use it, you rotate the range selector switch fully clockwise and there is a square wave and percentage symbol above the “OUT ms” label. The main readout can be set to show duty cycle (default is 50%) or positive pulse width. You can vary the frequency in quite small steps, from 0.5Hz to 4800Hz using the Hz buttons and you can vary the duty cycle widely as well using the “ms%” buttons. Output impedance of the square wave generator is 3.5kW (maximum) and the amplitude is fixed at 2.8V. This is really quite a useful inclusion and could be handy for all sorts of audio or logic circuit tests. It highlights the quite different approach taken by Agilent to produce their digital multimeter range. Even the styling and colour are different, with tones of blue and grey instead of the very common bright yellow. Notice the arrangement of the buttons above the range selector switch. This is also different, to highlight some of the special features. For example, there is battery check switch, which also toggles the blue display backlighting on and off – very handy when you are working in low light situations. Similarly, there is a Null button which you can use to zero out residual voltages before you make a measurement. Then there is the Shift button which can used when setting up the square generator or to change the mode of the two digital displays. The Shift button can also be used 80  Silicon Chip to change the measurement mode in conjunction with the selector switch. For example, you can switch between Siemens and Ohms for resistance measurements, between Diode Voltage test or Frequency measurement, Temperature or Capacitance and so on. When you are making voltage measurements, Shift button selects between AC & DC or DC + AC. For AC, the main display can be reading in dB while the minor display reads voltage. Also unique to the Agilent DMM are 50mV, 500mV and 1000mV ranges for both AC and DC voltage measurements, with very high input impedance greater than 1GW. Input impedance for other voltage ranges is the more normal 10MW, dropping to 1.1MW in dual display. The Agilent has a very good range of capacitance measurement, from 10nF to 100mF (full scale). By the way, that is not 100 microfarads; it is 1000 times bigger, at 100 millifarads! Got some supercaps to check? This DMM will do it. Accuracy is very high for DC voltage measurements – a basic ±0.03% plus 5 digits from 500mV to 1000V and ±0.05% plus 5 digits for the 50mV range. Battery life is good because of the auto-off feature but it also comes with a rechargeable battery and charger so Agilent has that point well covered. The U1252A can be used as a datalogger, with an infrared link and USB interface for PCs. And yes, it comes with software on a CD which also has the full instruction manual. In truth, there are so many features on this multimeter that it would take quite some time to become fully familiar with all its capabilities. This review is only a small sample. We are very impressed. Recommended retail price for the top of the range Agilent U1252A is $741.48 including GST. Contact: Measurement Innovation Pty Ltd 898 Anketell Rd, Wandi, WA 6167 Tel: (08) 9437 2550 Fax: (08) 9437 2551 Website: www.measurement.net.au siliconchip.com.au VAF’s new Octavio 1 will change the way you think about speakers VAF’s new Octavio 1 plays directly from Microsoft’s new Zune player and can also connect to a TV, DVD player, game console or other audio source to produce high-quality sound for all home entertainment components. It replaces conventional amplifiers and speakers and removes a lot of clutter from the average room. It can play loud and deep enough for music to be felt as well as heard and VAF say it’s great for use in a home theatre. “If there is bass in the recording, things in the room will shake with no subwoofer required,” says VAF’s Philip Vafiadis. Solidly constructed in first grade MDF and uniquely clad in a leatherstyle finish, it doesn’t just look cool it also damps unwanted cabinet resonances. At over 11kg, Octavio 1 is built like a true high-end home enter- tainment component. It features two powerful long throw 130mm woofers, a 200mm bass radiator and two highend fabric dome tweeters. With plenty of inbuilt digital amplification, it also incorporates sophisticated response correction to deliver low distortion, full range sound, flat from under 38Hz to over 20kHz. At just 110mm deep, it is a perfect match for modern plasma or LCD TVs and one simple control knob can adjust volume level as well as switch between all input sources. Shipped with every Octavio 1 are three patented acoustic skins. Users can choose a minimalist sleek black, white or pink look, or the very tough powerful leather style ‘naked’ finish. If that’s not enough, the firmware is also upgradeable via a computer interface in the back panel. In production and at just US$499, Octavio 1 can be bought through Amazon.com and will soon be available from major specialist consumer electronic retailers. Contact: VAF Research Pty Ltd 852-54 North Tce, Kent Town SA 5067 Tel: (08) 8363 9996 Fax: (08) 8363 9997 Website: www.vaf.com.au Circuit Wizard now includes breadboard simulation! New Circuit Wizard v1.1, from New Wave Concepts, adds a whole host of new features including PC board current flow animation, quality checking for identifying PC board faults and subsystem modelling. It also includes breadboard simulation, which allows users to select from a wide range of different breadboards and then add components and hookup test instruments – even connect life-like virtual instruments, for example multimeters and oscilloscopes. Centre Victoria RadioFest is on this month Now it’s time for the Victorians to have their (field) day! The Centre Victoria RadioFest will be held on Sunday, 22nd April at the Kyneton racecourse, less than an hour from Melbourne, Ballarat and Bendigo. It’s intended for radio hobbyists and electronics enthusiasts. Tickets go on sale at 9am and the gates open at 10am. Inside, visitors will find: • A trader hall with all major commercial traders. • Car-boot sales avenue of secondhand equipment. siliconchip.com.au • Dipole factory (build your own). • Undercover trestle table sales area. • Mini lecture program of interesting topics. • Come’n’try sniffer foxhunting. • WICEN (Vic) portable operations on display. There will be a number of lucky door prizes on the day including a Yaesu FT-857D HF/VHF/UHF mobile transceiver, provided by Vertex Standard (Australia). Further information can be found at radiofest.amateurradio.com.au Circuit Wizard’s breadboards are ideal for learning about the real things and make it quick and easy to prototype project ideas. Circuit Wizard is New Wave Concepts’ best-selling software package for designing and simulating circuits and PC boards, represented in Australia by 555 Electronics. SC Contact: 555 Electronics Pty Ltd McLaren Vale, South Australia 5171 Tel: (08) 8323 8442 Fax: (08) 8323 0022 Website: www.555electronics.com.au STEPDOWN TRANSFORMERS 60VA to 3KVA encased toroids Harbuch Electronics Pty Ltd 9/40 Leighton Pl. HORNSBY 2077 Ph (02) 9476-5854 Fx (02) 9476-3231 April 2007  81 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/ If Intel can do it with a Pentium. . . so can we with a Picaxe! Dual Core Picaxe Datacomms by Stan Swan What’s this? Twin Picaxes? Is this Stan’s idea of an April Fools Day Joke? Maybe he’s just seeing double . . . Dual Picaxes! The left Picaxe is the “sensor” while the right Picase is the “doer”. Each must be programmed individually. 86  Silicon Chip siliconchip.com.au I n contrast to their ceaseless quest for raw computing speed (typically now 3GHz) computer manufacturers have recently adopted multiple slower CPUs, with two (“duo”) and even four (“quad”) microprocessors under the PC lid. Doubled-up chips such as as Intel’s popular “Core Duo” offer paired microprocessors working at slower speeds (typically 1.5GHz), resulting in lower overall system energy consumption and reduced waste heat. Given the trend towards ever slimmer and lighter computers, these benefits are especially welcomed, since laptop battery life can be greatly enhanced, weight trimmed and noisy cooling fans reduced in size or even dispensed with altogether. Paired computing hardware may be akin to a twin engine aircraft – two smaller engines providing more performance than one larger engine – but the concept has even lead to Microsoft’s imaginative MultiPoint PC mouse software, potentially offering great appeal in developing world education. (Refer => www.microsoft.com/ presspass/features/2006/dec06/1214MultiPoint.mspx) Multiple USB mice may seem like a video game controller octopus but in resource-constrained countries with limited classroom computers, the ability to connect many mice (each with their own coloured screen icon) may allow valuable student collaboration, enhanced learning and simulation. Naturally, programs will need to be specially written to exploit the Multipoint’s potential. INFRARED SENSOR 3 λ 2 (EG, JAYCAR ZD1952) 1 1 siliconchip.com.au +4.5V IO CHANNELS 2 330Ω 22k 3 10k 1 2 7 IC1 3 PICAXE-08M “SENSOR” 6 4 5 (TO PC SERIAL PORT) 0 1 8 LED1 YELLOW + λ – 330Ω 2 3 4.7 µF PIEZO SOUNDER 4 +4.5V CON2 DB9 IO CHANNELS 2 22k 3 IC2 10k 5 1 2 3 PICAXE-08M 7 0 6 1 4 5 2 (TO PC SERIAL PORT) 8 BOTH PICAXE 08M HAVE COMMON SUPPLY & EARTH LED2 RED SERIAL DATA LINE “DOER” 330Ω 3 λ LED K 8 SC 2007 4 4 A 1 dual Picaxe infrared datacomms A Picaxe driving a Picaxe – not too different an approach now being taken by computer manufacturers. Ours is just a bit cheaper but you definitely won’t be able to play “Doom”. V+ 4.7kΩ 330Ω Seeing double already? There’s no reason why us Picaxe “little guys” can’t adopt the same paired approach, especially since the bare 08(M) chips are now so cheap (~$5) and their inbuilt features allow easy interconnection. Most Picaxeaware schools and hobbyists will, by now, have bulk stocks of the Picaxe08M as well, which makes for convenience against ordering specialized ICs. But just why would we want to do such doubling up? Given their modest energy demands (typically only a few tens of milliwatts) it’s obviously not going to help fight global warming! Although having extra system data memory available is appealing (especially for simple data logging), the real Picaxe benefit arises from SENSOR 4.7kΩ CON2 DB9 5 3 INFRARED 2 3 4 3 4 IR SENSOR + 4.7 µF 22kΩ PICAXE08M 4.5V (3x “AA” ALKALINE) * 330Ω IC1 IC2 5 3 2 330Ω 2 1 0 LED 1 22kΩ PICAXE08M LED 2 5 3 2 2 1 0 10kΩ 10kΩ 0V * OR 4.8V (4x NiCd OR NiMH) PIEZO SOUNDER BLUE NUMBERS – PROGRAMMING PINS GREEN NUMBERS – I/O CHANNELS Here’s how to put it together using our standard Picaxe “breadboard” approach (albeit on a protoboard!). This layout is basically identical to the photo at left. April 2007  87 enhancing the sequential nature of their program execution, since limited branching and interruption is normally tolerated. Several Picaxe commands even lead to the controller just sitting and endlessly waiting for a data signal, with most background tasks agonisingly ignored. It’s a bit like neglecting such boring tasks as doing the dishes while awaiting a possible phone call! Serial input (SERIN) in particular leads to a system hang-up if data fails to arrive and is only normally broken out of by resetting the Picaxe. Future Picaxes apparently may have a timeout setting to overcome this limitation. The example shown this month utilises a Picaxe 08M pair, with one working as a slaved “sensor” (for Infrared data – in tribute to Robert Adler, the TV remote co-inventor, who recently passed away => www.nysun.com/ article/48949) and the other a master “doer” (here accepting serial data and concurrently flashing a LED). If you’ve still got supplies of the original 08 then these could be used for the doer but only the 08M can read IR signals. For those who have just come in and are new to Picaxes, the inbuilt infrared (IR) commands of the more recent 08M have near-revolutionised IR datacomms, with both receiving (via a standard 3-leg receiver) and 38kHz sending (via an IR LED) seamless and cheap. But rather than using yet another 08M to generate IR codes, the sensor Picaxe here just accepts signals from any standard Sony-style IR remote. Your household junk cupboard is probably stuffed full of them. If you have several infrared remotes and are not sure if they are still working (perhaps the original equipment they came with has died?) it’s quite easy to check to see if the remote has output by aiming it at a video camera. Most video cameras are sensitive to infrared and the series of pulses will show up as either white or bright green/purple flashes. And how do you tell if it is a Sonytype infrared remote? If it’s not actually from a Sony device (that makes it really easy!) that is significantly more difficult without being able to read the timing of the pulses (eg, on a ’scope). All we can suggest here is to first determine that the infrared is still working, then try it out with the Picaxe circuit. Perhaps you might be able to borrow a known Sony infrared remote to ensure that the Picaxe circuit is working as it is supposed to. By the way, sophisticated universal IR remotes are increasingly turning up PICAXE BASIC LISTINGS – IRDO.BAS AND IRSENSE.BAS ‘IRSENSE.BAS for Picaxe-08M, supporting April 2007 Silicon Chip ‘Uses 2x 08Ms,one sensing & the other a doing Picaxe. ‘See companion program (IRDO) & duo layout ‘=> www.picaxe.orcon.net.nz/duo.jpg ‘Via => stan.swan<at>gmail.com 27th Feb. 2007 irsense: infrain2 if infra >9 then error high 4:pause 100 sound 2,(100,10) serout 4,t2400,(#infra) low 4 goto irsense ‘waits endlessly until IR data received ‘detects non numeric IR remote key push ‘pin set high alerts ‘doer’ 08M data RTS ‘Piezo + parallel LED key press confirm ‘send IR key value as ‘infra’ (a.k.a. b13) ‘handshake pin set low for ‘doer’ Picaxe ‘loop for further IR remote key presses error: sound 2,(60,5,0,5,60,5,0,5,60,5,0,5,60,5,0,5) ‘fruity wrong key alert goto irsense 88  Silicon Chip cheaply in “Dollar Shops”, so check them if your home junk box collection doesn’t feature a Sony type. Incidentally, although numeric keypads are available for around $10, their Picaxe driving is quite involved, so it may even be worth using such an IR remote as a “poor man’s keypad” when entering numbers to a Picaxe program. Naturally the wiring will be reduced and the sophisticated 127 codes of INFRAIN2 may appeal, as will full wireless control. When compared with Bluetooth, ZigBee and WiFi, IR datacomms is very slow and line of sight (LOS) but it offers ranges typically of 5m in sunlight and 20m in darkness and can readily be bounced around and directed by cheap lenses and mirrors. Of course you can still use the remote when watching TV as well! The “sensor” Picaxe is essentially devoted to just reading (via INFRAIN2) modulated IR signals at the 3 terminal receiver – here a Jaycar ZD1952 (~$8) although cheaper generic versions abound. These powerhouse sensors include an inbuilt detector, limiter, 38kHz band pass filter, demodulator, integrator and comparator. Naturally they need to be looking at the IR source for best response. A piezo sounder and (paralleled) yellow LED provides user key-push You can download from www.picaxe.orcon.net.nz/irsense.bas and www.picaxe.orcon.net.nz/irdo.bas ‘IRDO.BAS for Picaxe-08M supporting April 2007 Silicon Chip ‘Uses 2x 08Ms,one sensing & the other a doing Picaxe. ‘See companion program (IRSENSE) & duo layout => ‘www.picaxe.orcon.net.nz/duo.jpg ‘The received IR data values could be used in many ways, ‘perhaps as program variables,or actioned under SEROUT ‘for LCD display etc. Via => stan.swan<at>gmail.com irdo: if pin4=1 then serial high 2:pause 100 low 2:pause 100 goto irdo ‘RTS alert for serin to accept data ‘Sample ongoing activity-LED flashing ‘here but could be any Picaxe action ‘loop until RTS pin 4 detected high serial: serin 4,t2400,#infra b12=infra+1 if b12=10 then zero sertxd (#b12,13,10) goto irdo ‘Accept serial data pin 4 (‘infra’=b13) ‘Align IR remote keys & ‘infra’ values ‘Test for ‘0’ key which shows as ‘10’ ‘Use F8 to display IR remote key pressed zero: b12=0 sertxd (#b12,13,10) goto irdo ‘Ensure ‘10’ key shows as ‘0’ ‘Display on Editor’s F8 terminal program siliconchip.com.au feedback, with key presses other than the numeric 0-9 even sounding a fruity incorrect key warning. The correct serial data is then sent out from pin 4, preceeeded by a short HIGH signal to alert the recipient Picaxe data is about to follow. The “doer” Picaxe here simply flashes a LED as a background task, and continually looks at the status of the serial line (again Pin 4 here) while looping. If this is sensed high (logic 1) as a voltage sent from the “sensor” Picaxe, then the serial receiving routine is branched to and the data (here just the IR remote key number) accepted. Although still not entirely foolproof, as the handshaking Ready To Send (RTS) alert may be a false alarm causing the “doer” to endlessly wait, data should usually follow a RTS OK. The concept is perhaps akin to the phone ringing (thus RTS) as an alert that someone wants to speak with you (data) – it’s rare that a ringing phone will not have a caller on the other end of course! Since the INFRAIN2 values do not align with the actual key label, the Power Supplies number 1 is added to give compatibility. The 0 key label delivers a 10 on most remotes, so this too has a routine to ensure only a 0 is finally shown. Leaving the Picaxe programming lead connected to the “doer”, and running the editor’s inbuilt “F8” terminal program will usefully show these IR key press numbers on screen. Numerous enhancements of course are possible, perhaps using key values as b0-b9 variables in further programs or for LCD readout. The circuitry is again shown assembled on our now standardised three AA battery powered solderless breadboard Picaxe layout, with supply and ground common to each. Note that each Picaxe will have to be individually programmed! The programming lead will need to be swapped to the correct input points and although the order is incidental, ensure the “sensor” Picaxe has IRSENSE.BAS ported to it, with the 2nd 08M “doer” IRDO.BAS. If you look at the protoboard photo on page 86 you’ll see some purple ink around the three programming input pins (these are also shown clearly in Oscilloscopes RF Generators the component layout diagram on P87). There’s no reason why further Picaxes can’t be chained together in the style we’ve shown and serial communicated with to form – gasp - a simple network! Refer => http://www.kranenborg. org/ee/picaxe/twowirenetwork.htm Readers just at the HIGH 1: WAIT 1: LOW 1 stage, who are still exploring Picaxe LED flashing and the like, may find such a concept daunting. It perhaps may be best understood if related to everyday message and voice communications. “Alert. Message for Smith to hand. Message reads “....”etc”. Enthusiasts are encouraged to extend the multiple Picaxe concept, as all manner of control applications, including remote powering, can be performed by simple two-wire (power/signal and ground) links between microcontrollers, that would otherwise need multiple contact switches and numerous wires. Aside from circuit versatility, the present astronomical price of copper (around $10/kg), means it may make real sense to substitute silicon for costly copper in even modest projects. SC Frequency Counters Spectrum Analysers HAMEG Instruments have always been recognised for the consistent quality and nocompromise value of German engineering. And now the news is even better! With more new products, an attractive educational discount scheme and lower prices for 2007 you owe it to yourself to find out more. Call us please on 1-300-853-407 Test Equipment: Sales, Service and Calibration siliconchip.com.au 1-300-853-407 www.triosmartcal.com.au April 2007  89 Vintage Radio By RODNEY CHAMPNESS, VK3UG How To Build A Super Crystal Set This photo clearly shows the layout of the super crystal set. It’s built on a baseboard measuring 280 x 240mm. If you’ve never built a radio receiver, then a crystal set is a great place to start. Here’s a design that’s very easy to build and get going. R ADIO SETS using all sorts of detectors have been around since the dawn of “wireless” just over a century ago. Very early in the 1900s, one particular detector gained popularity due to its simplicity and relatively high output. This was the “cats whisker” galena crystal detector – hence the name “crystal set”. 90  Silicon Chip Basically, this detector consisted of a galena (lead sulphide) crystal held in a metal cup which formed one end. At the other end was a piece of hightensile wire wound into a short coil and attached to a positioning lever. The positioning lever was manipulated so that the “pointy” end of the wire – known as the “cats whisker” – made contact with the galena crystal. As a result, it had one annoying deficiency when compared to other detectors – you had to probe around the galena crystal with the “cats whisker” until a sensitive point on the crystal was found. This was fine until something or someone dislodged the “cats whisker” from its sensitive spot, which meant that the procedure had to be repeated. This was a nuisance which wasn’t overcome successfully until detectors like the OA47, OA79, OA91, GEX66 and 1N34A fixed point contact germasiliconchip.com.au nium diodes became available. These devices eliminated the “fun” of trying to find the sensitive spot on the galena crystal, as it had all been done by the manufacturer. If the set didn’t work, it was usual to look elsewhere for the fault, since these new detectors were very reliable. However, I remember reading in “Radio and Hobbies” many years ago – in the “Serviceman Who Tells” – about a crystal set that was brought in because it had ceased to work. There isn’t much that can to go wrong with a crystal set and is usual to expect the detector diode to be OK. However, in this particular case, the diode had failed, having been destroyed by a strong signal from an amateur radio transmitter next door. Of course, modern devices are much more rugged than those early types. Fig.1: the circuit for a basic crystal set. Coil L1 can be air-cored (see text for specifcations) or can be wound on a 100 x 20 x 5mm flat ferrite rod using 70 turns of 22 B & S enamelled wire tapped at 10, 20, 30 & 40 turns. High-performance sets Designing a high-performance crystal set isn’t quite as easy as it seems at first glance. A number of points need to be taken into consideration for a design to be successful. The first two essential items are a good, high, long antenna and a good earth. I wrote about antennas and earthing in the March 2003 issue and readers should refer to this to achieve good results. Unfortunately, the antenna/earth system I’d used for several years was inadequate for crystal set operation. The antenna was only about 6m high at the highest point and about 20 metres long. Its replacement has a maximum height of 9m and is around 27m long. It is also generally higher for most of its length than the previous antenna. Ideally, the antenna should be up to 15m high and around 30m long but achieving this on a suburban block isn’t always easy. However, in my case, the modest improvements in height and length noticeably improved the strength of the received signals. As an amateur radio operator, I have always been well aware that the antenna in use needs to be tuned to the operating frequency. This is particularly important when the antenna is much shorter than a tuned length, which 99.9% of broadcast band receiving antennas are. An antenna can be tuned by having a (loading) coil in series with the antenna wire where it connects to the crystal set, with either a tuning gang in series siliconchip.com.au Fig.2: the super crystal set circuit uses L1 & C1 to tune the antenna circuit, while L2 & C2 tune the received frequency. Transformer T1 is included for driving low-impedance headphones. Also included is an optional detector bias circuit consisting of VR1, switch S2, the 47mF capacitor, the 470W resistor & the battery – see text. with the coil or a ferrite rod inserted into the coil. The coil may be tapped to suit as well (more of this later). In practice, the addition of an antenna tuning mechanism is extremely effective when it comes to increasing the signal level into the set. When it comes to making coils, both the coils and coil formers need to be low loss. I’ve found that 60mmdiameter white PVC tubing (available from plumbing and hardware stores) is quite satisfactory for the job. By contrast, cardboard coil formers can attract moisture which increases coil losses. It is important that both the detector and antenna are matched to the tuned circuit(s) for best performance. This is achieved by simply connecting the detector and the antenna to the coil taps which provide optimum matching. Detector efficiencies can vary considerably and you can experiment with various germanium and silicon signal diodes is to achieve the best results. Note however, that silicon diodes usually require a biasing voltage to operate efficiently as detectors. Headphones Good quality headphones with good sensitivity are also needed to get the best performance from a crystal set. I have a pair of 4kW Kriegsmarine headphones which work well but are quite uncomfortable to wear. I also have a pair of Browns “F” type headphones but these have a relatively low impedance of about 150W. And I have a couple of other headphones of rather mediocre quality and a pair of 8-ohm padded stereo headphones. In the end, I wired up the phones socket on the crystal set so I could plug my stereo headphones into the set with the ear pieces in series. I also used a speaker transformer (as used in valve radios) to transform the high-impedance output from the April 2007  91 ferrite-rod coil crystal set, the coil information is as follows: 70 turns of 22 B & S enamelled wire tapped at 10, 20, 30 and 40 turns on a 100 x 20 x 5mm flat ferrite core. The experimental layout can be seen in one of the photographs. This photo shows the layout for the basic crystal set depicted in Fig.1. Super crystal set crystal set to a low impedance output for the headphones. This combination proved to be as sensitive as using the other phones on their own and is much easier on the ears. Crystal set experiments Over the years, I have built a variety of crystal sets ranging a little matchbox monstrosity (mine was anyway) to rather complex twin-tuned coil varieties. And what did I learn from all of this? I found the match box set a very poor performer, as was the twin-tuned coil unit. The latter unit used a 2-gang tuning capacitor and was a failure because, at that time, I didn’t understand that the two (identical) tuned circuits needed to “track” each other. In operation, each tuned circuit was being detuned according to where the antenna and detector connections were made to the respective coils. “Tracking” for those new to vintage radio is the requirement for both circuits to tune to the same frequency no matter where the tuning control is set on the broadcast band. Anyone who has built crystal sets will be aware that the station locations on the tuning dial alter if either the antenna or detector connections on the coil(s) are changed. As a result of my early experiments, I fell back on the old faithful singletuned circuit – see Fig.1. It isn’t the most sensitive or selective crystal set in the world but it works and is easy to get going. In my case, I built one with a normal air-cored coil and another using a ferrite rod as the former for the coil winding. They both worked but would only receive two stations clearly in the Shepparton area – the old 3SR 2kW station on 1260kHz around 20km away and the local 500W community station on 1629kHz about 10km away. If you want to experiment with a The photo shows the author’s Browns “F” type headphones plus two other miscellaneous units. High-impedance headphones (eg, 4kW) are necessary for the circuit shown in Fig.1. 92  Silicon Chip I’ve always wanted to design and build a “super crystal” radio receiver, so I did some experiments back in 2002 with methods of tuning the antenna. My early experimental antenna tuning system was described in the March 2003 issue of SILICON CHIP. Using this device, I could detect four radio stations instead of the single station I could normally receive on my “standard” crystal set. By this time, I had a reasonable idea of what might work well but without being too complex. However, I didn’t want to make a set which used exotic parts, or parts that were hard to make, or one that was so complex that a university degree was necessary to “drive” it. In particular, a twin-tuned circuit would not be suitable, as getting the two tuned circuits to “track” across the broadcast band using a single control would be impractical. By contrast, it would work if I used two independently tuned circuits but that would add additional complexity and the tuning would be a nightmare. And for best performance, the coupling between the two tuned circuits would need to be carefully done otherwise its performance would be inferior to a crystal set with a single tuned circuit. As stated, I had previously had quite good success using a loading coil in series with the antenna. This then connected to an antenna tap on the tuning coil. However, it was purely experimental and although it worked well (and improved the number of stations received), it was touchy to adjust. In particular, the position of the ferrite rod in the coil was quite critical and it had to be adjusted for each station received. What it did show was that the “Q” of the loading coil was quite high. For those unfamiliar with “Q”, it is basically a term relating to the quality (or “sharpness”) of a tuned circuit. The higher the “Q”, the better a circuit is at discriminating between stations across the broadcast band. After all, siliconchip.com.au we only want to listen to one station at a time! Detector bias Some crystal set designs use a battery and a potentiometer to bias the detector to the point where it just conducts. The reason for this is quite simple. Diodes all need a certain amount of voltage applied to them before they conduct. As a result, if we apply a DC voltage to a signal diode so that it just conducts, the diode will be in its most sensitive state and will thus give good performance in a crystal set. This “bias” voltage varies according to the diode used. For example, silicon diodes such as the 1N4148 and the 1N914 require around 0.6V of positive bias to operate, while a germanium diode only requires about 0.2V of bias. On the other hand, the OA47 diode I’ve used works quite well with no forward bias, which has kept my crystal set just that bit simpler. Your own experience may be different, however so be prepared to experiment. By the way, transistor radio detectors often use forward bias to improve sensitivity. (Editor’s note: forward bias on a diode detector also reduces harmonic distortion). Detector load The load that the detector works into is usually a pair of headphones which may have between 2kW and 4kW total resistance. However, the diode will be more efficient if it works into a higher load resistance and some designs use a resistor of about 15kW in series with the headphones to achieve this. In addition, a capacitor of around 1mF is placed in parallel across the resistor so that the audio is not noticeably attenuated. Although my 4kW headphones are good performers they are uncomfortable, so I compared the performance of other headphones against the 4kW pair. As stated above, I ended up using low-impedance stereo headphones fed through a speaker transformer. (Editor’s note: we also recommend the 32W earphones supplied with iPods and MP3 players). Putting it all together The set described here is not only easy to build and operate but outperforms many other so-called highperformance sets. siliconchip.com.au This view shows the front-panel layout for the super crystal set. A good aerial and earth are necessary to achieve good performance – see text. Fig.2 shows the circuit. L1 & C1 tune the antenna circuit, while L2 & C2 tune the received frequency. Transformer T1 is included for driving low-impedance headphones, while the optional detector bias circuit consists of VR1, switch S2, a 47mF capacitor, a 470W resistor and the battery. The set was built on a 12mmthick particle board measuring 280 x 240mm. This is fitted on the underside with four self-adhesive felt pads (available from hardware stores) to keep it clear of the bench. The front panel is made of thin plywood measuring 300 wide x 160mm high. This was given several coats of red paint from a spray can and the labelling on the front panel completed using red Dymo® embossing tape (to match the paint job). Tuning capacitors Tuning capacitors can be scrounged from old valve radios that are not worth restoring. For C2, I used one section of a 2-gang full-size 460pF tuning capacitor. This has a 3/8-inch shaft which suits few knobs (and certainly none of my collection). It did, however, have a dial drum which was left on. I fitted a cut-down top from a tin of cream spray paint over the top of the dial drum (it fitted perfectly), which makes it look better and acts as a “handspan” dial. I was more fortunate with C1 which is a 3-gang 450pF per section tuning capacitor, as this had a ¼-inch shaft. All three sections of the capacitor are used in parallel. The only disadvantage with this tuning gang is that it has a reduction drive, which means that more than a full turn of the knob is required to go from minimum to maximum capacitance. C3 is a 1mF polyester or greencap type, while C4 is a 1nF unit. The voltage ratings of these capacitors can be quite low. Resistors & switches Resistor R1 is used as a “static leak”. Its purpose is to prevent a high-voltage static charge from building up across C1 (eg, during storms) which could lead to flash-over. Note also that if a particularly big antenna is in use, it would be advisable to disconnect and earth it when the crystal set is not being used. Resistor R2 (15kW) is the DC load for the detector. Both R1 and R2 can be 0.5W or smaller. If detector biasing is used, R3 can be a 0.5W unit, while VR1 can be a standard 1kW linear trimpot or a normal potentiometer. VR1 will not normally require readjustment once set. S1 is a 12-position switch which selects one of 11 tappings on L1. Only 11 positions are used; the 12th is left with no connection so that the whole of L1 is in circuit. S2 (if fitted) turns the detector biasing on or off as required. T1 is a standard speaker transformer with a 5kW or 7kW primary impedance and a 3.5W secondary winding. This drives two 8-ohm headphone earpieces in series, so that the reflected impedance to the primary from a 16ohm secondary load is at least 20kW. Within reason, increasing the reflected April 2007  93 Silicon Chip Binders REAL VALUE AT $13.95 PLUS P & P 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: $A13.95 plus $A7 p&p per order. Available only in Aust. Silicon Chip Publications PO Box 139 Collaroy Beach 2097 Or call (02) 9939 3295; or fax (02) 9939 2648 & quote your credit card number. Use this handy form Enclosed is my cheque/money order for $________ or please debit my  Visa Card    Mastercard Card No: _________________________________ Card Expiry Date ____/____ Signature ________________________ Name ____________________________ Address__________________________ __________________ P/code_______ 94  Silicon Chip This view shows the author’s stereo 8Ω headphones at right and a pair of 4kΩ Kriegsmarine headphones at right. The latter can be used with the basic crystal set circuit shown in Fig.1. impedance will assist in maximising the audio output of the receiver. Winding the coils Now we come to the all-important coils (ie, L1 and L2). First, L1 is wound on a 100mm length of 60mm-diameter white PVC pipe. In my case, I wound on 102 turns of 0.63mm (22 B&S) enamelled wire over a length of 70mm. In hindsight, though, around 110 turns would have allowed somewhat more adjustment range to tune the antenna system. When winding L1, it should be tapped every seven turns and there should be 12 tapping points in all, starting right from the antenna end of the coil. If your antenna is significantly different from mine, then the number of turns on this coil to achieve optimum tuning will vary accordingly. L2 is also wound on a 100mm x 60mm-diameter white PVC water pipe and consists of 80 turns of 0.63mm (22 B&S) enamelled wire. This winding is spread over 60mm of the former’s length and the coil is tapped at 3, 6 & 35 turns from the “earthy” end. In my case, I found that using turn three as the tap gave good results. You will need to experiment here – you may need even fewer turns to the first tap if your antenna is larger than mine. Note that the correct position may vary from the high-frequency end of the band to the low-frequency end. Because the detector load is relatively high, it’s possible to connect the detector to a tap quite high up the coil. I found that 35 turns was optimum for best performance in my receiver. As can be seen from the photos, different tapping methods are used for the two coils. For example, L1 has the wire raised away from the former and twisted to make each tapping. By contrast, on L2, a match is slid under the wire at the first tapping point and is then slid along the winding to go under each successive tapping point as the coil is wound. This is the neater of the two methods but is difficult to do effectively if the winding is long and has lots of tappings. With either method, it is necessary to thoroughly clean the enamel off the wire at the tapping points so that a good soldered joint can be made. This can be done by scraping away the enamel using a sharp utility knife. Receiver layout The parts layout on the baseboard is not critical, although the coils should be mounted at the back of the receiver for ease of access. The accompanying photos show the author’s unit. In my case, tuning coil L2 was mounted at the right rear of the baseboard, with L1 in the opposite rear corner. It’s important that L1 is kept several centimetres away from L2, to minimise unwanted coupling between them. Diode biasing As mentioned earlier, some diodes (particularly silicon signal diodes) require about 0.6V of positive bias siliconchip.com.au to maximise sensitivity. Normally, without diode biasing, points A and B are connected together on the circuit. Conversely, if forward biasing is used, points A and B are separated and the small circuit consisting of B1 (a 1.5V dry cell), toggle switch S2, a 470W resistor, a 1kW trimpot (VR1) and a 47mF electrolytic capacitor added between these two points. This circuit is easily adjusted. Switch S2 is closed and trimpot VR1 is adjusted for best volume – simple. Summary Those who have never built a crystal set radio before will find this little set worth the effort. It works well, isn’t difficult to tune and provides good headphone volume on all local stations. For best reception, use a high, long antenna that’s clear of buildings and trees. A good earth is also necessary and a pipe driven about one metre into the ground and kept damp should suffice. Finally, if you wish to read about other people’s designs, the following list makes a good starting point: (1) Look on the Internet. Typing “crystal set society” into Google will give you many interesting sites (and lots of designs) that you can explore. (2) Look in SILICON CHIP for October Photo Gallery: Targan Airmaster MANUFACTURED BY TARGAN ELECTRIC PTY LTD in 1933, the Airmaster was a 3-valve TRF receiver in an upright wooden cabinet. It used the following valve types: 57 detector; 59 audio output; and 80 rectifier. Photo: Historical Radio Society of Australia, Inc. 1988 (crystal set), March 1990 (wave traps), October 1994 (Hellier Award crystal sets), March 2003 (antennas). (3) Look in “Electronic Australia” for June 1988 (crystal set), July 1994 (crystal sets), November 1998 (coils) and July 2000 (crystal set). (4) An excellent Australian book on crystal sets is “Crystal Sets ‘N’ Such” by Bob Young (7 Hayes Rd, Swanpool, Vic. 3673). He has a few available for SC $19:95 posted in Australia. Looking for real performance? NOT A REPRINT – 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 160 PAGES 23 CHAPTE RS Fr om the pu bli sh er s of boost systems • Switch devices on and off on the basis of signal frequency, temperature and voltage Intelligen • Build test instruments to check fuel injector duty cycle, fuel mixture and brake and coolant temperatures • Speedo Corrector, Turbo Timer, Nitrous Fuel Controller & Digital Thermometer Projects t turbo timer I SBN 095 852 294 9 7809 5 8 5229 4 $19.80 (inc GST) -4 s fuel cont rollers 6 NZ $22.00 (inc TURBO B OOST & nitrou GST) Mail order prices: Aust. $A22.50 (incl. GST & P&P); Overseas: $A26.00 via airmail. How eng in managemene t works Order by phoning (02) 9939 3295 & quoting your credit card number; or fax the details to (02) 9939 2648; or mail your order with cheque or credit card details to Silicon Chip Publications, PO Box 139, Collaroy, NSW 2097. siliconchip.com.au April 2007  95 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 PIC Programmer does not work with LCD I purchased the PIC Programmer & Testbed kit (SILICON CHIP, January 2001) from Dick Smith Electronics and have built it. My problem is that I cannot get the LCD module to work. No matter what I try, I am not getting a thing on it. I am using the provided program and I know the PIC chip has been programmed properly as the chaser works. I get nothing from the LCD. I purchased the product with the intention of doing programming on the system to write to the LCD but I cannot get it to work. Is there anything that you can do to help me in this regard? I also purchased another LCD module with the hope I might have blown the first one up but it didn’t work either so I am assuming I have a problem in delivering the signals. I have looked very carefully at the soldering for any problems but there are none. (S. O., via email). • This suggests a connection problem between the main circuit board and the LCD module. Here’s a troubleshooting procedure: (1). Start by checking that you have JP1-JP11 in the “b” positions. This connects the micro’s port pins to the LCD connector rather than the LEDs. (2). Try varying the CONTRAST adjustment (VR3) when running the test program. If this has no effect, use your multimeter (set to VOLTS) to measure between pins 2 & 3 of CON4 while varying the pot from minimum to maximum; you should get a reading of 0-5V. (3). If the above turns up nothing, then power off and use your meter (set to OHMS or CONTINUITY) to verify each of the connections to the LCD module. We suggest that you remove the PIC chip and measure between the ZIF socket pins and the pads on the rear of the LCD module. This checks all connections between the two units. Alternative use for ECG project Thanks for the Electrocardiograph project (SILICON CHIP, February 2005) which has provided quite interesting results. Apart from recording the actual heart beat waveforms using conventional electrodes, it turns out that it can also be used to sense heart beats using red and infrared diodes with a sensor attached to a finger, which also provide clear pulsing blood flows. However, there are problems in trying to analyse the results. The ratio of the red and IR values gives an indication of the oxygen content of the blood (refer to Oximetry on the internet). I tried using a PIC08M to extract pulse information from the analog waveform to the ADC but this proved unreliable and seemed point- less when it was already being done in the ADC anyway. However, the ADC output is at 38,400 bps which seems a bit fast for a PIC08M microprocessor and the ECG Sampler refuses to operate at the other listed settings of 9600 and 28,800. Can you suggest a means of accessing the ADC output at these lower speeds or dare I ask for access to the source code? (D. O., via email). • The sampling rate of the ECG Sampler is directly under the control of the firmware in the PIC16F84 micro, so you would really have to alter the firmware to achieve your aims. The source code is available on our website (ecgsampl.asm) and is fairly well commented, so if you’re used to programming PICs it will hopefully make your job a bit easier. The role of Diacs in lamp dimmers I wonder if you can explain to me what a Diac does in a Triac lamp dimmer circuit? I just don’t see why a resistor won’t do. If it is needed, why don’t they incorporate a Diac in to the Triac package? (C. B. via email). • Essentially a Diac is a symmetrical breakover device. Up to 30V or so in either direction it is an open-circuit but once the breakover voltage is exceeded, it breaks down to a low negative resistance. This is ideal to discharge an associated capacitor to Ultrasonic Eavesdropper Could Check Power Line Insulators Recently I had a chance to look at an “insulator checker” that the South Australian Electricity Trust has for locating noisy insulators. Basically, it looks like an ultrasonic microphone located at the focal point of a parabolic dish about 400mm in diameter. This is fed into an amplifier behind the dish to drive a small speaker as well as a meter. I assume that the amplifier is tuned to 96  Silicon Chip a specific frequency band in order to reject noises that are not required. I believe this device is very effective from reports I have heard. I wonder if you have ever described such a device or whether your Ultrasonic Eavesdropper (SILICON CHIP, August 2006) could be modified for the purpose? I would think this device would be of interest to many amateur radio operators as well as folk with severe power line interference to TV reception. (A. H., Kingston, SA). • Many years ago “Electronics Australia” had a feature article on the use of an ultrasonic microphone and dish for checking high voltage insulators. The principle is exactly the same as in our Ultrasonic Eavesdropper. siliconchip.com.au Antenna Fundamentals I have very poor knowledge about antennas; just enough to know that the design is linked to wavelength or the frequency. Could you please explain in basic terms what is the relationship between the size of the horizontal rods and the wavelength that is received by the antenna? What is the ratio between rod length and wavelength? Or is it put in terms of frequency? I have noticed the older type of TV antennas have rods with varying length whereas the new UHF antennas seem to have rods of a standard length. Could you please help me to understand why antennas are like this? (B. D., Auckland, NZ). • In essence, virtually all (except long-wire) antennas depend on resonance to work. Their elements trigger the Triac into conduction, in a light dimmer circuit. Some Triacs do incorporate a Diac. Soldering/clothing iron timer Have you ever published a circuit for a soldering/clothing iron timer? I envisage it working along the lines of the “vigo” (Vigilance Device) found on trains. After a settable delay, it would alert the user with sound/light and unless the user acknowledges the alarm by pressing a button within some interval, it will cut the power. (D. H., via email). • Have a look at the Universal Safety Timer for Irons and Kettles, in the August 1990 issue of SILICON CHIP. We can supply a photocopy of the article for $9.50, including GST and P&P (Australia). Electrical safety with fish tanks Is there a device available that could be plugged in-line between a power outlet and the power cord of some electrical machine that will display the amount of current being used and then sound an alarm if it drops below a threshold? Even if the power cuts out? There are two reasons I want one: (1) My marine fish tank has 12 devices siliconchip.com.au are typically about a quarter of the signal wavelength in the frequency bandwidth of interest. For example, a quarter-wave dipole designed for operation at 100MHz (in the FM band) will be close to one quarter of the signal wavelength at 100MHz. This is calculated by dividing the frequency into the speed of light (ie, the speed of all electromagnetic signals). Therefore, wavelength = 3 x 100,000,000/100,000,000 = 3 metres. One quarter of this 75cm. According to this, a dipole cut for 100MHz will be 75cm but in practice will be slightly shorter due to “end effect”. There is a huge amount of information on this topic available on the internet. plugged into power boards with cutouts. It is important to know if the power cuts due to one of the boards tripping or if the safety switch at the house’s power box is tripping. (2) I need to figure out why our electricity bills are so high. My wife suspects it is my marine fish tank. There are six big pumps, a water chiller, some heaters and some controllers that turn them on and off, so the current load varies and I want to check the different configurations. I can calculate it theoretically but I want to see actual figures. I do have a multimeter but it is a bit awkward trying to use that with mains power. My second question relates to current leaking from the water chiller. Even if it has not been activated by the controller, current leaks into the fish tank. I had an electrician measure it and although he said it was high, it was within the safe limits. However, I can feel it when I put my hand in the tank, especially through any cut in my hand, and leaking current has been blamed for certain illnesses in fish. I put a “sump grounding probe” in – a titanium probe in the (salt) water that is connected to a stake banged a metre into the ground outside. It reduced the feeling of electricity a fair bit but did not completely remove it. Do you have any suggestions on how to deal with this? JOIN THE TECHNOLOGY AGE NOW with PICAXE Developed as a teaching tool, the PICAXE is a low-cost “brain” for almost any project Easy to use and understand, professionals & hobbyists can be productive within minutes. Free software development system and low-cost in-circuit programming. Variety of hardware, project boards and kits to suit your application. Digital, analog, serial RS232, 1-Wire™, and I2C facilities. PC connectivity. Applications include: Datalogging Robotics Measurement & instruments Motor & lighting control Farming & agriculture Internet server Wireless links Colour sensing Fun games Distributed in Australia by Microzed Computers Pty Limited Phone 1300 735 420 Fax 1300 735 421 www.microzed.com.au April 2007  97 Serial I/O Controller & Analog Sampler I have just purchased the Serial I/O Controller & Analog Sampler kit, from the November 2005 issue. I want to use it to monitor and control the charge/discharge of some large batteries – a total of 48VDC at 700A. I want to monitor the temperature and voltage and switch load and charger during daylight and night. To do this, I need to be able to locate the temperature sensor and LDR remotely. Is this OK or will the long leads of up to five metres cause a problem? Also, what would I need to do to monitor up to 52V DC at the analog input port (normally 25V max) – a It really concerns me that so many cheap submersible electrical devices (pumps and heaters typically) are being sold to fish tank owners – often kids. I’ve had one decent electric shock from a submerged pump that had a cracked housing. The entire fish tank water became live and when I was cleaning the inside my elbow touched the grounded light housing above causing the shock. Sump grounding probes exist but are rarely known about and even though I have managed to get one, I’m not sure that I’m using it properly as it isn’t dealing with the current leaking from the chiller. (S. G.,Beachmere, Qld). • As far as measuring the power consumption of your fish tank set-up is concerned, you could build our Appliance Energy Meter, as described in the July & August 2004 issues. It will re- voltage divider? I assume software changes would be required in the Windows program as well. What about code in the PIC? (J. K., via email). • You should be able to mount the LDR remotely if you use shielded cable for the connection. Miniature 2-core microphone cable would be suitable. Wire the cable shield to ground. A 1kW resistor in series with pin 3 of the micro will help to protect it in the event of static discharge to the long cable run. The second analog input can be modified to accept 52V by modifying it as follows: cord instantaneous power and energy consumption over a period. However, it will not provide any alarm if there is a power cut. Perhaps that feature could be provided by the Aquarium Temperature Alarm described in the September 2006 issue. However, note that the Temperature Alarm would need to have battery backup otherwise it also would be rendered useless in the event of a power interruption. There is no doubt that your marine fish tank set-up could be responsible for a large power bill, especially if you are growing corals and need high-intensity halogen lights. The continuous power draw in a typical set-up could easily be 500 watts or more and over a 3-month period this could easily cost $140 or more, depending on your power tariff. As far as current leakage from heat- Marantz Amplifier Needs Loudspeaker Protection I have a Marantz amplifier in for repair and it has a faulty speaker protection IC that is no longer available. In your experience, how safe is it to “force” the protection relay? There are a number of direct-coupled amplifiers without this provision. I realise that the IC detects DC offsets, transistor failure, etc which can damage the speakers. There are no existing faults. Your comments would be appreciated. (I. M., via email). 98  Silicon Chip • We are not sure what you mean by “forcing” the relay. We think that all high-powered amplifiers should have loudspeaker protection. The consequences of an amplifier failure can be exactly as described in this month’s Serviceman’s pages. If you cannot get the original IC, we suggest you rebuild the circuit along the lines of one our loudspeaker protectors as described in August 2000 or April 1997. (1). Change the 330kW resistor to 110kW. (2). Change the 100kW trimpot (VR1) to 2kW. (3). Break the track between VR1 & LED4 (the ground connection) and insert an 11kW resistor in series with the pot. The above changes will give an input range of about 49V-59V full scale. Yes, you will need to modify the Windows software to get the correct reading. The source code for the software is written in VB5. The PIC firmware should not require modification. ers and chillers is concerned, the only safe way to tackle this problem is to run the whole system via a safety switch or RCD (residual current device). This will kill the power to the system if the leakage current exceeds a safe value and could prevent a nasty shock or fatality. Mind you, this will also mean that you need the Aquarium Temperature Alarm, as noted above. Comparing light outputs from LEDs The light output of LEDs is sometimes stated as so many milliCandelas or Candelas. Recently, I have seen LED light output stated in Lumens. Spotlights are rated as so many watts or in varying amounts of candlepower; eg, 500,000 candlepower. Could you explain the difference between these units and give some sort of equivalence table so that the light output from various sources can be effectively compared? (G. H, Camden, NSW). • The lumen is a measure of total light output, whereas the candela is a measure of the intensity of a light source in a given direction. While there is no general-purpose conversion between these two essentially different measurements, it might be possible to make some rough comparative calculations if the beam angle is known. Check out this website to get an idea of the maths involved: http://autolumination.com/brightness. html siliconchip.com.au Extending the frequency counter SILICON CHIP has given us a good design for the 50MHz frequency counter, now thoughtfully and usefully modified to accommodate pre-scaling and the display of frequencies in the GHz range (February 2007). But spare a thought for those of us who need really good resolution in the audio range: ±1Hz at around 160Hz, for example, is just not close enough for critical work. Could SILICON CHIP publish a neat little multiplier (say, x 100) to insert between the signal and this counter? And while I have the opportunity – ­ how about a decent sweep generator project to cover the frequency range from 5Hz to 50kHz, as a means of testing pre or main amplifier frequency responses? (J. G., via email). • We have not published a multiplier project but we did publish a good circuit to do exactly what you want. It was a “Frequency Multiplier for LF Measurements” in the Circuit Notebook pages of the February 2004 issue. An audio sweep generator could end up being quite a complex project. Instead, you could download a tone/ sweep generator program from the internet, such as http://www.nch.com. au/tonegen/index.html?ref=google&re f2=c10a1&gclid=CKXgjdrxrooCFRTW YAod3zeqsw Burglar alarm questions I am a year-12 student and about to start my major project. It is going to be the PC-Controlled Burglar Alarm Notes & Errata Ultra-LD 2 x 100W Stereo Amplifier (November & December 2001, January 2002): in the “Switching On The First Time” section (pages 71 & 72) of the third part of the series, a stepby-step procedure was presented for connection and testing of the various components of the system. A slight error in the sequence prevents the DC fault protection test from operating successfully. As described in the second paragraph of “STEP 9”, 2 x 1.5V cells are used to test the operation of the DC fault protection circuitry on the Loudspeaker Protection module. However, the negative speaker lead from the amplifier must remain connected to the Loudspeaker Protection module during the test. Without this connection, there is no earth return path back to the power supply, so the protection circuit will be inoperative. System in the February 2006 edition but I have a problem with some PIRs: they have positive, negative and two alarm terminals. The PC board in the magazine has provision for positive and negative (ground) and one terminal for the alarm signal. How does this work? How does it detect if the circuit is NO or NC? Do I need different PIRs? (N. P., Ulladulla, NSW). • Many PIR (Passive infrared) sensors have four terminals. Two terminals provide power for the sensor’s internal circuits and are often marked “+” (positive) and “-” (negative). These two Note that is still important to disconnect the positive lead from the amplifier during this test. As one hapless constructor discovered, if the positive lead is left connected and power is accidentally left on, connecting the battery will instantly destroy one of more of the amplifier’s output transistors, along with their associated emitter resistors! Studio Series Remote Control, April 2006: after power up, channel selection via the optional front-panel switches is not possible until after one channel change has been made via infrared remote. An update to the AT90S2313 microcontroller firm­ ware is available from our website to correct this problem. Constructors of the Studio Series Preamplifier kit do not need this update as channel selection switches were not part of the design. terminals connect to the “+12V” and “GND” terminal block outputs on the alarm board. The second two terminals provide “normally open” (NO) and “normally closed” (NC) outputs. Only one of these must be connected and it’s not important which one you choose. As described in the article, the NO or NC output of a sensor connect to one of the “ZONE” inputs on the alarm board. When running the alarm software, be sure to select “N/O” or “N/C” in the “Configuration” panel to match your SC sensor wiring. 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 April 2007  99 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. CLASSIFIED ADVERTISING RATES Advertising rates for these pages: Classified ads: $27.00 (incl. GST) for up to 20 words plus 80 cents for each additional word. Display ads: $49.50 (incl. GST) per column centimetre (max. 10cm). Closing date: 5 weeks prior to month of sale. To book your classified ad, email the text to silicon<at>siliconchip.com.au and include your credit card details, or fax (02) 9939 2648, or post to Silicon Chip Classifieds, PO Box 139, Collaroy, NSW, Australia 2097. _____________ _____________ _____________ _____________ _____________ PATENT ATTORNEY Dr Lance Roman-Miller Designs Patents www.BluePatents.com contact<at>BluePatents.com _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ 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:___________________ 102  Silicon Chip FOR SALE More control solutions for you! NEW Netiom UDP: a budget priced Ethernet card ($225) which you can use for control and monitoring. NEW Protocol Gateways: Lonworks to Modbus, Profibus to Modbus, Can(J1939) to Modbus, AB-DF1 to Modbus and more NEW Range of serial LCD displays and touch screens. Easily connected to a range of PLCs. NEW Low Cost Dual DC Amplifier Kit: perfect for Data Acquisition. Amplify signals from 1.5 to 10 or reduce signals by a factor of 0.7 to 0.1 Serial Stepper Motor Controller card will now control motors up to 7500pps Motor Controllers from Pololu: we have a range of DC motor and servo motors.These motor controllers have been designed for robotic applications. Electronic Thermostats with digital temperature display; 2 control relays can be used in heating and cooling. NTC thermistor or J T/C or Pt100 sensors. Isolated and Non Isolated RS232 to RS485 converters. USB to RS422/RS485 converter with 1500V Isolation, RTS or Auto Data Flow control. 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. siliconchip.com.au ELNEC IC PROGRAMMERS High quality Realistic prices Free software updates Large range of adaptors Windows 95/98/Me/NT/2k/XP VIDEO - AUDIO - PC distribution amps - splitters digital standards converters - tbc's switchers - cables - adaptors genlockers - scan converters bulk vga cable - wallplates CLEVERSCOPE USB OSCILLOSCOPES 2 x 100MSa/s 10bit inputs + trigger 100MHz bandwidth 8 x digital inputs 4M samples/input Sig-gen + spectrum analyser Windows 98/Me/NT/2k/XP IMAGECRAFT C COMPILERS ANSI C compilers, Windows IDE AVR, TMS430, ARM7/ARM9 68HC08, 68HC11, 68HC12 DVS5c & DVS5s High Performance Video / S-Video and Audio Splitters MD12 Media Distribution Amplifier QUEST ® Quest AV® HQ VGA Cables GRANTRONICS PTY LTD www.grantronics.com.au Satellite TV Reception SPK360 3/5/06 1:10 PM Page 1 20 years experience! 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 HI-FISPEAKER REPAIRS SPK360 YOUR EXPERT SPEAKER REPAIR SPECIALISTS Specialising in UK, US and Danish brands. Speakerbits are your vintage, rare and collectable speaker repair experts. Foam surrounds, voice coils, complete recone kits and more. Original OEM parts for Scan-Speak, Dynaudio, Tannoy, JBL, ElectroVoice and others! 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°. tel: 03 9647 7000 www.speakerbits.com DC, Stepper & Servo Motor controller kits. Serial and Parallel Port relay controller cards. PIC MicroProgrammers: serial and USB port operated. 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. 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 siliconchip.com.au Silicon Chip Circuit Ideas Wanted Do you have a good circuit idea? If so, sketch it out, write a brief description of its operation & send it to us. Provided your idea is workable & original, we’ll publish it in Circuit Notebook & you’ll make some money. We pay up to $100 for a good circuit idea or you could win some test gear. Silicon Chip Publications, PO Box 139, Collaroy, NSW 2097. VGA Splitter VGS2 AWP1 A-V Wallplate Come to the specialists... ® Quest Electronics® Pty Limited abn 83 003 501 282 t/a Questronix Products, Specials & Pricelist at www.questronix.com.au fax (02) 4341 2795 phone (02) 4343 1970 email: questav<at>questronix.com.au www.dontronics.com has 300 selected hardware and software products available from over 40 world wide manufacturers, and authors. Olimex Development Boards & Tools: ARM, AVR, MAXQ, MSP430 and PIC. Atmel Programmers And Compilers: STK500, Codevision C, Bascom AVR, FED AVIDICY Pro, MikroElektronika Basic and Pascal, Flash File support, and boot loaders. PICmicro Programmers And Compilers: microEngineering Labs USB programmers, adapters, and Basic Compilers, DIY (Kitsrus) USB programmers, MikroElektronika Basic, Pascal, DSpic Pascal Compilers, CCS C, FED C, Hi-Tech C, MikroElektronika C, disassembler and hex tools. CAN: Lawicell CANUSB, CAN232 FTDI: USB Family of IC ‘s. FT232RL, FT2452RL, also BL and others. 4DSystems LCD/Graphics: Add VGA monitor, or OLED LCD to your micro. Simple Serial I/F. Heaps And Heaps Of USB Products: TTL, RS-232, RS-485, modules, cables, analyzers, CRO’s. Popular Easysync USB To RS-232 Cable: Works when the others fail. Only one recommended by CBUS. Money back guarantee. www.dontronics-shop.com April 2007  103 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. RFMA 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. Advertising Index 555 Electronics............................. 59 Altronics.................................. 82-85 Send to: Retail Operations Manager - Jaycar Electronics Pty Ltd P.O. Box 6424 Silverwater NSW 1811 Email: jobs<at>jaycar.com.au Amateur Scientist CDs............... IBC Jaycar Electronics is an equal opportunity employer and actively promotes staff from within the organisation. Dick Smith Electronics............ 16-21 Av-Comm................................... 103 Dontronics.................................. 103 Ecowatch.................................... 103 Elan Audio.................................... 61 RF Modules Australia Grantronics................................. 103 Applications: NEW! BiM2A Rural UHF FM Transceiver UHF FM Transceiver Utilities In Stock NOW! In Stock NOW! Industrial Range: 500m+ Range: 250m Commercial Power: 25mW Power: 10mW Data rate 64kbps Government Data rate: 64kbps 33mm x 23mm x 4mm BiM2T & BiM2R coming Meter Reading RADIOMETRIX: Low Power, Licence Exempt Radio Modules Instant PCBs.............................. 103 Low Power Wireless Connectivity Specialists BIM2-433-64-5V RF Modules Australia. P.O. Box 1957 Launceston, TAS., 7250. Ph: 03-6331-6789. Email: sales<at>rfmodules.com.au. Web: rfmodules.com.au DOWNLOAD OUR CATALOG at www.iinet.net.au/~worcom WORLDWIDE ELECTRONIC COMPONENTS PO Box 631, Hillarys, WA 6923 Ph: (08) 9307 7305 Fax: (08) 9307 7309 Email: worcom<at>iinet.net.au MicroByte Electronics: PIC Micros – Development Board – Development tools & Components. Phone: (03) 9378 4288. info<at>microbyte.com.au; www. microbyte.com.au CLEARING ALL STOCKS of throughhole ICs for free. You pay $2.00 for post & pack. Limit 10 per customer. Go to www.lazer.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 LEDs! New old stock standard brightness and superbright brand name LEDs from just a few cents each. Cree X-Lamp XR-E LEDs $14.50. TA8050P bridge DC motor drivers $1.50. 20 x 2 OLED 104  Silicon Chip Parallax Basic Stamps The awesome simultasking 8-core Propeller Chip. Lots of sensors and Development kits + Robots. Ultrasonics, PIR accelerometer. Serial LCD display, serial keypads. Stepper Motor Controllers & Motors Micro stepping up to 25,600 fully protected industrial grade controllers at incredible prices. PCB mount units with full 32 bit indexer capability. DIN rail mount controller for factory applications. See our website for details and PDF file. Call or email us for application assistance. ron<at>nollet.com.au R T Nollet: Ph (03) 9338 3306; fax (03) 9338 4596; mobile 0407 804 712. www.nollet.com.au displays $39. Also LED and nixie clock kits and all sorts of other stuff. www. ledsales.com.au 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 Harbuch Electronics..................... 81 Jaycar ....................... IFC,49-56,104 JED Microprocessors..................... 5 Lance Roman-Miller................... 102 Measurement Innovation................ 7 MicroZed Computers.................... 97 Ocean Controls.......................... 102 Quest Electronics....................... 103 RCS Radio................................. 103 RF Modules................................ 104 Rockby Electronics......................... 9 RTN............................................ 104 Sesame Electronics.................. 104 Silicon Chip Binders................ 58,94 Silicon Chip Bookshop........ 100-101 Silicon Chip Subscriptions........... 79 SC Perf. Elect. For Cars.......... 65,95 Siomar Battery Industries............... 3 Speakerbits................................ 103 Splat Controls............................... 31 Trio Smartcal................................ 89 VAF.......................................... OBC WES Components........................ 61 Worldwide Elect. Components... 104 PC Boards Printed circuit boards for SILICON CHIP designs can be obtained from RCS Radio Pty Ltd. Phone (02) 9738 0330. Fax (02) 9738 0334. siliconchip.com.au