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SILICON CHIP Basslink SEPTEMBER 2008 ISSN 1030-2662 09 9 771030 266001 PRINT POST APPROVED - PP255003/01272 8 $ 50* NZ $ 9 90 INC GST INC GST HOW THEY MOVE 400,000V DC ACROSS BASS STRAIT ELECTRICIAN’S AS3017 TEST SET FREE! siliconchip.com.au 2008-9 CATALOG AUSTRALIA ONLY ALL-NEW RAILPOWER CONTROLLER h September 2008  1 witr d a ee r ! f n i ot rem SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings.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.21, No.9; September 2008 SILICON CHIP www.siliconchip.com.au Features 13 The Basslink High-Voltage DC Power Link How do you get 500,000V DC across 300km of wild water? Basslink is the longest undersea HVDC power link in the world – by Michael Goebel Railpower Model Train Controller – Page 22. 31 Review: Metrel Instaltest 3017 It not only prompts you through all the compulsory AS/NZS3017 electrical tests but also allows you to print out a report for the client as is now mandatory – by Leo Simpson Pro jects To Build 22 Railpower Model Train Controller It features infrared remote control, variable inertia and a pulse power output to ensure smooth control of your locomotives – by John Clarke Versatile LED/Lamp Flasher – Page 34. 34 Versatile LED/Lamp Flasher Looking for a replacement for the LM3909 LED flasher/oscillator IC? This versatile LED/lamp flasher module will do the job – by Thomas Scarborough 58 Ultra-LD Mk.2 200W Power Amplifier Module, Pt.2 Pt.2 this month gives the assembly details for this new high-performance module & describes a suitable power supply – by John Clarke & Greg Swain 72 DSP Musicolour Light Show; Pt.4 Simple add-on circuit lets you drive your new DSP Musicolour using a standard infrared remote control handpiece – by Mauro Grassi 76 LED Strobe & Contactless Tachometer, Pt.2 Pt.2 has the assembly details for the photo-interruptor and IR reflector amplifier modules. We also describe how the unit is used – by John Clarke Ultra-LD Mk.2 Amplifier Power Supply Module – Page 58. Special Columns 40 Serviceman’s Log One man’s trash is another man’s treasure – by the TV Serviceman 53 Circuit Notebook (1) Kill Those Adverts Quickly With The Supermute; (2) 4017 Counter Tester; (3) Water Tank Level Indicator; (4) PICAXE-Based Star 5W LED Control Unit; (5) Low-Power Class-A Valve Amplifier; (6) Sweep Frequency Generator For Audio Testing DSP Musicolour Remote Control – Page 72. 80 Vintage Radio The Raycophone “Pee Wee” Midget – by Rodney Champness Departments   2   4 38 92 Publisher’s Letter Mailbag Product Showcase Order Form siliconchip.com.au 88 Ask Silicon Chip 91 Notes & Errata 93 Market Centre PhotoInterruptor & IR Reflector Amplifier Modules – Page 76. September 2008  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 John Clarke, B.E.(Elec.) Technical Staff Ross Tester Jim Rowe, B.A., B.Sc, VK2ZLO Mauro Grassi, B.Sc.(Hons.) Photography Ross Tester Reader Services Ann Morris Advertising Enquiries Glyn Smith Phone (02) 9939 3295 Mobile 0431 792 293 glyn<at>siliconchip.com.au Regular Contributors Brendan Akhurst Rodney Champness, VK3UG Mike Sheriff, B.Sc, VK2YFK Stan Swan SILICON CHIP is published 12 times a year by Silicon Chip Publications Pty Ltd. ACN 003 205 490. ABN 49 003 205 490 All material 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 Digital TV is being wasted Anyone who watched the opening ceremony of the Beijing Olympics on a large-screen high-definition TV set or projector could not fail to have been impressed. Not only was the sweep and pageantry of the ceremony itself a wonderful showcase for Chinese civilisation and culture, the HDTV medium added to the gorgeous spectacle. In subsequent days, the competition has been inspiring and the HDTV pictures have given wonderful close-ups of the athletes in their all-out efforts. In watching this programming, it is very easy to conclude that HDTV is fantastic technology which everyone can enjoy. This is no doubt great for the Seven network and to a lesser extent, the SBS network which chose to cover certain events in full. This editorial is written just a few days after the opening ceremony so I don’t know how the Olympic Games will eventually pan out. No doubt it will be a great success for China but there is considerable doubt that any country staging the Olympics in future will decide to spend so much money. But after the Olympics, what is the future for HDTV programming? From my perspective, it looks pretty barren. Take away sport and there is not much to watch in HDTV. Sure, there is the occasional documentary which takes full advantage of the medium but the rest of network programming is just as good (or bad) as in standard definition. In fact, the extra channels provided by the introduction of digital TV are simply going to waste. In the case of the commercial channels, most of the time the broadcasts are exactly the same or maybe just time-shifted. And in the case of the ABC2 network, the programming is either puerile or a repeat of the previous day’s programs. If you were to give a mark out of ten for the benefits brought about by digital TV programming, all the networks except SBS would get a failing mark. Surely, digital TV can be put to better use than that! Even repeats of old movies (presently available in PayTV) would be better than much of the dross that is currently being served up. Why not put it to some real use? How about some educational programming? Surely there must be thousands of hours of educational programming available for the asking and the range of topics must be very wide. Wouldn’t it be wonderful, for example, if you could see a series on astronomy? Carl Sagan’s Cosmos comes to mind, as does the American series The Astronomers. In fact, I see the possibility of regular programming on astronomy forever. The field is infinite (pun intended). Or what about ballroom dancing (a subject close to my heart)? There is plenty of flashy programming along the lines of “So you think you can dance?” but nothing on actually learning to dance. There is great potential for such broadcasts, especially since the popular TV series and films on dancing have made it so popular. Or why not, perish the thought, some programming on electronics and a whole range of science-related topics? How about a detailed series on nuclear power? Such a series could not only explain how nuclear power is generated in great detail but would also give a better perspective on the storage of waste products. It could dispel a lot of the ill-informed paranoia that currently exists. You can see the potential. Digital TV, whether in standard definition or high definition, is a wonderful resource. Currently it is simply being wasted. Leo Simpson siliconchip.com.au For all those innovative, unique, interesting, hard to find products Portable HD & NAS Enclosures Cat. 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Dual head video cards are now in abundance, however if you require more than two displays it can still be an expensive exercise. Thankfully with MicroGrams new USB to VGA adapter you can add up to six extra displays, without even opening the case. (One adapter is required per additional display). Cat. 15179-7 $197 Voice Activated Universal Remote Control Operate any device that uses a remote control with only your voice. This intelligent universal remote control can store up to ten operations per single voice command and has a maximum of four different users. Cat. 8551-7 $389 Cat 8551 Intel LGA775 Motherboard with ISA slots Need a PC with ISA slots for expensive legacy cards? Some medical and industrial equipment still relies on old ISA cards to interface with a PC. As the cost of these interface cards can be thousands of dollars it is sometimes more cost effective to buy a new PC. MicroGram can supply a motherboard that has two ISA slots with the latest Intel CPU socket (LGA775). Cat. 17115-7 $649 Cat 17115 Cat 9526 12v Input ATX Power Supply Run a standard PC in a car, boat, or any other 12v DC source. Simply replace the ATX power supply in the PC with this unit & connect 12V DC from a suitable source and the PC runs as normal. Cat. 9526-7 $319 Not sure what product you need? Call us today for friendly advice! www.mgram.com.au Serial Add-on Cards Cat. 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More product lines available from MicroGram Point of Sale Hardware • 12v Mobile PCs & LCDs Data Logging & Control • Networking Products Video & Audio Equipment • Power Protection PC Sharing Switches • Thin Clients PC Device Extenders • Diagnostic Tools CD & DVD Duplicators • IP Surveillance EPROM Programmers • RAID & Backup Hardware Macro Keypads • USB Microscopes Express Cards • HDMI Switches & Splitters 1800 625 777 ask<at>mgram.com.au www.mgram.com.au September 2008  3 All prices subject to change without notice. For current pricing visit our website. Pictures are indicative only. SHORE AD/MGRM0508 1800 625 777 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”. Power meter reveals all I read the article debunking the claims of the Enersonic Power Saver (SILICON CHIP, May 2008) and chuckled with amusement. But another thing I gained from reading it was your mention of the Mains Energy Meter available from Jaycar (MS6115). I’ve often thought about doing a “power audit”, especially with all the talk about greenhouse emissions and energy use, etc. A few issues back, I read an article about being “greener” and one thing that was mentioned was the bad habit Australians have of keeping an extra “beer fridge” in the garage. Well, I have one such drink’s fridge and have been considering getting rid of it after reading that article. However, the power meter has revealed all. My drinks fridge is only about 1m high and gets opened on average about once per week. When the fridge is USB power injector is the right solution I was reading your article on the USB Power Injector and your problems operating an external hard drive with a “Y” cable (SILICON CHIP, June 2008). I’m pretty sure I can explain things. The USB specification says that devices can only draw up to 100mA by default. Any more and the device needs to ask for it, up to a maximum of 500mA. Even with a “Y” cable, a device can only talk to one USB running it draws 43W. As it cycles on/ off, in total over a week it uses 2kWh of electricity. This means that, at the current cost of 12 cents per unit, according to my last bill, that fridge is costing me 24 cents a week to run, which is a whopping $12.48 per year! If I get rid of my drink’s fridge, I’ll need a bigger fridge in the kitchen to hold the drinks, and since the kitchen fridge gets opened several times a day, I reckon this would end up using more power. To add to this, when I examine my electricity bill I see there is a fixed “supply charge” as well as the cost of actual consumption. The price per unit is so low that there’s little, if any, incentive to reduce consumption. If governments want to get serious about reducing emissions, then as part of that, they need to encourage us to reduce energy consumption. The fixed component of the bill should be significantly lower and the price per port to reconfigure it. This means the maximum power a device with a “Y” cable can be guaranteed to get is 600mA. Not all computers enforce power supply limits but it would seem that your “troublesome” computer is one of them! As a reliable way of satisfying power-hungry devices, a “Y” cable is next to worthless and your USB Power Injector really is the right way to go. Andrew Gregory, Duncraig, WA. unit should be significantly increased. I notice the situation is much the same with water – a high fixed cost and a low consumption cost. This tells me the suppliers are not interested in us reducing consumption of anything. Greg Newton, via email. Comment: we really think you just wanted an excuse to keep your beer fridge! Seriously, it is a good analysis. The current billing schemes do not encourage economy. Easy fuel consumption conversion Ray Smith seems to have “shot himself in the foot” with his letter published in the July 2008 issue. If I was going to drive 900km with a car using 9l/100km, I would only use 81 litres, which at $1.50/l would cost me $121.50. A conversion that readers might be interested in is that to convert MPG to l/100km or vice versa, simply divide 282 by the given number. For example, 9l/100 km converts to 282/9 = 31.33 MPG, or 25 MPG converts to 282/25 = 11.28l/100km. Alan Torrens, Hornsby, NSW. House rewiring is expensive Congratulations on providing information on sites to get information on the correct wiring of household electrical circuits (SILICON CHIP, June 2008). I am very poor and live in a house www.furzy.com We Create Electronic Controllers 4  Silicon Chip siliconchip.com.au Old wiring should not be disturbed I have some comments regarding the article on DIY wiring in the June 2008 edition, based on some know­ ledge of the situation. I personally have no problem with anyone removing switches or power points so that walls may be more easily painted, or replacing faulty lamp holders, etc. Who would know anyway? Most electricians wouldn’t care – they already have too much work. If the house is old and has rubberinsulated cables it would be better not to remove any fittings at all because the slightest movement of the wires may cause the insulation to fall off. Get the house rewired in this case. Running cables and having an inspector connect them just could not happen in Victoria. Cables must first be adequate for the current carried and run properly so that they won’t be damaged by people walking around in roofs and they have to be de-rated if enclosed in insulation or conduit. This takes a certain amount of experience to ensure a conforming installation. Inspectors are self-employed here and are used to inspect, not finish that has old cotton-covered wiring that at times catches on fire. My son had six down-lights installed by a licensed electrician and it cost him $1300. Ridiculous! Given the information you provided in the June issue, I can now make my home safe, at a reasonable price. I do not want to see electricians out of work but in my old fibro home I feel that is safer for all if I do the work. It is not a choice thing but a cost thing. If I could afford a sparkie I would choose to have the work done by one and stick to my own areas of expertise. I must say that I have been to every library I could around Sydney and have been unable to get any information on doing your own wiring. It is uncanny. I also think that it is strange that the manufacturers of power points and switches often fail to provide a circuit diagram. Every other electrical device siliconchip.com.au off, other people’s wiring. The NZ guide implies that they could add lighting fittings. Much attention has been given in Australia recently to ensuring that ceiling down-lights don’t set fire to the house. Where does the amateur installer get this knowledge, unless he studies AS/NZS:3000 intently and reads the trade magazines? In regard to the press release on page 17 of the June 2008 issue, this was issued by the electrical safety organisation of WA and is in line with what is mandated or intended in other states. That is, live work is prohibited except in exceptional circumstances. The possibility of electric shock is bad enough but on an industrial switchboard the fault current could well vaporise tools or other metal­ work in close proximity to the electrician in the event of a fault occurring, resulting in serious burns at least. In summary, I think that the status quo will remain and that your readers will do what they feel comfortable doing on their house wiring but it won’t be strictly legal, though generally safe. Name supplied but withheld at writer’s request. I buy has information on safe usage. Why not power points and switches? Name and address supplied but withheld at writer’s request. Comment: as pointed out in the Publisher’s Letter in the August 2008 issue, many people cannot afford the charges of electricians and certainly not for a complete rewire, as in your case. If you are going to proceed with new wiring, you would be wise to at least purchase a copy of AS/NZS 3018. It costs over $90.00 but where people need to do extensive re-wiring, we would strongly recommend it. To purchase it on-line, go to http:// www.saiglobal.com/shop Australians should not do their own wiring I wish to comment on the recent SILICON CHIP push for Australians to be able to do their own in house wiring. I completely disagree. These rules are 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 September 2008  5 Nuclear power should use molten salt reactors With regard to the Publisher’s Letter in the July 2008 issue, I would agree with using nuclear power generation but not utilising the types of reactors installed around the world now. In general, they are very wasteful of the fuel. In the 1950s and 1960s Oak Ridge National Labs (ORNL) developed the Molten Salt Reactor (MSR) which was dropped due to politics, just as they were about to build their third experimental MSR, the Molten Salt Breeder Reactor Experiment. This would have converted Thorium 232 to uranium for its fuel. there to protect innocent people from dodgy wiring. Being allowed to hack at your own wiring sounds good in theory but what happens when you sell your house? The new owners’ kids might get killed by the previous owner’s bad wiring. The new owner has NO way of knowing what the history of the house wiring is. By letting non-experienced people play with 240VAC wiring we are going to reduce the standard of wiring throughout Australia which will eventually lead to deaths. Now I have done my own wiring but I accept that it is not technically legal for me to do so. If I ever sell my place 6  Silicon Chip I will probably get a qualified electrician to look over it and give it the nod so I can feel comfortable that someone won’t die in the future because of something I did wrong. David Ferguson, Kincumber NSW. Comment: there are two problems with your point of view. First, as alluded to in the letter above, there are vast numbers of older homes in Australia which have dodgy wiring which really is a hazard and many people simply cannot afford to have it fixed by an electrician. That is why we think that electrical energy authorities should look at offering a subsidy to have the wiring fixed. Second, as will be obvious from the story on AS3017 testing on page 31 of this issue, electricians cannot simply “give the nod” to a house’s wiring. If they are asked to do a report, it will not be cheap. We also think that anyone purchasing an old house should have a full wiring safety report. If the report points up problems, this can be part of the sale price negotiation. The biggest advantage of MSRs is that the fuel is present as a hot liquid salt of about 0.9% uranium tetra­fluoride, in a mixture of other fluoride salts. All other advantages flow from this such as a thin-wall reactor vessel that is not pressurised and easy removal of reaction products. Molten Salt Reactors are stable if the reaction rate increases. There is a lot of information on the internet about MSRs. Currently there are no working MSRs as the last one, ORNL’s MSRE, was shut down in 1969. Derrick Watson, via email. Electrical engineers’ wiring course no longer available It would seem that New Zealand has more going for it than just Sauvignon Blanc. Wouldn’t it be nice if some sense prevailed in Australian electrical wiring regulations? Several years ago, I attempted to enrol in a TAFE course “Electrical Wiring for Electrical Engineers”. This 6-month course allowed electrical engineers to do their own domestic wiring. I finally tracked down the (ex) course coordinator who informed me that the course was no longer available due to lobbying by the ETU. I believe it was electrical engineers that wrote the wiring rules but we, like every non-electrician in Australia, are apparently not capable of applying them. Isn’t it time we changed this ludicrous situation? Craig Alexander B.E. (Elect), Wagga Wagga, NSW. Nuclear waste is a problem The Publisher’s Letter on nuclear power stations (July 2008) was right siliconchip.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.altronics.com.au JOIN THE TECHNOLOGY AGE NOW Mailbag: continued with PICAXE Developed as a teaching tool, the PICAXE is a low-cost “brain” for almost any project Easy to use and understand, professionals & hobbyists can be productive within minutes. Free software development system and low-cost in-circuit programming. Variety of hardware, project boards and kits to suit your application. Digital, analog, RS232, 1-Wire™, SPI and I2C. PC connectivity. Applications include: 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 8  Silicon Chip More detail on applying solder paste to SMDs I found myself reading and rereading the March 2008 issue. It really is a gem, probably reflecting the fact that the lead items on SMDs and the DDS VFO are both areas of my current project work. I wonder whether Jim Rowe could be persuaded to provide a little more detail on his solder-paste applying “mini-spatula”? I would particularly like to know the material he used for its blade. Similarly, could he provide details on his very narrow roller applicator that he mentions having also constructed? As to the use of the toaster oven, I have been meaning to try this method after first seeing it described in “Amateur Radio” magazine some 3-4 years ago. Jim’s detailed description of its use begs an immediate question though. How much more useful would the oven be if it had a suitable microcontroller to manage the temperature and timing? Indeed, two such controllers have appeared in “Elektor” magazine, most recently in the December 2007 issue. The first design was complex and used some rather esoteric components, meaning the project was expensive. The latter offering has been simplified design wise but is complicated by the fact that “Elektor” chose to make the project available only as a largely pre-assembled, bolt-together kit, at a price of 75 pounds. So how about a S ILICON CHIP SMD Toaster Oven Controller? This would seem to be a relatively easy application, perhaps one that would require only moderate reprogramming of an existing microcontroller project so that it can monitor the temperature on the target PC board near the chip in question and then to the point. However, as I understand it, there is one major hitch in that it seems to be uneconomic to dispose of the highly toxic waste from the process. I also laud your stand on DIY wir- control the switching to match the ideal temperature curve described in the March 2008 article. A useful extension though would be to also include switching software to allow the oven to also be used for the baking process to achieve MSL ratings. I believe the December “Elektor” design does have this added feature. Bill Maxwell, Powranna, Tas. Jim Rowe comments: the material used for the blade of the mini spatula was phosphor bronze: a strip 0.3mm thick, salvaged from one of the contact strips on an old relay. It was about 7mm wide and I cut off a 32mm length, leaving one of the original mounting holes near one end to allow mounting in a slot at the end of the “handle” (a 150mm length of 8mm diameter aluminium rod) using a single 2mm screw and nut. The outer end was then narrowed to a tapering rounded point, using tin snips and then a small grinder. The wheel for the narrow roller applicator was turned from 10mm diameter acetal rod, which was drilled with a 3mm centre hole and then cut off to give a disc 1mm thick. This was then mounted in a 1.1mm wide slot cut in the end of another 150mm length of 8mm aluminium rod, using a 3mm screw as the axle. The hole for the screw was tapped with an M3 thread. I just smeared out a quantity of the solder paste on a glass plate, and then picked up a small quantity on the spatula to smear it over the SMD pads. This seemed to make it easier to produce a reasonably even smear but you may find the alternative a bit easier for you. Whichever way you choose though, it’s not easy – a bit like trying to spread caviar in a stripe that is even in both width and thickness. ing. One circumstance where people should take care though is where there is little room to negotiate a good job. This is where an experienced electrician perhaps should be used. There are many power points and light switches siliconchip.com.au where the installer left a minimal amount of slack and that makes it difficult for us mortals to make a good firm contact. George Briansky, Emerald, Vic. Comment: storage of nuclear waste is a problem but ultimately, it should be possible to process spent nuclear fuel rods for re-use in power stations. HOPERF Slide scanner is a winner My mouth fell open when I saw the article on a slide scanner in the June 2008 issue because I had just “scanned” over 400 of my grandmother’s colour slides using a similar technique. The transparencies were up to 44 years old and were mostly in good shape, with only a few spoiled by mould, but their cardboard frames were delaminating and jamming in the projector. The lack of mould is probably because my grandmother lives in the UK; the house has been centrally heated since the early 1970s and I imagine that would keep the humidity low. It took me four hours to do the job and that included setting up. I did it with a very crude set-up due to time and materials constraints. My camera is a 3.2MP Canon Powershot A410. I tried two set-ups. My first attempt used a 20W compact fluorescent tube for illumination. I positioned a passive slide previewer with its viewing lens right next to the end of the CFL tube so that the light uniformly illuminated the translucent screen. Slides were simply propped against the translucent screen of the slide previewer (which in this application is being used back-to-front). I found that with this arrangement a lot of stray light from the CFL tube reflected from the front of the camera onto the front of the slide, so that a ghost of the camera was visible in the images. To solve this, I simply threw a towel over the CFL tube and slide previewer and tucked it tightly around the edges of the translucent screen but after only 10 minutes it all got so hot that the lens on the slide previewer melted and sagged! After that little accident I changed the light source to a single-AA-cell/ single-LED torch I happened to have siliconchip.com.au Digital Sensors RF IC & Modules Semiconductor Devices SAW Devices Distributed in Australia by Microzed Computers Pty. Limited Phone: 1300 735 420 Fax: 1300 735 421 www.microzed.com.au with me. I unclipped the unharmed translucent screen from the slide previewer and sticky-taped it to the end of a tube of aluminium foil, placing the LED torch in the other end of the foil tube. The illumination of the translucent screen using this method wasn’t quite as uniform as using the lens on the slide previewer but you’d have to examine the images pretty closely to notice. I kept the room dark to avoid reflections from the viewing side of the slides. I took each shot with the camera balanced on my thumbs, to enable me to frame the shot to suit each slide, and pressed the shutter release between heartbeats and with my breath still – there is no obvious blurring in the resulting images. My camera was set to auto white balance, and the colour balance on the resulting images looks fine. Many of the older slides were in a 1:1 aspect ratio, with the transparency both wider and higher than in 35mm slides and I mostly chose to crop them (my camera has a 4:3 aspect ratio), concentrating on just getting all the people into the frame. With group shots, in addition to snapping the full slide I moved the camera closer to the slide to get more September 2008  9 Mailbag: continued Helping to put you in Control Peripheral Devices We have a selection of peripheral devices for your controller New Relay Cards Each relay can be operated by 0 -5V, NPN and PNP open collector signals. 12V or 24V powered. Cards available with 2,4 and 8 relays. Can be fitted with DIN rail Mount. Prices from $21.50+GST. RS232 To TTL Interface Convert RS232 to TTL and vice versa (TX and RX). This will allow your microcontroller to communicate with a computer. $15+GST Annemometer Our KTA-250 interface allows you to connect a Davis Instruments anemometer to a PLC, Data Acquisition system or SCADA system. 4-20mA, Modbus and alarm outputs $159+GST DIN Rail Terminals Paying too much for Din Rail Terminals, Fuse Terminals, Test Switch Terminals and Earth Terminals. Great quality at a low price From $1.60+GST Accelerometers Accelerometer Breakout boards range from +/-2G to +/10G. Available as 2 and 3 axis. From $39+GST Nylon Cable Glands IP68 rating. Sizes PG7 to PG29 Prices from $1.50+GST Contact Ocean Controls Ph: 03 9782 5882 www.oceancontrols.com.au 10  Silicon Chip Loudspeaker protector is desirable for Bridge Adaptor The Bridge Adaptor for Power Amplifiers featured in the July 2008 issue looks useful. You use an SC480 amplifier as an example, which uses a Polyswitch for speaker protection. For whatever reason, some people do not like Polyswitches wired into their amplifiers. Some amplifiers use other means of speaker protection which as a rule use transistors or ICs plus a relay for this purpose. This type of speaker protection has detailed shots of individuals. I found that I had to manually adjust the aperture for a small proportion of the shots where the background was either significantly lighter or darker than the faces – a newer camera with face detection would make this unnecessary. I did the whole shoot on a single charge of a pair of 2500mAH NiMH AA cells in the camera and the OEM single AA cell in the LED torch. I have burned the images onto a DVD so that my grandmother can show them by just popping the disk into her DVD player. But I have cautioned her to hang onto the original slides, as the image quality of the slides is far superior to that of the digital copies. Andrew Partridge, Toowoomba East, Qld. 2.4GHz airways museum project I am working on a 1:72 scale model of a 33MHz airways navigational aid for our museum (see www.airwaysmuseum.com). This is to be a working model with the wavelength to scale, requiring a frequency of 2.4GHz. The aid was based on a German development and was used in Australia between 1939 and 1952. It was called “flying on the beam” and its proper name was a “Radio Range” (a history of radio ranges is at the above website at site search, key word “radio range”). I have two problems for which I would like assistance but first I need to describe how the full-size system often been featured in SILICON CHIP projects as well. Glen King, via email. Comment: you make a good point. And as you point out, we have featured speaker protectors and how they should be wired into a stereo amplifier on a number of occasions. The most recent was in the July 2007 issue, involving the Speaker Protector for the 20W Class-A Stereo Amplifier. The method of installation is exactly the same for a stereo amplifier used in bridge mode. works. It has a ground-based transmitter, with a compatible receiver in the aircraft. The transmitter antennas consist of a vertical ½-wave active dipole, with >½-wave dipoles ¼-wave away on each side. The side dipoles have relays at their centres which are open or closed alternately. When closed, the dipole acts as a reflector; when open the dipole cannot affect the radiation pattern. The 33MHz carrier is amplitude modulated with a 1kHz tone. The side relays are opened and closed alternately, one for 7/8 second and the other for 1/8 second. Thus the radiation pattern is thrown from side to side, one side for 7/8 second and the other for 1/8 second. When “on course” the patterns are of equal amplitude and the aircraft pilot hears a steady tone, ie, he is “flying the beam”. Note that the aircraft radio must receive amplitude modulation and must not have a fast AGC action; only a slow one to allow for the relatively slow aircraft progress to or from the ground station (the model will not need even slow AGC). For the model to simulate this at 2.4GHz we can use an AWM630 transmitter module but the AWM630 receiver module is of no use as it has a fast AGC action and does not produce audio tones with a level proportional to the incoming carrier strength. The AWM630 TX is amplitude-modulated by feeding its power input with a 1kHz square wave of 5V amplitude. To provide the necessary gain I have siliconchip.com.au Tips on light switches The article in the June 2008 edition on doing your own electrical work contained a few surprises. In New Zealand, I believed all the home handyman could do was to repair corded devices and replace wall plugs and light fittings. Thanks for the clarification. I feel sorry for my Australian counterparts. The situation highlights the often wide disparity between the law and commonsense. I work as a mechanical engineer and have routinely done all my own electrical work in my home. It’s neither difficult nor particularly dangerous if you understand what it is you are dealing with and simple precautions are taken. I’ve spent a lot of time on industrial sites where electrical work was being carried out. I’ve always claimed electricians are the messiest tradesmen of the lot and if they are involved in any fitting work, they are shockers. Before you think Australia is all bad, we now have a situation with our building regulations that parallels your electrical situation. A spate of residential housing that developed serious water leaks, in combination with untreated timber framing, poor architectural and regulatory practices, poor quality building work and the use of monolithic wall cladding systems has led to a hooked up a DEM 13LNA 2.4GHz preamplifier, a germanium point-con­ tact diode, an audio preamp and an audio amplifier, all small enough to fit in a 1:72 model DC3 aircraft. Antennas are BC7048 coaxial dipoles (Google if details are required). Now to the problems: first, we obtain about 0.5-metre range without the RF preamp and no more with it in circuit! To make a working model display for the museum I need about at least a 3- metre range. The 2.4GHz preamplifier was specially imported from the USA and I am not sure that it works. (I need to borrow a microwave signal generator or take the gear to where there is one). I am looking for a person who would siliconchip.com.au clamp down on permitted owner modifications. It is now almost a crime for the house owner to pick up a hammer. The irony is that it wasn’t the fault of the good builders or the home handyman. As for light switches and their removal for painting or whatever, I have a couple of tips. When the light switch is pulled from the fitting, put a plastic bread bag over it, and put a piece of masking tape around the neck to hold it in place. This has the advantage that there will be no paint splashes on the switch and it can still be used. To get out the little plastic plugs over the screws out without damage, I use a piece of duct tape to stick to the buttons and pull them out. It will take more than one go to do it, you need a super sticky tape and I recommend when you install the buttons not to push them in too hard. What does concern me about doing my own electrical work at home are the insurance implications. I’m not talking about my own work but about the attitude of insurance companies to unlicensed work. Would this affect a claim in some other area? Insurance companies can be slippery. Andrew Buchanan, Tawa, NZ. Comment: spare plastic plugs can often be found on the rear of light switches and power points and are available from hardware stores. like to participate in this project, which is interesting, challenging, and useful to our museum. Ron Rye, Heidelberg West, Vic. ronrye<at>optusnet.com.au Modification to IR remote tester With regard to the story on repairing an industrial microwave oven (Serviceman’s Log, June 2008) I should point out that running diodes in parallel doesn’t work; the weakest one always blows first. On another subject, I wanted to test a TV remote control and remembered seeing a circuit in a previous issue (Circuit Notebook, September 2007). I PRIME ELECTRONICS Est. 1987 â 115 Compact DMM 3 YEAR WARRANTY CAT III 600V True RMS AC/DC Volts 600V AC/DC Amps 10A Resistance Continuity Frequency Capacitance List Price $245.00 Diode Test Analog Bar Graph Backlight Min/Max/Avg Display Hold Auto/Manual Range Holster Our Price $199.00 179/EDA2 Combo Kit LIMITED LIFETIME WARRANTY CAT III 1000V CAT IV 600V Kit Contains ● ● ● ● ● ● ● Fluke 179 True RMS DMM TL224 SureGripTM Silcone Test Lead Set TL910 Electronic Test Probe Set AC280 SureGripTM Hook Clip Set TPAK Magnetic Hanger 80BK Intergrated DMM Temp Probe C35 Soft Meter Case List Price $585.00 Our Price $499.00 Prices exclude GST Call for a 2008 Fluke Catalogue www.prime-electronics.com.au Brisbane (07) 3252 7466 Sydney (02) 9704 9000 September 2008  11 Mailbag: continued Tiny URLs eliminate long URLs I have a tip on easier computing with long URLs. For example, the address on soldering SMDs is rather long: http://www.curiousinventor.com/guides/surface_mount_ soldering/101I Instead, try this: http://tinyurl. com/5ngmpl This gives the same result. Tiny URLs work by shortening a long web collected the parts and made a circuit board, put it all together and found that it didn’t work. I came to the conclusion that the TLC 7555CP was not as sensitive as the Intersil version so I replaced the IR LED with a Jaycar ZD-1952 IR LED receiver using a 5.6kW resistor to reduce the voltage to it. It now works beautifully. Ted Irving, Heathcote, NSW. Safe disposal of used fluorescent lamps I watched the ABC’s 7:30 Report on July 1st, 2008. The lead topic was on the phasing out of incandescents and the safe disposal of compact fluorescent lamps. I was disturbed at its lack of thoroughness. There seem to be at least two widely- address which can be either typed in or “cut and pasted” in the shortened format. Result: fewer mistakes when entering web addresses. If you set it up correctly, all that’s required to change an address to a tiny URL is to click on the tinyURL tab set up in either Firefox, Internet Explorer or the new Flock browser – see www.flock.com/ John Vance, Bundoora, Vic. held misconceptions, or a general failure to acknowledge that (1) the tubular fluorescents we have been using for decades also require safe disposal and (2) the very popular low-voltage halogen down-lights are also not only incandescent but even less efficient than ordinary 240V bulbs. There is an even stronger case for them to be replaced, particularly if very efficient high-brightness LED fixtures can replace them. David Pulford, Forestville, NSW. Valve circuit errata 78 years too late? I noticed that the circuit you published for the AWA C103/43 shortwave converter from the 1930s (SILICON CHIP, April 2008) shows an internal connection from the screen grid in V1 and V2 to a mysterious grid connected between the cathode and the normal grid. This obviously doesn’t make any sense in terms of a valve’s operation. I was wondering if this was an error in the original circuit diagram or is it a transcription error? Roger Forsey, Seaholme, Vic. Rodney Champness comments: I would say that this was one of the funny ways in which valve elements and their order in a valve were shown in earlier days. It’s not incorrect but strange compared to the more sensible ways that valve layouts were drawn in later years. Easy way to reverse a fan In reply to the question about reversing a brushless DC fan motor (Ask SILICON CHIP, May 2008) it could be added that the easiest way to reverse the airflow is to simply physically reverse the fan assembly; four screws and it’s done. Usually it has an arrow on the side to confirm orientation. Also worth mentioning is that for maximum fan efficiency and airflow, an equal area of inlet or exhaust is required on the opposite side of the cabinet, otherwise you are trying to partially pressurise or depressurise the cabinet. John Williamson, SC Cheltenham, Vic. Australia’s Lowest Priced DSO! Now you’ve got no excuse ... update your old analogue scopes! Whether you’re a hobbyist, TAFE college or university workshop, the GW GDS-1022 has the price and performance for you. GW GDS-1022 25MHz 25MHz Bandwidth, 2 Ch 250MS/s Real Time Sampling 4k Memory Per Channel TFT Colour Display 19 Auto Measurements Built-in USB & SD Card Slot GW Brand - 28 years in Australia Sydney Melbourne Tel 02 9519 3933 Tel 03 9889 0427 Fax 02 9550 1378 Fax 03 9889 0715 email testinst<at>emona.com.au 12  Silicon Chip Brisbane Tel 07 3275 2183 Fax 07 3275 2196 Adelaide Tel 08 8363 5733 Fax 08 83635799 Perth ONLY $ Tel 08 9361 4200 Fax 08 9361 4300 web www.emona.com.au 499 inc GST SAVE $ 50 EMONA siliconchip.com.au Basslink Basslink the high voltage DC power link between Victoria & Tasmania – the longest undersea power link in the world by Michael Goebel Back in February 2000 a tender was granted for building a high voltage DC power link between Victoria and Tasmania. It was finally commissioned in April 2006 and now feeds power in both directions between Victoria and Tasmania, depending on demand in those states. siliconchip.com.au September 2008  13 V ictoria and Tasmania have different power supply problems. Victoria has Australia’s most inefficient thermal power stations, burning brown coal – Loy Yang power station and mine is shown above. So it makes sense to use Tasmania’s hydo-electricity when it is available, especially during peak power periods. On the other hand, when Tasmania suffers droughts they often do not have enough hydro-electric power capacity to meet their own demand. When that happens, Tasmania can draw power from Victoria’s grid. But there is a problem – the 300km-wide stretch of often-wild water between the two called Bass Strait. And connecting them is not quite as easy as erecting a couple of giant pylons and stringing some cable over the water. Enter Basslink Basslink is a 400kV DC bi-directional, undersea electricity interconnector, rated to transmit 500MW continuously and 630MW peak from Tasmania. The link can operate at up to 600MW for up to 10 hours, providing that it is ‘precooled’ (six hours at no more than 300MW). In the other direction, up to 480MW can be sent to the relatively small Tasmanian grid. Basslink consists of: • a 290km-long submarine power cable, the longest of its type in the world, from McGaurans Beach near Giffard in Victoria’s Gippsland, to Four Mile Bluff, above George Town on Tasmania’s north coast. • a 60.8km overhead power line to the Victorian coast. 14  Silicon Chip • a 6.6km underground cable in Victoria. • an 11km overhead line section to the Tasmanian coast. • a 1.7km underground cable in Tasmania. The high voltage cable used for the Basslink is 15cm thick. The undersea cable alone weighs 17,400 tonnes. From McGauran Beach it runs for a few kilometres as an underground cable and finally emerges as an above- ground line running 70km to Loy Yang power station. There, the high voltage DC from Tasmania is converted into AC with the help of thyristor “converter valves” so it can be fed into the 3-phase power system. These valves have nothing to do with thermionics or vacuum tubes but are entirely solid state. The thyristors are made of pure mono crystalline silicon and are effectively used as switches. When Victorian power is being fed to Tasmania, a similar station in Tasmania transforms the DC into AC. So power transmission can be made in both directions, with similar conversion equipment for AC to DC and DC to AC at each end. Why DC? In an AC distribution system, voltage conversion is simple – just use a transformer. However, above certain power levels and over long distances, for submarine cables, high voltage AC transmission links have significant disadvantages compared to DC, despite DC having to be converted twice. For a long transmission path, the smaller losses and siliconchip.com.au reduced construction cost of a DC line can offset the additional cost of converter stations at each end of the line. Also, at high AC voltages significant amounts of energy are lost due to corona discharge, the capacitance between phases or in the case of buried cables, between phases and the soil or water in which the cable is buried. Long undersea cables have a high capacitance. While this has minimal effect for DC transmission, the current required to charge and discharge the capacitance of the cable causes additional I2R power losses when the cable is carrying AC. In addition, some AC power is lost in the dielectric. HVDC can carry more power per conductor, because for a given power rating the constant voltage in a DC line is lower than the peak voltage in an AC line. This voltage determines the insulation thickness and conductor spacing. Therefore DC transmission line corridors can be used to carry more power into an area of high power consumption, which can again lower costs. Another advantage of HVDC systems is that they require only two cables as opposed to the three needed for three phase current transmission. As a result, an HVDC overhead line also requires less space. So the key advantages of a DC link over an AC link are: • It allows power transmission between AC networks with different frequencies, or networks which cannot be synchronised. A good example of this is Japan which has 50Hz and 60Hz power grids. • Inductive and capacitive parameters do not limit the transmission capacity or the maximum length of a DC overhead line or cable. • In addition, the full conductor cross section is utilised because there is no “skin effect” at DC. Thyristor “valves” The outdoor valves for earlier systems were designed with oil-immersed thyristors with parallel/series connection of thyristors and an electromagnetic firing system. Further development went via air-insulated, air-cooled valves to the air-insulated, water cooled design, which is the state-of-the-art in HVDC valve design. The development of thyristors with higher current and voltage ratings has eliminated the need for parallel connection and reduced the number of series-connected thyristors per valve. Light triggered thyristors It has long been known that injecting photons into the gate instead of electrons can turn on thyristors. See Fig 5. The route of the predominantlyundersea HVDC interconnect between the Loy Yang power station in Victoria’s Gippsland and the Tasmanian hydro grid connection at George Town, near Launceston in northern Tasmania. This is known as LTT (Light triggered thyristor) technology and reduces the number of components in the thyristor control by up to 80%. This simplification results in increased reliability and availability of the transmission system. With LTT technology, the gating light pulse is transmitted via fibre-optic cable (itself providing high isolation), through the thyristor housing directly to the thyristor wafer. Therefore no elaborate electronics, including auxiliary supplies, are needed to control the high potential. Innovations in almost every other area of HVDC have been constantly adding to the reliability of this technology with economic benefits for users throughout the world. Light Pipe Cu Si Cu Mo A graphical diagram of one of the Siemens laser-controlled LTT thyristors which make up the “valve” used in the AC/ DC and DC/AC conversion in Basslink, with an exploded photo of the device at right. siliconchip.com.au September 2008  15 The high-performance thyristors installed in HVDC plants today typically have silicon wafer diameters of up to 125mm (6 inches), blocking voltages up to 8kV and current carrying capacity up to 4kA DC. Thus no parallel thyristors need to be installed, however, series connection is necessary to handle the HVDC voltages. The required optical gate power is just 10mW. The forward overvoltage protection is integrated into the wafer. Further benefits of direct light triggering are the unlimited black start capability and operation during system undervoltage or system faults without traditional limitations. In the case of convential (electrically triggered) thyristors (ETT), this is only possible if sufficient firing energy is stored long enough in the thyristor electronics. A simple voltage divider circuit made from standard off-the-shelf resistors and capacitors allows monitoring of the thyristors performance. Monitoring signals are transmitted at very-much-safer ground potential through another dedicated set of fibre optic cables as for the LTT. All electronic circuits needed for the evaluation of performance are now located at ground potential in a protected environment, further simplifying the system. The extent of monitoring is the same as for the ETT. It is expected that this technology will become the industry standard in HVDC thyristor valves of the 21st century, paving the way towards maintenance-free thyristor valves. Laser control The thyristors in the Basslink project are controlled by 10mW laser flashes, transmitted via glass fibres. These thyristors, which have a diameter of 100mm, were produced by Infineon and are made of silicon, molybdenum and copper. To achieve a DC voltage of 400kV, several dozen thyristors per converter valve are connected in series. All of these thyristors must trigger within 1µs in order to ensure that none are overloaded or damaged. Valve Design The modular concept of the Siemens thyristor valves permits different mechanical setups to best suit each application: single, double, quadruple valves or complete six-pulse bridges, either free standing or suspended from the building structure. The standard Siemens valves for long distance transmission are suspended from the ceiling of the valve hall to allow them to withstand earthquakes, especially important in areas prone to seismic activity such as Japan and New Zealand. The suspension insulators are designed to carry the weight and additional loads originating for example from The old and the new: at left is a bank of six mercury-arc rectifiers for a 100kV, 140A high-voltage DC supply from around 1942. At right are the HVDC valve towers in the 3000MW. ±500kV, 1000km HVDC transmission link between Guizhou and Guangdong in China. Basslink is a smaller distance but is predominantly under water, which brings in a whole new set of problems to overcome (photo courtesy Siemens). 16  Silicon Chip siliconchip.com.au an unbalanced weight distribution due to insulator failure, an earthquake or during maintenance. Connections between modules (piping of cooling circuit, fibre optic ducts, buswork and suspension insulator fixtures) are flexible in order to allow stress-free deflections of the modules inside an MVU (multiple valve unit) structure. Each valve is made up of three modules. Four arresters, each related to one valve, are located on one side of the valve tower. Ease of access for maintenance purposes, if required, is another benefit of the Siemens valve design. By varying the number of thyristors per module and the number of modules per valve, the same design can be used for all transmission voltages that may be required. Thyristor cooling The thyristors are stacked in the module with a heatsink on either side. The water connection to the heatsinks can be designed in parallel or series. The parallel cooling circuit provides all thyristors with the same water temperature. This allows a better utilisation of the thyristor capability and offers the additional advantage that electrolytic currents through the heatsinks – the cause for electrolytic corrosion – can be avoided by placing grading electrodes at strategic locations in the water circuit. The parallel wafer cooling principle has been in use for more than 25 years, with no corrosion problems ever encountered. Water cooling also does not require any deoxygenising equipment. Fire! With such enormous power involved, arcing and fire is a constant risk. This has been minimised through many steps: • All oil has been eliminated from the valve and its components. Snubber capacitors and grading capacitors use SF6 as a replacement for impregnating oil. • Only flame-retardant and self-extinguishing plastic materials are used. • A wide separation between the modular units ensures that any local overheating will not affect neighbouring units. • Careful design of the electrical connections avoids loose contacts. The past has shown that Siemens HVDC installations have never been exposed to a hazardous fire risk. The tests performed on actual components and samples in the actual configuration as used in the valve indicate that the improved design indeed is flame retardant and the risk of a major fire following a fault is extremely low or even non existent. REPLACE One end of BassLink – the 400kV DC valve hall near the Loy Yang power station in Victoria’s Gippsland. The valves hang from the ceiling, predominantly to allow them to move, protecting them from damage in case of earthquake. siliconchip.com.au September 2008  17 High Voltage DC: how it works As noted elsewhere in this article, the basic element in all HVDC conversion is the light triggered thyristor (LTT) or SCR (silicon controlled rectifier). These are connected in series banks of a hundred or more SCRs, to give a total rating which may be 500kV DC or more and hundreds of Amps. When connected in such a way, they are referred to as “valves” and each valve can be regarded as a single device. In reality, to function in this way, all the SCRs in a valve must be triggered on within one microsecond of each other. This is achieved by a laser light pulse fed to the every SCR in the valve. Once an SCR is triggered, it breaks into conduction and it continues to conduct until the load current falls to a very low value (below the “holding” current) or the voltage across it is reversed in polarity. So in effect, once an SCR or valve is triggered into conduction, it behaves just like a conventional diode, albeit a very large diode! So how are these banks of LTTs, or valves, connected to perform the conversion from AC to DC or DC to AC? And how does the same setup perform either AC/DC or DC/AC without altering the connections? To keep it simple, let’s first consider the conversion of AC to DC. Consider that all power grids are 3-phase systems, with the difference between respective AC phases being 120°. Fig.1 shows a 3-phase transformer connected to a 6-SCR bridge rectifier. Incidentally, this is exactly the same connection as used in a standard car alternator (it has six large diodes pressed into its casing.) Each diode (or LTT) conducts when + +DC THREE-PHASE TRANSFORMER (STAR/STAR) φ1 RED R φ3 φ2 BLUE W WHITE 0V PHASE 2 18  Silicon Chip D3 B it has a forward voltage across it and so each diode conducts for a maximum of 60°. The result is a DC voltage with a superimposed 300Hz AC ripple (for a 50Hz grid), as shown in Fig.2. At any one time, only two diodes will be conducting, for example, D1 & D5 or D6, D2 & D4 or D6 and so on. The result is that there are six diode-conduction periods providing the AC to DC conversion which is more familiarly known as rectification. Exactly the same setup can be used to convert the DC back to AC except that the power flow is in the other direction. In DC/AC conversion, only two SCRs conduct at any one time (as in rectification) but they need to be triggered into conduction at the right time to energise the particular transformer windings. However, the resultant waveforms on the output side of 3-phase transformers are anything but a clean sine wave. Hence quite heavy filtering is required in order to prevent large harmonics in the distribution grid. PHASE 3 T – D2 Fig.1: AC to DC conversion in an HVDC system is D4 D6 D5 essentially the same as the rectification process 0V in a 3-phase power system, whether it is the alternator of a car or in a country’s electric power grid. Six diodes (or SCRs) are required and two diodes will be conducting at any one time. Note that while we show a star-connected transformer in this case, it could just as easily be a delta-connected system. DC OUTPUT PHASE 1 D1 Fig.2: This set of waveforms shows how a 3-phase system is converted to DC using the schematic of Fig.1. The three voltage phases are separated by a phase difference of 120° and the resultant DC from the rectifiers has a superimposed ripple at six times the mains frequency, ie, 300Hz for a 50Hz grid. Because there are six periods (or combinations) of SCR conduction in this DC/AC conversion process, this is referred to as a 6-pulse converter; six trigger pulses are required for one cycle of AC which will be 50Hz or 60Hz, depending on the country where it is used. In reality, the setup outlined in Fi.g.1 is not used now. Instead, we have a more complicated system, shown in Fig.3. This uses a 3-phase transformer with star and delta-connected secondaries feeding a set of 12 SCRs or valves. This makes use of the fact that while the three phases are separated by 120°, when the outputs of a star and delta system are connected together, you effectively have six phases separated by 60°. When used for AC/DC conversion (ie, rectification), the resultant DC has 600Hz ripple (for a 50Hz grid) and there are 12 combinations of SCR conduction. To consider just one 30° conduction period, when D1 conducts, so will D5, D8 & D11 or D6, D9 & D12. Since there are 12 conduction periods, this is referred to as a 12-pulse converter. The six voltage waveforms from the star and delta windings are depicted in Fig.4. Note that we have shown the Star and Delta winding outputs with their normal amplitude relationship, whereby the phase-to-phase (delta) voltage is √3 times the phase to neutral (star) voltage, to highlight how the 6-phase system comes about. siliconchip.com.au +DC STAR SECONDARY φ1 PRIMARY WINDING THREEPHASE φ2 AC φ3 D1 D2 D3 D4 D5 D6 D7 DELTA SECONDARY D10 D8 D9 D11 D12 HIGHVOLTAGE DC 0V Fig.3: the schematic of a 12-pulse AC to DC converter. While this circuit is ostensibly an AC to DC converter, it can just as easily be run in the opposite direction, converting DC to 3-phase AC by triggering the SCRs at appropriate times to energise the relevant transformer windings. In reality, we assume that their amplitudes will be the same. For DC/AC conversion, the process is exactly the same as for a 6-pulse system except that we now have 12 SCRs (or valves) which are triggered at 12 points in the waveform to energise the star and delta windings. Because the harmonics in a 12-pulse converter are twice as high Fig.4: the phase relationship in a + 3-phase system using star and delta waveforms together, to drive the converter circuit of Fig.3. The resultant phase waveforms are separated by only 60° and the 0V resultant DC from rectification has ripple at 12 times the mains frequency, ie, 600Hz for a 50Hz system. Note that the harmonics produced in conversion can run as high as the 30th or higher and – require elaborate filtering. in frequency and reducing in amplitude by the same amount, it is much easier to filter them out and prevent them being fed into the distribution grid. Note that the schematic of Fig.3 is much simplified compared to reality and does not show all the filtering, protection and ancillary components. Note also that the DC/AC conversion process assumes that there is already 3-phase power available on the AC grid, to provide the essential triggering and synchonisation of the SCR valves. In a complete HVDC system there is DELTA φ1 STAR φ4 DELTA φ2 STAR φ5 DELTA φ3 STAR φ6 T an AC/DC converter at each end of the transmission line and in the case of the Basslink system and others throughout the world, they can transfer power in both directions. See Fig.5. So was Edison right all along? Anyone familiar with the history of electrical energy will know that Thomas Edison was a very strong proponent of DC and many early systems in towns and cities were based on DC. Ultimately though, the sheer advantages of the AC system, as promoted by Westinghouse and largely invented by Nicola Tesla, won out and now AC generation and transmission of power are universal, usually at 50Hz or 60Hz. So why is high voltage DC now being promoted? In fact, the advantages of AC over DC are still manifest. However, for power transmission over very long distances, say 800km or more or for distances of 50km or more undersea, DC has advantages in that usually only one cable instead of three, in the case of 3-phase AC transmission, is involved. By transmitting electrical power at very high voltages, eg, 400kV or higher, the resistance losses are reduced, as are the weight of the cable, its supporting structure and so on. Furthermore, DC transmission makes it possible to transfer power between two electrical grids that operate at different frequencies (50Hz & 60Hz), as happens in Japan. So Edison did not get it right. High voltage DC power transmission is the solution to problems that Edison is unlikely to ever have foreseen. SC +DC φ1 AC GRID1 φ2 φ1 AC–DC CONVERSION HIGH-VOLTAGE DC TRANSMISSION φ3 AC–DC CONVERSION φ2 AC GRID2 φ3 0V Fig.5: a complete HVDC system in schematic form. In very long distance systems, as used in China or Brazil, power transmission is usually in one direction only but a complete AC to DC and DC to AC converter is required at the start and finish of the transmission line. siliconchip.com.au September 2008  19 SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: dicksmith.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: dicksmith.com.au Into model railways? Then you’ll want to Build the RAILPOWER This ultra-high performance model train controller features infrared remote control. We believe it’s the best build-it-yourself train controller ever published! O nce upon a time model trains were every kid’s dream hobby – but nowadays they are much more likely to be the province of their dads and grand-dads. To a true model railway enthusiast, realism of rolling stock, track layout, scenery and train operation is paramount – and it’s not hard to spend up to a thousand dollars or more on a good loco. (Some model railway “widows” insist it’s the spender that’s loco!) Many model railway enthusiasts have permanent setups occupying vast areas of their homes – inside and out! We’ve heard of model railway enthusiasts who have bought a new house simply on the basis that it lends itself to their hobby. Bedrooms? Bathrooms? Kitchen? Who cares, as long as there 22  Silicon Chip is room for his “trains”! One thing that every enthusiast understands is that the old-fashioned rheostat-type controller is simply not up to the task – to achieve that realism we mentioned earlier, they must have a high-performance train controller, one that can vary the speed, direction and be able to simulate the inertia of a full-size train. And one with switchmode (pulse power) operation for really good low speed control. Finally, infrared remote control (so you can direct operations from anywhere on your layout) is practically essential – and not just on larger layouts. Railpower Mk IV Our latest Railpower train control- ler (actually the fourth one we’ve published in our 20+ years) is simply outstanding. The completely new design, based on a PIC microcontroller, provides all those wanted features and more. Those who have had a chance to try it out reckon it’s right up there with the best commercial controllers costing hundreds of dollars more. This latest Railpower design is packed full of features to enable a locomotive to be driven smoothly over its full speed range. And while all of the control features can be accessed from the handheld remote, there is also a large knob on the front panel to control the speed – for those who like to feel “in control”! There are also four pushbuttons on the siliconchip.com.au IV Design by JOHN CLARKE front panel to adjust all the settings as well as providing Direction, Stop and Inertia on/off. Infrared remote control A standard pre-programmed remote is used to access all the standard features such as speed, direction, braking (stop) and inertia on/off. And since we are using a standard remote control, we have allocated the standard buttons to control particular functions. For example, the volume up and down buttons control the speed, the mute button is used for braking (stop) while the channel up and down buttons select forward or reverse, respectively. Just like the real world, the direction siliconchip.com.au Features • Pulse power for extra smooth low spee • Back-EMF detection for speed regulat d operation ion • Infrared remote control • Front panel speed control • Speed setting displayed as bargraph an d percentage value • Actual speed bargraph display • Adjustable simulated inertia with on/of f control • Adjustable braking (stop) ine rtia • Forward and reverse lockout • Indication of stop, direction, inertia an • Overload protection with visual and aud lockout dible indication of the locomotive cannot be changed if it is running above a certain speed (which we call the “lockout” speed). So if you want to change direction you have to slow down the locomotive before the Railpower will let you change the direction. This prevents derailments which can be catastrophic if you are using a locomotive (or two/three) ahead of a long train. Using the Stop (Mute) function brings the locomotive to a stop when pressed and lets the train return to its original speed setting when pressed again. Just like in TV operation, if you have pressed the Stop (mute) button, pressing the Speed (volume up) button, returns the train to its original setting. However, if you have Stop pressed, you can also use the Volume Down button to reduce the speed setting while the train is stationary. Inertia Real trains have huge amounts of inertia. A big coal drag or iron ore train may be 20,000 tonnes or more and you can bet that when the driver calls for an increase in speed, nothing happens quickly. In fact, the driver of a real train must not apply full power quickly otherwise the train couplings can be easily broken. In the modelling situation we wish to simulate that huge inertia so that changes in speed setting are not immediately reflected by a change in actual train speed. We can adjust the September 2008  23 Specifications Output Voltage.........................16-17V pulse width modulated in 819 steps up to 80% duty cycle Output current..........................up to 6A Pulse Frequency.......................122Hz, 488Hz or 1953Hz Speed setting display...............60-step bargraph and percentage from 0-100%. Actual speed display................60-step bargraph Minimum speed setting...........adjustable Lockout speed setting..............adjustable Default speed setting...............adjustable Infrared remote codes..............Philips RC5; TV, SAT1 and SAT2 Infrared remote range..............8m (indoors) Inertia adjustment....................From 0-100 corresponding to about 1 to 100s (dependent on minimum and maximum settings) Stop adjustment.......................From 0-100 corresponding to about 1 to 100s (dependent on minimum and maximum speed settings) Back EMF Feedback control.....Adjustable from 0 to 100 corresponding to no back-EMF control through to a maximum Speed ramp rate.......................From 0 to 255 corresponding to the rate of speed setting change with remote control Bi-colour LED...........................Shows track voltage and direction amount of simulated inertia over a wide range, to simulate the effect of locomotive running in “light engine” (ie, no carriages or wagons) to that large coal drag we mentioned above. Simulating train inertia adds greatly to the operation of model trains. Instead of trains accelerating like jack rabbits or coming to a screeching halt (which surely would cause fatal injuries to passengers and a lot of rolling stock damage if duplicated in real life operation!) they move off slowly, or even ponderously, in case of long freight trains. Inertia can be toggled on or off with the remote control’s On/Off switch (normally used to turn the TV on or off). When you are running a train along a layout you will want inertia switched on but when shunting or other delicate manoeuvring, you will probably want to switch the inertia off. When inertia is set to off, the locomotive motor responds almost instantly to speed setting changes. Run & braking inertia Actually, the Railpower IV provides for two inertia settings. The first is for running a train, giving very gradual increase or decreases in train speed in response to a given setting. The second is braking inertia which means that the train can be brought to a stop smoothly and quickly when you press the Stop button. However, if you have the Inertia switched off, there is no braking inertia and the train will come to an immediate jarring stop if you press the Stop button. As we mentioned before, these and all the other settings can be adjusted via the front panel buttons. Pulse power Given the amazing control that the Railpower IV gives the model train enthusiast, there is certainly not much to it, thanks to the power of the PIC16F88-I/P. It is built on two PC boards (one for the display) and mounts in a 260 x 85 x 180mm ABS case. It offers both local and infrared control. 24  Silicon Chip Having realistic inertia counts for nothing if the train controller cannot provide smooth reliable acceleration from a standing start. To provide smooth low speed control and very smooth starts, you cannot use smooth DC or unfiltered DC operation. It just will not work properly and the result can be a locomotive which is stalled until you wind up the voltage to such a level that when the loco finally does move, it takes off like a startled rabbit and may even spin its driving wheels furiously. The only way to ensure reliable low speed operation, apart from havsiliconchip.com.au +5V IR DETECTOR λ +17V +5V LOCAL SPEED VR1 MOTOR Q1 Q2 REMOTE SPEED MICROCONTROLLER (IC1) LCD Q3 'H' BRIDGE Q4 OVER CURRENT BACK EMF SWITCHES MOTOR BACK EMF OVERLOAD SIREN Fig.1: the block diagram of the Railpower IV belies just how powerful this new train controller is. It’s by far the best we have ever published and is only made possible through the use of a PIC microcontroller. ing clean track and regularly cleaned locomotive wheels, is to use what railway modellers refer to as “pulse power” and what electronics people call switchmode or pulse width modulation (PWM). Whatever it is called, it involves driving the locomotive with high amplitude (typically 16-17V) pulses which easily overcome track/wheel contact resistance and motor stiction (static friction) to ensure smooth starting and low speed running. EMF of the locomotive motor. This is the voltage which opposes current flow through the motor due to the applied voltage. In permanent magnet DC motors, as used in most model locomotives, back-EMF is directly proportional to speed. Therefore, if we want the controller to maintain a set speed, we monitor back-EMF to provide a feedback signal to the circuit. It works very well. Speed regulation A 2-line Liquid Crystal Display (LCD) indicates train speed and speed settings, as well as direction, stop and The other way to ensure good low speed operation is to monitor the back- Liquid crystal display Railpower operation driving a 470W resistor load. The top (yellow) trace is the junction of Q2/Q4 with Q2 being driven by the pulse signal. The bottom (green) trace is the junction of Q1/Q3, with Q3 being turned fully on. The small amplitude signal is mostly due to the voltage across the 0.1W sensing resistor. The voltage across the motor (load) is the difference between the two signals. siliconchip.com.au whether inertia is switched on or off. The train and speed settings are shown as horizontal bargraphs. The speed setting is also shown as a percentage from 0 to 100%. The lower bargraph shows the speed setting while the upper bargraph shows the actual train speed. If the Railpower IV is overloaded or the output is shorted, the top line of the LCD shows ‘OVER’ in place of the direction arrow, padlock icon (lockout), S and I indicators. An internal overload siren also sounds and power to the motor is stopped until the current overload is ended. As already mentioned, you can change all the settings with the front panel switches below the LCD panel. We will discuss those details next month. The Railpower IV is presented in a large instrument case that houses the power transformer and circuitry. At the rear panel is the mains input and power switch and two terminals for connection to the track layout. Circuit details A block diagram of the circuit is shown in Fig.1. It comprises the PIC microcontroller and this drives the LCD module, the H-bridge and overload siren. It also monitors signal from the infrared detector, the front panel switches, the over-current monitor and the back-EMF from the locomotive motor. The H-bridge drive circuit com- This shot shows Railpower operation in the reverse direction. The top trace now shows a small amplitude signal with Q4 being turned fully on. The green trace shows Q1 being fed by the pulse signal. Note that both these scope shots show operation at 488Hz. Operation at the other frequencies of 122Hz and 1953Hz is similar. September 2008  25 26  Silicon Chip siliconchip.com.au SC 2008 E IRD1 2 3 A X1 2MHz K A K B C LED E C 1 6 15 Vss 5 1k AN4 PWM RB2 RB1 MCLR 4 13 17 18 2 3 9 8 7 RB7 12 RB6 11 RB5 10 RB4 RA0 RA1 AN3 IC1 PIC16F88-I/P OSC2 OSC1 AN2 RB0 14 Vdd 100nF 16 27pF 2.2k +5V BD649, BD650 27pF LOCAL SPEED VR1 10k 1N5404 1 100 µF 16V 100 µF 16V RAILPOWER CONTROLLER MK4 C BC337 GND OUT 7805 1 IN B 2 λ 3 IRD1 IR DETECTOR/ DECODER 470Ω +5V S1 10 9 12 13 S3 1k RS B 7 IC2b IC2a Vdd 2(1* ) E 1k B 2.2k Q9 BC337 C 100k 10k 10k A 10k 2 x 2200 µF 25V +17V * JAYCAR MODULE GND 1(2* ) 1k B VR3 10k Q3 BD649 K A K K A A K K A K λ λ E C 12V E C 240V 5.1k 15k K POWER S5 22 µF A K E C B E C _ + PIEZO SIREN +17V E N 240V AC A Q10 BC337 100k 2.2k F1 1A B B Q6 BC337 1k D6 1N4004 +5V B Q8 BC337 IN4004 A B LED1 DIRECTION T1 12V/60VA 10 µF 16V VR2 10k Q4 BD649 E C K A Q2 BD650 TO TRACK 10k 10k 2.2k Q1 BC650 A 1N4148 A E C C E +17V D1–D4: 1N5404 R/W 5 3 0.1 Ω 5W CONTRAST 10nF 10k E B Q7 BC337 C Q5 BC337 B E C 100nF LCD MODULE 6 3 100 µF 25V K D5 1N4004 D7 D6 D5 D4 D3 D2 D1 D0 14 13 12 11 10 9 8 7 EN S4 1k 6 4 A D7 1N4148 K 5 4 2 1 (OVER CURRENT) 100k 8 10nF IC2c IC2: 74HC00 11 GND IN UP/ SET/ SELECT/ DOWN/ INERTIA RUN DIRECTION STOP S2 1k 10M 14 IC2d (BACK EMF) 10 µF 16V OUT REG1 7805 Railpower operation with a 12V permanent magnet motor. The top (blue) trace is the pulse (PWM) signal from IC2a which drives Q6 and Q2. The yellow trace shows the voltage across the motor for a duty cycle of 30.7%. The back-EMF is the shelf part of the waveform corresponding to the low (off) times of the blue trace. In this case the back-EMF is being measured by the horizontal cursor at 5V. The same set-up as previously but with a PWM frequency of 122Hz instead of 488Hz. The PWM duty cycle is 50%. In this case the motor back-EMF is much higher, as would be expected with a high average driving voltage. In general, permanent magnet motors work better with lower pulse frequencies as their inductance has less effect. The uneven tops of the yellow trace are caused by 100Hz ripple on the 17V supply. prises four power transistors Q1, Q2, Q3 and Q4 which drive the motor (ie, locomotive) in switchmode as well as providing for forward or reverse operation. For forward operation, Q1 & Q4 are switched on while Q2 & Q3 are switched off, to provide current in one direction through the motor. Similarly, for reverse operation, Q2 & Q3 are switched on while Q1 & Q4 are switched off, providing current through the motor in the opposite direction. At same time, to provide the switchmode operation (pulse power), Q1 is pulsed on and off at the preset rate (which may be 122Hz, 488Hz or 1953Hz) while Q4 is switched fully on (forward operation). Similarly, for reverse operation, Q2 is pulsed at 122Hz etc while Q3 is fully on. A common sensing resistor, connected to the emitters of Q3 & Q4 is used to monitor the current drain by the locomotive motor. We also monitor the motor when all transistors are off (ie, in the off periods of the switchmode signal) to determine the back-EMF of the motor and thereby its loading. The full circuit is shown in Fig.2. IC1 is a PIC16F88-I/P microcontroller. We are using its PWM (pulse width modulation) output at pin 9 and three analog inputs to monitor the signals for over-current, backEMF and the front panel speed potentiometer VR1. The remaining input/output pins are used to monitor the infrared detector (IRD1), drive the LCD panel and piezo siren and to monitor the four front panel switches. Fig.2 (opposite): the circuit of the Railpower IV consists mainly of a PIC microcontroller and an H-bridge motor driver. The PIC also drives the LCD module directly. With the exception of the local speed control and direction LED, everything is mounted on two PC boards. You have the choice of complete remote control (with a range of up to 8m indoors) or “local” control with a speed pot and push-buttons on the front panel. Just to whet your appetites, here’s the Railpower IV mainboard which we will fully describe next month. Almost everything is mounted on this or the display board. The connections to this board are (clockwise from top right) 230V power from the mains input socket/ fuse/switch, earth connection to back panel, output to terminals on back panel, track direction LED and local speed potentiometer (both on front panel). siliconchip.com.au H-bridge drive IC2, a 74HC00 quad CMOS NAND gate and transistors Q1-Q8 provide the H-bridge drive. This is somewhat more September 2008  27 This scope shot shows the Railpower operating at full power, with a pulse duty cycle of 80.4% and pulse frequency of 122Hz. The back-EMF, measured in the off periods, can be seen to be quite high, as the motor will be running at full speed. complicated than the simplified schematic of Fig.1 but you can see the similarity, with Q1 to Q4 being the heavy-duty Darlington power transistors. The high gain of these transistors is further boosted by Q5 to Q8. The H-bridge drive circuit works as follows. Outputs RB1 and RB2 (pins 7 & 8) of IC1 drive NAND gates IC2d & IC2c which are then inverted by IC2a & IC2b. These gates drive Q5 and Q6 via 10kW resistors to their bases. Outputs RB1 and RB2 also drive the bases of Q7 & Q8, respectively. These outputs (ie, RB1 & RB2) work in complementary fashion so that when RB1 is high, RB2 is low and vice versa. So when RB1 is high, Q6 turns on Q2 and Q7 turns on Q3, giving the forward operation described previously. Similarly, when RB2 is high, Q5 turns on Q1 and Q8 turns on Q4, giving reverse operation. So RB1 selects forward operation while RB2 selects reverse operation. At the same time, the PWM output of IC1 (pin 9) is gated through IC2d and IC2c, depending on the state of RB1 and RB2. So the PWM signal provides switchmode operation of Q1 and Q2, as previously described. Note that, as well as providing considerable current gain in the Hbridge circuit, the eight transistors also provide voltage level translation between the flea-power 5V signals from the micro to the 17V pulses to 28  Silicon Chip Operation at the highest frequency of 1953Hz and with a duty cycle of close to 80% gives an apparently smoother waveform, since motor hash and power supply ripple are not evident. However, typical motors will run more slowly at this high pulse rate. the locomotive motor. Over-current monitoring The 0.1W 5W resistor provides motor current sensing. The voltage across this resistor is fed to the AN4 input (pin 3) of IC1 via a 10kW resistor while a 100nF capacitor filters the signal preventing transients from being detected. IC1 converts the voltage to a digital value and switches off power to the motor should the current exceed 6A. 6A corresponds to 0.6V at AN4. Power is switched off by taking both the RB1 and RB2 outputs low so that none of the transistors are on to drive the motor. But IC1 restores motor drive momentarily every 0.2s and if the sensed current is below the 6A, the motor is again allowed to run. If current is still over 6A, then the power to the motor is removed again. At the same time as an overload is detected, output RA1 (pin 18) drives transistor Q10 to sound the piezo siren which has an inbuilt oscillator. The RA1 output is also used to send data to the LCD module. To avoid turning on Q10 with the data signal, a 22mF capacitor at its base filters out the short periods of high data signal from RA1. So when we want to drive the transistor we must apply the high signal from RA1 for about 100ms before Q10 will switch on. Back-EMF monitoring Back-EMF from the locomotive motor is monitored using two 10kW And here’s the display board which mounts on the back of the front panel. This particular board has the Jaycar LCD; the white outline on the board to its right shows the mounting position for the alternative Altronics LCD. siliconchip.com.au Parts List – Railpower IV 1 PC board coded 09109081, 217 x 102mm 1 PC board coded 09109082, 141 x 71mm 1 12V 60VA mains transformer (2167L type) (T1) 1 LCD module, Altronics Z-7001or Jaycar QP-5516 1 front panel label, 243 x 76mm 1 plastic instrument case, 260 x 190 x 80mm 1 aluminium rear panel, 243 x 76 x 1.5mm 1 chassis-mount male IEC connector with fuse and switch 1 M205 1A fuse (F1) 1 IEC 3-core 240VAC mains lead with 3-pin plug 1 universal infrared remote control (see text) 1 PC mount piezo buzzer (Jaycar AB3458 or equivalent) 1 DIP18 IC socket for IC1 1 DIP14 socket cut to suit LCD connector 1 14-pin DIL header strip for Jaycar LCD module or 1 SIL 14-pin header strip for Altronics LCD module with 2.54mm pin spacing 1 3-way header strip with 2.54mm pin spacings 1 mini heatsink 19 x 19 x 9.5mm 1 2MHz crystal (X1) 1 2-way PC-mount screw terminals with 5.08mm pin spacing 2 binding posts 1 10kW linear potentiometer (VR1) 1 knob to suit VR1 4 SPST PC-mount tactile snap action switches (S1-S4) 2 10-pin IDC line sockets 1 10-pin IDC vertical header 1 10-pin IDC right angled header 1 200mm length of 10-way IDC cable 1 200mm length of 7.5A green/yellow mains wire 1 100mm length of 7.5A brown mains wire 1 150mm length of black hookup wire 1 150mm length of red hookup wire 1 150mm length of green hookup wire 1 150mm length of 0.8mm tinned copper wire 5 4.8mm female insulated quick connect spade connectors 1 6.4mm female insulated quick connect spade connector 1 chassis mount quick connect spade terminal (6.4mm) resistors connected to the collectors of Q3 and Q4. Depending on which direction the motor is running, the back-EMF will come from the collector of Q3 or Q4, whichever transistor happens to be off at the time. Note that the back-EMF signal will be attenuated by the 10kW resistor connecting to the transistor which happens to be on but this does not matter as we need to further attenuate the signal with trimpot VR2 anyway. This is needed to limit the back-EMF signal so it is below the 5V maximum to the AN3 input for IC1. However, there is a further condition to monitoring back-EMF and that siliconchip.com.au 2 5.3mm ID eyelet quick connector 6 100mm cable ties 4 M3 x 10mm screws 4 TO-220 insulating kits (silicone washer and bush) 5 M3 nuts 5 M4 x 10mm screws 5 M4 nuts 3 4mm star washers 6 No.4 self-tapping screws 4 M3 tapped x 6mm Nylon spacers 4 M3 tapped x 12mm spacers 4 3mm Nylon washers 12 M3 x 6mm screws 4 M3 x 6mm countersunk screws 4 PC stakes Semiconductors 1 PIC16F88-I/P programmed with 0910908A.hex (IC1) 1 74HC00 quad NAND gate (IC2) 1 infrared detector/decoder (IRD1) 2 BD650 PNP Darlington power transistors (Q1,Q2) 2 BD649 NPN Darlington power transistors (Q3,Q4) 6 BC337 NPN transistors (Q5-Q10) 4 1N5404 3A rectifier diodes (D1-D4) 2 1N4004 1A rectifier diodes (D5,D6) 1 1N4148 switching diode (D7) 1 dual colour LED with two leads (LED1) Capacitors 2 2200mF 25V PC electrolytic 1 100mF 25V PC electrolytic 1 100mF 16V PC electrolytic 1 22mF 16V PC electrolytic 2 10mF 16V PC electrolytic 2 100nF MKT polyester 2 10nF MKT polyester 2 27pF ceramic Resistors (0.25W 1%) 1 10MW 3 100kW 1 15kW 4 10kW 1 5.1kW 4 2.2kW 7 1kW 1 470W 1 0.1W 5W 2 10kW horizontal trimpots (code 103) (VR2,VR3) is that it can only be done while the motor is not being energised, ie, in the times when the PWM signal from IC1 is off. To that end, transistor Q9’s base is switched by the PWM signal so that it is on when the PWM signal is high. This shunts the back-EMF signal to 0V so that we are only monitoring “pure” back-EMF and not a mix of back-EMF and applied voltage. The signal from Q9 is fed via diode D7, filtered with a 10nF capacitor and passed to the AN3 input. D7 prevents the voltage at AN3 dropping to zero each time Q9 switches on. A 10MW resistor discharges the 10nF capaci- tor over a 100ms period so the input can respond to a falling back-EMF signal. IC1 converts the back-EMF signal to a 10-bit digital value and this is used to modify the PWM signal to the motor. If the back-EMF is falling, the pulse width (duty cycle) is increased in order to maintain the motor speed. Similarly, if the back-EMF increases (maybe when going downhill) the pulse width is reduced. Trimpot VR2 is adjusted to suit a range of locomotives that you might have on your layout. Potentiometer VR1 is the front panel speed control. It varies the voltage September 2008  29 At left is the rear of the Railpower IV case. It looks pretty spartan – but that’s deliberate. All you have is the switched and fused IEC mains input on the right and the two binding post terminals on the left which supply power to the track. Because the track polarity can be either way (as selected by the user) these are not colour coded. The bicolour LED on the front panel indicates direction. to the AN2 input (pin 1) between 0 and 5V. Again, this voltage is converted to a 10-bit digital value and sets the speed of the motor when the Railpower is set to “local” (ie, front panel) control. Switches and LCD drive The four pushbutton switches S1 to S4 connect to the RB4 to RB7 lines for IC1. Normally, the RB4 to RB7 lines are set (by the software) as inputs, with internal pullup resistors. When a switch is pressed, then the corresponding input is pulled to 0V and IC1 detects this event. The same RB4 to RB7 lines also drive the LCD and to do this they are set as outputs. 1kW resistors are included in series with the switches to prevent the RB4-RB7 lines becoming shorted to ground when a switch is pressed and when the lines are set as outputs. Driving the LCD occurs only momentarily at a slow repeat rate and so for most of the time the RB4-RB7 lines are ready to monitor the switches. The LCD data is sent in 4-bit wide words. The DB0-DB3 data lines are not used. The RA1 output from IC1 drives the register select input to the LCD while the RA0 line provides the enable signal. The display contrast is set with trimpot VR3. Note that the supply pin numbering is different for the Jaycar and Altronics modules. Infrared decoding IRD1 detects the infrared signal from the handheld remote. This is encoded as bursts of 38kHz signal. The IR detector converts each burst as low (0V) and high (5V) in the absence of 38kHz. The decoded signal is sent to the RB0 input of IC1. IC1’s software further decodes the signal sent by the IR remote and it will only accept encoding that is part of the Philips RC5 code. This encoding is set on your handheld remote when you select a Philips or an affiliated company’s brand of appliance. The software within IC1 will decode RC5 code for a TV, Satellite 1 and Satellite 2. This means that you could use three separate Railpower controllers with their own IR remotes on the one layout, in conjunction with block switching. Furthermore, an additional Railpower could be employed with local (ie, non IR remote) to give four controllers on a large layout. The Philips RC5 code for infrared transmission (also used with Marantz, Resistor Colour Codes o o o o o o o o No. 1 3 1 4 1 4 7 1 Value 10MW 100kW 15kW 10kW 5.1kW 2.2kW 1kW 470W 4-Band Code (1%) brown black blue brown brown black yellow brown brown green orange brown brown black orange brown green brown red brown red red red brown brown black red brown yellow violet brown brown 30  Silicon Chip    5-Band Code (1%) brown black black green brown brown black black orange brown brown green black red brown brown black black red brown green brown black brown brown red red black brown brown brown black black brown brown yellow violet black black brown Grundig and Loewe equipment) comprises 2-start bits and 1-toggle bit. The toggle bit alternates high and low on successive same key presses. The code includes five system address bits and six command bits for a total of 14 bits. It uses bi-phase encoding with a high to low transition equal to a low signal and a low to high transition equal to a high signal. Each bit is transmitted at a 1.778ms rate. The entire code is 24.889ms in length and the code is repeated every 113.778ms. IC1 operates at 2MHz using crystal X1. This frequency was chosen because it allowed the PWM frequency to be as low as 122Hz with 10-bit resolution. The crystal also provides an accurate source of timing so that the infrared RC5 code can be decoded at the correct rate. Power supply The Railpower uses a 12VAC 60VA transformer to drive a bridge rectifier comprising four 3A diodes. The rectifier output is filtered with two 2200mF capacitors to give about 17V DC (depending on the mains input voltage). This feeds the H-bridge driver for the motor. The 17V DC is also applied via diode D5 to 5V regulator REG1 which supplies IC1 and the rest of the circuit. Next month we will complete the description of the Railpower with all the construction details and the set-up procedure. SC Capacitor Codes Value 100nF 10nF 27pF mF Code IEC Code EIA Code 0.1mF 100n 104 0.01mF 10n 103 NA 27p 27 siliconchip.com.au Did you know that it’s now mandatory for electricians to provide a written safety test report when they install new wiring or do repairs to your home, office or factory? That is quite an onerous and time-consuming task but the Metrel Instaltest 3017 does all the tests specified in the AS/NZS3017 standard. As well, it provides a step-by-step guide for electricians when they are doing visual checks as well as the electrical tests. A “must-have” for every electrician and contractor: Metrel Instaltest 3017 By Leo Simpson siliconchip.com.au September 2008  31 P roviding a comprehensive report after an electrician has made repairs or changes to a home or building is a fairly onerous requirement. Not only does the electrician have do the actual wiring or repairs but they now also needs to provide a report, termed the Electrical Safety Certificate, as specified by the relevant organisation in each state. They need to give a copy of the report to the customer and they need to keep a copy for their own records. Preparing this certificate is no simple task, as it must indicate that all required visual checks have been made and the electrical tests done, including the actual test readings where appropriate. All told, this can add up to quite a lot of work and it means that the electrician must be well organised to do the tests and then create the report for the customer, often after hours when all the “proper work” has been done. To indicate just how much work can be involved, consider a typical large home these days with multiple power and light circuits. If it is a complete wiring job, each power point and light socket needs to be tested and noted on the report. Enter the Metrel Instaltest 3017. It has been designed to take the drudgery and much of the paper work out of the process. As well as compliance testing, the Instaltest 3017 can be used for trouble-shooting and also as a cable locator (with an optional kit). The instrument itself is quite compact and measures about 230mm wide, 103mm high and 117mm deep. It has an LCD screen flanked by membrane switches on the front panel. At the top of the case is connector panel with a sliding door which allows access to a USB socket and a PS2 socket for serial communication to a computer and a DC socket for charging the internal batteries. The LCD can be illuminated for viewing in poor lighting conditions. Tests are unambiguous and give a simple go/no go result. This one is for neutral line resistance to earth. The instrument was designed specifically for Australian/NZ conditions. These are the actual screens shown to the electrician during testing. The Instaltest connects to the PC via a USB port, from where a printed report can be prepared for the customer, as is now required by law. 32  Silicon Chip siliconchip.com.au For visual checks of wiring, switchboards and so on, the Instaltest 3017 has a number of inbuilt procedures and as you step through them, you can tick the boxes as you go. There is no need to have separate paperwork. Then, you can do the actual tests such as electrical continuity & resistance, insulation resistance, polarity, correct connections, fault loop and RCD tests. Most of these tests, with the exception of polarity (testing whether Active is at 240VAC and Neutral is 0V with respect to earth) are done with no power in the system. In order that the Instaltest can verify that the Active, Neutral and Earth connections in GPO (general purpose output, power point) are correct, a test box must be connected to the circuit at switchboard, with power disconnected via the circuit breaker. The test box connects a 10W resistor between Active & Earth and 5W resistor between Neutral and Earth. The Instaltest can then check for correct polarity and earth continuity. Insulation tests are done at 1000V (internally generated). The test shows the insulation resistance (up to 30 megohms) and the test voltage. The instrument can also be used to test the insulation resistance of heating elements (in hot water tanks etc). The Instaltest 3017 has a very good procedure for checking RCDs (residual current devices) and checks each one for six parameters. Having nominated the RCD type (ie, 10mA, 30mA, 100mA etc), the Instaltest tests at half, one and five times the rated current at normal and reverse polarity (180 degrees) and gives the trip times in milliseconds. Each time it trips the RCD, you need to reset it whereupon the Instaltest will do the next step, for all six test. As each test is completed, you press the F2 button to commit the data to memory and then continuing through until all tests are done. After the job is complete and the electrician is able to do normal paperwork tasks such as invoicing, the Instaltest is connected via the USB or serial port to a computer and all the data downloaded to that reports can be compiled for the clients. The printed reports can then be presented to the customer, together with the invoice. Using an optional transmitter box, the Instaltest can also be used for cable tracing in complex power systems. All told, the Metrel Instaltest 3017 should be the answer to an electrician or contractor’s prayers, providing fully documented reports to cater for all repairs and new installations. Along with the AS3017 Instaltest instrument itself, the package contains a comprehensive set of test leads and add-ons to cover all tests required under AS/NZS3017. These include tests for voltage and frequency, insulation resistance, fault loop impedance, RCDs and phase rotation. Optional kits also allow earth resistance metering and cable locator/circuit tracing. Not shown here is the comprehensive instruction manual, also included. For further information on performance and availability of the Instaltest 3017, contact the Australian distributors, Emona Instruments Pty Ltd, 86 Parramatta Road, Camperdown, NSW 2050. Phone (02) 9519 3933 or via their website, www.emona.com.au SC into MICROS OR PICS? There’s There’s asomething reference to to suit suit every every microcontroller maestro in the SILICON CHIP reference bookshop: see the bookshop pages in this issue Microcontroller Projects in C – by Dogan Ibrahim Graded projects introduce microelectronics, the 8051 and $ 8100 programming in C. Programming 16-Bit Microcontrollers in C – by Luci Di Jasio Learning to fly the PIC24. Includes a CD ROM with source code in C, Microchip C30 complier $ 8050 and MPLAB SIM. Hands-On ZigBee – by Fred Eady An in-depth look at the clever little 2.4GHz wireless ZigBee chip that’s now being found in a wide range $ equipment from 9650 of consumer to industrial. PIC in Practice – by DW Smith Ideal introduction to PICs. Based on popular short courses for the PIC for professionals, techs, hobbyists, $ 60 students and teachers. PIC Microcontroller – know it all ( Newnes) Newnes have put together the best of subjects their authors have written on over the past few years $ 7995 into this one handy volume! The PIC Micro – personal intro course – by John Morton A very practical guide which assumes no prior knowledge. So it is an introduction to the widely$ 52 ideal used PIC micro. ! Audio ! RF ! Digital ! Analog ! TV ! Video ! Power Control ! Motors ! Robots ! Drives ! Op Amps ! Satellite siliconchip.com.au September 2008  33 What do you do for a LED flasher now that the LM3909 is no more? LM3909 Replacement Modules Module: by Thomas Scarborough it’s even more versatile! The LM3909 was a legendary IC, which the designers (National Semiconductor) modestly described as a “LED Flasher/Oscillator”. Its popularity was surely due both to its great simplicity and versatility. It could flash a LED off a wide range of voltages, at a wide range of frequencies. It could also flash LEDs in parallel, could produce a tone in a loudspeaker, trigger a Triac or pulse an incandescent bulb – among other things. Sadly, though, the LM3909 has been discontinued and is now very difficult to find. T he module shown here is designed to do just about everything that the original LM3909 did – and more! There are a couple of differences – the most obvious one is that the module is quite a bit larger than the DIP-sized LM3909. Supply voltage is much more usable 3V-18V, compared to the LM3909’s 1.15V to 6V. Current consumption may be as low as 100µA, rather than the LM3909’s typical 0.55mA. Pulse width may be controlled more easily than it could with the LM3909. 34  Silicon Chip And not least, this circuit can pulse two LEDs alternately. It will also serve, among other things, as a quartz clock driver and continuity tester. Rather than present a host of similar circuits, however, a single module is shown here, along with a table showing how the module can be used in a variety of ways. Circuit description IC1a is a Schmitt RC oscillator or “clock generator”. Only the capacitor, C1, can be regarded as a fixed part of the oscillator; R1, R2, RX, RY and D2 are all components which can be changed to allow the module to perform in different ways. The output of the oscillator charges and discharges capacitor C2 through IC1b, connected as an inverting buffer. The charge on C2 then controls IC1c. When the output of IC1c is combined with the the output of IC1d (which is the inverted output of IC1a), brief pulses are sent in opposite directions between IC1c and IC1d. Depending on their direction, these pulses cause either LED1 or LED2 to flash. siliconchip.com.au Two of the many possible versions of the LM3909 Replacement Module – on the left, the alternate LED flasher with LINK2, RX at 4.7MW, RB at 1kW, no R2 and RB (hidden behind capacitor at top) at 47kW. At right is the LED/bulb flasher, with LINK3, RX at 2.2MW, R2 at 470kW (in series with its diode), RB at 1kW and no RY. Note the MOSFET lamp driver is also in place on this PC board. For most of the time, LINK1 stays in place (the circuits won’t work without it). RX sets the frequency of the flash, while RY sets the pulse width (or “on” time) of one or both of the LEDs. Resistor RB limits the current through the LEDs to safe values. LINK1 is a switch which either enables (when connected to +V) or disables the oscillator (tying pin 1 to 0V via R1). In all except one case, LINK 1 stays in place unless you want to stop the circuit oscillating. In fact, LINK1 could be replaced by a switch if you want to make it even more convenient. LINKS 2 and 3 can be changed to make their respective gates operate in different ways, in turn affecting the operation of the module. It is this which gives the module significantly D1 1N4001 K 100 µF 25V + Q1 IRF540 IC1: 4093 (ENABLE/ DISABLE) 1 IC1a 2 A C1 470nF +3-18V* * VALUES SHOWN ARE FOR 12V SUPPLY LINK1 100kΩ (R1) A 3 13 Rx K D2 1N4148 12 5 R2 Ry 14 11 LAMP D G S IC1d Rb IC1b 4 6 LINK2 LINK3 K A C2 470nF LED1 8 9 λ LED2 λ K IC1c A 10 OUTPUT TO PIEZO, CLOCK, ETC 7 0V 1N4148 A SC 2008 1N4004 K A LEDS K LED/LAMP FLASHER K A IRF540 D G D S Where the LM3909 had just about everything inside the DIP package, the replacement module requires a few more components – but it does more than the LM3909 ever did! siliconchip.com.au more flexibility than the LM3909 it is replacing. LINK2 is used where a short pulse width is required and LINK3 is used where a square wave is required. Various possibilities are shown in the table overleaf. Component values in this table are selected for 12V operation and will likely need to be modified for other supply voltages. One of the other features of this module which you didn’t get (as much) with the LM3909 is that it allows significant experimentation and modification of values. With the exception of RB, changing any of the resistors (even going down to 0W) will not cause any damage to the module (RB limits LED current through the LEDs and should never be less than about 470W). Finally, if LEDs are wired in parallel, these should best have individual current-limiting resistors, the combined resistance of which should not be less than about 330W. As mentioned earlier, one of the features of this module is its wide supply voltage range (3-18V). This is connected via a terminal block on the left side of the module which is in turn protected against incorrect polarity by diode D1 and is decoupled (smoothed) by the 100mF capacitor. This capacitor is specified as 25V to allow up to an 18V supply; if you are never going to use a supply greater than 12V, a physically smaller 16V capacitor can be used. September 2008  35 Q1 Ry + 100 µF K A D2 IC1 4093B 1 4148 EV- A LINK2 LINK1 + 1 1 8 0 8 0 0 11N4001 +V (3-18V DC) 0V 470nF R1 C1 Rx LINK3 K 100k 470nF LED2 D1 LAMP C2 LED1 pm a l Rb IRF540 G D S P MAL RE HSALF OUTPUT (PIEZO, MOTOR, ETC) R2 The same-size photo above matches the component overlay at right. The photo is of the Alternate LED Flasher. While this PC board might look like a double-sided type, it’s not: it was produced in a panel which included a double-sided board so pads also appear on the top side, along with pads and tracks on the bottom side. The lamp, its terminal block and the lamp driver (MOSFET Q1) are optional – if you don’t want to drive a lamp, simply leave them out. Construction This project could hardly be simpler – simply mount the components as shown on the overlay, also using the photograph as a guide. Start with the terminal blocks. For most uses a two-way block will suffice on each side of the PC board (the four-way on the left side is only required for the incandescent lamp driver). Follow these with the three header pin sets (for LINKS 1, 2 and 3), then the resistors and capacitors, next the LEDs, the MOSFET (if required) and finally the diode D1 and IC1. The diode D2 could be left out if you don’t want to build the lamp driver or modified alternate LED flasher but given its low cost, it might as well be included. Without R2 in place, it will have absolutely no effect. Note that all components except the resistors and the two “block” capacitors are polarised – the circuit won’t work if you put them in the wrong way around (and you could damage them). Also be very careful when soldering in components with close lead spacing (especially the IC). It’s very easy to bridge across adjacent pads and once again, this will stop the project working and could cause damage. And if you want to experiment with different values, here’s a tip: solder in some PC stakes for all resistor values which you might want to change (R2, RB, RX and RY). It’s a lot easier to tack resistors across the stakes rather than solder them into the PC board and take them out again (besides, it’s easy to damage the PC board tracks with too much soldering and desoldering). This shows how the two outputs from IC1d (yellow) and IC1c (green) add to give double the drive signal to the LEDs (white trace). 36  Silicon Chip Parts List – LED Flasher Module 1 PC board, 62 x 50mm, code 11009081 3 2-way PC-mount terminal blocks 3 2-way header pin sets 1 4093 quad Schmitt NAND gate 1 IRF540 MOSFET (Q1 – optional) 1 1N4004 power diode (D1) 1 1N4148 small signal diode (D2) 2 5mm LEDs, colours as required 1 small incandescent lamp, voltage to suit supply voltage (optional) Capacitors 1 100mF 25V electrolytic capacitor 2 470nF MKT metallised polyester capacitors Resistors (0.25W, 1%) 1 100kW (R1) Other resistors to suit application – see component selection guide The flasher board set up for a 50% duty cycle flasher. In fact, it is not quite 50%, due to the differing positive and negative switching thresholds in the gates. siliconchip.com.au LED Flasher Modules – Component Selection Guide RX RY RB R2 Links LEDs LED Flasher 2.2MW 47kW 1kW None LINK 1 IN LINK 2 IN LED1 Alternate 4.7MW 47kW 1kW None LED Flasher LINK 1 IN LINK 2 IN LED1 LED2 Micropower 4.7MW 10kW 2.2kW None LINK 1 IN LED1 Alternate LINK 2 IN LED2 LED Flasher Square Wave 4.7MW None 1kW None Alternate LED Flasher LINK 1 IN LINK 3 IN Notes: Ultrabright LEDs are required here. A 47kW resistor is wired in series with the power supply’s +V. The circuit draws about 100µA. Remove resistor R1 to minimise current drain. LED1 LED2 Modified 2.2MW None 1kW 470kW LINK 1 IN LED1 Square Wave and diode LINK 3 IN LED/Bulb Flasher The 470kW and diode are wired in parallel with RX. Depending on the orientation of the diode, the LED will be illuminated longer or shorter than half of a complete cycle. By making IC1d pin 11 power a MOSFET, this configuration may be used to flash an incandescent bulb. Modified 4.7MW 47kW 1kW 1MW LINK 1 IN LED1 Alternate and diode LINK 2 IN LED2 LED Flasher The 1MW and diode are wired in parallel with RX, yet the diode’s polarity is immaterial here. The effect is a pulsing of the two LEDs “in twos”. Quartz Clock Motor Driver RY and RB may need to be altered, depending on the characteristics of the quartz clock’s stepper motor. This is merely an experimental circuit, since an RC timer will not provide good time keeping. 10MW 150kW 470W None LINK 1 IN Stepper variable LINK 2 IN motor Externally Pulsed None 150kW 470W None LINK 1 IN Stepper Quartz Clock LINK 2 IN motor Motor Driver The external pulses need to match the supply voltage of the module. These may need to be further lengthened. This may be done by wiring a diode between the source of the pulses and IC1a pin 2, with the cathode to pin 2 and a resistor in parallel with C1 (try 2.2MW). Continuity Tester 2.2kW None None None LINK 1– Piezo The piezo sounder is wired to the wired to 0V sounder sounder outputs for LED1. The via a 1MW continuity tester’s leads are taken resistor from the LINK1 terminals. R1 can be (see note) increased to 1MW for the continuity tester – alternatively 1kW to avoid obtaining a signal for high impedance SC continuity. siliconchip.com.au September 2008  37 PRODUCT SHOWCASE High output from small LEDs Cree, Inc, represented in Australia by Cutter Electronics, claim a new standard for lighting-class LEDs with the introduction of the XLamp XP-E and XP-C LEDs. At just just 3.45mm square by 2mm high, these breakthrough LEDs have the smallest footprint in the industry for lighting-class LEDs—providing the same high-quality lighting performance and proven reliability as Cree XR-E and XR-C LEDs in an 80% smaller package. Thanks to their small size and low profile as well as a wide viewing angle and symmetrical package, the new XLamp LEDs, suit applications as diverse as Altronics moves into Queensland backlighting, signage, outdoor, indoor and portable lighting, etc. The XP-E LEDs offer 100 lumens minimum at 350mA in cool white (500010000°K) and 80.6 lumens at 350mA in warm white (2600-3700°K). Contact: Cutter Electronics 5 Highgate Way, Rowville, Vic 3178 Tel: (03) 9753 9911 Fax: (03) 9753 9455 Website: www.cutter.com.au Aluminium 19-inch rack-mount cases The new RM family of 19” rack cases from Hammond Electronics are available in 1, 2 and 3U heights and depths of 203mm, 330mm and 457mm. They are suitable for housing a wide range of equipment, either mounted in a 19” rack or, if required, used as a desktop enclosure. The all-aluminium construction consists of a heavy-duty extruded frame, removable vented or plain top and bottom covers and optional 19” rack mounting angles and self-adhesive rubber feet. The front and rear panels are removable and interchangeable and they are of flat construction to make machining and screening a simple process. Front panel handles that mount to the rack mounting angles are optionally available to assist with insertion and removal from a rack; to provide greater support heavy loads, rear-mounting brackets can also be specified. They are finished in durable black powder coat paint as standard. Contact: Hammond Electronics Pty Ltd 11-13 Port Rd, Queenstown, SA 5014 Tel: (08) 8240 2244 Fax: (08) 8240 2255 Website: www.hammondmfg.com Even more LEDs: Tenrod’s Sealed Flexible Lights These flexible LED strip lights from Tenrod Australia can create a delightful ambience enhancement effect. They blend into furniture or ceiling features, window frames or curtain pelmets and with a choice of colours from warm white to blue, the lights are easily installed. The flexible LED light strip operates from 12V DC and will wrap around curved surfaces, is sealed against water and dirt in a transparent envelope and offers easy mounting with its peel and stick adhesive taping. There are 300 high-brightness LEDs in the 5-metre reel, splitable at any 3-LED unit. Colours include white, warm white, blue, green, yellow and red. 38  Silicon Chip Altronic Distributors has recently expanded its wholesale sales operations opening an office in Eight Mile Plains (in Brisbane’s south) to cater for the Queensland market. They are pleased to announce the appointment of Daniel Neuss as the Queensland state manager. Daniel brings considerable electronics and customer service skills to this position, with over 10 years experience in the industry. Altronic Distributors see this is as a way to provide Queensland customers with a greater level of service. Contact: Altronic Distributors (Qld) Tel: 1300 780 999 Fax: 1300 790 999 Website: www.altronics.com.au email: daniel.neuss<at>altronics.com.au ANTRIM TRANSFORMERS manufactured in Australia by Harbuch Electronics Pty Ltd harbuch<at>optusnet.com.au Toroidal – Conventional Transformers Power – Audio – Valve – ‘Specials’ Medical – Isolated – Stepup/down Encased Power Supplies Encased Power Supply Contact: Tenrod Australia Units 1&2, 24 Vore St Silverwater NSW 2128 Tel: (02) 9748 0655 Fax: (02) 9748 0258 Website: www.tenrod.com.au www.harbuch.com.au Harbuch Electronics Pty Ltd 9/40 Leighton Pl, HORNSBY 2077 Ph (02) 9476 5854 Fax (02) 9476 3231 siliconchip.com.au Portable Sound Level Meter The Testo 815 sound level meter from Testo provides a simple solution to PA volume problems. With an accuracy of class 2, it is also ideal for checking air conditioning or heating noise, disco noise, machine noise or noise in combustion systems. Features Include: • Accuracy class 2 to IEC 60651 • Frequency weighting to Characteristic A and C • Maximum and minimum value memory • Built-in tripod knuckle screw (1/4 inch) • Switchable Fast/Slow time weighting • Easy to adjust (adjustment screwdriver included) HOPERF nsors Contact: RS Components 25 Pavesi St, Smithfield NSW 2164 Tel: (02) 9681 8558 Fax: (02) 9681 8614 Website: www.rsaustralia.com RF IC & Modules Microzed has Hope Microzed Computers have been appointed the Australian distributors of Hope Microelectronics Co. This major Chinese organisation uctor SAW Devices manufactures a range of digital s sensors, RF integrated circuits and modules, RF semiconductor components, devices,by and RF/Sensor Distributed inSAW Australia application solutions. zed Computers Pty. Limited Products to be stocked by Microzed 300 735 420 pressure Fax: 1300 735 421 include sensors, barometer sensors, humidity sensors, 16-bit www.microzed.com.au ADC’s, FSK wireless modules and solutions for 315/433/868/915MHZ, wideband RF transistors, SAW filters and SAW resonators. Contact: Microzed Computers Pty Ltd PO Box 5103, Chittaway Bay NSW 2261 Tel: 1300 735 420 Fax: 1300 735 421 Website: www.microzed.com.au siliconchip.com.au Hemipro LED worklights HEMIPRO high power LED worklights from GO Distribution are designed to meet the rigorous standards of the automotive repair market – which also makes them highly suited to applications such as industrial, heavy vehicle, electrical, farm and machinery maintenance workshops. They are also versatile around homes, cars, boats, caravans, motor homes and holiday houses where people need a tough, long-lasting light source that can be simply plugged into the mains for recharging. (12V chargers are also available.) Designed to provide high performance for 10 years or more of normal use, HEMIPRO incorporate a tough polycarbonate patent-pending “Lumiguard” lens shield which protects the lens and can be easily and quickly replaced if it gets scratched, cracked or tarnished. Rather than throwing Ozitronics Tel: (03) 8677 1411 Fax: (03) 9011 6220 Email: sales2008<at>ozitronics.com RF Data Link – A series of 4 kits to transmit data over a 433MHz RF link. K173. Tx with serial data input K174. Rx with serial data output K175. Tx with parallel data input K176. Rx with parallel data output Documentation shows how to use with other kits for remote operation. K173/5 - $52.80, K174/6 - $60.50 More kits & documentation available on website: www.ozitronics.com: away the entire work light, users can simply replace the Lumiguard in less than two minutes. Using either two or three highpower LEDS, the HEMIPRO 2-LED and 3-LED work lights provide exceptionally powerful beams which equal or exceed the light area intensity of a 60W or 75W beam, respectively. Contact: GO Distribution PO Box 7229, East Albury NSW 2650 Tel: (02) 6026 4886 Fax: (02) 6026 4889 Website: www.cliplight.com Hameg 200kHz LCR Bridge from Rohde & Schwarz For around $2600 the HM8118 20kHz LCR Bridge has a list of features that most of the competition cannot touch. Key features of the HM8118 include: • Basic Accuracy of 0.05%. • Measurement functions L, C, R, |Z|, X, |Y|, G, B, D, Q, È, Ä, M, N with test frequencies from 20Hz -200kHz. • Up to 12 measurements per second in both parallel and series mode. • Optional binning and limits for parts sorting. • Internal programmable voltage and current bias as well as transformer parameter measurement. • External capacitor bias up to 40V is also included. • The HM8118 also includes a number of key measurement accessories including a Kelvin cable and 4-wire SMD Test adapter, as well as a galvanically isolated USB/RS-232 Interface. Several additional accessories to provide for component testing. These include the four-wire transformer cable HZ186, a four-wire test adapter including shorting plate HZ181, an eight-bin handler interface HO818 (installation only ex-factory) and a galvanically isolated IEEE-488 (GPIB) interface HO880. For more information, data sheets, flyer and press information please visit Hameg’s website www.hameg.com or contact the Australian distributors, Rohde & Schwarz. SC Contact: Rohde & Schwarz (Aust) Pty Ltd Unit 2, 75 Epping Rd, North Ryde NSW 2113 Tel: (02) 8874 5111 Fax: (02) 8874 5199 Website: www.rohde-schwarz.com.au September 2008  39 SERVICEMAN'S LOG One man’s trash is another man’s treasure There’s an old saying that “one man’s trash is another man’s treasure”. Personally, I think it’s all treasure so you can imagine my overwhelming joy when a friend recently found an old valve car radio for me to fix! A friend of mine was rummaging around inside his deceased grandfather’s old shed when he came across a couple of old car radios. They weren’t easy to physically locate as they were on the bottom of what used to be a set of shelves which had now collapsed on top of them. Besides that, there was a lot of “junk” in front of them as well. Note that I use the term “junk” loosely here, as this stuff was really treasure. There’s no such thing as junk in my book. When he got the first one out into the open, he recognised it as the radio his grandfather had had in his old 1955 Chevrolet. Unfortunately, the old Chevy had also gone to God many years ago. The car radio was a 1954 Astor (National Automatic Service Co) RM Air Chief. This was a 12V 6-valve plus vibrator AM manual car radio made in Melbourne. Anxious to find out whether it still worked, my friend connected it to a battery and switched it on. The on/off switch needed a little coaxing but eventually the dial-lamp came on. But that was all. The set was otherwise completely dead and that was when he brought it to me. I gave the vibrator a bit of a knock and although it tried hard, the 44-year old Ferrocart The wax paper capacitors inside the old Air Chief AM car radio were all replaced with Philips axial polyester types. Apart from the capacitors, the only other problem was a faulty vibrator assembly. 40  Silicon Chip Items Covered This Month • • • Astor RM Air Chief Car Radio Celestial ChangHong LT3200HD LCD Grundig Elegance 82 MW822101 TV set (NIC/Dolby CUC2058 chassis) PM238 non-synchronous vibrator just couldn’t quite make it. In the end, there was nothing for it but to (literally) cut open the metal can to get to the vibrator points and clean them up with a bit of fine wet and dry paper. Thankfully, the points were not too pitted and the reed relay wasn’t open circuit. The spacing was set for “8 thou” (.008 inches or about 0.2mm) and the vibrator then put back in the radio. When power was applied, you could now hear the vibrator working but there was still no sound from the radio. I reached for my multimeter, intending to connect it to the cathode output (pin 7) of the 6X4 rectifier (to check the HT), but by now smoke had begun pouring from the PT182 transformer. At first I thought there was a short circuit on the +245V HT rail, probably due to one of the electrolytics. However, the ohmmeter said otherwise. The problem was elsewhere. There are 15 wax paper Ducon capacitors in this set, which I knew would not be in the best of condition after 44 years. I was hoping that one of these would be responsible for the smoke and so I began replacing them. First, I changed a .05mF paper capacitor which is adjacent to the vibrator. This made no difference, even though the capacitor measured leaky and was way off value. The next cab off the rank was the buffer capacitor, a .008mF (8.2nF) 2kV unit across the anodes (pins 1 & 6) of the rectifier valve. This measured short siliconchip.com.au what. Personally, I would now build a solid-state multivibrator to replace the noisy mechanical vibrator. I love you, hate you The operating manual for the old Air Chief car radio was also found. circuit so I was on the right track. The value of this component is fairly critical as it sets the resonating frequency of the transformer, which in this case should be 150Hz (the frequency of the vibrator). I didn’t have an 8.2nF capacitor in stock so I had to parallel up 3.9nF and 4.7nF ceramic capacitors rated at 6kV to give 8.6nF, a 7% increase in value. That fixed the fault and the radio now worked, drawing 2.5A at 12V. Next, I replaced the remaining 13 paper capacitors with the now rare Philips axial polyester types and the radio worked even better than before. The extra RF and IF stages (6BA6/ EF93) fitted to this set improve the gain (and the reception) quite markedly compared to a modern AM radio. These radios were also fitted into the early GM Holden range, probably the FJ series. Unfortunately, the noisy vibrators let the show down some- siliconchip.com.au My love affair with computers continues – not! Following my bad experience recently with my PC, I decided to upgrade my 80Gb hard drive to a 250Gb 7200 RPM drive (IDE type). I had already upgraded the machine to Service Pack 3 (SP3) but had not installed all the upgrades for my third party software. Anyway, I bought a Seagate Barracuda ST3250820A and to make the changeover easy, I downloaded the Seagate Acronis Disc Wizard CD from their website. The beauty of this is that you simply boot from this CD and it automatically partitions and formats the new drive and then copies all the data across from the old drive – in my case over a period of about two hours. It is even easier to use than Ghost and you can even remove old partitions (if present) by using the advanced mode. When it was all done, I booted up with the new hard drive and started to use it immediately. All was fine and I used it every day for over a month. And then, one morning, Mrs Serviceman switched the computer on and left it to boot while she went to make some coffee. When she returned, she fully expected the computer to be ready for use. Instead, all she got was a flashing cursor in the top lefthand corner of the screen that wouldn’t change no matter how long she waited. She called me and I rebooted the computer to find it wouldn’t go any further. In 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 fact, the fault appeared immediately after the POST routine (power on self test). My first approach was to boot from a WinXP CD and press R for repair at the screen prompt. From there, I then tried September 2008  41 Serviceman’s Log – continued a slave, so I’ve now got lots of space left for lots of marvellous new stuff. Celestial LCD TV CHKDSK/R, FIXMBR and FIXBOOT but that didn’t fix it. FIXMBR, by the way, writes a new master boot record, while FIXBOOT writes a new partition boot sector to the drive. Next, I tried reinstalling XP Professional SP2 onto the drive (over the top of the previous installation) but even that did not fix the symptoms. I then asked for advice from several acquaintances but no-one had any ideas. It was time to eat humble-pie and ask a real guru (the one who is always lecturing me about the amount of stuff I have installed on my computers). After a brief discussion, he suggested that I try cloning the installation onto another 250Gb hard drive. If that failed, his advice was that I might simply have to bite the bullet and reformat the drive and re-install XP. My protests that that wasn’t an option, because it would take too long to reinstall all my stuff, were met with an unsympathetic shrug. I just hate computer gurus! When I slaved the troublesome new drive in another machine, I could see that all my data was OK. So it looked as though the boot sector had been damaged or corrupted in some way on the new drive. As a result, I decided to follow my friend’s advice about cloning, so I bought yet another hard 42  Silicon Chip drive, this time a Seagate 320Gb unit. It took another two hours to clone the faulty hard drive to the new 320Gb unit. However, the gamble paid off because when I booted from the new clone, it fired up and everything initially appeared to work normally. Well, if that works, I reasoned, why don’t I try cloning back to the faulty disk to see what happens? Well, I did just that and somewhat annoyingly, the 250Gb drive now also worked. However, because I had tried to reload XPSP2 back onto that disk, both disks now needed the installation to be completed, as the computer had stopped after the first reboot. This was done and I then re-ran the SP3 update to get everything up to date and working again. All was going well – almost too well. It even handled the reboot and continued installing software as it booted up. The main screen came up again without a problem but on the very next reboot I got the message that C:\windows\system32\config\ system was faulty, missing or corrupt. Eventually, I solved the problem by cloning my original 80Gb drive onto the new 320Gb drive, which is really what I should have done in the first place. As for the 250GB drive, I’ve reformatted it and installed it as Our first Celestial Chang­Hong LCD TV came in under warranty. This new LT3200HD model is an 81cm high-definition LCD (1366 x 768) TV with an integrated HD tuner and normally gives a very good picture. Unfortunately, this particular set had a weird intermittent fault. When it was hot, all the blacks went green. I had never encountered such a fault before and it really scrambled my tiny brain as to where to start looking. What is excellent about this set is that the back can be removed without having to first remove the stand (ie, the set can remain in a vertical position). Almost all other LCD TVs (and monitors) have to be placed face down and their stands removed first. This meant that, in the case of the Celestial TV, I could remove the back while the set was warm and running. Unfortunately though, due to the cold weather we had been having, as soon as I removed the well-ventilated back, the fault would disappear. So the fault was obviously heat-sensitive. Eventually, with the aid of a towel, hairdryer and freezer, I managed to isolate the problem to IC U20 (AZ1084), a 3-terminal 3.3V IC regulator which runs very hot. This supply feeds the processor. When the fault occurred, the DC voltage remained correct but the ripple increased. Freezing the IC would fix the symptoms immediately but unfortunately this surface-mounted component is not available as a spare part. As a result, the entire motherboard had to be replaced. The new IC felt as hot as the old one but the symptoms did not re-occur. Stormy weather When you are asked to do a service call for a TV that has snowy pictures – especially after a thunderstorm – you can never really be sure what you are going to find. Recently, I was called out to look at a number of sets, all displaying the same symptoms. However, the causes were all completely different. The first was a Philips TV. During the storm, the lights had gone out due to a power cut. The set’s owner had then stumbled over an object in the siliconchip.com.au Adelaide Electronic Component Specialists Red Seven-Segment 7.62mm Digit LED Display Common Anode Bright LED 7x5 Dot Matrix Display Bicolour Red/Green 53.2mm x 38.5mm $8.70 Each lounge room and as she fell, her shoulder grazed the TV set and moved it slightly. Unfortunately for her, the aerial lead to the VCR, which was sitting on top of the TV, was very short and tight. Moving the “telly” had pulled the RF lead out of the VCR, causing the snowy picture. If only they were all that easy. The next set was a Sony rear-projection TV that had gone snowy after a lightning strike. This turned out to be a damaged VCR power supply which prevented signal getting to the TV. Ironically, with snowy pictures, you normally get a hissing sound. In this instance, the hissing also came from a crack in the insulation of the HV unit inside the rear projection TV. This was replaced and the hiss went away for good. The last case I had was an old Teac MV-1440TV TV/VCR. The cause this time was that the tuner was intermittently drifting. These sets are made (I think) by Funai for Fujitsu General and Teac. However, the tuner IF is manufactured by Sharp and is the same as that fitted in the Fujitsu General VGX-715A. Unfortunately, it is no longer available and one can only attempt to repair it. Apart from dry joints, there is the 36.9MHz blue SAW filter to check, along with the AN5135NK 28-pin IC and an electrolytic capacitor on the AGC line. After that, the next parts to check are the 33V zener diode, IC1105 (L531), IC1102 (LA7913) and D1101 (1N4002), plus the surrounding electros. Finally, if all that fails, you sell the client a new digital set-top box which will fix most faulty aerial problems too and alleviate technology obsolescence! $5.50 for 10 7-Segment RED 4 x 15mm Digit LED Display 50 x 19mm $3.30 Each $3.00 for 10 3mm Bi-Colour LED Diffused Orange/Green Common Cathode Flexible LED 12V Strip Available in these colours Blue Red Green RGB Tricolour Cool or Warm White $4.95 each 50mm / 3 LEDs max run of 5m $9.90 each 100mm 3 LEDs Also Available In Waterproof Force Electronics Holden Hill Shop 4, 650 Main North Road, Holden Hill, SA 5088 8261 7088 forcehh<at>adam.com.au Aztronics Pty Ltd 170 Sturt Street, Adelaide, SA 5000 8212 6212 www.aztronics.com.au Grundig TV set Some time ago, I wrote about a Grundig CRT TV. It was a 2000 Elegance 82 MW82-2101 NIC/Dolby using a CUC2058 chassis and at the time, its power supply had radically spat the dummy. Following repairs, it had been working well for about three months when the owner phoned to complain about hissing noises coming from the rear of the set. I wasn’t especially concerned about this as we had just been going through a particularly long rainy period and dampness often creates problems in EHT sections – espesiliconchip.com.au cially European TVs that whose designers somehow don’t fully appreciate the need for tropical insulation. Anyway, he agreed to bring the set in so that it could be fixed before it got worse and failed completely. When it arrived, I removed the back and could immediately see that it was arcing from the small flyback transformer (TR53010). I cleaned the whole area around this transformer with CRC2-26 and used a paintbrush and clean cloth to make it all almost sparkling new again. However, despite my efforts, I could still detect hissing September 2008  43 Serviceman’s Log – continued from where the EHT leads connected to the transformer. I showed the owner the problem and told him that normally I would build up a thin layer of silicone rubber over the areas where the arcing was taking place. However, my stock of silicone had dried up which meant that he would have to wait until I got some in. My customer, who happened to be a mechanic, then told me that he had some red (high-temperature) silicone which he used for sealing gaskets in engines. What’s more, he had some in his car which he immediately retrieved. I wasn’t too sure what its electrical properties were but on his assurance (and by implication his responsibility), I agreed to use it to seal the insulation of the flyback transformer. The rubber cures fast and it had gone off in about two hours. The result was that the set was now really quiet, as it should be. When he returned to collect the set, I explained that due to the nature of the fault, I could offer no guarantees. I also told him that a replacement transformer was expensive, so the silicone treatment was worth trying. I didn’t charge him for the work I had done and he left with the understanding that he was pretty much on his own. Two weeks later he telephoned again to say that the set was dead again. I overlooked the emphasis he gave to “dead again” and agreed to look at it again if he brought it in. When it arrived, I plugg­ed it in and could see that the set wasn’t actually “dead” but was in fact stuck in “standby mode”. It was actually trying to start but just couldn’t make it. I measured the +A 155V rail all the way to the collector of the line output transformer. In addition, the E+ 8V line was going to the line driver until the set switched back to standby. As I had worked on the EHT insulation only a fortnight earlier, I suspected that the transformer had probably now 44  Silicon Chip failed completely. This was confirmed when I connected a CRO probe to the collector of the line output transistor (T53001) and could see a severe ringing instead of perfect line pulses. At this point, I felt that I would be quite within my rights to simply quote for a new flyback transformer and leave it at that. However, I had a niggly feeling that everything wasn’t quite kosher. Two weeks earlier, I had been confident that the insulation problem had been completely fixed and even now there were absolutely no signs of stress in the flyback transformer, apart from the ringing indication on the scope. As a result (and also to satisfy my curiosity), I removed the flyback transformer and checked it using both a shorted turns tester and an HR Line Output Transformer Tester. Both pieces of equipment reported a clean bill of health and it was tested up to 18.2kV. Feeling somewhat alarmed by now, I then checked the three secondary voltages derived from the flyback transformer. The 16V output was OK but the 45V and 200V outputs were both very low, so I spent a lot of time investigating these circuits until I could be sure nothing was wrong with them. Next, I spent some time looking at the deflection yoke and even completely disconnected it while making sure that the A+ voltage was still reaching the line output stages. This all checked out and I then spent a lot of time checking the vertical output stages and the East West circuitry but they were all in good working order. In the end, I kept coming back to the flyback transformer as this was the last known area where a problem had been detected two weeks earlier. I tried disconnecting the focus lead from the transformer to the CRT socket in case it was arcing inside one of the spark gaps but all that was hunky dory too. So what was left? The cabinet? Well, there was the EHT lead to the CRT final anode but it looked absolutely virgin. What could go wrong with that? And so, to make sure I had left no stone unturned, I disconnected the EHT lead from the flyback transformer and switched on again, not expecting much. To my surprise, the set fired up with sound and the ringing vanished from the collector of the line output transistor (T53001). To all intents and purposes, the set was now running normally, except of course there was no picture because of no EHT. What had happened was that the picture tube was “down to air” and it was arcing internally. Disconnecting the final anode or removing the CRT socket allowed the set’s electronics to resume normal service. I told my disbelieving client that the picture tube was faulty – probably due to the set having been dropped – and that it was beyond economic repair. Begrudgingly, he had to accept the facts, however I never got paid nor even thanked for all the diagnostic work I had done. You would have thought that being a mechanic, he more than most would SC have appreciated what I did! siliconchip.com.au SEPTEMBER 2008 150WRMS Sub Amplifier Module This module is designed to go into a subwoofer enclosure to complete an active sub for a home theatre system or multimedia application. It can be driven from line-level stereo, 5.1 sub or speaker inputs. $ HOME AUDIO SUB AMPLIFIER MODULES 600WRMS Sub Amplifier Module The bigger brother of our AA-0507, this module is rated for a massive 600WRMS and is suitable for serious home cinema applications, or as a building block for an active sub in an auditorium, conference centre or larger venue. Partner it with one (or more) of our 12” or 15" drivers for a truly earthshattering bass experience. It accepts stereo line level inputs, a 5.1 subwoofer input or speaker level inputs. It also has a balanced XLR input or a DI feed. Mains powered. Full specifications on website • Power output: 600WRMS <at> 4 ohms • Frequency response: 32 - 250Hz $ • Dimensions: 265(W) x 240(H)mm • Mounting depth: 90mm min. Cat: AA-0509 149 Cat: AA-0507 Specifications: • Power output: 150WRMS <at> 4 ohms • Frequency response: 32 - 250Hz • Dimensions: 240(W) x 240(H) • Mounting depth: 90mm 299 RC HELICOPTERS COMBAT PAIR $30 UNIVERSAL LAPTOP POWER SUPPLY This laptop power supply has adaptors to fit the major manufacturers' power sockets. It also displays the output voltage and automatically adjusts the output for the adaptor used. • 138(L) x 58(W) x 37(H)mm • 90W • Will charge $ 95 newer Dell model laptops! Cat: MP-3474 59 Each chopper is equipped with a 280-round IR 'gun' to blow your opponent away. When you register a hit, your enemy's chopper falls out of the sky until revived. 20 minutes charge gives about 8 minutes flight time. Safe for indoor use. Approx 170mm long. $ 95 Suitable for Ages 8+ Was $99.95 Cat: GT-3216 69 HID SPOTLIGHT CONVERSION KIT This is a simple single version of a High Intensity Discharge (HID) headlamp that you are now seeing on up market cars. It is one lamp set only. It is basically intended to convert a spotlight on, say a large boat, to a much more powerful and effective spotlight. The kit includes a 35W Xenon HID lamp, 6000*K, with H4 base, ballast unit and wiring harness. It is a very simple installation. $ 95 Light output approximately Cat: SL-3368 3000 lumens at 12V. . 89 MODIFIED SINE WAVE INVERTER 2000W 24VDC to 230VAC This high-powered inverter is ideal for operating most 240-volt equipment and will run microwave ovens, large TVs and display systems etc. The inverter is ruggedly built and has high/ low battery voltage alarms; over temperature alarm and output overload protection. Ideal for trucks, buses, and solar installations. A good basic inverter built to last. • 295mm long. $ See our New Pure Sine Wave Cat: MI-5116 Inverters featured on page 8) 629 USB SLIDE/FILM SCANNER Convert your negatives and slides to digital images quickly and easily with this USB scanner. Images are scanned in about half a second for high-speed conversion and editing using the included Arcsoft Photoimpression software or other image manipulation software. • Colour or B&W film or slides • Negative & slide holders included $ • 1,800 dpi resolution Cat: XC-4881 • Windows XP, Vista 169 USB 40MHZ 2 CH OSCILLOSCOPE A PC-based digital storage 'scope for less than the cost of an analogue CRO. PC-based instruments are the way to go $ - smaller, lighter and cheaper, they Cat: QC-1931 offer as-good or better performance than the analogue equivalents, with the advantages digital operation offers, such as trace storage and memory capability. Probes included. • See our website for full specifications & features. 499 LOW DISTORTION AMPLIFIER MODULE KIT Ref Silicon Chip Aug. & Sept. 08 This ultra low distortion amplifier module uses the new ThermalTrak power transistors and is largely based on the high-performance Class-A amplifier which was featured in SILICON CHIP during 2007. This improved circuit has no need for a quiescent current adjustment or a Vbe multiplier transistor and has an exceptionally low distortion figure. Kit supplied with PCB & all electronic components. • Heatsink and power supply (see below) not included. • Output Power: 135WRMS into 8 ohms & 200WRMS into 4ohm $ 95 • Freq Resp. at 1W: 4Hz to 50kHz Cat: KC-5470 • Harmonic Distortion: <.008% from 20Hz to 20kHz 89 Power Supply Kit for Ultra-LD Mk2 200W Amp Ref Silicon Chip Aug. & Sept. 08 This power supply kit is specifically designed to provide a balanced +/- 55VDC supply to power this fantastic amp kit. $ • Kit includes PCB and all electronic components. See who’s at the door with this great door phone. You can view and talk to guests before letting them in or sound an alarm to turn away unwanted visitors. The camera can also be used at night thanks to its CCD sensor and infrared illumination. You can even hook up one additional monitor and camera to make a comprehensive front & back door personal surveillance system. • 7" TFT screen • AV output • AV input • Mains powered • Remote door release output • Spare doorbell unit for QC-3616 $99 Free Call: 1800 022 888 for orders! www.jaycar.com.au 54 95 Cat: KC-5471 HANDS FREE COLOUR VIDEO DOOR PHONE $ 399 Cat: QC-3615 1 Digital TV offers superior picture and sound quality and there is a surprising amount of free-to-air digital content being broadcast already. The analogue network will be progressively shut down over the next few years and now is the time to upgrade your antenna system and take advantage of the free-toair digital only programs that are now available. UHF Phased Array TV Antenna Digimatch VHF/UHF X-type Colinear 27 Element Receives Bands 4 & 5 (Ch 28-69) Receives Band 3, 4 & 5 (Ch 612 & 28-69) This wideband antenna suits analogue or digital TV, and is ideal for fringe areas, where ghosting is a problem, or you aren't in direct line of sight of the transmitter. • UHF channels - 21 to 69 (27 to 62 in NZ) $ • Gain 11-13.5dB • 610mm x 890mm An excellent all purpose antenna suitable for VHF, UHF digital and analogue TV. • 27 Elements • Channels: 6-12 VHF, 21-69 UHF (27 to 62 in NZ) • Gain - VHF 7dB, UHF 11dB $ • Boom Length - 1320mm Cat: LT-3195 Kingray VHF/UHF Distribution Amplifier These splitters are sealed and in a metal case with mounting bracket. They are suitable from 5-900mHz, VHF, UHF TV and FM radio. • With mounting screws An excellent choice for difficult low-level digital signal areas. Very low noise & high gain. • Freq range: 44-860MHz +/- 0.5dB • Gain: 19dB • F-type connectors Cat: LT-3138 139 This versatile material looks like ordinary PVC electrical tape but is actually a handy sealing system that fuses together to form a removable, waterproof seal $ 95 once it has been applied. 12mm wide x 1.5m long. Cat: NM-2828 5.8GHz AV Sender $ 169 Cat: AR-1840 $30 Extra receivers sold separately AR-1841 $99.00 Battery Powered 2.4GHz AV Sender $10 Wireless & compact, this is the ideal solution when power availability & space are a consideration. Both transmitter & receiver operate on battery power. Connection to the AV source is via 3.5mm to RCA composite video & audio lead • 2 x 1m leads included Was $79.95 Each unit requires 2 x AA batteries (SB-2425) $ 119 95 Cat: LT-3252 UNIVERSAL REMOTES TAKE CONTROL OF YOUR TV, DVR & MORE WITH THESE UNIVERSAL REMOTE CONTROLS 8 in 1 Universal Remote Control with LCD Display $15 This universal remote control can operate up to 8 different devices at once including TV, DVD Players, VCR, RCVR, Satellite TV, Cable TV, Stereos and Air Conditioning units. It comes pre-programmed for easy set up, quick search and works with over 100 brands of electrical devices. • 210mm long $ 95 Was $34.95 19 $ 69 95 Cat: AR-1852 LCD Touch Screen Universal Remote Control Controls up to 16 devices: TV, Satellites, Cable TV, VCR, DVD, Tape, Hi Fi's, CD Players, Radios, MP3 Players, Amplifiers, Digital Recorders and other Audio devices. • 60(W)x210(H)x25(D)mm • Power: 4 x AAA Batteries required (SB-2413) 4 Way HDMI Multimedia Splitter • A simple device for switching between two high definition multimedia (HDMI) sources. Supplied with an I/R receiver fitted to a 2m cable. • Size 80(L) x 55(W) x 17(H)mm Was $89.95 $20 Connect an HDMI device to up to four displays. Supports HDCP compliant devices and 720 or 1080p resolution. • Supply voltage: 5V at 2A • Dimensions: 168(W) x 76(H) x 25(D)mm Was $299 $ 69 95 229 Cat: AC-1696 Cat: AC-1692 Capable of taking up to 80kg, these heavy-duty LCD or plasma TV brackets will save valuable floor space and keep your investment out of reach of mischievous fingers. Two types are available: • CW-2822 has a 30° range of tilt movement only Cat: CW-2824 • CW-2824 is able to tilt 30° & swivel left & right through 80° and extend up to 30cm away from the wall. Note: TV not included $ 149 95 $ 59 95 Cat: AR-1727 HIGH QUALITY HDMI CABLES $70 High Quality HDMI, Digital Video Cables HEAVY DUTY PLASMA/LCD WALL BRACKETS 2 Cat: LT-3045 Cat: AR-1725 SAVE ON HDMI ACCESSORIES Remote Controlled Two Input HDMI Switcher $ 8 95 9 WATCH CABLE TV ALL OVER THE HOUSE - EVEN OUTSIDE Hassle-free sharing of audio and video signals all over the house without the inconvenience and cost of running wires. This powerful 5.8GHz sender will ensure crystal clear reception. Was $199.00 $ Coax Seal Tape Suitable for both analogue and digital free-to-air TV reception, this distribution amplifier is suitable for MATV applications. • Frequency range: 44 - 230/ $ 95 520 - 860MHz • Gain: 27dB - 32dB Cat: LT-3243 ALL THE TV & AV ACCESSORIES YOU’LL NEED TO HAVE A FANTASTIC TIME F Connector Diecast Metal Case TV Splitters Digital Masthead Distribution Amp (Kingray) 64 95 149 95 DIGITAL TELEVISION $ 89 95 Cat: CW-2822 MALE TO MALE LEADS • WQ-7400 1.5m $39.95ea • WQ-7402 3.0m $49.95ea • WQ-7404 5.0m $64.95ea • WQ-7405 10m $99.95ea HDMI TO DVI CABLE • WQ-7406 3.0m $39.95ea HDMI ADAPTORS • PA-3640 HDMI Skt to Skt $14.95ea • PA-3642 HDMI Plug to DVI-D Skt $14.95ea • PA-3644 HDMI Plug to DVI-D Plug $14.95ea Free Call: 1800 022 888 for orders! www.jaycar.com.au EVERYTHING YOU NEED FOR YOUR FOOTY PARTY GET READY FOR THE 15" Party Speakers 200W PA Combo Amp/Speaker These specialised party speakers provide good performance in back yards, tents, party rooms or community halls etc. Although rated at 120 Watts RMS plus, they can be driven by amplifiers with modest outputs and still provide impressive sound. Overload CHEAPER protected. THAN • 15 inch Woofer HIRING • Piezo tweeters 399 $ 179 Cat: CS-2515 Rave Fog Machine This unit produces clouds of white fog on demand. Fantastic for use with laser light shows, mirror balls and other party lighting. Mains powered. Indoor/Outdoor Speakers Addittional Fog Juice - 1 litre AF-1212 $11.95 These speakers sound so good that you would expect them to be much bigger. Just the thing to put under the eaves near the BBQ or pool etc. $ 79 95 Cat: AF-1214 69 95 Infrared Wireless Stereo Headphones $ 199 Cat: AM-4078 Smart and stylish design that will suit your home or office, this unit features a CD player, AM/FM radio, alarm clock, USB port, fullfunction remote control and iPod® not included an iPod® docking station. What more could you ask for? • Recharges iPod® batteries $ • 340(L) x 270(D) x 172(H)mm Cat: GE-4067 • See website for full details BBQ ACCESSORIES Solar LED Umbrella Light Provide light for your outdoor setting. The solar panel screws onto the top of the pole to charge during the day and connects into the light fixture. • 200mm dia. • Suits poles 35-50mm dia. • Rechargeable batteries included 2 x 100 WRMS Stereo Amplifier with Remote Control This is a good looking, nononsense stereo amplifier that is rated at a generous 100 watts RMS per channel and will form the heart of an impressive stereo system. $ • Inputs for Mic, Tape, Tuner, AV1, AV2, CD, Phono Cat: AA-0470 • Approx 420mm wide 199 $ 39 95 Cat: ST-3293 $5 Equipped with a radio to help pass the time and an LED torch. It also features a timer and clock with an alarm. The fan connects to a long $ 95 flexible gooseneck with clamp. See website for further details Was $49.95 Cat: GG-2308 44 BBQ Cleaner with Light Clean off that built-up grime with this handy BBQ cleaner. It even has a built in scraper and LED light for those hard to see dark corners. 95 • Requires 8 x AA batteries (SB-2333) $ • Measures: 295(L)mm Cat: TH-2542 24 Ultrasonic Pest Repeller The 'Frequency Shifting' technology used may be effective against most common household pests including rats, mice, cockroaches, silverfish etc. • Supplied with mains plugpack and guide. • 120mm dia x 75mm high Cat: SL-2942 WEATHER STATIONS Features a large LCD with clock and calendar functions, dual in/out temp. readings, humidity, barometric pressure & weather trend. Includes one external transmitter. $ $ 49 95 This LCD desktop weather station projects the time onto the wall or ceiling. It receives data from the supplied outdoor transmitter and features a coloured LCD, which shows the barometric pressure, weather trend & temp. For further details visit our website. $ 95 Was $99.95 59 Cat: XC-0340 Fan with Radio & LED Torch 199 69 95 With Coloured Display & Projection 129 Retro CD Player with iPod Docking Station $ Cat: XC-0335 Add a lapel clip wireless mic to your set-up. The transmitter clips to your belt or fits into your pocket. Requires 9V battery. Suitable for wireless receivers AM-4077 and AM-4079. • Transmission range: 100m max • Frequency: 16Ch, $ 770-800MHz • 95(H) x 62(W) x 22(D)mm Cat: AM-4076 Cat: AA-2049 Simple but effective! Coloured lights switch in time with the music. Supplied with a red, yellow, green, and blue globe ES 240V reflector globes. • 435mm wide • Spare globes available ask in-store With Wireless RF Sensor Wireless Microphone Belt Pack 49 95 4 Colour Light Chaser Sound Modulated INCLUDES 2 MICS This 2 channel system supports 2 separate microphones. Each channel has a separate balanced XLR output. A single unbalanced (mixed) line output is also available. Includes 2 mics and batteries, receiver unit and plugpack. Cat: CS-2430 A great pair of entry-level wireless headphones. Setup is quick & easy & the sound clarity is excellent. The ultralight design allows them to comfortably sit on your head and you’ll hardly know they're there. • Operation distance: up to 15m • Requires 2 x AA batteries $ (SB-2424) $ Dual Channel UHF Wireless Microphone • 30WRMS • 70Hz tp 20kHz • 195mm high • Sold as a pair A PA system in a box. 3 channels with balanced and unbalanced inputs, RCA inputs for an auxiliary source. The ideal small PA for schools, sports organisations, churches, $ weddings, conferences or Cat: CS-2517 solo acts. 29 95 Cat: YS-5520 $40 POOL PARTY Hand-Held pH Meter Checks pH levels in your pool or fish tank simply and easily. Supplied with buffer solution and calibration tool. More accurate than messy chemicals. Great for fish tanks or swimming pools. $ 95 Replacement Buffer Solution to suit available Cat: QM-1670 separately QM-1671 $6.95 59 Solar Powered Pool Lights Make your pool come alive this spring. The in-built light sensor lights them up at night making them fantastic for nighttime parties. Colours available: red ST-3120, white ST-3122 or blue ST3124. • Push on / off button • 110mm (diameter) • Solar powered - charge in sunlight $ 95 for 12 hours to enjoy 24 hours All colours (each) of continuous use Free Call: 1800 022 888 for orders! www.jaycar.com.au 19 3 ACCESS CONTROL - SECURITY & SURVEILLANCE PRO SURVEILLANCE GEAR SAFE & SECURE Professional 8CH MPEG4 DVR Economy Four Zone Wireless Alarm A complete 8 channel professional surveillance recorder with sophisticated monitoring and recording functions including network connect, DVD burner, PTZ camera control via PELCO D, GPRS support, MPEG4 compression, and 250GB HDD. Crystal clear image clarity with minimal disk consumption. Rack mountable. • Maximum frame rate 200ips (25fps/channel) • Maximum image resolution 720 x 576 pixels • 16 channel model also available • See web site for full specifications and range Professional 16CH MPEG4 DVR with DVD Backup and GPRS Support Cat. QV-3041 ONLY $1999 $ 1499 Cat: QV-3040 17" Active Matrix TFT Security Monitor $ $ 49 95 39 95 Cat: LA-5137 Cat: LA-5136 2.4GHz Wireless LCD Video Monitor This portable monitor is ideal for keeping an eye on a sleeping baby or kids in the back yard pool. Also useful for small office & commercial locations. Accepts up to four cameras. • 65mm colour screen $ • Audio & video output • Battery or mains power $ 549 Cat: QM-3419 $ Transmit VGA signals across a standard UTP or STP Cat-5 cable for distances up to 135 metres. Use for home or commercial applications including classrooms, lecture halls, auditoriums, tradeshows, etc. 12 95 Wireless Alarm Remote Control $ 149 95 Cat: QC-3428 Low Cost RFID Access Control Keypad This low cost RFID unit is designed to control door strikes in home or business installations. It allows access by RFID card, password, or a combination of both. Push button exit and duress output signal. • 12VDC powered. • Read range:140mm(Max.) • Operating temperature: -15°C to 55°C $ • Housing material: ABS Was $79 Cat: LA-5124 59 95 29 95 $ Cat: LA-5138 59 95 Cat: LA-5139 $ Cat: LR-8820 This excellent doorbell has 32 melodies and is completely wireless. Just mount the transmitter near your door and the receiver in a convenient location. Suitable for homes and offices. 2 Station Wireless Intercom Great for communicating around your home. Transmits through the electrical cable already laid in your house. Additional units can be added for multi-point communications. $ 74 95 Cat: AI-5500 High Volume Wireless Doorbell with Strobe for the Hearing Impaired When this doorbell rings, the sound is accompanied by bright flashes from the receiver's built in strobe light so a hearing impaired person will know that someone is at the door. Can be taken from room to room or used outdoors. Choose $ 95 from seven melodies. 210mm long. Requires 4 x C cells. Cat: LA-5002 89 95 Cat: LA-5193 B&W Video Door Phone See who's at the door before you let them in. Up to three additional monitors can be fitted so you can answer the door from upstairs, downstairs, or even the garage. Includes monitor handset, 1 x CMOS infrared camera unit and plugpack. Works with our LA5078 electric door strike shown below. Additional cameras sold separately QC-3603 $99.95 $ 129 Cat: QC-3602 Electric Door Strike Release This excellent 2.4GHz wireless surveillance system comes complete with an indoor colour CMOS camera and hand-held LCD monitor. You can link the monitor to a VCR and record the camera image or display on a normal TV. Unlock doors with the push of a button. Works with our door phones and access systems. 199 $ 29 Cat: AM-4310 Wireless Baby Monitor Commercial Grade Door Entry Beam 89 95 Cat: LA-5134 A simple low cost solution for communicating out to garage or keeping tabs on a sleeping baby. Battery powered & supplied 20 metre connecting cable. 49 $20 $ Repeater/ Extender Sensor Cat: LA-5018 $ $10 2 Station Wired Intercom Wireless Doorbell with 32 Melodies VGA Video Baluns 4 Wireless Reed Switch Sensor Wireless PIR Sensor 89 These rugged high performance TFT monitors are purpose-built for demanding security applications and feature a toughened glass screen to prevent damage. The monitors will accept VGA, S-Video, or composite video input and have Interlaced to Progressive scan. (19" Monitor also available QM-3420 $649) Ideal for use in retail and commercial environments. It has an effective range of 2 - 8 metres, so it is suitable for most entry points. Includes mains plugpack. An affordable system that provides reliable protection for your home, apartment or small office. The system is simple to install and the alarm panel will detect and 'learn' which sensors have been installed. The control unit also monitors the system status and sensor battery condition to ensure system reliability. Includes control panel with keypad, a passive IR motion sensor, and a reed switch sensor for door or window protection. Wireless installation makes the system ideal for tenants. Batteries and power supply included. For full specification see website or catalogue. Additional Sensors - Available separately Was $99.95 $ • 2.4 inch colour TFT-LCD screen • Can work with up to 4 cameras Cat: QC-3258 • 10 IR LED illuminator • Monitor measures: 65(L) x110(H)x 23(W)mm • Supplied with 1 camera (Additional cameras sold separately QC-3259 $99.95) Mini Personal Alarm This tiny personal alarm has a loud 100dB (A) siren and is small enough to fit in your purse or around your neck. • Batteries included. $ $ 44 95 Cat: LA-5078 9 95 Cat: LA-5182 Free Call: 1800 022 888 for orders! www.jaycar.com.au COMPUTER & NETWORKING USB ACCESSORIES USB Missile Launcher with Webcam Upgrade to the latest in workstation weapons. Co-developed with Microsoft, this USB missile launcher is equipped with a detachable Webcam and software, which allows you to communicate via the MSN Instant Messenger service. Navigate and hone-in on your target via the on-board crystal clear Webcam for a more accurate shot. Also now with added sound effects, it will produce a swooshing sound of a missile and siren. The fun is endless! Invite friends from different parts of world and declare war or remotely log on to your home machine and blast any unsuspecting target that comes too close to your machine! • 3 foam WMDs included • Shoots up to 5 metres • Dimensions: 110(W) x 125(D) x 185(H)mm • For full specification see website $ 89 95 USB Digital TV Stick Watch high definition digital telly on your desktop or laptop PC for the same cost as a standard definition set-top box. Simple to set up and use, just connect the USB stick, plug in the antenna, install the software and away you go. Windows PCs only. Mini 4 Port HUB USB 2.0 The perfect add-on to increase the number of USB ports on your computer. It is plug and play with auto-detection and safe removal from your USB port. 99 Cat: XC-4859 $ 19 95 Cat: XC-4864 69 $ 29 95 Cat: XC-4966 4 Input USB Video Recorder 4eyeGrab is a surveillance device that allows you to record 4 camera inputs at the same time on a PC. It connects to the USB 2.0 port and makes real-time monitoring a breeze with 4 composite video inputs to accept any camera (cameras not included). Variable frame rate with instant or $ scheduled recording. • Single/four screen display mode Cat: QV-3081 • Camera ID, date & time display 149 149 95 $ 802.11n Wireless Broadband Router Cat: YN-8302 Wireless Networking Antenna 5dB Gain 95 An elegant and unobtrusive solution for indoor wireless LAN applications. Ceiling mounted. • Frequency range: 2.4 - 2.483GHz • Gain: 3dB $ • 180mm dia. VGA to Composite & S-Video A compact and versatile device that lets you use your wide screen plasma or LCD screen as a computer monitor for gaming or presentation use. Great for watching DVDs, gaming, presentations, or just having a big screen on your computer. • No software is required. • For full specifications see our website 1 metre 3 metre 5 metre 49 95 WC-7800 WC-7802 WC-7804 $13.95 $24.95 $34.95 8 Port 10/100 Network Switch Expand your connections! Network your computers or share your ADSL connection, and avoid hassles with file sharing and Internet access. Operates up to 10 / 100 Mbps. $ 29 95 Cat: YN-8084 $ LAPTOP POWER SUPPLIES 89 95 Cat: XC-4871 This compact unit accepts a range of video input signals and converts them to VGA specification for use on CRT, LCD, etc. Also accepts YPbPr input for DVD players, Xbox®, Wii®, or other video sources up to 1080i. Simple on-screen set up. No software required. Includes remote control. $ • 145mm wide. • For full specifications see our website 150W Laptop Power Supply 15-24VDC This power supply has a universal input voltage 100-240VAC 50/60Hz and has a regulated output. It features short circuit and overload protection and an LED power indicator. Supplied with 9 adaptor plugs to suit the majority of laptop computers including, ACER, IBM, DELL, Apple, $ 95 Sony, Toshiba, Samsung, Compaq, Sony, Panasonic etc. Cat: MP-3471 99 89 95 Cat: XC-4873 IDE to SATA / SATA to IDE This versatile SATA/IDE adaptor allows you to connect a SATA drive to an IDE controller or an IDE drive to a SATA controller. Powered from a standard drive power connector. No software required. Includes SATA and power adaptor cable. Cat: YN-8304 Allows you to move your wireless antenna for optimum performance. • SMA Plug to Plug • Gold plated connectors • RG316 High Quality Coax cable Cat: AR-3271 CONVERTERS 59 95 SMA Coaxial Leads 2.4GHz CeilingMount Antenna Composite Video to VGA $20 $ 95 Cat: AR-3270 $ 802.11n USB Wireless Network Adaptor Cat: YN-8300 $ 19 USB VoIP Phone with LCD & Hands Free You can call another VoIP user for free or call a landline for a low-cost price. This unit plugs into a spare USB port on your computer and has a hands free function. It is compatible with Skype, MSN, Yahoo Messenger, Xten, Dialpad, MediaRing, and Net2Phone and is perfect for home of office use. Save a fortune on your next phone bill. Was $49.95 802.11n PCI Wireless Network Card Here's a quick and inexpensive way to improve the range of your wireless network. This antenna is specifically designed for 2.4GHz applications and 802.11 wireless networking is an $ ideal use. Cat: GE-4084 HIGH SPEED WIRELESS NETWORKING 802.11N These impressive devices operate at up to 300Mbs and use MIMO technology to significantly improve transmission range and minimise transmission errors. They are backward compatible to 802.11b and 802.11g systems and support Windows (98SE, ME, 200, XP, & Vista), Linux, and MAC operating systems. $ 29 95 150W Car Laptop Power Supply Higher powered for the bigger laptops that draw more juice. 8 different plug adaptors to fit popular models and variable output from 15 to 24VDC <at> 6A. • Cigarette lighter cable • Selectable output voltage: 15, 16, 18, 19, 20, 22, 24VDC • Dimensions: 115(L) x 60(W) x 35(H)mm Cat: XC-4841 Free Call: 1800 022 888 for orders! www.jaycar.com.au $ 59 95 Cat: MP-3472 5 AUTOMOTIVE CAR AUDIO Our WINNING 5 Channel Full Range Car Amplifier OBD II LCD Scan Tool This award winning amplifier has four full range channels and a subwoofer channel plus a host of features including adjustable gain and variable high-pass filters. $ 499 • Power <at> 4 ohm 14.4V: 60WRMS x 4ch + 225WRMS x 1 ch • Power <at> 2 ohm 14.4V 90WRMS x 4 ch + 340WRMS x 1 ch • Power Bridged <at> 4 ohm 14.4V 180WRMS x 2 ch + 340WRMS x 1 ch Cat: AA-0458 1000WRMS Linkable Monoblock Car Amplifier $ 399 Cat: AA-0460 129 Cat: QP-2294 Non-Contact Thermometer with Dual Laser Targeting Speedo Corrector MkII Refer: Silicon Chip Magazine December 2006 This kit alters the speedometer signal up or down $ from 0% to 99% of the original 95 signal. With this improved model, Cat: KC-5435 the input setup selection can be automatically selected and it also features a 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-6015 $2.50 Large Digit Thermometer with Min/Max Memory 49 Ideal for easy viewing across a room. Shows inside or outside temperature and stores the highest & lowest recorded. $ Includes clock function 29 95 WORKLIGHTS & TORCHES Work Light Magnetic - Rechargeable $ 299 Component Car Speakers with Ribbon Tweeters Everything you need to install a good quality split system in your car. 6.5" PMI/Kevlar ® composite cones, ribbon tweeters for crisp highs, separate crossovers with screw terminals. Mounting hardware included. • Frequency response: 60Hz - 40kHz • Crossover: 12dB/octave $ 299 Cat: CS-2338 This rechargeable super bright light is perfect for boating, camping, working on the car or for emergencies. 61 super bright LEDs provide enough light for any situation and two powerful magnets enable it to be fixed to a metal surface leaving your hands free. It can be recharged with a 95 mains charger or via a car cigarette $ lighter outlet. Was $49.95 Cat: ST-3021 $10 39 10 Million Candle Power Rechargeable Spotlight Features a super powerful 12V 100 Watt Halogen globe. A switch for dim lighting to conserve power when high brightness is not required, and twin fluorescent globes for reading or as a work light. The spotlight is powered by a rechargeable $ 95 12V 7Ah battery that can be charged either at home or in the car. Includes Cat: ST-3308 carry strap, 240VAC / car charger. 79 Precision RESPONSE 10" Subwoofer Our new range of Response Precision subwoofers truly sound as good as they look! Ideal for reverse installation with the basket displayed. • Nominal impedance: 4 ohms • Power handling: 250WRMS • Efficiency: 84dB SPL<at>1W $ 199 Cat: CS-2352 Refer: Silicon Chip Magazine March 2007. This advanced and versatile ignition system can be used on both two & four stroke engines. Can be used to modify the factory ignition timing or as the basis for a stand-alone ignition system with variable ignition timing, electronic coil control and anti-knock sensing. Kit includes PCB with overlay, programmed micro, all electronic components, and die cast box. • Timing retard & advance over a wide range • Suitable for single coil systems • Dwell adjustment • Single or dual mapping ranges $ 95 • Max & min RPM adjustment • Optional knock sensing, coil driver Cat: KC-5442 89 Measure the temperature of a surface from a safe distance. • Dual laser sighting for accuracy. • Temp range: $ -50 to +650°C Cat: XC-0126 Cat: AA-0426 6 $ Cat: QM-7221 Car Amp 4 x 100WRMS 12" model also available CS-2354 $249 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 can be used to diagnose engine codes and turn off check engine lights, erase diagnostic trouble codes and reset OBD II monitor status etc. Also retrieves VIN code from post 2002 vehicles. AUTOMOTIVE KITS Programmable High Energy Ignition Kit 109 Monstrous, eardrumperforating power. You also get variable bass boost, adjustable phase shift, low pass filter and master/slave operation. Optional remote bass gain controller. If you are looking for an ultra-powerful 4-channel amplifier then this is an excellent choice. Power output exceeds 100WRMS per channel or 300WRMS in bridged mode at 4 ohms. AUTOMOTIVE TOOLS & ACCESSORIES Dynamo Torch with Radio, Clock & Alarm The ultimate outdoor companion. This useful device features full alarm clock functions, AM/FM radio, LED torch, reading lamp and siren. It also features an external mobile phone charger. 5 minutes cranking will fully charge the internal battery. Was $49.95 $10 Motor Speed Controller $ 23 95 Cat: KC-5225 Refer: Silicon Chip Magazine June 1997 Ideal for controlling 12VDC motors in cars such as fuel injection pumps, water/air intercoolers and water injection systems. You can also use it for headlight dimming and for running 12V motors in 24V vehicles. The circuit incorporates a soft start feature to reduce inrush currents, especially on 12V incandescent lamps. Includes PCB and all electronic components. Battery Zapper Kit MkII Ref: Silicon Chip Mag May 2006 Like its predecessor this kit attacks a common cause of failure in wet lead acid cell batteries - sulphation. The circuit produces short bursts of high-level energy to reverse the damaging sulphation effect. The improved unit features a battery health checker with LED indicator, new circuit protection against badly sulphated batteries, test points for a DMM and connection for a battery charger. Kit includes machined case with screen-printed lid, circuit board, alligator clips and all electric components. $ 95 • Suitable for 6, 12 and 24V batteries • Powered by the battery itself Cat: KC-5427 99 Reversing Camera System $ 39 95 Cat: ST-3352 A complete rear-view safety package including a TFT LCD monitor and CMOS camera. It has adjustable spring-loaded brackets to fit different sized mirrors and includes a slimline remote control. • Composite video input. • Includes 5m video/power camera cable. $ 299 Cat: QM-3762 Free Call: 1800 022 888 for orders! www.jaycar.com.au HARDCORE & POWER SOLDERING & LAB MAGNIFIERS Super Pro Gas Soldering Tool Kit This quality kit contains a soldering iron with adjustable temp. up to 580°, 25 to 125W and various tips. • Quality storage case. • Cleaning sponge and tray. $ 139 Cat III Multimeter with Temperature A budget-priced meter with everything you need - capacitance, temperature and 10A on AC and DC, compact and light weight with rugged moulded case. • Data hold • Relative measurement • Category: Cat III 600V • Display: 4000 count • Ave/RMS: True RMS • Case included $ • 137(H) x 65(W) x 35(D)mm For full specifications see our website IEC LOCKING SOCKETS & LEADS This range of IEC sockets is ideal for heavy-duty environments, such as industrial applications, server rooms, PA or music applications. The plugs lock into the sockets and can only be removed by disengaging the locking tab, so you don't lose the juice to your equipment if someone bumps or knocks it. • All are 3-pin with earth connection. 34 95 Cat: QM-1323 Cat: TS-1328 TOOLS & SERVICE AIDS Goot Soldering Station This soldering station is a precision, Japanese manufactured instrument with excellent temperature stability and anti-static characteristics. The light weight soldering pencil has a grounded tip and incorporates a ceramic heater with an integral temperature sensor. $ • 230-240VAC supply voltage • 65 Watt capacity heater Cat: TS-1440 • 200 - 480°C temperature range 249 Illuminated Gooseneck Magnifier This handy hobbyist's magnifier has a 2X main magnifier lens with 5X insert lens and 2 LED lights, all mounted on a flexible arm. Can be freestanding or clamped to a surface up to 38mm thick. • Lens 110mm (dia.) • Requires 3 x AAA batteries (SB-2333) Was $29.95 $ 19 95 Cat: QM-3532 $10 Precision Digital Vernier Calipers A precision tool for accurate measurements. Simple and easy to use with digital readout • Accurate to 0.01mm • Metric or Imperial measurement $ 39 95 Replace your car's interior lights LEDs and never have a blown globe again. These festoon replacements have wide dispersion angle, are much brighter than conventional globes and use less power. Three sizes available: • ZD-0484 - 31mm Festoon LED Globe $9.95 • ZD-0486 - 36mm Festoon LED Globe $9.95 • ZD-0488 - 41mm Festoon LED Globe $12.95 High Efficiency MEPS Rated Plug Packs These high efficiency mains adaptors meet the 'Minimum Energy Performance Standard' and consume very little standby power. They will fit side-by-side in a powerboard and have a low profile. 5, 6, 9, & 12VDC models are available in two power ratings. • 5 watt models MP-3144/45/46/47 All $17.95ea. • 15 watt models MP-3480/82/84/86 All $21.95ea. 5 Watt Ultra-slim Switchmode Power Adaptors 4 Outlet Remote Control Powerboard Control individual sockets even when it is buried behind your home theatre or computer system etc. Save on your power bill by switching things off when they are not in use. • Overload circuit-breaker protection • Surge and spike protection • LED power indicator • 433.92MHz $ • 10A, 2400W total load 59 95 Cat: MS-6150 $ 3 15 Cat: PP-4174 Fused Male IEC Panel-Mount Snap-in, requires a mounting hole 32 x 28mm. Suits panels up to 1.6mm thick. Connection is by solder tabs, 10A rated. Accepts standard $ 65 M205 fuses. 5 Cat: PP-4178 Male 16A IEC Panel-Mount Telescopic Magnetic Pickup Tool with LED Sunday arvo, 5 o'clock and you drop the last bolt into the crankcase. With this handy tool, you can see where it is with the built-in LED torch and retrieve it with the magnetic tip. $ 95 • Picks up over 100g in weight • Batteries included Cat: TH-1877 • Extends to 870mm • 170mm long (closed) 14 Screw mounting, requires a mounting hole 32 x 24mm. Suits panels up to 6mm thick. Connection is by solder tabs, 16A rated. $ 5 75 Cat: PP-4182 Female IEC Panel-Mount Socket Snap-in female socket for slave power applications, such as powering a computer monitor from a tower. Requires a mounting hole 32 x 25mm, suits panels up to 1.6mm thick. Connection is by solder tabs, 10A rated. $ 3 60 Blow dust out of keyboards and other difficult places with this duster in a can. $ Screw mounting, requires a mounting hole 27 x 20mm. Suits panels up to 6mm thick. Connection is by solder tabs, 10A rated. Cat: TD-2082 Aerosol Dust Remover Festoon LED Globe Unfused Male IEC Panel-Mount Cat: PS-4176 IEC Locking Leads 16 95 Cat: NA-1018 POWER PRODUCTS 15 Watt Switchmode Slim High Power Suitable for use with the mating panel-mount sockets. All are 2 metres long and lock into the socket until the locking tab is disengaged. Three types available: • IEC Locking Mains Lead - 2m (Suits either PP-4174/4178) PS-4170 $14.95 • IEC Locking Extension Lead - 2m (Suits PS-4176) PS-4172 $14.95 • IEC 16A Locking Mains Lead - 2m (Suits PP-4182) PS-4180 $19.95 E-Charger Power Bank 12V/USB Mains Power Meter The meter can tell you how much an appliance is costing to run and tracks the actual power being used. It can also display the instantaneous voltage or current being drawn as well as peak levels etc. • 10A max rating. Was $39.95 $ 29 95 Cat: MS-6115 Excellent for 12V vehicles and assists if the starter motor turns the engine over too slowly to start. With USB and a female automotive socket this unit serves as a backup for other equipment such as mobile phones, PDAs, iPods® etc. See website for full specifications. Was $69.95 $10 $10 Free Call: 1800 022 888 for orders! www.jaycar.com.au $ 59 95 Cat: MB-3597 7 POWER PURE SINE WAVE INVERTERS MI-5160 MI-5162 MI-5164 MI-5166 MI-5168 MI-5169 180 Watt 12VDC to 230VAC 380 Watt 12VDC to 230VAC 600 Watt 12VDC to 230VAC 1000 Watt 12VDC to 230VAC 1500 Watt 12VDC to 230VAC 2000 Watt 24VDC to 230VAC 900mAh 900mAh 2,500mAh 2,500mA AAA AAA AA AA $3.50 $11.95 $5.95 $19.50 These fantastic batteries feature ultra-low self-discharge technology and have an 85% charge retention after 1 year. They are supplied in a charged state and can be used immediately after purchase. A handy storage case is included. AA and AAA styles are available SB-2426 SB-2413 SB-2334 SB-2331 8 6021 9699 9709 9678 9369 9905 4620 4365 9439 9476 9821 4965 4721 8832 9267 6788 4699 2822 9669 3899 4130 7155 3433 4799 6221 3100 3799 8337 3121 1614 Available in black & red. Sold per metre. Red $ 8 40 per metre Cat: WH-3064 $ 14 95 Black $ 8 40 per metre Cat: WH-3066 4GA Gold Plated Power Terminal Recharge up to 4pcs of AA or AAA Ni-Cd or Ni-MH batteries with this handy charger. With Delta V voltage detection, the batteries are charged to their optimal level. Charge state can be monitored on the integrated LCD which is backlit. Includes 240V $ 95 plug pack and car Cat: MB-3543 charging cable. $ Cat: HC-4062 2GA Gold Plated Power Terminal 49 6 95 $ 6 95 Cat: HC-4066 This microprocessor controlled charger will accept a combination up to 10 x AA or AAA cells and 2 x 9 Volt batteries. The integrated discharger can help minimise memory effects and negative Delta V sensing ensures maximum battery life. • Includes 240V plug pack and car charging cable. • Includes charging timer. $ 95 • Individual LEDs show battery status. • 220mm wide. Cat: MB-3551 59 $14.95 $24.95 Australia Freecall Orders: Ph 1800 022 888 NEW SOUTH WALES Albury Ph (02) Alexandria Ph (02) Bankstown Ph (02) Blacktown Ph (02) Bondi Junction Ph (02) Brookvale Ph (02) Campbelltown Ph (02) Erina Ph (02) Gore Hill Ph (02) Hornsby Ph (02) Liverpool Ph (02) Newcastle Ph (02) Penrith Ph (02) Rydalmere Ph (02) Sydney City Ph (02) 110 Amp 4GA OFC Super Power Cable - Red Smart Battery Charger Ni-Cd & Ni-MH AAA SIZE YOUR LOCAL JAYCAR STORE Cat: ZM-9012 Battery Charger with LCD Pre-Charged Rechargeable Batteries Eclipse batteries are made to the same specifications as those well known expensive brands advertised on TV, but at a realistic price. We are very proud of these batteries and stand behind them unconditionally! 16 95 Cat: MB-3552 Each Pack of 4 Each Pack of 4 SB-1752 AAA 800mAh - Pk 4 SB-1750 AA 2000mAh - Pk 4 $ Recharges 2 x AA or 2 x AAA Ni-Cd or Ni-MH batteries using Delta V voltage detection which ensures the batteries are charged to their optimal levels for long life. Keep a spare set of batteries topped up and ready to go, wherever you are. Nickel Metal Hydride (Ni-MH) batteries can be recharged many times and provide considerable savings in battery cost and greenhouse gas reduction. They have no memory effect and provide high current performance at a cost effective price. Light on your wallet and good for the planet. SB-1723 SB-1739 SB-1744 SB-1738 $199.00 $229.00 $349.00 $649.00 $899.00 $1049.00 In-Car Battery Charger Rechargeable Batteries Hobby Solar Module - 500mA Idea for powering solar projects, hobbies, model solar cars and educational applications. • 3 cells per module, rated at 1.5V. • Open circuit voltage: 1.5V • Short circuit current: 500mA • 120 x 62 x 4mm • Weight: 33g These inverters provide clean 230VAC power to run sensitive electronic equipment such as clocks, TVs, medical equipment, and electronic scales, etc. from your car's battery. We have models suitable for running your laptop in the bush to powering a microwave in a motor home. They have fan assisted cooling and electrical isolation for safety. AAA - Pk 2 AAA - Pk 4 AAA - Pk 12 AAA - Pk 24 AA SIZE $2.25 $3.95 $7.95 $12.95 Taren Point Tweed Heads Wollongong VICTORIA Coburg Frankston Geelong Melbourne Ringwood Springvale Sunshine Thomastown QUEENSLAND Aspley Cairns Ipswich Maroochydore Mermaid Beach SB-2425 SB-2333 SB-2330 SB-2332 Ph (02) 9531 7033 Ph (07) 5524 6566 Ph (02) 4226 7089 Ph Ph Ph Ph Ph Ph Ph Ph (03) (03) (03) (03) (03) (03) (03) (03) 9384 9781 5221 9663 9870 9547 9310 9465 1811 4100 5800 2030 9053 1022 8066 3333 Ph Ph Ph Ph Ph (07) (07) (07) (07) (07) 3863 4041 3282 5479 5526 0099 6747 5800 3511 6722 ECLIPSE ALKALINE BATTERIES AA - Pk 4 AA - Pk 12 AA - Pk 24 AA - Pk 40 $3.95 $7.95 $12.95 $19.95 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 Gepps Cross Ph (08) 8262 3200 WESTERN AUSTRALIA Maddington Ph (08) 9493 4300 Midland Ph (08) 9250 8200 Northbridge Ph (08) 9328 8252 NORTHERN TERRITORY Darwin Ph (08) 8948 4043 9 VOLT SB-2423 9V - Each $3.95 SB-2417 9V - Pk 6 $13.95 NEW ZEALAND Christchurch Ph Dunedin Ph Glenfield Ph Hamilton Ph Manukau Ph Newmarket Ph Palmerston Nth Ph Wellington Ph Freecall Orders Ph (03) 379 1662 (03) 471 7934 (09) 444 4628 (07) 846 0177 (09) 263 6241 (09) 377 6421 (06) 353 8246 (04) 801 9005 0800 452 9227 Prices valid to 30th September 2008 Free Call: 1800 022 888 for orders! www.jaycar.com.au 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. 10k 10k 10k 10k 1 7 3V BATTERY 6 100nF 5 S1 S2 S3 A Vdd GP0 GP3 GP1 GP4 IC1 PIC12F675 GP2 pushbutton switches raise or lower the volume. It is set for a Sony TV which has a simple IR protocol – a 5-bit address to identify the device being controlled (TV, DVD player, VCR, etc) and 7-bit commands. The carrier frequency is 40kHz. The PIC program uses the SLEEP function to limit the off-state current to less than 1mA and is woken from SLEEP with any change on input ports 1, 2 or 3. You can determine the bit pattern by a web search or by measurement with the device’s original remote, an IR detector on a breadboard and an oscilloscope. The emergency stop button is an industrial Allen Bradley unit. Jaycar have a cheap latching button emergency stop (Jaycar SP-0786) that can be converted easily to non-latching but it is not as robust. Jaycar also have a number of large momentary contact pushbutton switches. The software can be downloaded from the SILICON CHIP website. Andrew Buchanan, Tawa, NZ. ($50) 33 10k GP5  LED1 IRLED 4 K 3 D Q1 2N7000 G 2 S Vss 8 VOLUME VOLUME MUTE ON/OFF DOWN UP 2N7000 IR LED K A D G S Kill those adverts quickly with the Supermute The Supermute is a TV remote that turns the TV on or off, mutes the sound and varies the volume up or down, using only three buttons. The mute/on/off button is an industrial emergency stop button which makes it easy to kill pesky adverts. The circuit comprises a Microchip PIC12F675 8-pin microcontroller, FET Q1, infrared LED1, the emer- gency stop button and two small pushbutton switches for the volume control. Holding the emergency stop button down for a second or more alternatively turns the television on or off. A quick slap of the emergency stop button with an open hand (or closed fist!) or a prod with the foot mutes or un-mutes the TV. The 4017 counter tester This circuit can be used to test 4017 decade counters. Flashing LED1 drives the clock input of the 4017 under test (IC1) and this sends each output high in turn. Outputs 0, 2, 4, 6 & 8 are ORed together by diodes D1-D5 (functioning as an OR gate) to drive LED2 which flashes on and off with a 50% duty cycle. When any one of the five connected outputs goes high, LED2 is on. The flash rate is half that produced by flashing LED1 because only alternate outputs are used. Why not connect all 10 outputs via diodes? This would not be useful, as LED2 would be continuously lit. In use, a known good 4017 would normally be installed in the test socket. You would then switch on, observe both LEDs flashing normally, then switch off and install the 4017 to be tested. It should behave in exactly the same way. Switch S1 is optional. A. J. Lowe, Bardon, Qld. ($35) siliconchip.com.au S1 LED1 (FLASHING) D1-D5 1N4148 16 A Vdd  O0 O1 K O2 14 CP0 O3 O4 9V BATTERY A K A K 10 A K 5 A K A K 3 2 4 7 IC1 4017B O5 1 100 F 470 16V O6 15 13 MR O7 O8 CP1 O9 Vss 8 6 9 11 O5-9 12 A  LED2 K 470 1N4148 A K K A September 2008  53 Circuit Notebook – Continued PICAXE-based Star 5W LED control unit D1 1N4004 K 10k 100nF B C1 C K A LED1  K SCR1 A S1 K G 100nF RING MAGNET SEALED IN DOUGHNUT SHAPED FLOAT S2 N S 9V BATTERY * 270  FOR 9V SUPPLY, 180  FOR 6V SUPPLY E 100nF N S A Q1 BC337 100nF N S A D2 1N4004 560 10k +12V N S LED2  K A SCR2 A 1N4004 K G 100nF A K BC337 N S B (SWITCHES S3–13, LED3–13 AND SCR3–13 NOT SHOWN) E C LEDS S14 REED SWITCHES IN WATERTIGHT PVC TUBE IN WATER TANK A LED14  K SCR14 A K A K G 100nF LED15  K A S15 SCR1–15: C106Y SCR15 A A K G 100nF K Water tank level indicator By contrast with some previous tank water level indicators which relied on a resistor string progressively shorted out by the water level, this tank uses a series of reed switches which are closed by a magnet attached to a float. In practice, the reed switches are mounted inside a sealed tube inside the tank and a donut shaped float with a ring magnet is tethered by the tube, rising up and down with the varying water level. You can have as many switches and indicator lights as you like although the wiring to only four switches is depicted on the circuit. It works as follows. When any reed switch closes, it allows current to flow from the 10kW resistor to the associated SCR’s gate, turning on the SCR and its associated LED. 54  Silicon Chip A G Since the SCR gate voltage is initially low (and shunted by a 100nF capacitor), the closing of a reed switch will cause one end of C1 (100nF) to go low and momentarily pull the base of transistor Q1 low. This will turn off Q1 and allow the SCR which was previously latched on to turn off. As soon as C1 charges back up again, Q1 will turn on, allowing the triggered SCR to turn on and illuminate its LED. When power is first applied and no reed switch is turned on by the float, no LED will be illuminated. It will therefore be necessary to manually raise (or lower) the float to turn on the nearest reed switch. One side of all the reed switches is connected to a common stiff wire inside the tube and the other sides can be brought out the top via Cat5 cable. Ron Groves, Cooloola Cove, Qld. ($50) This circuit uses a PICAXE 08M to control an MC34063 DC-DC converter driving a 1W LED. The MC34063 is simply configured with the current through the LED monitored by a 0.27W resistor in series with it. The voltage across the resistor is amplified using an op amp and applied to the feedback pin of the MC34063. This is similar to the approach used in the SILICON CHIP LED control unit of May 2004 except that the LED is driven directly by the MC34063. It is recommended that readers refer to this article and to the datasheets for the MC34063. The PICAXE 08M’s PWM output is fed via trimpot VR2 and diode D1 into the MC34063’s feedback input and is used to override the LED’s current feedback from IC3, causing the MC34063 to reduce the current in the LED. Inputs to the PICAXE comprise a pushbutton (normally open) and a voltage divider network (R1-R3) to allow monitoring of the supply voltage. Pot VR1 is used to vary the strobe rate. Outputs are the PWM signal and red LED1 acts as a locator beacon and for acknowledgement of button presses. There are three programs for different operating modes: (1) An off delay lamp (designed for camping) to provide an efficient light that powers down automatically to conserve batteries. (2) A normal on/off lamp with three power levels. (3) A strobe with varying flash rates. For the off delay lamp, resistors R1R3 and VR1 are omitted. With the On/ off lamp, VR1 is omitted but the three resistors are installed. For the strobe, VR1 and resistor R3 are installed. In all cases, the MC34063 is set up without the PICAXE connected. VR3 is adjusted to set the maximum current through the LED or a 10W resistor (in its place). The PICAXE is then programmed and connected to the rest of the circuit via link LK1. VR2 is adjusted to ensure that the LED is off when it should be, ie, when the PWM output on pin 5 of the PICAXE is full on. No LED current should flow when the PICAXE’s PWM output is full on. siliconchip.com.au siliconchip.com.au VR3 2k 78L05 IN COM OUT 1k 15k 0.27  5W 1k K A D2 1N5819 2 K 1N5819 A Cin- Ct 3 470pF IC2 MC34063 GND 4 SwE 1 DrC Vcc SwC 8 6 7 Ips LED1 4.7k A K L1 220 H 470 F 16V LOW ESR – + 3.6k ADJUST LED CURRENT 4 A LED2  STAR 5W K LED 2 3 8 IC3 LM358 15k 1 100nF 1 1 1 4.7k 680pF K 10k 22k 0V 3 10k 2 ICSP PROG PLUG S1 1 100 F 25V K * THESE RESISTORS USED ONLY IN ON/OFF VERSION  LED1 A 470 8 Vss P4 3 2 SER IN P3 4 7 P0 IC1 5 PICAXE P2 -08 1 Vdd P1 6 100nF K VR2 2k R3 2.2k VR1 5k 100 F 16V GND A 1N4148 10 F 1k CAL R2 LK1 2.4k* A D1 1N4148 * SEE TEXT 5 +12–15V R1 6.8k* FLASH RATE +5V OUT IN REG1 78L05Z +12–15V NOM When powered up the LED will briefly flash then remain off until the pushbutton is pressed for 3s. In the case of the off delay lamp, after six minutes the PWM output (pin 5) of the PICAXE will ramp up to override the feedback to the MC34063 until the LED is extinguished. This happens gradually to alert users that the light is about to go off. The LED flickers briefly before going off as a final alert to users. At this point, a press of the button will bring it back to full brilliance for another six minutes. At any stage when the LED is on, a second press will reset the time to six minutes. Another press of the button will further extend the time to 20 minutes. Note that the settings for the time durations can be changed if longer times are desired. Holding the button pressed for about 2s will turn off the LED. When off, indicator LED1 will flash, serving as a locator beacon at night. LED1 also flashes when the button is pressed. In the case of the on/off lamp, the initial setting up is similar. Successive presses of the pushbutton can select three light levels. When the button has not been pressed for 1s, the next press will turn the unit off. The different light levels are achieved by varying the mark/space ratio of the PWM output of the PICAXE. The voltage divider network referred to above senses the supply voltage and this is fed into the IC1’s ADC1 input. When the battery voltage falls below a set point, the LED will dim to save power. If the voltage falls further, the LED turns off to protect the battery. At turn on, the different light levels can be cycled through for a set number of times before the unit will default to the lowest light level. In this mode, it will not shut down due to low battery voltage. This provides an emergency mode where you will still have light. The strobe function is a simple program but can be adapted by using the analog input from the pot to also vary the mark-space ratio of the strobe. Be cautious in testing as certain strobe rates can induce epileptic fits or seizures in some people. For others, sensations of nausea can occur. The three .bas program listings will be available on our website. Peter Shooter, Fremantle, WA. Peter S h is this m ooter onth’s winne Peak At r of a las Instrum Test ent September 2008  55 100nF 100nF VR1a 100k 220k 2 3 7 100k 0.5W 4 1k 6 100nF 300V 180k 8 5 470 100nF LEFT SPEAKER 6V 1 10 F +270V DC VOLUME 100nF 1k 4 3 180k 5 100nF 100nF 300V 100nF 1 6 V2a T1 240V AC 12V RIGHT SPEAKER V2b V1(4), V1(5), V2(4) V2(5) 12V T3 7 2 RIGHT INPUT 8 6V 220k 10 F 470 100k 0.5W 240V VR1b 100k D1–D4: 1N4007 T2 K 12V 240V This class-A stereo valve amplifier uses two 12AX7 or related twin triodes and low-voltage mains transformers for the power supply and output stages. The power supply is based on two 12V transformers, T1 & T2, connected back-to-back to provide an isolated 240VAC winding. This is rectified and filtered to provide about 300V DC. At the same time, transformer T1 provides the heater supply for the two valves. The second triode of each 12AX7 is used as the output stage, driving a 240V to 6V transformer to drive 8-ohm loudspeakers. Typically, the frequency response of small mainspower transformers is not anywhere near flat but would be adequate for this application. The estimated power output is about 1W per channel. This is really a project for recycled parts but if you have to buy new components, the valves and sockets can be obtained from Jaycar Electronics while the 400V capacitors can be obtained from Altronics. Dayle Edwards, Taylorville, NZ. ($60) Note: do not leave out transformer T2. It is absolutely necessary to ensure safe isolation from the mains. LEFT INPUT T4 V1b 240V A low-power class-A valve amplifier V1a 240V Circuit Notebook – Continued A +300V DC A K A K 12V K V1, V2: 12AU7/12AT7/12AX7/ECC81/ECC82 T1: 240V TO 12V AT 300mA T2: 240V TO 12V AT 150mA T3,T4: 240V TO 6V AT 150mA 1k 1W 100 F 400V A 12AU7/ECC81 6 WARNING: DANGEROUS VOLTAGES ARE PRESENT ON THIS CIRCUIT. DO NOT BUILD IT UNLESS YOU KNOW EXACTLY WHAT YOU ARE DOING 100 F 400V D1–D4: 1N4007 A K 7 5 8 9 4 3 2 1 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 56  Silicon Chip Thyristor & Triac Analyser, with the compliments of Peak Electronic Design Ltd www.peakelec.co.uk So now you have even more reasons to send that brilliant circuit in. Send it to SILICON CHIP and you could be a winner. You can either email your idea to silicon<at>siliconchip.com.au or post it to PO Box 139, Collaroy, NSW 2097. siliconchip.com.au MARKER DISPLAY TRIGGER OUT CON2 This circuit was developed to test the frequency response of amplifiers, filters and other audio equipment. It is controlled by a Parallax SX28AC/DP microcontroller (IC1). It has two frequency ranges. The first is 0.1Hz or 100Hz to 100kHz and is used to test IR communication devices, ultrasonic and audio circuits. The second is 50Hz to 15kHz for more precise testing of audio equipment. Trigger and marker (frequency) outputs are provided for use with an oscilloscope. The resistor ladder network provides a sinewave output which can be adjusted in level by potentiometer VR1 and range switch S8. These controls should be adjusted and the frequency range selected with switches S6 & S7. The circuit must be powered from a regulated 5V rail. The programmed SX28AC/DP micro can be obtained from Parallax at www.parallax.com. Alternatively, the software will be available from the SILICON CHIP website. William Oliver, Clarks Summit, PA. ($50) CON4 10k 10k 2 110  1% 20k 1% 17 18 16 15 20k 1% 10k 1% 10k 1% 20k 1% 19 4 2 IC1 SX28AC/DP PARALLAX (PROG) 20 20k 1% 10k 1% 10k 1% 21 20k 1% 10k 1% 20k 1% 22 24 23 20k 1% 20k 1% 10k 1% 6 25 20k 1% 100nF 10k 1% 5 IC2b 4 7 VR1 5k 10k 1% IC2: AD822AN HI LO S8 +5V 3 IC2a 8 1 10k 16V 100 F 100nF CON3 MARKER OUT SWEEP AUDIO OUT CON5 0V +5V Sweep frequency generator for audio testing Looking for real performance? 26 27 9 8 5 3 1 7 6 11 12 28 10 * 50MHz CERAMIC RESONATOR X1* FINE RESET I SBN 0958522 94 -4 & 9 78095 8 5229 46 $19.80 (inc GST) NZ $22.00 (inc GST) How management works It’s all in . . . Performance Electronics For Cars 4 +5V 3 2 1 COARSE DOWN PROGRAM HEADER S1 UP S2 S3 UP S5 S4 DOWN S6 1M S7 10k 10k 10k 10k 10k 10k siliconchip.com.au engine management systems • Projects to control nitrous, fuel injection Intelligent and turbo boost turbo timer TURBO BO systems OS nitrous fuel conT trollers engine • Switch devices according to signal frequency, temperature & voltage • Build test instruments to check fuel injector duty cycle, fuel mixtures and brake & temperature From the publis hers of 10k 13 • Learn about Mail order prices: Aust. $A22.50 (incl. GST & P&P); Overseas $A26.00 via airmail. See www.siliconchip.com.au for ordering details. September 2008  57 Ultra-LD Mk.2 200W Power Amplifier All the assembly details plus building a power supply Last month, we introduced our new Ultra-LD Mk.2 200W Amplifier module and described the circuit. This month, we give the assembly details and describe a suitable power supply. T HIS NEW 200W audio amplifier module gives superlative performance – better than any of our previous class-AB amplifiers. That’s been made possible by the use of On Semiconductor’s new ThermalTrak power transistors, a circuit based largely on our high-performance Class-A Amplifier (published in 2007) and a new doublesided PC board with plated-through holes. As mentioned last month, the double-sided PC board is critical to the performance of this amplifier module. 58  Silicon Chip It not only simplifies the supply wiring but has also been designed to largely cancel the magnetic fields produced by the asymmetric currents drawn by each half of the class-B output stage. In addition, the double-sided board eliminates the need for wire links, the exception being a couple of 0W resistors. The assembly is really quite straightforward although there’s a fair bit of work involved to do the job properly. When building a high-power amplifier module like this, it’s important to take your time, do a neat job and check your work carefully at each assembly stage. After all, blowing up expensive output transistors can be a real pain. Transistor quality We’ll begin the assembly details shortly but first a word about the transistors used in this module. To ensure published performance, the NJL3281D & NJL1302D power transistors must be On Semiconductor branded parts, while the 2SA970 lownoise devices must be from Toshiba. siliconchip.com.au Pt.2: By JOHN CLARKE & GREG SWAIN Be wary of counterfeit parts (although it’s probably too early for counterfeit versions of the power output devices). We recommend that all other transistors used in this project be from reputable manufacturers, such as Philips (NXP Semiconductors), On Semiconductor and ST Microelectronics. This applies particularly to the MJE15030 & MJE15031 output driver transistors. PC board changes Fig.9 shows the parts layout on the siliconchip.com.au double-sided PC board. This board is coded 01108081 and measures 135 x 115mm. The orange tracks and pads show the copper on the top of the board, while the blue-grey tracks are on the underside of the board. The first thing to note is that the PC pattern differs slightly from that used for the prototype module. That’s because we subsequently decided to increase the number of vias used to link the top and bottom supply rail tracks. Up to 4.5A peak can flow through each output transistor when the module is operated into a 4W load, so it’s important to ensure sufficient current-carrying capability. However, the main reason for increasing the number of vias was to make sure that a fault in the output stage would not cause the vias to fuse, instead of the 5A fuses blowing. If that happened, the board would be difficult to repair, as the solder mask goes right up to the edges of the vias. As a result, we’ve increased the number of parallel vias in the high-current paths, generally grouping them together in patterns of five or more (so that they look like the face of a dice). Note that, unlike the outer vias, the middle via of each group of five has a solder pad on both sides of the board. This allows a tinned copper wire “feed-through” to be fitted to each of these middle vias and soldered in place. These tinned copper wire feedthroughs ensure that the vias can not possibly fuse in the event of an output stage fault. They also ensure very low resistance between the top and bottom track sections. We’ve also added extra vias to connect the low-current signal tracks on both sides of the PC board, in the interests of redundancy. This is a “belts ‘n braces” measure but is still good practice. Finally a 390W 1W resistor was added to the board to provide the headphone output. As part of this change, CON3 was changed from a 2-way terminal block to a 3-way terminal block to give the “Phones Out” terminal (note: these changes are not shown on the photos). A few minor changes were also made to improve component fit. Board assembly Fig.9 shows the assembly details. Begin by installing the tinned copper WARNING! High AC & DC voltages are present on the power supply and power amplifier modules when power is applied. In particular, make sure you don’t get across the two 40V AC input terminals on the power supply. The 40V AC transformer windings that connect to these terminals are wired in series, so there’s 80V AC between them. Similarly, note that there is 110V DC between the +55V and -55V supply rails, both on the power supply module and the amplifier module. Do not touch any of this AC or DC supply wiring (including the fuseholders) when the amplifier is operating, otherwise you could get a very nasty shock which could even prove fatal. wire feed-throughs to the middle pad of each group of five vias. It’s simply a matter of pushing the wire through each via and soldering it on one side. When you do this, the solder should run up inside the via and onto the solder pad on the other side of the board. If not, solder it on the other side of the board as well, then cut the wire off short on both sides of the board. Note that it isn’t really necessary to fit feed-throughs to the vias immediately below the fuseholders, since the fuseholder pins themselves act as feed-throughs. However, they can be installed if you wish. Don’t forget the via that sits under the two 0.1W resistors at top left. Once the feed-throughs are in, install the two 1N4148 diodes (D1 & D2), followed by the resistors (but not the 5W types) and the capacitors. The resistor colour codes are shown in Table 1 but we strongly advise that you also check each value using a multimeter before it is installed. Mount them so that they all face in the same direction, to facilitate checking later on. Make sure that the diodes and electrolytic capacitors are all installed with the correct polarity. If you make a mistake, it’s not as easy to remove a component from a double-sided board with plated-through holes as it is from a single-sided board. It can be done, although you usually have to sacrifice the part – see the panel headed “Removing Parts From The PC Board” for details on removing components. We suggest that you leave the two September 2008  59 MJE15030 MJE15031 BF470 L1 6.8  1W 10  1W 100pF 100V 12k 6.8 H 390  1W BF469 Q9 6.2k NJL1302D 18080110 FUSE 2 (5A) reifilpmA 2.KM DL-artlU 0.1  5W 100 100nF Q7 2.2k 1000 F 63V Q5,Q6: BC556 2.2k Q5 Q6 100nF 100nF 6.8k 1W 100 100 100 47 F 35V 47 F 47 0.1  5W 0.1  5W FUSE 1 (5A) 6.2k 100nF Q15 NJL1302D Q11 Q10 1000 F 63V Q14 0.1  5W NJL3281D 100 Q13 NJL3281D 2.2k Q12 2 x 2SA970 100 510 12k 1M 47 F NP 820pF 220 F 10 0 D1 4148 4148 D2 Q8 BC639 0 Q3 Q4 CON2 2 x BC546 470 F 63V 100nF 22k 150nF 400V Q1 Q2 68 100 68 100 CON3 SPEAKER + SPEAKER – PHONES OUT CON1 SIG COM +55V 0V –55V Fig.9: follow this parts layout diagram and the instructions in the text to build the UltraLD Mk.2 Amplifier module. Note that you should install a tinned copper wire feed-through wherever there’s a via with a solder pad, typically in the middle of each group of five vias. 1000mF electrolytic capacitors off the board for the time being, as this makes it easier to secure transistors Q10 & Q11 to the heatsink later on. Even with the capacitors in place, you still have good screwdriver access to these transistors. However, there’s a risk that one of these capacitors could be damaged if the screwdriver slips while doing up the mounting screws. Note that the 100pF capacitor on the collector of transistor Q9 should be rated at 100V. Alternatively, use a 3kV type, such as the Altronics R-2882. Now install the four 0.1W 5W resistors. These have their leads bent down through 90° some 5mm from their bodies and should be mounted about 1.5mm above the surface of the PC board, to allow the air to circulate beneath them for cooling. The easiest way to do this is to use a strip of cardboard about 20mm wide and 1.5mm thick as a spacer. You simply push the resistor all the way down onto the cardboard, solder the leads, then pull the cardboard back out. Mount the 5W resistors with their values all facing up and reading in the same direction. Again, this makes it easier to check them later on. The fuse clips are next on the list. Note the each fuse clip has a little lug on one end which stops the fuse from moving lengthways. If you install the clips the wrong way around, those lugs will stop you from fitting the fuses. It’s a good idea to use sticky tape to hold the fuse clips in place while you solder their leads. This same trick is also useful when it comes to mounting some of the other parts, such as the screw terminal blocks. Small signal transistors The leads of the TO-92 transistors should be cranked to fit their mounting holes in PC board using a pair of needle-nose pliers. Here’s how it’s done. 60  Silicon Chip The small-signal (TO-92-package) transistors (2SA970s, BC546s, BC556s & BC639) can now go in. As supplied, these transistors usually have their leads in a straight line, although the centre lead may sometimes be cranked out. These leads should be splayed siliconchip.com.au This prototype module differs slightly from the version shown in Fig.9. Take care to ensure that all transistors go in their correct locations and are correctly orientated. It’s a good idea to slightly splay the bottom fins of the heatsinks fitted to Q7 & Q9, to increase the clearance to the solder pads of the adjacent 6.2kW & 2.2kW resistors. outwards and cranked to fit nicely into their allocated holes. The way to do this is as follows: first, grip the three leads adjacent to the transistor body using a pair of needlenose pliers and bend the centre lead back and up by about 70° (if it hasn’t already been cranked). That done, grip each of the two outer leads in turn and bend them outwards and up by about 70°. Finally, grip each lead in turn at the end of the pliers and bend it downwards again – see photos. Install each transistor after dressing its leads. If the leads are dressed correctly, the transistors will each sit siliconchip.com.au about 4mm proud of the PC board. Note that transistor pairs Q1 & Q2, Q3 & Q4 and Q5 & Q6 are installed with their flat sides facing each other. Make sure that you don’t install these transistors in the wrong positions. Inadvertently swapping 2SA­ 970s for BC556s will cause problems (even though they are both PNP types) because their pin-outs are different. Similarly, swapping BC546 NPN transistors for BC556 or 2SA970 PNP types could cause serious damage when the amplifier is powered up. You have been warned! The TO-126-package transistors, Q7 & Q9, are fitted to U-shaped flag heatsinks before they are soldered to the PC board. The best approach is to first loosely attach one transistor to the inside face of its heatsink using an M3 x 10mm screw, nut and two flat washers – see Fig.10. The assembly is then be fitted in position and pushed all the way down until the heatsink contacts the PC board. That done, the transistor’s leads are soldered and the heatsink mounting screw tightened. As with the fuse clips, you can use some sticky tape to hold the assembly in place while the leads are soldered. It’s best to lightly September 2008  61 6021 TYPE TO-220 HEATSINK BF469/470 TRANSISTOR SILICONE INSULATING WASHER M3 x 10mm SCREW M3 NUT FLAT WASHER FLAT WASHER PC BOARD Fig.10: follow this diagram to attach the BF469 and BF470 transistors to their respective heatsinks. The silicone insulating washer is optional but it’s not a bad idea to isolate the heatsinks from the transistor collectors to prevent accidents when testing. solder one lead first and then make any adjustments that may be necessary before soldering the other two leads. Repeat this procedure for the other transistor. Be sure to use a BF470 (PNP) transistor for Q7 and a BF469 (NPN) for Q9. Don’t get them mixed up, otherwise the smoke will get out when you apply power! It’s important to centre these heatsinks so that their fins cannot contact the solder pads of the adjacent 6.2kW and 2.2kW resistors (splay the bottom fins of each heatsink slightly if necessary). If you’re fussy, you can fit TO-126 silicone insulating washers to isolate the collectors of the transistors from the heatsinks (we did this to avoid accidents with test probes while testing the prototype). However, provided you centre the heatsinks correctly, it’s not really necessary. Table 2: Capacitor Codes Winding the choke Value 150nF 100nF 820pF 100pF The next step is to wind the 6.8mH inductor. This is done by closewinding about 1.5m of 1mm-diameter enamelled copper wire onto a plastic bobbin (Altronics L-5305 or Jaycar LF1062). This bobbin can have an inside diameter of either 10mm or 11.8mm (OD = 20mm or 21mm). It order to do a neat job, it’s necessary to make a small winding jig to hold the bobbin. This jig not only prevents the bobbin from being damaged but also makes the job much easier. The accompanying panel (“Making A Winding Jig For The 6.8mH Inductor”) shows how the winding jig is made. Once you have the jig, begin the winding by feeding about 40mm of the wire through one of the bobbin slots and the exit hole in the jig (loosen the handle if necessary to do this). Bend this end back through 180° to secure it, then tighten the handle and wind on 25.5 turns as evenly and tightly as possible. Finish by bending the remaining wire length through 90° so that it exits down through the opposite slot. The windings are now secured using a couple of layers of insulation tape and the bobbin removed from the jig. That done, cut off the excess leads at each end, leaving about 10mm protruding. Finally, complete the inductor by fitting some 20mm-diameter (9mm wide) heatshrink tubing over the windings. Be careful when shrinking it down with a hot-air gun though – too much mF Code 0.15mF 0.1mF .001mF NA IEC Code 150n 100n 820p 100p EIA Code 154 104 821 101 heat will damage the bobbin. You can now test fit the finished inductor on the PC board, bending its leads as necessary to get the bobbin to sit down flush on the board. It’s then just a matter of stripping the enamel from the wire ends and tinning them before soldering the inductor in place. Heatsink transistor mounting As shown in the photos, the driver and output transistors (Q10-Q15) are all mounted on a large finned heatsink measuring 200 x 75 x 48mm (L x H x D); eg, Jaycar HH-8546. You’ve got two choices when it comes to mounting these transistors: (1) drill 3mm holes right through the back of the heatsink and attach the transistors using M3 screws, nuts and washers; or (2) drill and tap mounting holes and attach the transistors using M3 screws and washers. Drilling the holes right through the heatsink is the easiest option but note that you will have to offset the module horizontally by 10mm towards one end so that the holes go between the heatsink fins. Alternatively, if you elect to tap the heatsink, the module can be centred horizontally. This method also makes it easier to install Table 1: Resistor Colour Codes o o o o o o o o o o o o o o o o o 62  Silicon Chip No. 1 1 2 1 2 3 1 1 8 2 1 1 1 1 4 2 Value 1MW 22kW 12kW 6.8kW 1W 5% 6.2kW 2.2kW 510W 390W 100W 68W 47W 6.8W 1W 5% 10W 10W 1W 5% 0.1W 0W 4-Band Code (1%) brown black green brown red red orange brown brown red orange brown blue grey red gold blue red red brown red red red brown green brown brown brown orange white brown brown brown black brown brown blue grey black brown yellow violet black brown blue grey gold gold brown black black brown brown black black gold not applicable black 5-Band Code (1%) brown black black yellow brown red red black red brown brown red black red brown not applicable blue red black brown brown red red black brown brown green brown black black brown orange white black black brown brown black black black brown blue grey black gold brown yellow violet black gold brown not applicable brown black black gold brown not applicable not applicable black siliconchip.com.au Making A Winding Jig For The 6.8mH m Inductor ➊ ➋ ➍ ➌ These photos show how the winding jig is used to make the 6.8mH inductor. First, the bobbin is slipped over the collar on the bolt (1), then an end cheek is attached and the wire threaded through the exit slot (2). The handle is then attached and the coil tightly wound onto the bobbin using 25.5 turns of 1mmdiameter enamelled copper wire (3). The finished coil (4) is secured using a couple of layers of insulation tape and a band of heatshrink tubing. The winding jig consists of an M5 x 70mm bolt, two M5 nuts, an M5 flat washer, a piece of scrap PC board material (40 x 50mm approx.) and a scrap piece of timber (140 x 45 x 20mm approx.) for the handle. In use, the flat washer goes against the head of the bolt, after which a collar is fitted over the bolt to take the bobbin. This collar should have a width that’s slightly less than the the mounting screws. The heatsink drilling details are shown in Fig.11. You should also refer to the accompanying panel for information on drilling and tapping aluminium, since there are some special techniques to be followed if the job is to be a success. We’ll assume here that you’ve tapped the heatsink, ie, by drilling and tapping the white holes marked “A” on Fig.11. siliconchip.com.au width (height) of the bobbin and can be wound on using insulation tape. Wind on sufficient tape so that the bobbin fits snugly over this collar without being too tight. Next, drill a 5mm hole through the centre of the scrap PC board material, followed by a 1.5mm exit hole about 8mm away that will align with one of the slots in the bobbin. The bobbin can be slipped over the collar, after which Begin the heatsink assembly by attaching the two driver transistors, Q10 & Q11. Fig.12 (A) shows the mounting details for these devices. Note that they must each be electrically insulated from the heatsink using a TO-220 silicone insulating washer and insulating bush. However, because Q10 & Q11 are quite close together, it’s necessary to trim about 1mm off the adjacent sides of each insulating washer so that they don’t overlap. the scrap PC board “end cheek” is slipped over the bolt (ie, the bobbin is sandwiched into position between the washer and the scrap PC board). Align the bobbin so that one of its slots lines up with the exit hole in the end cheek, then install the first nut and secure it tightly. The handle can then be fitted by drilling a 5mm hole through one end, then slipping it over the bolt and installing the second nut. Use an MJE15030 for Q10 and an MJE15031 for Q11 – don’t get them mixed up. Both devices are secured using an M3 x 6mm screw and flat washer. Do the screws all the way up but don’t tighten them yet. Next, fit a 10mm spacer to each of the four corner mounting positions on the PC board. When they’re on, sit the board assembly on a flat surface and then lower the heatsink assembly into position so that Q10 & Q11’s leads go September 2008  63 Drilling & Tapping The Aluminium Heatsink CL 60 55 B A B A B B 41 25 20 30 25 11 B 55 50 A B A 75 A A 30 5.5 5.5 200 HOLES A: DRILL 2.5mm DIAMETER, TAP FOR M3 SCREW 100 HOLES B: DRILL 3.5mm DIAMETER (SCALE 1/2) Fig.11: this half-size diagram shows the drilling details for the heatsink. For tapped holes, mark out and drill the white holes marked “A” to a depth of 7mm (2.5mm drill, M3 tap). Alternatively, if you intend drilling right through the heatsink, drill the blue holes marked “B” (3.5mm drill). F IG.11 ABOVE SHOWS the heatsink drilling details. The white holes are drilled if you intend tapping the holes, while the blue holes are drilled if you want to drill right through the heatsink (ie, between the fins). If you intend drilling right through the heatsink, simply mark out the blue hole locations using a sharp pencil, then accurately drill the holes using a drill press. Use a pilot drill to begin with – the holes have to go between the fins so it’s vital to accurately position them. Be sure to use a suitable lubricant when drilling the holes. Kerosene is the recommended lubricant for aluminium but we found that light machine oil (eg, Singer) also works well for jobs like this. Don’t try drilling the holes in one go. When drilling aluminium, it’s important to regularly remove the bit from the hole and clear away the metal swarf. If you don’t do this, the aluminium has a habit of migrating onto the drill bit and ruining it. Don’t even think of using a hand-drill for this job by the way. There’s no way you’ll get the holes perfectly perpendicular to the mounting face. Once the holes have been drilled, deburr them using an oversize drill to remove any metal swarf from the mounting surface. This is vital to prevent punch-through of the insulating washers. Finally, the heatsink should be thoroughly scrubbed cleaned using water and detergent and allowed to dry. Drilling & tapping Alternatively, if you want to centre the module horizontally on the heatsink, you will have to drill and tap holes to accept M3 screws in the locations shown (ie, the white holes). This method is more time-consuming than drilling right through but it does make it easier to mount the transistors when it’s done. To do the job, you will need a 2.5mm drill, an M3 intermediate (or starting) tap and an M3 finishing tap. If you are unable to obtain a finishing tap, you can make one by grinding most of the tapered end off an intermediate tap. The first step is to mark out and drill the mounting holes to a depth of exactly 7mm using a 2.5mm drill. As before, be sure to regularly clear the hole and the drill bit of any metal swarf and keep the drill bit well-lubricated. Once the holes have been drilled, tap each one in turn, starting with the M3 intermediate tap and then finishing with the M3 finishing tap. The trick here is to take it nice and slowly. Keep the lubricant up and regularly wind the tap out to clear the metal swarf from the hole. You will know when you’re coming to the end of the hole by the increased resistance to turning the tap handle. Do not at any stage apply undue force to the tap. It’s easy to break a tap in half and if the break occurs at or below the heatsink’s face, you can scratch both the tap and the heatsink (and about $25). As before deburr the holes using an oversize drill and scrub the heatsink clean using water and detergent. Make sure that the mounting surface is perfectly smooth before moving installing the heatsink transistors. 64  Silicon Chip through their mounting holes. The four output devices (Q12Q15) can now be fitted. As shown in Fig.12 (B), these devices must also be insulated from the heatsink by using silicone insulating washers. Start by fitting Q12. The procedure here is to push its leads into their PC mounting holes, then lean the device back, feed through the mounting screw, hang the insulating washer off the end of the screw and finally loosely screw the assembly to the heatsink. The remaining three devices are installed the same way, taking care to fit the correct transistor type at each location. Once they’re in, push the board down so that all four spacers are in contact with the benchtop – this automatically adjusts the transistor lead lengths and ensures that the bottom of the board sits exactly 10mm above the bottom edge of the heatsink. Now adjust the PC board assembly horizontally so that each side is 32.5mm in from its adjacent heatsink end, then do up the transistor mounting screws while keeping the insulating washers correctly aligned. The next step is to lightly solder the outside leads of Q12 & Q15 to their pads on the top of the board. The assembly is then turned upside down and the remaining heatsink transistor leads soldered. Before soldering the leads though, it’s important to prop the front edge of the board up so that the board sits at right-angles to the heatsink. If you don’t do this, it will sag under its own weight and will remain in this condition after the leads have been soldered. Complete the soldering, then turn the board right way up again and tighten down the transistor mounting screws. They should be tight to ensure good thermal coupling between the devices and the heatsink. Checking device isolation Now check that each device is indeed electrically isolated from the heatsink. That’s done by switching your multimeter to a high ohms range and checking for shorts between the heatsink mounting surface and the collectors of the heatsink transistors (note: the collector of each device is connected to its metal face or tab). In practice, it’s simply a matter of checking between the fuse-clips closest to the heatsink and the heatsink itself. That’s because the device colsiliconchip.com.au lectors in each half of the output stage are connected together and run to their respective fuseholder. In each case, you should get an open-circuit reading. If you do find a short, undo each transistor mounting screw in turn until the short disappears. It’s then simply a matter of locating the cause of the problem and remounting the offending transistor. Be sure to replace the insulating washer if it has been damaged in any way (eg, punched through). MAIN PLATE OF HEATSINK SILICONE INSULATING WASHER SILICONE INSULATING WASHER INSULATING BUSH FLAT WASHER 6mm LONG M3 SCREW 10mm LONG M3 SCREW M3 TAPPED HOLE Completing the assembly The assembly can now be completed by installing the two 1000mF 63V cap­ acitors and the three screw terminal blocks (CON1-CON3). Take care when installing the latter – the access holes must face outwards. You should also remove the two support spacers from the edge of the board adjacent to the heatsink. In fact, it’s quite important that the rear edge of the board be supported only by the heatsink transistor leads. Basically, this avoids the risk of eventually cracking the PC tracks and pads around the heatsink transistors due to thermal expansion and contraction of their leads as they heat up and cool down. In short, the rear spacers are installed only while you install the heatsink transistors and must then be removed. They play no part in securing the module. Instead, this edge of the module is secured by bolting the heatsink itself to the chassis. This can be done by tapping M3 or M4 holes into the main plate on the underside of the heatsink or by using right-angle brackets. The front of the board can be secured using the two M3 x 10mm spacers fitted earlier. That completes the assembly of the power amplifier module. The next step is to build the power supply module. Power supply As noted last month, this new design dispenses with the regulated power supply used for the original Ultra-LD amplifier module. Instead, the Mk.2 module is powered using unregulated ±55V rails only. Fig.13 shows the circuit details of the power supply. It’s based on a centre-tapped (toroidal) mains transformer (T1) with two 40V windings and two 15V windings. As shown, the two 40V windings are connected together to give 80VAC siliconchip.com.au (HEATSINK FINS) NJL3281D OR NJL1302D TRANSISTOR (TO-264) MJE15030 OR MJE15031 TRANSISTOR (TO-220) AMPLIFIER PC BOARD M3 TAPPED HOLE A AMPLIFIER PC BOARD B Fig.12: this diagram shows the mounting details for the TO-220 driver transistors (A) and the four output transistors (B). After mounting these transistors, use your multimeter to confirm that they are properly isolated from the heatsink – see text. centre-tapped and this arrangement drives bridge rectifier BR1. This in turn feeds six 4700mF 63V electrolytic capacitors (ie, 14,100mF on each side) to provide balanced ±55V DC supply rails to power the amplifier. In addition, two LEDs are connected in series with 3.3kW 5W current-limiting resistors across the ±55V supply rails. These serve two purposes: (1) they provide a handy indication that power is present on the supply rails; and (2) they (slowly) discharge the filter capacitors when the power is switched off (see warning panel). The two 15V windings are also connected together (to provide 30VAC centre-tapped) and these drive bridge rectifier D1-D4 and two 2200mF filter capacitors to derive unregulated rails of about ±20V. These rails are then fed to 3-terminal regulators REG1 & REG2 to derive regulated ±15V supply rails to power a preamplifier module. In addition, the +20V rail is also made available as an output, along with a 30VAC output. The +20V rail can be used to power the “Universal Speaker Protector & Muting Module” (SILICON CHIP, July 2007), while the 30VAC output is connected to the “AC Sense” input of this module (it’s used to quickly disconnect the speaker when the power goes off, to avoid switch-off thumps). By the way, if you’re looking for a preamplifier to use with the Ultra-LD Mk.2 amplifier, the preamplifier module described in August 2007 SILICON CHIP (and used in the Class-A Stereo Amplifier) is ideal. Note, however, that 3-terminal regulators REG1 & REG2 on that preamplifier board must be replaced by wire links if powering it from the power supply described here. These links are connected between what were the IN and OUT pads for each regulator on the preamplifier board. Power supply assembly Fig.15 shows the parts layout for the power supply board. This board is coded 01109081 and carries all the parts following the transformer except for 35A bridge rectifier BR1 which must be mounted on a metal chassis to ensure adequate heatsinking. Begin by installing diodes D1-D4, the two LEDs and 3-terminal regulators REG1 & REG2. Make sure these parts are all orientated correctly and don’t get REG1 & REG2 mixed up. Both regulators are mounted with their metal tabs flat against the PC board. To install them, first bend their centre leads down through 90° about 5mm from their bodies, then bend their outer leads down through 90° about 7mm from the bodies. The regulators can then be fitted to the PC board and secured using M3 x 6mm screws, flat September 2008  65 BR1 35A/600V + ~ T1 CON1 TERMINAL 1 ~ 4700 F 63V  LED1 4700 F 63V 4700 F 63V K 3.3k 5W 40V POWER S1 0V F1: 5A A – TERMINAL 2 0V A 40V 0V 4700 F 63V TERMINAL 3  LED2 4700 F 63V 4700 F 63V K 3.3k 5W 15V N +55V A 0V –55V CON3 15V CON5 30V AC 0V E T1: 240V TO 2x 40V/300VA, 2x 15V/7.5VA CON4 D1–D4: 1N4004 K +20V 0V K A A K K REG1 7815 +15V OUT IN GND 2200 F 25V A A CON2 100 F 16V 0V 2200 F 25V LEDS 1N4004 A IN –15V OUT REG2 7915 K A K 100 F 16V GND 7815 7915 GND SC 2008 ULTRA-LD AMPLIFIER MK2 POWER SUPPLY GND IN GND IN IN OUT OUT Fig.13: the power supply is based on a toroidal transformer (T1) with two 40V windings and two 15V windings. The two 40V windings are connected in series and drive bridge rectifier BR1 and six 4700mF filter capacitors to produce the ±55V rails. Similarly, the 15V windings drive a bridge rectifier based on diodes D1-D4. This feeds 3-terminal regulators REG1 & REG2 to produce ±15V rails for a preamplifier. The +20V rail, derived from the output of D1-D4, is used to power the loudspeaker protector. washers and nuts. Tighten the screws firmly before soldering the device leads. Note that there’s enough room on the PC board to fit mini-heatsinks to the regulators. This will depend on the current drawn by the preamplifier you elect to use but should not be necessary in most cases. The three Quick-Connect male spade terminals (TERMINAL1-TERMINAL3) are next on the list. These are used to terminate the connections from bridge rectifier BR1 and the centre-tap of the 40V transformer windings. They are each secured in place using an M4 x 10mm screw, nut, flat washer and star washer – see Fig.14. The trick here is to use a Phillipshead screwdriver to hold the M4 screw 66  Silicon Chip stationary while you do up the nut with a ratchet-driven socket. Once all the Quick-Connect terminals have been tightly secured to the PC board, you can then install the remaining parts. These include the two 3.3kW 5W resistors, the electrolytic capacitors and the screw terminal blocks. Note that the two 5W resistors should be stood off the board by 1-2mm, to allow the air to circulate beneath them for cooling (use a cardboard spacer). Be sure to install the electrolytic capacitors with the correct orientation. These things have a nasty habit of exploding if they’re installed the wrong way around so double-check them. Be sure also to dovetail connectors CON3 & CON5 together (to form a 5-way connector) before installing QUICK CONNECT PC BOARD M4 STAR WASHER M4 FLAT WASHER M4 x 10mm SCREW & NUT Fig.14: here’s how the single-ended male Quick Connects are secured to the Power Supply module PC board. them on the PC board. If you solder one connector to the board first, you may not be able to dovetail them. The same goes for connectors CON4 & CON2. Putting it in a case The completed amplifier module and its power supply should be housed siliconchip.com.au Fig.15: install the parts on the power supply board as shown here, taking care to ensure that all the electrolytic capacitors are mounted with the correct polarity. Be sure also to use the correct regulator at each location. The two LEDs indicate when power is applied and remain lit until the 4700mF capacitors discharge after switch-off. We modified the power supply PC board after this prototype was produced, so that heatsinks could be fitted to the two 3-terminal regulators if necessary. This will depend on the current drawn by the preamplifier. siliconchip.com.au September 2008  67 HEATSINK EARTH LUGS SECURED TO CHASSIS MALE IEC CONNECTOR WITH 5A INTEGRAL FUSE 18080110 reifilpmA 2.KM DL-artlU T1 240V PRIMARY LEADS 0V Q1 Q2 CON2 0V -57V SHIELD 0V 1 5V AMPLIFIER BOARD Ultra-LD Mk.2 Amplifier power CON2 CON4 INSULATE ALL MAINS CONNECTIONS WITH HEATSHRINK SLEEVING 40 V – BR1 ~ + CON5 01109081 4 0V ~ POWER SUPPLY BOARD AUDIO INPUT LED2 CON1 SECURE EARTH LUGS TO CHASSIS USING M4 x 10MM SCREW, LOCKWASHER & TWO NUTS - SEE FIG.17 0V TO SPEAKER TERMINALS VIA LS PROTECTOR COM +57V V 0V CON3 SIG 15 LED1 S1 (TOP REAR) Fig.16: here’s how to wire the completed power amplifier and power supply boards into a metal case. The mains wiring at right would be typical of most installations but ensure that all exposed terminals are fully insulated. in an earthed metal case but we’ll leave the details of this up to you. However, don’t get involved in mains wiring unless you are experienced and know exactly what you are doing. Fig.16 shows the suggested wiring layout (but without a speaker protector or preamplifier). Make sure that the chassis is securely earthed via the mains and be sure to insulate all exposed mains terminals. Note that you will have to use a piggyback female spade connector (eg, Altronics H-2016A) to terminate the commoned 40V & 0V connections from the toroidal transformer. This connector plugs into the 0V terminal (TERMINAL 2) on the power supply module. The female spade connector fitted to the green earth lead is then plugged into the back of this connector. The other end of this earth lead is crimped to an earth lug. Similarly, 68  Silicon Chip the mains earth lead (green/yellow) is crimped to a second earth lug and the two earth lugs are securely bolted to the chassis. Once the assembly is complete, check your wiring very carefully. In particular, make sure that BR1’s positive and negative terminals connect to the correct terminals on the power supply board. You should also use a multimeter to confirm that the chassis is correctly earthed. Do that by checking for continuity between the earth terminal of the IEC socket and the chassis. Testing the power supply It’s now time to check that the power supply is functioning correctly but first a warning: avoid contact with the ±55V rails, both on the power supply module and on the amplifier module. There’s 110V between them and getting across the two rails simultaneously could have serious consequences. The same goes for the transformer secondary windings – make sure that you don’t get across either of the two 40VAC windings or the 80VAC that’s applied to bridge rectifier BR1. You must also allow the 4700mF filter capacitors on the power supply module to discharge down to a couple of volts before attempting to work on this module. Don’t just rely on the LED indicators – use your multimeter to confirm that the supply rails have indeed dropped to a low value before touching it. Similarly, make sure these capacitors have discharged before connecting the power supply to the amplifier module or disconnecting it (otherwise you could damage the amplifier). To check the power supply, first siliconchip.com.au Power Supply Parts List PC Board Module The 68W 5W test resistors are soldered to the fuse-clip pads on the underside of the PC board. make sure that the supply wiring is disconnected from the amplifier. That done, apply power to the power supply board and check the various DC outputs. You should be able to measure close to ±55V on CON1, +20V on CON4, ±15V on CON2 and 30VAC on CON5. If you don’t get the correct voltages, switch off immediately and check for wiring and component errors. Testing the power amplifier Assuming you do get the correct voltages, switch the power supply off and follow this step-by-step procedure to check the power amplifier module: STEP 1: remove the fuses from the amplifier module and install two 68W 5W resistors in their place. The best way to do this is to tack solder the resistors across the fuseholder pads on the underside of the PC board. They should be mounted about 5mm away from the edge of the board, to prevent heat damage during testing – see photo. The 68W resistors are there to limit the current through the output stage to about 800mA if there is a fault in the amplifier that turns the output transistors hard on. This protects the output transistors from damage but note that the 68W resistors will quickly burn out under such circumstances (since they will be dissipating over 40W). STEP 2: use your multimeter to again check that the heatsink transistors are all isolated from the heatsink. If one of these is shorted, its corresponding siliconchip.com.au 68W 5W resistor will again quickly burn out if power is applied. STEP 3: check that the power supply is off and that the filter capacitors are discharged, then connect the +55V, 0V and -55V supply leads to the amplifier at CON2. Make sure these are connected correctly, otherwise the amplifier will be damaged when power is applied. STEP 4: apply power and check the supply voltages at the fuseholders (ie, at the ends furthest away from the heatsink). You should get +55V at FUSE1 (with respect to the 0V rail) and -55V at CON2. STEP 5: check the voltage across each 68W 5W resistor. This should be in the range from 9-14V (depending on the supply rails and the exact value of the 68W test resistors). Switch off immediately and go to the troubleshooting procedure if you get a value that’s much higher than 14V. STEP 6: check the voltage at the loudspeaker terminals. You should get a reading of ±30mV or less. STEP 7: check the voltage across each of the 0.1W 5W emitter resistors in the output stage. This voltage should be between 7-10mV. This equates to a current of 70-100mA through each output transistor which means that the total output stage quiescent current is in the range of 140-200mA. Be careful not to short a resistor lead to the adjacent +55V and -55V tracks on the top of the board when making these voltage checks. 1 PC board, code 01109081, 126 x 96mm 3 3-way PC-mount terminal blocks, 5mm pitch (Altronics P2035A or equivalent) (CON1-CON3) 2 2-way PC-mount terminal blocks, 5mm pitch (Altronics P2034A or equivalent) (CON4-CON5) 3 chassis-mount single-ended Quick Connect (spade) terminals (TERM1-TERM3) (Jaycar PT-4910 or equivalent) 3 M4 x 10 screws 3 M4 a 10mm nuts 3 M4 flat washers 3 M4 shakeproof washers 4 M3 x 9mm tapped Nylon spacers 6 M3 x 6mm screws 6 M3 nuts 2 M3 shakeproof washers Semiconductors 4 1N4004 diodes (D1-D4) 1 7815 15V regulator (REG1) 1 7915 -15V regulator (REG2) 2 3mm red LEDs (LED1,LED2) Capacitors 6 4700mF 63V electrolytic 2 2200mF 25V electrolytic 2 100mF 16V electrolytic Resistors 2 3.3kW 5W Additional Parts 1 300VA transformer with 2 x 40VAC 300VA windings and 2 x 15VAC 7.5VA windings 1 35A 400V bridge rectifier (BR1) 1 chassis-mount IEC male socket with fuseholder (eg, Jaycar PP-4004, Altronics P-8324) 1 DPST mains switch (S1) 1 M205 5A fuse Miscellaneous Earth crimp lugs, female Quick Connectors, 240VAC cable, machine screws & nuts, etc. If the voltage across the 0.1W 5W emitter resistors exceeds 10mV, increase the 47W resistor between the supply rail and Q7’s emitter to 56W, or even to 68W if necessary to bring September 2008  69 Removing Parts From The PC Board If you need to remove components such as resistors or transistors from this doublesided board, the easiest way to do it is to first remove as much solder as you can from each pad using a solder sucker. Next, you clip away the body of the component using small sidecutters, then grab each lead with needle-nose pliers on the top of the board while you heat up its copper pad underneath. The lead can the voltage back into the 7-10mV range. This resistor is located on the far lefthand side of the PC board, immediately below a 100nF capacitor. Do not reduce Q7’s emitter resistor to less than 47W. STEP 8: check the voltages marked on the circuit diagram (Fig.1) last month. These should all be close to the indicated values. STEP 9: if everything is correct, switch off and allow the power supply filter capacitors to discharge to a low level (around 2V or less). When they reach this level, disconnect the power supply, remove the 68W 5W resistors from then be pulled out from the top. You then use solder-wick (or desoldering braid) to remove the residual solder in the plated through holes but be careful not to overheat the PC pads, as they may detach themselves from the board. Often, it will be necessary to drill out the holes to clear the solder, so that you can install the new component’s leads. the amplifier module and install the 5A fuses. STEP 10: connect an audio signal source and a loudspeaker (preferably via a loudspeaker protector module), then re-apply power and test the amplifier module with music. Troubleshooting If the voltage across the 68W test resistors is much greater than 14V (eg, close to the supply rail), switch off immediately (note: the resistors may burn out before you do this). The first thing to check is that the heatsink transistors are all correctly isolated from the heatsink. If this checks out, apply power to the amplifier without the fuses or test resistors in place – ie, so that the output stage (Q10-Q15) is left unpowered. Now check the voltage between the bases of transistors Q10 & Q11. This should be close to 2.2V. If it’s much higher than 2.2V, this indicates that the DQ12-DQ15 diode string is open circuit. This could be due to an opencircuit track on the PC board or more likely, a missed solder connection on one of the output transistor leads (ie, the “A” & “K” diode leads). If the voltage across the diode string is correct, check the base-emitter voltage of each transistor in the amplifier. In each case, you should get a reading of 0.6-0.7V if the transistor is working correctly. Check that the correct transistor has been used at each location. Finally, be sure to use this module with a loudspeaker protector, as a fault in the output stage can quickly burn out an expensive loudspeaker system (and maybe even start a fire due to a red-hot voice-coil). The recommended unit is the “Universal Speaker Protector & Muting Module” SC (see SILICON CHIP, July 2007). Radio, Television & Hobbies: the COMPLETE archive on DVD YES! NA R MO E THA URY ENT QUARTER C NICS O OF ELECTR ! Y R O T IS H This remarkable collection of PDFs covers every issue of R & H, as it was known from the beginning (April 1939 – price sixpence!) right through to the final edition of R, TV & H in March 1965, before it disappeared forever with the change of name to EA. For the first time ever, complete and in one handy DVD, every article and every issue is covered. If you’re an old timer (or even young timer!) into vintage radio, it doesn’t get much more vintage than this. If you’re a student of history, this archive gives an extraordinary insight into the amazing breakthroughs made in radio and electronics technology following the war years. And speaking of the war years, R & H had some of the best propaganda imaginable! Even if you’re just an electronics dabbler, there’s something here to interest you. • Every issue individually archived, by month and year • Complete with index for each year • A must-have for everyone interested in electronics Please note: this archive is in PDF format on DVD for PC. Your computer will need a DVD-ROM or DVD-recorder (not a CD!) and Acrobat Reader 6 or above (free download) to enable you to view this archive. This DVD is NOT playable through a standard A/V-type DVD player. Exclusive to SILICON CHIP ONLY 62 $ 00 +$10.00 P&P HERE’S HOW TO ORDER YOUR COPY: BY PHONE:* (02) 9939 3295 9-4 Mon-Fri BY FAX:# (02) 9939 2648 24 Hours 7 Days <at> BY EMAIL:# silchip<at>siliconchip.com.au 24 Hours 7 Days BY MAIL:# PO Box 139, Collaroy NSW 2097 * Please have your credit card handy! # Don’t forget to include your name, address, phone no and credit card details. 70  Silicon Chip BY INTERNET:^ siliconchip.com.au 24 Hours 7 Days ^ You will be prompted for required information siliconchip.com.au STIC FANTAIDEA GIFT UDENTS FOR SFT ALL O S! AGE THEAMATEUR SCIENTIST An incredible CD with over 1000 classic projects from the pages of Scientific American, covering every field of science... THE LATEST VERSION 4 – WITH EVEN MORE FEATURES! Arguably THE most IMPORTANT collection of scientific projects ever put together! This is version 4, Super Science Fair Edition from the pages of Scientific American. As well as specific project material, the CDs contain hints and tips by experienced amateur scientists, details on building science apparatus, a large database of chemicals and so much more. ONLY 62 $ 00 PLUS $10 Pack and Post within Australia NZ P&P: $AU12.00, Elsewhere: $AU18.00 “A must for every science student, science teacher, science lab . . . or simply for those with an enquiring mind . . .” Just a tiny selection of the incredible range of projects: ! Build a seismograph to study earthquakes ! Make soap bubbles that last for months ! Monitor the health of local streams ! Preserve biological specimens ! Build a carbon dioxide laser ! Grow bacteria cultures safely at home ! Build a ripple tank to study wave phenomena ! Discover how plants grow in low gravity ! Do strange experiments with sound ! Use a hot wire to study the crystal structure of steel ! Extract and purify DNA in your kitchen !Create a laser hologram ! Study variable stars like a pro ! Investigate vortexes in water ! Cultivate slime moulds ! Study the flight efficiency of soaring birds ! How to make an Electret ! Construct fluid lenses ! Raise butterflies as experimental animals ! Study the physics of spinning tops ! Build an apparatus for studying chaotic systems ! Detect metals in air, liquids, or solids ! Photograph an ant's brain and nervous system ! Use magnets to make fluids into solids ! Measure the metabolism of an insect . . . ! and many, many more (a thousand more, in fact!) See the V2 review in SILICON CHIP, October 2004. . . or read on line at siliconchip.com.au This is the ALL-NEW Version 4 . . . it’s even BETTER! HERE’S HOW TO ORDER YOUR COPY: BY PHONE:* (02) 9939 3295 9-5 Mon-Fri BY FAX:# <at> (02) 9939 2648 24 Hours 7 Days BY EMAIL:# silicon<at>siliconchip.com.au 24 Hours 7 Days BY MAIL:# BY PAYPAL:# PO Box 139, Collaroy NSW 2097 silicon<at>siliconchip.com.au 24 Hours 7 Days * Please have your credit card handy! # Don’t forget to include your name, address, phone no and credit card details. BY INTERNET:^ siliconchip.com.au 24 Hours 7 Days ^ You will be prompted for required information There’s also a handy order form inside this issue. Exclusive in SILICON Australia to: CHIP siliconchip.com.au siliconchip.com.au September 2008  71 DSP Musicolour: adding a remote control With a small and low-cost add-on PC board, the DSP Musicolour can be operated via an infrared remote control – very handy if you want to use it in hard-to-reach places. Part Four – by Mauro Grassi R emote control adds so much more convenience! After completing the DSP Musicolour design (as published in the June, July and August issues) we looked at the possibility of adding infrared remote control. It turned out to be really simple – so here we describe how to build a simple remote control receiver PC board to allow the DSP Musicolour to be operated via a remote control which uses RC5 codes – the vast majority – or a universal remote control. The DSP Musicolour firmware contains the decoding functions. The schematic for the remote control receiver board is shown overleaf It contains little more than an infra72  Silicon Chip red receiver module that amplifies and demodulates the remote control signal. The signal is then decoded by the firmware. Apart from the IDC header which connects the Remote Control PC board back to the main board, there are only three other components: a 47mF capacitor to bypass the supply rail (taken from the DSP Musicolour’s 5V MUSICOLOUR - THE MOVIE! It’s quite hard to put into words just how sensational the DSP Musicolour lightshow really is . . . so you’ll be able to see it! Around the time this issue appears, we hope to have ready a short demonstration movie which can be accessed via the SILICON CHIP website. rail) and a 100W resistor to limit the current and further isolate the infrared module from the supply rail. Finally, there is a 330W resistor. As the RF6 pin of the microcontroller (IC1) can function as an output as well as input, this resistor is used on the output of the module to limit the current into the data output of the infrared receiver module. Construction This is a simple board that should take a matter of minutes to build. Simply refer to the component overlay and the accompanying photograph. Begin by installing the resistors. There are only two of them so it’s going siliconchip.com.au to be particularly difficult to mix them up. (Hint: the 100W has bands which start with brown and black while the 330W has two orange bands!) But if in doubt, check them with a DMM. Next is the 47mF capacitor which, being polarised, must be oriented correctly as shown in the component overlay. To make the PC board as low in height as possible, it must be “laid over” 90° so that it lies along the board. Therefore you will need to bend both leads down 90° before soldering it in. Then solder in the infrared receiver module, allowing around 7mm of lead. Similarly to the electrolytic, it mounts so that it lies flush with (ie, parallel with) the PC board surface, as shown in the enlarged photo at right. The last thing to solder in is the 10-way IDC header. The remote control board connects to the main board via a 10-way ribbon cable, from CON1 on the remote control board to CON3 on the main board. We explained how to make a 26-way ribbon cable connecting the main board to the display board in the July 2008 issue (page 26 under Ribbon Cable Assembly). The 10-way ribbon cable used to connect the remote control board is made in the same way. The completed remote control PC board sits between the red acrylic front panel and the display board, as photographed below. It actually sits Here’s the DSP Musicolour Infrared Controller Receiver, shown much larger than life size for clarity. Note how both the infrared detector itself and the electrolytic smoothing capacitor are both “laid over” to give minimum height to the Receiver and allow it to be sandwiched between the red acrylic front panel and the display PC board. on top of some resistors between LED array 3 and two 74HC595 ICs. It is secured in place with a selfadhesive foam pad or two (available at any newsagent or stationer). Being a couple of millimetres thick, these pads have the added advantage of providing insulation between the remote control board and the components on the display board underneath. You will need to open the case to install it so you must first make absolutely certain that the IEC mains power lead is not plugged in. The ribbon cable connecting to the remote control PC board also helps locate the board – when its IDC con- nector is plugged in, the top edges of both the controller PC board and the display board are in alignment, with just enough room for the IDC cable to go over the top of the display board and wedge between the display board and case top. Once the board is connected, close the case and insert the screws which hold the two halves together, then (and only then) power up the DSP Musicolour. Don’t be tempted to take a short cut and leave the screws out! Defining the codes There are only nine remote control codes used to control the DSP Musi- Here’s where the add-on remote control receiver board fits, between the display and IC3 & 4. It’s held in place by an adhesive foam pad on its back, which also insulates it from the components underneath on the the display board. Inset at left is the board in situ, looking down. siliconchip.com.au September 2008  73 100Ω IRD1 5 8 47 µF 16V 3 λ 10 330Ω 1 Parts List – Remote Control for DSP Musicolour CON1 1 PC Board coded 10107083 measuring 24mm x 44mm 1 infrared remote control using RC5 code, at least nine buttons (see text) 9 2 4 Semiconductors 1 infrared receiver module (IRD1) (Jaycar ZD1952, Altronics Z1611) 2 Miscellaneous 1 10-way right-angled IDC header (Jaycar PP1118, Altronics P5060) 1 10-way ribbon cable, approx 20cm long 2 10-way IDC cable line sockets (Jaycar PS0984, Altronics P5310) 2 self-adhesive foam pads (adhesive both sides) 3 SC 2008 IRD1 DSP MUSICOLOUR REMOTE CONTROL RECEIVER 1 3 If you can find a simpler circuit, good luck! The Infrared Detector both receives and decodes the signal from the Remote Control. The microcontroller in the DSP Musicolour does all the hard work! colour. These must be defined at least once, using the front panel buttons, before operating the DSP Musicolour with a remote control. First, you must make sure that your remote control is an RC5-compliant remote control. RC5 is a protocol designed by Philips but not all remote controls in use today actually work with this protocol. Other protocols will not work with this decoder, so you should make sure that you have an RC5 remote control. If you are using a universal remote, there is a good chance of it working if you set it to a Philips appliance (eg, a TV set or VCR). Go to SYSTEM>Remote Control and follow the prompts. You will be asked to define each of the nine keys in turn, keys 1 to 7 correspond to the buttons on the front panel in the following order: UP, SET, DOWN, CH1, CH2, CH3 and CH4. The corresponding button LED will light and you should press the key on your remote control that you want to use to emulate that key on the front panel. Naturally, you would use the channel up and channel down buttons for up and (RIBBON CABLE TO MAIN BOARD) 1 2 CON1 CS 3 8 0 7 0 1 0 1 9 10 47 µF 100Ω 330Ω + IRD1 BEND BOTH OVER 90 o Here the Infrared Receiver PC board and component overlay are shown life size. And there’s not much to it! Watch the polarity on the 47mF electrolytic capacitor and note which way around the pins go on the infrared detector (actually, if you get this back to front, the lens will face down into the PC board – a pretty good indication that it’s not quite right!). 74  Silicon Chip Capacitors 1 47mF 16V electrolytic, PC board mounting Resistors (0.25W, 1%) 1 330W 1 100W down – it makes it easier to remember. After the seven buttons on the front panel, the next two buttons are used to emulate the SELECT potentiometer and require you to enter a key for “+” and “-” to emulate the analog potentiometer. Again, you would normally define these two buttons as Volume UP and Volume DOWN on your remote control. Even universal (programmable) remote controls normally have channel up/down and volume up/down labeled. To test that the DSP Musicolour is correctly understanding the remote control signal you can go to the SYSTEM>RC5 Echo submenu. This will display (in hexadecimal) the 12-bit code received by the Musicolour. You should see the numbers displayed as you send commands to the Musicolour using your remote control. We have tested the DSP Musicolour with the Digitech AR-1725 (Jaycar AR-1725) universal remote shown earlier, and we set it up as follows (most other universal remotes will work too). We had intended to use the much cheaper Select1 remote control (Jaycar AR1703) but found it only had seven buttons, so was not suitable. However, if your household is typical, you probably have a growing collection of once-used infrared remote controls. One of these may be suitable if it uses the Philips (RC5) protocol. If you don’t know and can find the code sheet for it, program it for any Philips device and try it out. You can’t do any harm, even if it is wrong. It simply won’t work! Of course, it may be that the batteries are flat . . . If it doesn’t have a visible LED tell-tale, the easiest way to check Here’s the display for programming your remote control – as each LED lights, you press the appropriate button on your remote control. siliconchip.com.au Button on Front Panel to Emulate Press this key on remote control when prompted AUTO/UP “Volume UP” button SET/OK “OK” button USER/DOWN “Volume DOWN” button CH1/A “1” button CH2/B “2” button CH3/C “3” button CH4/D “4” button Potentiometer + control (*) “Channel UP” button Potentiometer – control (*) “Channel DOWN” button Table 1: this shows a suggested remote control code definition sequence using a Digitech AR-1725 universal remote control (or any RC5 remote control with 9 buttons or more) and the optional remote control decoder PC board. Note (*): this control is not a button on the front panel, but is used to emulate the SELECT potentiometer on the front panel using the remote control. that an infrared remote control is actually outputting infrared is to view it through just about any digital or video camera. Most are sensitive to infrared and you should see bright white (or sometimes green) flashes in the viewfinder when aimed at the remote control. If you are using the Digitech remote control, set it for the VCR 115 code (this is the code for a Philips VCR, although many other Philips codes should work too). Go to the SYSTEM>Remote Control submenu. There you will see whether the remote control has been defined. If it indicates that it has not been defined, you may press SET to define the remote control codes. You will be asked for confirmation and if you proceed, you will be able to define the remote control codes to suit your remote. You’ll be prompted to define each of the nine keys in turn. You can refer to Table 1 giving a suggested definition (you can of course choose another sequence of keys to define if you wish). Once you’ve defined the remote control codes, the DSP Musicolour will respond to both the buttons on the front panel and to the remote control keys you have defined. So you can operate the DSP Musicolour with either. Finally, an errata: on the Display PC board component overlay published on page 26 of the July issue, the ICs labelled IC1, IC2, IC3 and IC4 should be labelled IC3, IC4, IC5 and IC6 respectively to agree with the circuit diagram published in June. The actual type numbers of those ICs are all correct as published. SC This screen is for checking the remote control: it displays the received codes from your remote control as decoded by the firmware. siliconchip.com.au September 2008  75 Pt.2: By JOHN CLARKE LED Strobe & Tachometer Last month, we published the circuit of our new LED Strobe & Tachometer and showed how to build the main unit and the strobe light. This month, we describe the assembly of the optional Photo-Interruptor and IR Reflector Amplifier boards. We also describe how the unit is used. L ET’S START WITH the assembly of the Photo-Interruptor board – see Fig.11. This board is coded 04108083 and carries just the photo-interruptor itself, a 150W resistor and three PC stakes. The assembly should take only a few minutes. Just be sure to install the photo-interruptor with the correct orientation, ie, with its diode symbol (indicated in blue on Fig.11) on the righthand side. It should be secured to the PC board using two M3 x 6mm screws and nuts before the leads are soldered. The completed assembly is wired 76  Silicon Chip to a 3.5mm jack plug using 2-core shielded cable, with the shield wire used as the 0V (GND) connection (ie, it goes to the sleeve) – see Fig.6 in Pt.1 last month. Make sure that the tip and ring connections are made correctly. The tip connection is right at the end of the plug, while the ring is the separate section just behind the tip. The 0V or ground terminal is the main body connection. Use your multimeter to identify the jack plug terminals if you are unsure. To test the unit, plug it into the main unit, apply power, set the unit to Trigger mode and then return to the main RPM display. If a slotted disc (or some other opaque shape) is now rotated through the photo-interruptor, a reading should appear on the display. In addition, the strobe should flash each time the light path is interrupted. If this doesn’t happen, check your connections. In practice, this unit is intended to be used with a small slotted disk (see photo) that spins within the gap of the photo-interruptor (ie, the disk is driven by the rotating machinery). You will need to manufacture the disk to suit your application. The completed Photo-Interruptor siliconchip.com.au RE G GIRT LA CITP O E B ORTS 3.5mm PLUG A slotted disc attached to a shaft rotates through the slot in the photointerruptor, to interrupt the light path. The resulting pulses are then fed into the tacho unit. 0V TIP SLEEVE E RING 150 04107083 PHOTO INTERRUPTOR BOARD Fig.11 (above): make sure you get the photointerruptor the right way around when building the photointerruptor board (ie, diode symbol to the right). The PC board is mounted on Nylon standoffs, to avoid shorting the tracks. board can be attached to a fixed section the machine. Be sure to mount it using Nylon (not metal) spacers at the output end, to prevent shorts to the soldered joints. IR reflector amplifier This circuit is built on a PC board coded 04108084 and measuring 53 x 32mm. This is housed in a plastic utility box measuring 82 x 53 x 31mm. Fig.12 shows the assembly details. Begin by installing the resistors. Follow these with IC2, making sure it goes in with the correct orientation, then install the three electrolytic capacitors. Be sure to mount these capacitors with the correct polarity. Finally, complete the board assembly by installing the three PC stakes, the infrared LED (IRLED1) and the infrared photodiode (IRSENS1). Note that IRLED1 is mounted at full lead length, so that it can later be bent over horizontally to protrude through the side of the box. Take care with the orientation of both these parts. An accompanying photo shows how the board is mounted in its plastic case. It sits on four M3 x 6mm tapped Nylon spacers and is secured using M3 x 12mm countersink Nylon screws and M3 nuts. Two holes are drilled in one end of the box for the IR LED and photodiode, while another hole is drilled at the other end of the box to accept a cable gland. As before, the PC board is wired to a 3.5mm jack plug using 2-core shielded cable, with the earth shield used as the 0V (GND) connection – see Fig.7 last month. Once again, make sure you get the tip and ring connections correct. Testing the IR reflector board Having completed the assembly, the next step is to test the IR Reflector Amplifier board for correct operation. To do this, first plug it into the trigger input of the LED Strobe & Tachometer unit, then set the Trigger mode and return to the main RPM display. Now wave your hand in front of the sensor end of the IR Reflector box and check that the LCD shows an RPM reading. If this doesn’t happen, check your wiring connections. Note that as well as picking up reflected signals from IRLED1, the circuit will also detect signals from other infrared sources, such as incandescent lights running on the 50Hz mains. This means that RPM measurements are best done in natural light or subdued light. Measuring the RPM of a machine should be done with the sensor about 30-40mm away from the rotating shaft or fan. This means that you have to exercise a great deal of caution, to ensure that neither the sensor or any part of your body touches any moving parts. In complex situations, the best approach may be to mount this sensor unit in a fixed position before switching the machine on. In short, use your common sense. Note that as well as displaying the RPM value, the LCD also indicates rotation by displaying an Up or Down arrow that flashes on and off. Note also that it may be necessary to average the readings to account for slight TIP SLEEVE E 1k 3.5mm PLUG ebortS 470k 150 10k 480701140 100 F 1k IC2 LM358 100k RING 10 F 100 F IR SENS1 K A K A 100k IR LED1 150 IR REFLECTOR AMPLIFIER BOARD The IR reflector amplifier board must also be mounted on Nylon spacers, to avoid shorting tracks. siliconchip.com.au Fig.12: follow this diagram to build the IR reflector amplifier. Take care to ensure that IR SENS1 & IR LED1 are installed with the correct polarity. September 2008  77 Using White LEDs As Strobes: Busting A Myth B EFORE ATTEMPTING TO use a white LED as a strobe we had to be sure of its suitability. Initially, we had our doubts because we had read somewhere that white LEDs cannot be strobed at a fast rate. The reason given was that unlike coloured LEDs, white LEDs contain a phosphor and the persistence of this phosphor prevents them from switching on and off at a fast rate. One of the reasons behind this story is that most of the phosphors we are familiar with do have long persistence. These include those used in toys that glow for hours after being exposed to light and in fluorescent lights that continue to glow for a short time after being switched off. Similarly, some white LEDs do glow for a short period after the power is switched off. In this case, we wanted to use a Luxeon white LED as a strobe for this project so we set out to test its suitability. First, we checked the manufacturer’s data sheet and this specified less than 100ns for both the turn-on and turn-off periods. From this, it is clear that white Luxeon LEDs do indeed switch on and off very quickly and so would be quite suitable for our proposed strobe. How they’re made Further research on the web revealed that there are several ways in which white LEDs can be made. One way is to use red, green and blue LED chips and mix their outputs together to produce white light. These have a fast response because no phosphor is involved in converting the colour. Another way to achieve white light is to use a phosphor that converts the emission from a single colour LED into a white spectrum. There are two types, one based on a blue LED and the other on a near-ultraviolet LED. The blue-LED-based white LEDs use a speed variations while the machine is running. Using the strobe/tacho unit Each time you switch it on, the unit shows the main readout on the LCD. This will either be in Generator mode or Triggered mode, depending on the last selection. 78  Silicon Chip FTP100 phosphor that adds in colours to+5V ward the yellow end of the spec1k trum so that the combination of the blue light and the phosphor C E emission produces a white light. B C This construction is the most TO B FTP100  OSCILLOSCOPE common form used for white E LEDs. However, the phosphor 100 used does not phosphoresce but emits light by a process Fig.13: this simple phototransistor circuit called “scintillation”, an effect was used measure the response time CIRCUIT FORto MEASURING RESPONSE TIME OF of WHITE LED that has no light persistence. the white LED used in the strobe. The alternative white LED construction is not so comand a Cree XR-C white LED from 10% to mon and is based on a near UV LED 90% full brightness to be just 290ns which and a mixture of a red and blue emitting is really quite fast. The “fall-time” response phosphors plus a green emitting copper from 90% to 10% brightness was 360ns. and aluminium doped zinc sulphide. The Next, we wanted to make sure that emission works in a similar manner to were measuring the response time of the fluorescent lights. We do not have any phosphor rather than the light from the information about the response time for blue LED itself. To do this, we placed a these LED types but presumably these Polaroid red circular polarising filter over do have a long persistence. the white LED to block the blue spectrum For our strobe, we use the more comfrom the phototransistor. When we did this, mon blue-LED-based white LED. This the response times remained the same, type is manufactured by Luxeon, Cree although the amount of light available for and several others. the measurement diminished markedly. Measuring the response time This all means that the white LED response is very likely to be better than To further assess its suitability, we 100ns, just as the manufacturers claim. decided to measure the response time of The slower response times we measured a 1W Luxeon white LED. This was done are actually the phototransistor response using a phototransistor to detect the white times – ie, the phototransistor is slower light as shown in Fig.13. than the white LED. This circuit uses a low-value (1kW) From this, it is clear that the 1W white collector resistor to ensure that the photoLEDs specified are more than fast enough transistor switches on quickly. In addition, for strobe applications. However, one the 100W resistor from base to ground question remains: if white LEDs do have ensures that the phototransistor quickly a fast response, why do some continue switches off in the absence of light. to glow for a short time after the power is By pulsing the LED and monitoring this switched off? on one channel of a 200MHz oscilloscope, The main reason is because they are we could measure the response at the coloften driven by a supply with a filter capacilector of the phototransistor on the second tor and it takes time for the filter capacitor channel of the oscilloscope. We measured to discharge after switch off. the rise-time for both a 1W white Luxeon In Triggered mode, the LCD shows the RPM on the top line, then the word “Trig” and either an up or down arrow if there are incoming trigger signals from an external sensor. This arrow will flash on and off, with an up arrow displayed when rising edge triggering is selected and a down arrow when falling edge triggering is selected. The second line shows the frequen­ cy in Hz and following that the division ratio (ie, 0.5 and 1-8). An asterisk (*) on the far righthand side is displayed whenever the strobe is flashing correctly but is not displayed when the strobe LED is continuously lit (as happens when the flash period is longer than the time between flashes). siliconchip.com.au In the Generator mode, the display shows the RPM in the top line followed by the word “Gen”. The second line shows the frequency in Hz. As before, an asterisk (*) is shown on the righthand side when the strobe LED is flashing. In this mode, RPM adjustments are made using the Up and Down switches and the fine adjust potentiometer. The Up and Down switches adjust RPM in 100 RPM steps, while the potenti­ o­meter adjusts in 1 RPM steps over a 100 RPM range. Selection of either mode is made using the Mode switch. When pressed, the display shows ‘Trig/Gen’ on the top line and the selection (either ‘Gen or Trig’) on the second line. The selection is then made using the Up or Down switch. The Infrared Reflector Amplifier board is mounted in a small plastic case. Note how the IR sensor and IR LED are arranged. Options When the Generator mode is selected, a further press of the Mode switch brings up the “Flash Mode” option. This can be set to either “Automatic” or “Fixed” using the Up and Down switches. Pressing the Mode switch again brings up the “Flash Period” setting. If the “Fixed” mode is selected, the period can be adjusted from 32ms to 6.5ms in 25.4ms steps. The display shows the value in “ms” for readings less than 1000ms (1ms) and in ms for readings above 1ms. Note that because the flash period is fixed, it is possible for the frequency of the RPM signal to be high enough for the LED to stay fully lit (as indicated earlier), ie, when the unit is flashed at a faster rate than the update period. Correct operation is indicated by an asterisk (*) at the lower righthand side of the LCD. When the asterisk appears, the strobe is flashing. Conversely, if the strobe is lit continuously, the asterisk is off. If the Automatic mode is selected, then the display will show the automatic percentage value from 1-10% (ie, this is the strobe’s duty cycle). These value is altered using the Up and Down buttons. Press the Mode switch again returns the unit to the main tachometer display mode (showing RPM and frequency). Flash Mode, Flash Period and Averaging (of the reading). As before, these are selected using the Mode switch. First, the trigger edge can be set to either rising to falling. In this case, the LCD shows “Edge” on the top line, while the second line shows either “Rising” followed by an up arrow or “Falling” followed by a down arrow (depending on the selection). The Up and Down switches allow the setting to be changed. The Division selection allows the number of incoming trigger pulses to be divided by a set value, to give the correct reading on the LCD. When this is selected, the top line shows the word “Division”, while the second line shows the divide-by value. Division values of 0.5 and from 1-8 are available and are again selected using the Up and Down switches. For example, if you wanted to use the IR reflector sensor to measure the rotational speed of a 3-bladed fan, the division value would be set to three. The Flash Mode and Flash Period settings are adjusted in the same way as for the Generator mode. The Averaging mode is included to smooth out irregular measurements on a machine that is not running smoothly. You can average over 1-10 measurements and this is set using the Up and Down buttons. Higher averaging may be useful when the measured machine rotation varies markedly. Finally, when the main RPM and frequency reading is displayed, the strobe firing position can be altered using the Up or Down switches. Note that this feature is available only when the division is set to two or more. Using a Hall Effect sensor If you wish, you can use a Hall Effect trigger instead of the photointerruptor. As with the latter, this can be wired directly to the tachometer unit using 2-core shielded cable and a stereo 3.5mm jack plug. Note that the supply for the Hall effect sensor connects between the ring (+5V) and the ground 0V. The tip connection is for the Hall effect senSC sor’s output signal. Issues Getting Dog-Eared? Keep your copies safe with these handy binders Trigger mode 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. The Trigger mode allows even more selections. These are Edge, Division, Buy five and get them postage free! siliconchip.com.au REAL VALUE AT $13.95 PLUS P&P September 2008  79 Vintage Radio By RODNEY CHAMPNESS, VK3UG The Raycophone BroadcastBand “Pee-Wee” Midget Manufactured by Raycophone around 1933, the Pee-Wee Midget is an early superhet receiver with a regenerative IF stage. It’s an interesting set but is does have a few design problems that limit its performance. I N THE 1920s and into the early 1930s, tuned radio frequency (TRF) receivers were the norm. Experimenters and manufacturers were still feeling their way with radio receiver design and felt comfortable with TRF circuits despite their increasingly obvious limitations. 80  Silicon Chip By then, however, the more adventuresome were experimenting with superheterodyne receivers. In fact, a few superhets such as the RCA 26 (see SILICON CHIP, August 2008) were already being sold in Australia and overseas. Despite this, superhets were very thin on the ground, as very few people understood this “tricky” new technology. The Raycophone company One interesting Australian company at that time was Raycophone Pty Ltd. This company was run by Raymond Allsop who was both the director and siliconchip.com.au the chief engineer. Radio was just one aspect of his involvement with electronics, his main interest being with sound movie equipment in the pre-WW2 era. At that time, Raycophone was still relatively unknown as far as radio was concerned. And despite some considerable research, I have been unable to discover when they commenced operation and when they closed. The only reference to the production of radio receivers is in the “Radio Trade Annual and Service Manual” for 1939, which contains circuits and rudimentary technical information on several receivers produced by Raycophone in 1933. However, I have been unable to find any circuits in the “Australian Official Radio Service Manuals”. Raycophone Pty Ltd was located at Booth and Trafalgar Streets, Annandale, NSW. During WW2, they produced Fortress amplifiers, signalling lamps, anti-submarine equipment, movie (sound) projectors and cathoderay oscillographs. As an aside, Raycophone projectors are still in use at a cinema in Swanpool (a small township south of Benalla in Victoria), even though they were built in 1948. The Raycophone “Pee-Wee” is a compact unit that’s housed in an attractive wooden cabinet. The lack of a dial and indistinct markings around the tuning knob makes it difficult to tune to a wanted station. The Raycophone “Pee-Wee” I first saw a circuit of this 1933 receiver several years ago and wondered whether I would ever see one. Recently, however, I found out that one of our local vintage radio club members had a working unit and he readily agreed to lend it to me. As shown in the photos, the set is installed in a fairly small cabinet which is made of quite heavy timber. The cabinet is quite attractive when viewed as a mantel receiver, although the underside of the cabinet is untreated bare timber. It would have been better if some small buffers had been fastened to the bottom of the cabinet, so that it could be made to look like the rest of the cabinet. The front of the receiver is quite attractive, with the speaker in the centre and two controls (tuning and volume) either side of it. In this set, the tuning control is on the left and the volume control on the right, which is the opposite to that used on other sets (the right hand is normally used for tuning). Both controls have some indistinct lettering near them. siliconchip.com.au The chassis is easy to remove but care must be taken to avoid damaging the under-chassis components.The parts mounted on the top of the chassis are all easily accessible. Strangely enough, the volume control is wired to increase in volume as it is turned anti-clockwise, which is somewhat annoying. The tuning control is fitted with a medium sized knob. This is connected directly to the shaft of the tuning gang, which makes tuning rather critical. There are no markings on the knob and this, coupled with the indistinct markings on the surround, further complicates tuning. Basically, it’s impossible to know what station or part of the band the set is tuned too. A glance inside the cabinet shows that there is little spare space, with the components squeezed quite close together. It’s easy to remove the chassis from the cabinet, however. All you have to do is remove the two knobs and four bolts on the underside of the cabinet. The chassis then slides out. September 2008  81 Fig.1: the circuit is a 4-valve superhet with the first stage functioning as an autodyne converter (ie, it functions as both a local oscillator and a mixer). The components used in the early 1930s were quite large by today’s standards. As a result, the large components mounted on top of the chassis nearly fill all the available space. Most of the components on the underside of the chassis are mounted on a large component board. This is neatly done but it does make it difficult to access the valve pins underneath it without first disconnecting quite a few leads. The aerial and oscillator coils and the regenerative intermediate frequency (IF) transformer are all located under the chassis. None of them are shielded in any way and care must be taken to ensure that none of their leads are broken when working on the set. Circuit details Fig.1 shows the circuit details of the receiver. Basically, the Pee-Wee was an “austerity-model” 4-valve receiver built towards the end of the depression of the 1930s. The set’s basic circuit design was commonly called a “SuperGainer” in amateur radio circles. As shown in Fig.1, the signal from the tuned antenna circuit is presented to the grid of a 57 pentode. This functions as an autodyne converter stage – ie, it functions as both a local oscillator and a mixer. 82  Silicon Chip Note that because the valve is being used as an autodyne converter, its cathode resistor (R1) is considerably higher than it would be if the valve was simply configured for RF amplification. The IF output from this stage is at 465kHz and this is fed to an IF transformer. It is then fed via a potentiometer to a second 57 valve which functions as a fixed tuned regenerative detector. The potentiometer functions as the volume control (V.C.). In operation, variable capacitor C5 feeds back a portion of the amplified RF signal (ie, from the plate), which is then re-amplified. This capacitor is adjusted so that the receiver does not go into oscillation due to excessive feedback when the volume control is fully anti-clockwise. In addition, the audio signal on the plate of the second 57 is fed out via R4 and C9 to the 2A5 audio output valve. Note that R4 and C7 act as an RF attenuator to prevent IF signals getting into the audio output stage. The 2A5 is connected as a conventional cathode-biased audio output stage. It drives a 5-inch (127mm) electrodynamic loudspeaker via a speaker transformer. The power supply is quite conventional with two filament windings, one at 2.5V and the other at 5V. The high-voltage secondary drives either an 80 or a 280 rectifier valve. This functions as a full-wave rectifier with two 8mF electrolytic capacitors and the speaker’s field coil filtering the rectifier’s output. Restoration As supplied to me, the receiver had only quite recently been restored to working order. The cabinet had also had work done it and looked to be in good order. The circuit details indicate that all but one of the low-value fixed capacitors are mica types but they are, in fact, mostly paper types. As usual, they were all quite leaky and had been replaced, some with polyester types and others with silver mica capacitors. The electrolytic capacitors had also been replaced. However, the high-voltage chassis-mount units had been left in-situ to maintain the above-chassis appearance. Instead, they had simply been disconnected and replaced with much smaller modern pigtail types mounted under the chassis. A couple of out-of-tolerance resistors had been replaced as well. Finally, a new 3-core power cord had been fitted and anchored into position. At this stage, I decided to apply siliconchip.com.au The parts are laid out quite neatly under the chassis but the long component strip is difficult to remove. This means that the parts under it can only be accessed for service after a lot of work. power and see how well the set performed. Well, it worked but not as well as expected. Even local stations were quite weak and the set oscillated in many places across the broadcast band. Troubleshooting It was time for some troubleshooting. First, I checked the “start-up” voltage at the output of the rectifier and got a rather unpleasant surprise. During warm-up, the voltage on the electrolytic capacitors rose to just over 500V. However, one of the electrolytics fitted was rated at 350V, while the other had a 450V rating (the person who originally drew up the circuit diagram had neglected to note any of the voltages expected within the receiver). I certainly could not leave those capacitors in circuit or a rather dramatic failure would occur within a short period of time. Unfortunately, I didn’t have any 8mF 500V capacitors but I did have some 4.7mF 500V capacitors. I placed one 4.7mF capacitor on the output of the 80 rectifier and connected another two in parallel across the HT line after the field coil. Note that the voltage ratings of the capacitors that had been fitted were quite adequate once the set had commenced operating. Directly heated rectifiers like the 80, 5Y3GT, etc are operational within a couple of seconds of switch on. By contrast, indirectly heated valves take up to around 15 seconds to start to draw current and during this time there is no voltage drop to speak of into MICROS OR PICS? There’s There’s asomething reference to to suit suit every every microcontroller maestro in the SILICON CHIP reference bookshop: see the bookshop pages in this issue Microcontroller Projects in C – by Dogan Ibrahim Graded projects introduce microelectronics, the 8051 and $ 8100 programming in C. Programming 16-Bit Microcontrollers in C – by Luci Di Jasio Learning to fly the PIC24. Includes a CD ROM with source code in C, Microchip C30 complier $ 8050 and MPLAB SIM. Hands-On ZigBee – by Fred Eady An in-depth look at the clever little 2.4GHz wireless ZigBee chip that’s now being found in a wide range $ equipment from 9650 of consumer to industrial. PIC in Practice – by DW Smith Ideal introduction to PICs. Based on popular short courses for the PIC for professionals, techs, hobbyists, $ 60 students and teachers. PIC Microcontroller – know it all ( Newnes) Newnes have put together the best of subjects their authors have written on over the past few years $ 7995 into this one handy volume! The PIC Micro – personal intro course – by John Morton A very practical guide which assumes no prior knowledge. So it is an introduction to the widely$ 52 ideal used PIC micro. ! Audio ! RF ! Digital ! Analog ! TV ! Video ! Power Control ! Motors ! Robots ! Drives ! Op Amps ! Satellite siliconchip.com.au September 2008  83 There’s not much room left inside the cabinet when the chassis is slid into place, although the valves can still be replaced. Note the thickness of the timber used to make the cabinet. across the rectifier or across components such as the field coil. This means that the peak voltage that the supply can deliver on no-load is substantially more than the loaded voltage. It is therefore necessary to allow for the very high start-up voltage which occurs at switch-on. Curing the instability The instability (oscillation) problems in the RF sections of the receiver proved difficult to fix. And although I have made major improvements, I have not been 100% successful. First, resistor R1 had previously been replaced with a wirewound unit which would be inductive. As a result, I replaced it with a carbon resistor and this reduced the instability somewhat with the set no longer oscillating at all times in certain locations. Next, I tried adding extra filter capacitors to the HT line for both 57 valves and this gave a further slight improvement in one of the locations (ie, to the first 57). I then tried swapping the two 57 valves but this made no difference. My next step was to examine the set’s earthing arrangement. This revealed that all stages are earthed via an insulated lead that runs from one end of the chassis to the other. That meant that the RF section was earthed at the furthest end of the chassis and I felt that this could be contributing to instability problems. As a result, I separated the earth wire part way along the component strip board. The front-end was then directly earthed to chassis near the converter stage, using a much shorter lead. This simple modification again improved the stability but it still wasn’t the complete answer. Alignment checks This view shows the unshielded 465kHz IF transformer windings. The leads are easily damaged when the chassis is removed. 84  Silicon Chip Next, I took a look at the alignment and this proved to be a bit of a mess, probably due to the age of the set. The problem here is that none of the coils can be adjusted, as iron-dust adjustments slugs were still to become popular when this set was made. The receiver tuned from around 5501500kHz and I extended this to around 1550kHz to cater for a local station. In practice, the set will tune to above 1700kHz if the oscillator trimmer capacitor is reduced almost to its minimum value. However, the aerial stage cannot be peaked for best performance if this is done. This led me to suspect that the aerial coil had too much inductance. The wire used to wind this coil is quite fine and its location makes it difficult work on without risking damage, so I decided to leave it alone. In the past, I’ve noticed that coil inductance can increase in some very old sets, perhaps due to moisture ingress into the coil former. As a result, the alignment of the aerial and oscillator coils in this set are a bit of a compromise. The secondary winding of the IF transformer also gave quite a broad response, with only a slight peak. However, the owner had fitted a 50kW volume control potentiometer across the winding in place of the 500kW unit that had originally been fitted. Initially, I reasoned (incorrectly) that the lower resistance would damp out any tendency for the stage to oscillate, as I couldn’t turn C5 to reduce the regeneration feedback. I was wrong and after fitting a 500kW potentiometer, the IF winding peaked nicely and the set’s tendency to oscillate dropped dramatically. However, it would still oscillate on some stations and it turned out that there were further problems, which came to light later. Special potentiometer The original potentiometer was apparently a special unit and was possibly an anti-log type. However, I didn’t have a direct replacement. With some of the potentiometers I tried, earthing the frame (ie, when the pot was mounted) reduced the performance of the set. Apparently, the tuning of the IF transformer’s secondary was being affected by the capacitance between the potentiometer’s elements and its frame (which is earthed). In addition, only a very small portion of the pot’s travel was having any effect on the volume. In the end, I decided to go back to the 50kW potentiometer and install a 390kW resistor in series with its siliconchip.com.au “earthy end. This arrangement gave 440kW of resistance across the winding and allowed the pot to vary the volume over almost all of its travel. As before, I found that earthing the frame of the potentiometer had the undesired effect of reducing the volume. As a result, I insulated the pot’s frame from the chassis using insulated washers and an O-ring. I then retuned the secondary winding of the IF transformer and this fixed the problem. It’s worth noting that conventional potentiometers are not rated for RF work so it was not surprising that I struck this problem. Following these modifications, the set is now probably performing as well as it did when new. However, it is very much an “austerity receiver” and its performance is only reasonable. It has no AGC so the volume control has to be manually adjusted to reset the level when tuning between weak and strong stations. In practice, weak stations are not worth listening to, although the set would probably work better if the aerial coil had the right inductance. What’s more, it still shows signs of instability when tuned to some stations. Photo Gallery: Philips Model 112E Receiver Made in the Philips’ South Australian factory in 1949, the Model 112E was a 4-valve mantel set housed in a pale-blue bakelite cabinet. An unusual feature was the dial glass which protruded from the top of the set. The valve line-up was as follows: 6X5GT rectifier, ECH35 converter, EBF35 IF amplifier and EL33a audio output valve. This radio was restored by Tony Lightfoot of the HRSA. Photo by Kevin Poulter. Summary The Raycophone “Pee Wee” is an interesting little set but like most “austerity receivers”, its performance is nothing remarkable. I have always been interested in superhets that use a regenerative IF stage and they can perform quite well if properly designed and constructed. In this set, direct access to parts under the component strip is almost impossible (unless the strip is removed). This can make servicing it difficult. In addition, the clearance between the bottom of the chassis lip and many of the parts mounted under the chassis is only a millimetre or so. The coils in particular are quite vulnerable to damage when sliding the chassis in and out of the cabinet. Another problem is that some sections of the set that are working at RF have quite long leads, This is bad design practice and can cause instability. The tuning is also quite touchy due to the direct-drive coupling and the relatively small control knob. This is made worse by the lack of a tuning indicator. With more thought given to its design and component layout, this little set could have been much better than it is, both in terms of stability and overall performance. It could have been made easier to service as well. In summary, the Raycophone Pee Wee has a number of design inadequacies that compromise its performance and make it difficult to use SC and service. into VIDEO/TV/RF? Television & Video Technology – by KF Ibrahim New edition has a full and comprehensive guide to video and TV technology including HDTV 50 and DVD, starting with $ 60 fundamentals. DVD Players and Drives – by KF Ibrahim DVD technology and applications ideal for engineers, technicians, students, installation and $ 85 sales staff. Practical Guide To Satellite TV – by Garry Cratt There’s something to suit every RF fan in the SILICON CHIP reference bookshop: see the bookshop pages in this issue RF Circuit Design The book written by an Aussie for Aussie conditions. Everything you need to know – including what you cannot do! $ – by Chris Bowick A new edition of this classic RF design text - tells how to design and $ RF components into 67 integrate virtually any circuitry. Hands-On Zigbee Practical RF H’book 49 – by Fred Eady An in-depth look at the clever little 2.4GHz wireless chip that’s starting to be found in a wide range of $ from 9650 equipment consumer to industrial. – by Ian Hickman A reference work for technicians, engineers, students and the more specialised enthusiast. Covers the key topics in RF that $ 80 all you need to understand. ! Audio ! RF ! Digital ! Analog ! TV ! Video ! Power Control ! Motors ! Robots ! Drives ! Op Amps ! Satellite siliconchip.com.au September 2008  85 Silicon Chip Back Issues January 1994: 3A 40V Variable Power Supply; Solar Panel Switching Regulator; Printer Status Indicator; Mini Drill Speed Controller; Stepper Motor Controller; Active Filter Design; Engine Management, Pt.4. August 1996: Introduction to IGBTs; Electronic Starter For Fluores­cent Lamps; VGA Oscilloscope, Pt.2; 350W Amplifier Module; Masthead Amplifier For TV & FM; Cathode Ray Oscilloscopes, Pt.4. February 1994:90-Second Message Recorder; 12-240VAC 200W Inverter; 0.5W Audio Amplifier; 3A 40V Adjustable Power Supply; Engine Management, Pt.5; Airbags In Cars – How They Work. September 1996: VGA Oscilloscope, Pt.3; IR Stereo Headphone Link, Pt.1; HF Amateur Radio Receiver; Cathode Ray Oscilloscopes, Pt.5. March 1994: Intelligent IR Remote Controller; 50W (LM3876) Audio Amplifier Module; Level Crossing Detector For Model Railways; Voice Activated Switch For FM Microphones; Engine Management, Pt.6. April 1994: Sound & Lights For Model Railway Level Crossings; Dual Supply Voltage Regulator; Universal Stereo Preamplifier; Digital Water Tank Gauge; Engine Management, Pt.7. May 1994: Fast Charger For Nicad Batteries; Induction Balance Metal Locator; Multi-Channel Infrared Remote Control; Dual Electronic Dice; Simple Servo Driver Circuits; Engine Management, Pt.8. June 1994: A Coolant Level Alarm For Your Car; 80-Metre AM/CW Transmitter For Amateurs; Converting Phono Inputs To Line Inputs; PC-Based Nicad Battery Monitor; Engine Management, Pt.9. July 1994: Build A 4-Bay Bow-Tie UHF TV Antenna; PreChamp 2-Transistor Preamplifier; Steam Train Whistle & Diesel Horn Simulator; 6V SLA Battery Charger; Electronic Engine Management, Pt.10. August 1994: High-Power Dimmer For Incandescent Lights; Dual Diversity Tuner For FM Microphones, Pt.1; Nicad Zapper (For Resurrecting Nicad Batteries); Electronic Engine Management, Pt.11. September 1994: Automatic Discharger For Nicad Batteries; MiniVox Voice Operated Relay; AM Radio For Weather Beacons; Dual Diversity Tuner For FM Mics, Pt.2; Electronic Engine Management, Pt.12. October 1994: How Dolby Surround Sound Works; Dual Rail Variable Power Supply; Talking Headlight Reminder; Electronic Ballast For Fluorescent Lights; Electronic Engine Management, Pt.13. November 1994: Dry Cell Battery Rejuvenator; Novel Alphanumeric Clock; 80-M DSB Amateur Transmitter; 2-Cell Nicad Discharger. December 1994: Car Burglar Alarm; Three-Spot Low Distortion Sinewave Oscillator; Clifford – A Pesky Electronic Cricket; Remote Control System for Models, Pt.1; Index to Vol.7. January 1995: Sun Tracker For Solar Panels; Battery Saver For Torches; Dual Channel UHF Remote Control; Stereo Microphone Pre­amp­lifier. February 1995: 2 x 50W Stereo Amplifier Module; Digital Effects Unit For Musicians; 6-Channel LCD Thermometer; Wide Range Electrostatic Loudspeakers, Pt.1; Remote Control System For Models, Pt.2. March 1995: 2 x 50W Stereo Amplifier, Pt.1; Subcarrier Decoder For FM Receivers; Wide Range Electrostatic Loudspeakers, Pt.2; IR Illuminator For CCD Cameras; Remote Control System For Models, Pt.3. October 1996: Send Video Signals Over Twisted Pair Cable; 600W DC-DC Converter For Car Hifi Systems, Pt.1; IR Stereo Headphone Link, Pt.2; Multi-Channel Radio Control Transmitter, Pt.8. November 1996: 8-Channel Stereo Mixer, Pt.1; Low-Cost Fluorescent Light Inverter; Repairing Domestic Light Dimmers.. December 1996: Active Filter For CW Reception; Fast Clock For Railway Modellers; Laser Pistol & Electronic Target; Build A Sound Level Meter; 8-Channel Stereo Mixer, Pt.2; Index To Vol.9. January 1997: Control Panel For Multiple Smoke Alarms, Pt.1; Build A Pink Noise Source; Computer Controlled Dual Power Supply, Pt.1; Digi-Temp Thermometer (Monitors Eight Temperatures). February 1997: PC-Con­trolled Moving Message Display; Computer Controlled Dual Power Supply, Pt.2; Alert-A-Phone Loud Sounding Telephone Alarm; Control Panel For Multiple Smoke Alarms, Pt.2. January 1999: High-Voltage Megohm Tester; A Look At The BASIC Stamp; Bargraph Ammeter For Cars; Keypad Engine Immobiliser. March 1999: Build A Digital Anemometer; DIY PIC Programmer; Build An Audio Compressor; Low-Distortion Audio Signal Generator, Pt.2. April 1999: Getting Started With Linux; Pt.2; High-Power Electric Fence Controller; Bass Cube Subwoofer; Programmable Thermostat/ Thermometer; Build An Infrared Sentry; Rev Limiter For Cars. May 1999: The Line Dancer Robot; An X-Y Table With Stepper Motor Control, Pt.1; Three Electric Fence Testers; Carbon Monoxide Alarm. June 1999: FM Radio Tuner Card For PCs; X-Y Table With Stepper Motor Control, Pt.2; Programmable Ignition Timing Module For Cars, Pt.1. July 1999: Build A Dog Silencer; 10µH to 19.99mH Inductance Meter; Audio-Video Transmitter; Programmable Ignition Timing Module For Cars, Pt.2; XYZ Table With Stepper Motor Control, Pt.3. August 1999: Remote Modem Controller; Daytime Running Lights For Cars; Build A PC Monitor Checker; Switching Temperature Controller; XYZ Table With Stepper Motor Control, Pt.4; Electric Lighting, Pt.14. September 1999: Autonomouse The Robot, Pt.1; Voice Direct Speech Recognition Module; Digital Electrolytic Capacitance Meter; XYZ Table With Stepper Motor Control, Pt.5; Peltier-Powered Can Cooler. October 1999: Build The Railpower Model Train Controller, Pt.1; Semiconductor Curve Tracer; Autonomouse The Robot, Pt.2; XYZ Table With Stepper Motor Control, Pt.6; Introducing Home Theatre. March 1997: 175W PA Amplifier; Signalling & Lighting For Model Railways; Jumbo LED Clock; Cathode Ray Oscilloscopes, Pt.7. November 1999: Setting Up An Email Server; Speed Alarm For Cars, Pt.1; LED Christmas Tree; Intercom Station Expander; Foldback Loudspeaker System; Railpower Model Train Controller, Pt.2. April 1997: Simple Timer With No ICs; Digital Voltmeter For Cars; Loudspeaker Protector For Stereo Amplifiers; Model Train Controller; A Look At Signal Tracing; Pt.1; Cathode Ray Oscilloscopes, Pt.8. December 1999: Solar Panel Regulator; PC Powerhouse (gives +12V, +9V, +6V & +5V rails); Fortune Finder Metal Locator; Speed Alarm For Cars, Pt.2; Railpower Model Train Controller, Pt.3; Index To Vol.12. May 1997: Neon Tube Modulator For Light Systems; Traffic Lights For A Model Intersection; The Spacewriter – It Writes Messages In Thin Air; A Look At Signal Tracing; Pt.2; Cathode Ray Oscilloscopes, Pt.9. January 2000: Spring Reverberation Module; An Audio-Video Test Generator; Parallel Port Interface Card; Telephone Off-Hook Indicator. June 1997: PC-Controlled Thermometer/Thermostat; TV Pattern Generator, Pt.1; Audio/RF Signal Tracer; High-Current Speed Controller For 12V/24V Motors; Manual Control Circuit For Stepper Motors. July 1997: Infrared Remote Volume Control; A Flexible Interface Card For PCs; Points Controller For Model Railways; Colour TV Pattern Generator, Pt.2; An In-Line Mixer For Radio Control Receivers. October 1997: 5-Digit Tachometer; Central Locking For Your Car; PCControlled 6-Channel Voltmeter; 500W Audio Power Amplifier, Pt.3. November 1997: Heavy Duty 10A 240VAC Motor Speed Controller; Easy-To-Use Cable & Wiring Tester; Build A Musical Doorbell; Replacing Foam Speaker Surrounds; Understanding Electric Lighting Pt.1. December 1997: Speed Alarm For Cars; 2-Axis Robot With Gripper; Stepper Motor Driver With Onboard Buffer; Power Supply For Stepper Motor Cards; Understanding Electric Lighting Pt.2; Index To Vol.10. February 2000: Multi-Sector Sprinkler Controller; A Digital Voltmeter For Your Car; Safety Switch Checker; Sine/Square Wave Oscillator. March 2000: Resurrecting An Old Computer; 100W Amplifier Module, Pt.1; Electronic Wind Vane With 16-LED Display; Build A Glowplug Driver. May 2000: Ultra-LD Stereo Amplifier, Pt.2; LED Dice (With PIC Microcontroller); 50A Motor Speed Controller For Models. June 2000: Automatic Rain Gauge; Parallel Port VHF FM Receiver; Switchmode Power Supply (1.23V to 40V) Pt.1; CD Compressor. July 2000: Moving Message Display; Compact Fluorescent Lamp Driver; Musicians’ Lead Tester; Switchmode Power Supply, Pt.2. August 2000: Theremin; Spinner (writes messages in “thin-air”); Proximity Switch; Structured Cabling For Computer Networks. January 1998: 4-Channel 12VDC or 12VAC Lightshow, Pt.1; Command Control For Model Railways, Pt.1; Pan Controller For CCD Cameras. September 2000: Swimming Pool Alarm; 8-Channel PC Relay Board; Fuel Mixture Display For Cars, Pt.1; Protoboards – The Easy Way Into Electronics, Pt.1; Cybug The Solar Fly. February 1998: Telephone Exchange Simulator For Testing; Command Control For Model Railways, Pt.2; 4-Channel Lightshow, Pt.2. October 2000: Guitar Jammer; Breath Tester; Wand-Mounted Inspection Camera; Subwoofer For Cars; Fuel Mixture Display, Pt.2. May 1995: Guitar Headphone Amplifier; FM Radio Trainer, Pt.2; Transistor/Mosfet Tester For DMMs; A 16-Channel Decoder For Radio Remote Control; Introduction To Satellite TV. April 1998: Automatic Garage Door Opener, Pt.1; 40V 8A Adjustable Power Supply, Pt.1; PC-Controlled 0-30kHz Sinewave Generator; Understanding Electric Lighting; Pt.6. November 2000: Santa & Rudolf Chrissie Display; 2-Channel Guitar Preamplifier, Pt.1; Message Bank & Missed Call Alert; Protoboards – The Easy Way Into Electronics, Pt.3. June 1995: Build A Satellite TV Receiver; Train Detector For Model Railways; 1W Audio Amplifier Trainer; Low-Cost Video Security System; Multi-Channel Radio Control Transmitter For Models, Pt.1. May 1998: 3-LED Logic Probe; Garage Door Opener, Pt.2; Command Control System, Pt.4; 40V 8A Adjustable Power Supply, Pt.2. December 2000: Home Networking For Shared Internet Access; White LED Torch; 2-Channel Guitar Preamplifier, Pt.2 (Digital Reverb); Driving An LCD From The Parallel Port; Index To Vol.13. April 1995: FM Radio Trainer, Pt.1; Balanced Mic Preamp & Line Filter; 50W/Channel Stereo Amplifier, Pt.2; Wide Range Electrostatic Loudspeakers, Pt.3; 8-Channel Decoder For Radio Remote Control. July 1995: Electric Fence Controller; How To Run Two Trains On A Single Track (Incl. Lights & Sound); Setting Up A Satellite TV Ground Station; Build A Reliable Door Minder. June 1998: Troubleshooting Your PC, Pt.2; Universal High Energy Ignition System; The Roadies’ Friend Cable Tester; Universal Stepper Motor Controller; Command Control For Model Railways, Pt.5. August 1995: Fuel Injector Monitor For Cars; A Gain Controlled Microphone Preamp; Identifying IDE Hard Disk Drive Parameters. July 1998: Troubleshooting Your PC, Pt.3; 15W/Ch Class-A Audio Amplifier, Pt.1; Simple Charger For 6V & 12V SLA Batteries; Auto­ matic Semiconductor Analyser; Understanding Electric Lighting, Pt.8. September 1995: Railpower Mk.2 Walkaround Throttle For Model Railways, Pt.1; Keypad Combination Lock; Build A Jacob’s Ladder Display. August 1998: Troubleshooting Your PC, Pt.4; I/O Card With Data Logging; Beat Triggered Strobe; 15W/Ch Class-A Stereo Amplifier, Pt.2. October 1995: 3-Way Loudspeaker System; Railpower Mk.2 Walkaround Throttle For Model Railways, Pt.2; Nicad Fast Charger. September 1998: Troubleshooting Your PC, Pt.5; A Blocked Air-Filter Alarm; Waa-Waa Pedal For Guitars; Jacob’s Ladder; Gear Change Indicator For Cars; Capacity Indicator For Rechargeable Batteries. November 1995: Mixture Display For Fuel Injected Cars; CB Trans­verter For The 80M Amateur Band, Pt.1; PIR Movement Detector. October 1998: AC Millivoltmeter, Pt.1; PC-Controlled Stress-O-Meter; Versatile Electronic Guitar Limiter; 12V Trickle Charger For Float Conditions; Adding An External Battery Pack To Your Flashgun. May 1996: High Voltage Insulation Tester; Knightrider LED Chaser; Simple Intercom Uses Optical Cable; Cathode Ray Oscilloscopes, Pt.3. June 1996: Stereo Simulator (uses delay chip); Rope Light Chaser; Low Ohms Tester For Your DMM; Automatic 10A Battery Charger. July 1996: VGA Digital Oscilloscope, Pt.1; Remote Control Extender For VCRs; 2A SLA Battery Charger; 3-Band Parametric Equaliser. November 1998: The Christmas Star; A Turbo Timer For Cars; Build A Poker Machine, Pt.1; FM Transmitter For Musicians; Lab Quality AC Millivoltmeter, Pt.2; Improving AM Radio Reception, Pt.1. December 1998: Engine Immobiliser Mk.2; Thermocouple Adaptor For DMMs; Regulated 12V DC Plugpack; Build A Poker Machine, Pt.2; Improving AM Radio Reception, Pt.2; Mixer Module For F3B Gliders. How To Order: 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. Price: $A9.50 each (icl. GST) in Australia or $A13 each overseas. Prices include postage and packing. Email: silicon<at>siliconchip.com.au 86  Silicon Chip 10% OF SUBSCR F TO IB OR IF Y ERS OU 10 OR M BUY ORE January 2001: How To Transfer LPs & Tapes To CD; The LP Doctor – Clean Up Clicks & Pops, Pt.1; Arbitrary Waveform Generator; 2-Channel Guitar Preamplifier, Pt.3; PIC Programmer & TestBed. February 2001: An Easy Way To Make PC Boards; L’il Pulser Train Controller; A MIDI Interface For PCs; Build The Bass Blazer; 2-Metre Groundplane Antenna; LP Doctor – Clean Up Clicks & Pops, Pt.2. March 2001: Making Photo Resist PC Boards; Big-Digit 12/24 Hour Clock; Parallel Port PIC Programmer & Checkerboard; Protoboards – The Easy Way Into Electronics, Pt.5; A Simple MIDI Expansion Box. April 2001: A GPS Module For Your PC; Dr Video – An Easy-To-Build Video Stabiliser; Tremolo Unit For Musicians; Minimitter FM Stereo Transmitter; Intelligent Nicad Battery Charger. May 2001: 12V Mini Stereo Amplifier; Two White-LED Torches To Build; PowerPak – A Multi-Voltage Power Supply; Using Linux To Share An Internet Connection, Pt.1; Tweaking Windows With TweakUI. June 2001: Universal Battery Charger, Pt.1; Phonome – Call, Listen In & Switch Devices On & Off; Low-Cost Automatic Camera Switcher; Using Linux To Share An Internet Connection, Pt.2. July 2001: The HeartMate Heart Rate Monitor; Do Not Disturb Tele­ phone Timer; Pic-Toc – A Simple Alarm Clock; Fast Universal Battery Charger, Pt.2; Backing Up Your Email. August 2001: DI Box For Musicians; 200W Mosfet Amplifier Module; Headlight Reminder; 40MHz 6-Digit Frequency Counter Module; Using Linux To Share An Internet Connection, Pt.3. September 2001: Making MP3s; Build An MP3 Jukebox, Pt.1; PCControlled Mains Switch; Personal Noise Source For Tinnitus; Directional Microphone; Using Linux To Share An Internet Connection, Pt.4. November 2001: Ultra-LD 100W/Channel Stereo Amplifier, Pt.1; Neon siliconchip.com.au Tube Modulator For Cars; Audio/Video Distribution Amplifier; Build A Short Message Recorder Player; Useful Tips For Your PC. December 2001: Infrared Transceiver For PCs; 100W/Channel Stereo Amplifier, Pt.2; Pardy Lights Colour Display; PIC Fun – Learning About Micros. January 2002: Touch And/Or Remote-Controlled Light Dimmer, Pt.1; A Cheap ’n’Easy Motorbike Alarm; 100W /Channel Stereo Amplifier, Pt.3; Build A Raucous Alarm; FAQs On The MP3 Jukebox. February 2002: 10-Channel IR Remote Control Receiver; 2.4GHz High-Power Audio-Video Link; Touch And/Or Remote-Controlled Light Dimmer, Pt.2; Booting A PC Without A Keyboard; 4-Way Event Timer. March 2002: Mighty Midget Audio Amplifier Module; 6-Channel IR Remote Volume Control, Pt.1; RIAA Pre­-­Amplifier For Magnetic Cartridges; 12/24V Intelligent Solar Power Battery Charger. April 2002:Automatic Single-Channel Light Dimmer; Pt.1; Water Level Indicator; Multiple-Output Bench Power Supply; Versatile Multi-Mode Timer; 6-Channel IR Remote Volume Control, Pt.2. May 2002: 32-LED Knightrider; The Battery Guardian (Cuts Power When the Battery Voltage Drops); Stereo Headphone Amplifier; Automatic Single-Channel Light Dimmer; Pt.2; Stepper Motor Controller. August 2002: Digital Instrumentation Software For PCs; Digital Storage Logic Probe; Digital Therm./Thermostat; Sound Card Interface For PC Test Instruments; Direct Conversion Receiver For Radio Amateurs. September 2002: 12V Fluorescent Lamp Inverter; 8-Channel Infrared Remote Control; 50-Watt DC Electronic Load; Spyware – An Update. June 2004: Dr Video Mk.2 Video Stabiliser; Build An RFID Security Module; Simple Fridge-Door Alarm; Courtesy Light Delay For Cars; Automating PC Power-Up; Upgraded Software For The EPROM Programmer. July 2004: Silencing A Noisy PC; Versatile Battery Protector; Appliance Energy Meter, Pt.1; A Poor Man’s Q Meter; Regulated High-Voltage Supply For Valve Amplifiers; Remote Control For A Model Train Layout. October 2006: Thomas Alva Edison – Genius, Pt.2; LED Tachometer With Dual Displays, Pt.1; UHF Prescaler For Frequency Counters; Infrared Remote Control Extender; Picaxe Net Server, Pt.2; Easy-ToBuild 12V Digital Timer Module; Build A Super Bicycle Light Alternator. August 2004: Video Formats: Why Bother?; VAF’s New DC-X Generation IV Loudspeakers; Video Enhancer & Y/C Separator; Balanced Microphone Preamp; Appliance Energy Meter, Pt.2; 3-State Logic Probe. November 2006: Radar Speed Gun, Pt.1; Build Your Own Compact Bass Reflex Loudspeakers; Programmable Christmas Star; DC Relay Switch; LED Tachometer With Dual Displays, Pt.2; Picaxe Net Server, Pt.3. September 2004: Voice Over IP (VoIP) For Beginners; WiFry – Cooking Up 2.4GHz Antennas; Bed Wetting Alert; Build a Programmable Robot; Another CFL Inverter. December 2006: Bringing A Dead Cordless Drill Back To Life; Cordless Power Tool Charger Controller; Build A Radar Speed Gun, Pt.2; Heartbeat CPR Training Beeper; Super Speedo Corrector; 12/24V Auxiliary Battery Controller; Picaxe Net Server, Pt.3. October 2004: The Humble “Trannie” Turns 50; SMS Controller, Pt.1; RGB To Component Video Converter; USB Power Injector; Remote Controller For Garage Doors & Gates. November 2004: 42V Car Electrical Systems; USB-Controlled Power Switch (Errata Dec. 2004); Charger For Deep-Cycle 12V Batteries, Pt.1; Driveway Sentry; SMS Controller, Pt.2; PICAXE IR Remote Control. December 2004: Build A Windmill Generator, Pt.1; 20W Amplifier Module; Charger For Deep-Cycle 12V Batteries, Pt.2; Solar-Powered Wireless Weather Station; Bidirectional Motor Speed Controller. January 2005: Windmill Generator, Pt.2; Build A V8 Doorbell; IR Remote Control Checker; 4-Minute Shower Timer; The Prawnlite; Sinom Says Game; VAF DC-7 Generation 4 Kit Speakers. October 2002: Speed Controller For Universal Motors; PC Parallel Port Wizard; Cable Tracer; AVR ISP Serial Programmer; 3D TV. February 2005: Windmill Generator, Pt.3; USB-Controlled Electrocardiograph; TwinTen Stereo Amplifier; Inductance & Q-Factor Meter, Pt.1; A Yagi Antenna For UHF CB; $2 Battery Charger. November 2002: SuperCharger For NiCd/NiMH Batteries, Pt.1; Windows-Based EPROM Programmer, Pt.1; 4-Digit Crystal-Controlled Timing Module. March 2005: Windmill Generator, Pt.4; Sports Scoreboard, Pt.1; Swimming Pool Lap Counter; Inductance & Q-Factor Meter, Pt.2; Shielded Loop Antenna For AM; Cheap UV EPROM Eraser; Sending Picaxe Data Over 477MHz UHF CB; $10 Lathe & Drill Press Tachometer. December 2002: Receiving TV From Satellites; Pt.1; The Micromitter Stereo FM Transmitter; Windows-Based EPROM Programmer, Pt.2; SuperCharger For NiCd/NiMH Batteries; Pt.2; Simple VHF FM/AM Radio. January 2003: Receiving TV From Satellites, Pt 2; SC480 50W RMS Amplifier Module, Pt.1; Gear Indicator For Cars; Active 3-Way Crossover For Speakers. February 2003: PortaPal PA System, Pt.1; SC480 50W RMS Amplifier Module, Pt.2; Windows-Based EPROM Programmer, Pt.3; Fun With The PICAXE, Pt.1. March 2003: LED Lighting For Your Car; Peltier-Effect Tinnie Cooler; PortaPal PA System, Pt.2; 12V SLA Battery Float Charger; Little Dynamite Subwoofer; Fun With The PICAXE, Pt.2 (Shop Door Minder). April 2003: Video-Audio Booster For Home Theatre Systems; Telephone Dialler For Burglar Alarms; Three PIC Programmer Kits; PICAXE, Pt.3 (Heartbeat Simulator); Electric Shutter Release For Cameras. May 2003: Widgybox Guitar Distortion Effects Unit; 10MHz Big Blaster Subwoofer; Printer Port Simulator; PICAXE, Pt.4 (Motor Controller). June 2003: PICAXE, Pt.5; PICAXE-Controlled Telephone Intercom; PICAXE-08 Port Expansion; Sunset Switch For Security & Garden Lighting; Digital Reaction Timer; Adjustable DC-DC Converter For Cars; Long-Range 4-Channel UHF Remote Control. July 2003: Smart Card Reader & Programmer; Power-Up Auto Mains Switch; A “Smart” Slave Flash Trigger; Programmable Continuity Tester; PICAXE Pt.6 – Data Communications; Updating The PIC Programmer & Checkerboard; RFID Tags – How They Work. August 2003: PC Infrared Remote Receiver (Play DVDs & MP3s On Your PC Via Remote Control); Digital Instrument Display For Cars, Pt.1; Home-Brew Weatherproof 2.4GHz WiFi Antennas; PICAXE Pt.7. September 2003: Robot Wars; Krypton Bike Light; PIC Programmer; Current Clamp Meter Adapter For DMMs; PICAXE Pt.8 – A Data Logger; Digital Instrument Display For Cars, Pt.2. October 2003: PC Board Design, Pt.1; JV80 Loudspeaker System; A Dirt Cheap, High-Current Power Supply; Low-Cost 50MHz Frequency Meter; Long-Range 16-Channel Remote Control System. November 2003: PC Board Design, Pt.2; 12AX7 Valve Audio Preamplifier; Our Best Ever LED Torch; Smart Radio Modem For Microcontrollers; PICAXE Pt.9; Programmable PIC-Powered Timer. December 2003: PC Board Design, Pt.3; VHF Receiver For Weather Satellites; Linear Supply For Luxeon 1W Star LEDs; 5V Meter Calibration Standard; PIC-Based Car Battery Monitor; PICAXE Pt.10. January 2004: Studio 350W Power Amplifier Module, Pt.1; HighEfficiency Power Supply For 1W Star LEDs; Antenna & RF Preamp For Weather Satellites; Lapel Microphone Adaptor For PA Systems; PICAXE-18X 4-Channel Datalogger, Pt.1; 2.4GHZ Audio/Video Link. February 2004: PC Board Design, Pt.1; Supply Rail Monitor For PCs; Studio 350W Power Amplifier Module, Pt.2; Shorted Turns Tester For Line Output Transformers; PICAXE-18X 4-Channel Datalogger, Pt.2. March 2004: PC Board Design, Pt.2; Build The QuickBrake For Increased Driving Safety; 3V-9V (or more) DC-DC Converter; ESR Meter Mk.2, Pt.1; PICAXE-18X 4-Channel Datalogger, Pt.3. April 2004: PC Board Design, Pt.3; Loudspeaker Level Meter For Home Theatre Systems; Dog Silencer; Mixture Display For Cars; ESR Meter Mk.2, Pt.2; PC/PICAXE Interface For UHF Remote Control. May 2004: Amplifier Testing Without High-Tech Gear; Component Video To RGB Converter; Starpower Switching Supply For Luxeon Star LEDs; Wireless Parallel Port; Poor Man’s Metal Locator. siliconchip.com.au Your LPs To CDs & MP3s; Turn an Old Xbox Into A $200 Multimedia Player; Picaxe Net Server, Pt.1; Build The Galactic Voice; Aquarium Temperature Alarm; S-Video To Composite Video Converter. April 2005: Install Your Own In-Car Video (Reversing Monitor); Build A MIDI Theremin, Pt.1; Bass Extender For Hifi Systems; Sports Scoreboard, Pt.2; SMS Controller Add-Ons; A $5 Variable Power Supply. May 2005: Getting Into Wi-Fi, Pt.1; Build A 45-Second Voice Recorder; Wireless Microphone/Audio Link; MIDI Theremin, Pt.2; Sports Scoreboard, Pt.3; Automatic Stopwatch Timer. June 2005: Wi-Fi, Pt.2; The Mesmeriser LED Clock; Coolmaster Fridge/ Freezer Temperature Controller; Alternative Power Regular; PICAXE Colour Recognition System; AVR200 Single Board Computer, Pt.1. July 2005: Wi-Fi, Pt.3; Remote-Controlled Automatic Lamp Dimmer; Serial Stepper Motor Controller; Salvaging & Using Thermostats; Unwired Modems & External Antennas. August 2005: Mudlark A205 Valve Stereo Amplifier, Pt.1; Programmable Flexitimer; Carbon Monoxide Alert; Serial LCD Driver; Enhanced Sports Scoreboard; Salvaging Washing Maching Pressure Switches. January 2007: Versatile Temperature Switch; Intelligent Car AirConditioning Controller; Remote Telltale For Garage Doors; Intelligent 12V Charger For SLA & Lead-Acid Batteries. February 2007: Remote Volume Control & Preamplifier Module, Pt.1; Simple Variable Boost Control For Turbo Cars; Fuel Cut Defeater For The Boost Control; Low-Cost 50MHz Frequency Meter, Mk.2. March 2007: Programmable Ignition System For Cars, Pt.1; Remote Volume Control & Preamplifier Module, Pt.2; GPS-Based Frequency Reference, Pt.1; Simple Ammeter & Voltmeter. April 2007: The Proposed Ban On Incandescent Lamps; High-Power Reversible DC Motor Speed Controller; Build A Jacob’s Ladder; GPSBased Frequency Reference, Pt.2; Programmable Ignition System For Cars, Pt.2; Dual PICAXE Infrared Data Communication. May 2007: 20W Class-A Amplifier Module, Pt.1; Adjustable 1.3-22V Regulated Power Supply; VU/Peak Meter With LCD Bargraphs; Programmable Ignition System For Cars, Pt.3; GPS-Based Frequency Reference Modifications; Throttle Interface For The DC Motor Speed Controller. June 2007: 20W Class-A Amplifier Module, Pt.2; Knock Detector For The Programmable Ignition; 4-Input Mixer With Tone Controls; Frequency-Activated Switch For Cars; Simple Panel Meters Revisited. July 2007: How To Cut Your Greenhouse Emissions, Pt.1; 6-Digit Nixie Clock, Pt.1; Tank Water Level Indicator; A PID Temperature Controller; 20W Class-A Stereo Amplifier; Pt.3; Making Panels For Projects. August 2007: How To Cut Your Greenhouse Emissions, Pt.2; 20W Class-A Stereo Amplifier; Pt.4; Adaptive Turbo Timer; Subwoofer Controller; 6-Digit Nixie Clock, Pt.2. September 2007: The Art Of Long-Distance WiFi; Fast Charger For NiMH & Nicad Batteries; Simple Data-Logging Weather Station, Pt.1; 20W Class-A Stereo Amplifier; Pt.5. October 2007: DVD Players – How Good Are They For HiFi Audio?; Electronic Noughts & Crosses Game; PICProbe Logic Probe; Rolling Code Security System, Pt.1; Simple Data-Logging Weather Station, Pt.2; AM Loop Antenna & Amplifier. September 2005: Build Your Own Seismograph; Bilge Sniffer For Boats; VoIP Analog Phone Adaptor; Mudlark A205 Valve Stereo Amplifier, Pt.2; PICAXE in Schools, Pt.4. November 2007: Your Own Home Recording Studio; PIC-Based Water Tank Level Meter, Pt.1: Playback Adaptor For CD-ROM Drives, Pt.1; Rolling Code Security System, Pt.2; Build A UV Light Box For Making PC Boards. October 2005: A Look At Google Earth; Dead Simple USB Breakout Box; Studio Series Stereo Preamplifier, Pt.1; Video Reading Aid For Vision Impaired People; Simple Alcohol Level Meter; Ceiling Fan Timer. December 2007: Signature Series Kit Loudspeakers; IR Audio Headphone Link; Enhanced 45s Voice Recorder Module; PIC-Based WaterTank Level Meter; Pt.2; Playback Adaptor For CD-ROM Drives; Pt.2. November 2005: Good Quality Car Sound On The Cheap; Pt.1; PICAXE In Schools, Pt.5; Studio Series Stereo Headphone Amplifier; Build A MIDI Drum Kit, Pt.1; Serial I/O Controller & Analog Sampler. January 2008: PIC-Controlled Swimming Pool Alarm; Emergency 12V Lighting Controller; Build The “Aussie-3” Valve AM Radio; The Minispot 455kHz Modulated Oscillator; Water Tank Level Meter, Pt.3 – The Base Station; Improving The Water Tank Level Meter Pressure Sensor. December 2005: Good Quality Car Sound On The Cheap; Pt.2; Building The Ultimate Jukebox, Pt.1; Universal High-Energy Ignition System, Pt.1; Remote LED Annunciator For Queue Control; Build A MIDI Drum Kit, Pt.2; 433MHz Wireless Data Communication. February 2008: UHF Remote-Controlled Mains Switch; UHF Remote Mains Switch Transmitter; A PIR-Triggered Mains Switch; Shift Indicator & Rev Limiter For Cars; Mini Solar Battery Charger. January 2006: Pocket TENS Unit For Pain Relief; “Little Jim” AM Radio Transmitter; Universal High-Energy Ignition System, Pt.2; Building The Ultimate Jukebox, Pt.2; MIDI Drum Kit, Pt.3; Picaxe-Based 433MHz Wireless Thermometer; A Human-Powered LED Torch. March 2008: How To Get Into Digital TV, Pt.1; The I2C Bus – A Quick Primer; 12V-24V High-Current DC Motor Speed Controller, Pt.1; A Digital VFO with LCD Graphics Display; A Low-Cost PC-to-I2C Interface For Debugging; One-Pulse-Per Second Driver For Quartz Clocks. February 2006: PC-Controlled Burglar Alarm, Pt.1; A Charger For iPods & MP3 Players; Picaxe-Powered Thermostat & Temperature Display; Build A MIDI Drum Kit, Pt.4; Building The Ultimate Jukebox, Pt.3. April 2008: How To Get Into Digital TV, Pt.2; Charge Controller For 12V Lead-Acid Or SLA Batteries; Safe Flash Trigger For Digital Cameras; 12V-24V High-Current DC Motor Speed Controller, Pt.2; Two-Way Stereo Headphone Adaptor. March 2006: The Electronic Camera, Pt.1; PC-Controlled Burglar Alarm System, Pt.2; Low-Cost Intercooler Water Spray Controller; AVR ISP SocketBoard; Build A Low-Cost Large Display Anemometer. April 2006: The Electronic Camera, Pt.2; Studio Series Remote Control Module (For A Stereo Preamplifier); 4-Channel Audio/Video Selector; Universal High-Energy LED Lighting System, Pt.1; Picaxe Goes Wireless, Pt.1 (Using the 2.4GHz XBee Modules). May 2006: Lead-Acid Battery Zapper ; Universal High-Energy LED Lighting System, Pt.2; Passive Direct Injection (DI) Box For Musicians; Picaxe Goes Wireless, Pt.2; Boost Your XBee’s Range Using Simple Antennas; Improving The Sound Of Salvaged Loudspeaker Systems. June 2006: Pocket A/V Test Pattern Generator; Two-Way SPDIF-toToslink Digital Audio Converter; Build A 2.4GHz Wireless A/V Link; A High-Current Battery Charger For Almost Nothing. July 2006: Mini Theremin Mk.2, Pt.1; Programmable Analog On-Off Controller; Studio Series Stereo Preamplifier; Stop Those Zaps From Double-Insulated Equipment. August 2006: Picaxe-Based LED Chaser Clock; Magnetic Cartridge Preamplifier; An Ultrasonic Eavesdropper; Mini Theremin Mk.2, Pt.2. September 2006: Thomas Alva Edison – Genius, Pt.1; Transferring May 2008: Replacement CDI Module For Small Petrol Motors; High-Accuracy Digital LC Meter; Low-Cost dsPIC/PIC Programmer; High-Current Adjustable Voltage Regulator. June 2008: DSP Musicolour Light Show, Pt.1; PIC-Based Flexitimer Mk.4; USB Power Injector For External Hard Drives; Balanced/Unbalanced Converter For Audio Signals; A Quick’n’Easy Digital Slide Scanner; Altitude 3500-SS Stereo Valve Amplifier Reviewed. July 2008: DSP Musicolour Light Show, Pt.2; A PIC-Based Musical Tuning Aid; Balanced Mic Preamp For PCs & MP3 Players; Bridge Adaptor For Stereo Power Amplifiers. August 2008: Ultra-LD Mk.2 200W Power Amplifier Module; Planet Jupiter Receiver; LED Strobe & Contactless Tachometer; DSP Musicolour Light Show, Pt.3; Printing In The Third Dimension. PLEASE NOTE: issues not listed have sold out. All listed issues are in stock. We can supply photostat copies of articles from sold-out issues for $A9.50 each within Australia or $A13.00 each overseas (prices include p&p). When supplying photostat articles or back copies, we automatically supply any relevant notes & errata at no extra charge. A complete index to all articles published to date can be downloaded free from our web site: www.siliconchip.com.au September 2008  87 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 Speed controller for motorised shutters I have an extension to my house which has motorised shutters in the roof. The motor looks like those used in car windscreen wipers. A control unit applying +12V or -12V to the motor performs opening and closing the shutters. The system works fine except that the motor is too fast, resulting in the shutters crashing closed. Possible solutions include changing the gear ratios in the motor mechanism or using an electronic controller to the motor. The second option would seem to be preferable. Your 12V 10A Motor Speed Controller (SILICON CHIP, June 1997, Jaycar KC5225) would appear to do the job well, however the motor needs to be able to operate in the forward and reverse direction so that the shutters open and close. Obviously I cannot simply reverse the supply polarity to the Motor Speed Controller unit. Is there a simple solution to this problem? Can the output polarity of the Motor Speed Controller be reversed? Is there another circuit better suited to this situation? (G. B., via email). • The output from the Motor Speed Controller cannot be reversed but the connections to the motor can. Presumably the control unit switches off power once the shutters are fully open or closed and power is off after partially opening or closing the shutters. Depending on whether the control unit for the shutters is electro-mechanical (ie, just switches and a relay) you should be able to supply the controller with power via the Motor Speed Controller. The control unit for the shutters will then provide the supply reversal for the motor. The reverse diode for the motor used in the Motor Speed Controller should be connected across the output terminals of the Motor Speed Controller and not the motor. If the control unit for the shutters is electronic then it will need to be powered directly via the 12V supply. The Motor Speed Controller would then have to be powered by connecting it to the + and - terminals of a bridge rectifier (rated at 35A) and the AC terminals of the bridge rectifier connected to the control unit outputs that normally connect to the motor. The Motor Speed Controller outputs would then connect to a DPDT relay rated for the motor. You could use the Jaycar SY-4008 cradle relay. Connect the NO (normally open) contact of the first pole to the NC (normally closed) contact of the second pole and this connects to one output of the shutter controller. Connect the NC contact of the first pole to the NO contact of the second pole and connect to the other shutter controller output. The common relay terminals connect to the motor. The relay coil connects across the output of the control unit for the shutters (like the AC terminals for the diode bridge do). As before, the reverse diode for the motor should be connected across the output terminals of the Motor Speed Controller and not the motor itself. Altering class-A operation conditions I would like to know if lowering the quiescent current of the 20W Class-A amplifier would lower the heatsink temperature. Does lowering the operating temperature of a working amplifier have any detrimental effect? (D. G., via email). • If you lower the quiescent current substantially you will certainly reduce the power dissipation and the operating temperature of the amplifier. However, it will then no longer be operating in Class-A over most of its power range and the performance will not be as good. How Are Windmills Synchronised To The Grid? There is quite a lot of interest over our way in wind farms. I would like to know how all those wind turbines, all rotating at different speeds, manage to generate electricity at 50Hz and do it so that they are in phase with each other and also the national grid into which they feed? Come to think of it, how do all the other generators supplying power to the national grid keep in phase? We even have a direct current link between the North and South Islands and that really has me foxed. Could you please explain how it is 88  Silicon Chip done and thus solve for me one of life’s great mysteries? (C. S., Lower Hutt, NZ). • We wrote briefly about this subject in our feature story on Australia’s first grid-connected wind farm, in the January 1999 issue. In fact, the windmills do not rotate at widely different speeds. Their blades are constantly adjusted for pitch so that the power output is more or less constant. The alternator speed is, in fact, constant although the blade speed can vary by about ±10%. Synchronising alternators to the grid is quite easy. All that needs to be done is to run the turbine/ alternator at the correct speed and frequency, ensure that the alternator phase is matched to the grid and then the “switch” can be thrown to connect the alternator to the grid. After that, the alternator is always locked to the grid unless a serious fault develops. The article on the BassLink (Tasmania to Victoria) HVDC link in this issue should answer your last question. This uses the same principles as the NZ HVDC link. siliconchip.com.au Yes, the heatsink gets quite warm but all parts operate well inside their ratings. How to reform electrolytic capacitors I have been searching unsuccessfully through your online archived magazine indexes for a specific article I know to have been printed. It was an article relating to the “Forming of Capacitors”. I thought it was around August 2006 but can find no mention of it on this site. Can you help? (B. G., via email). • The article was in October 2006. Protection from microwave wanted I am looking to purchase a kit that will protect my family from microwaves and/or EMF. Can you help me? (D. F., Louisville, KY, USA). • Unless you and your family live permanently in a Faraday cage (ie, a room made of metallic mesh to screen out electromagnetic radiation) or in a deep underground cave, there is no way to avoid microwaves or electromagnetic radiation. However, unless you are exposed to high-power fields from, say, nearby airport or ships’ radar, cell-phone or TV broadcast towers, there is little to worry about. Claims for Browns Gas refuted I have been researching HHO or Browns Gas. I am not sure but it looks like there are two camps regarding the manufacture of HHO or Browns Gas. One camp makes small amounts of gas through very simple electrolysis (using 8-25A) and their argument is that only a small amount of gas is needed as it makes the petrol burn more efficiently. The other camp (Stan Meyers and others) makes all sorts of claims but produces huge amounts of gas through some sort of pulse technology and is able to produce these amounts at very low amps. My personal feeling is that Stan Meyers and others are on the right track with this pulse technology and a number of problems have been fixed. If you look at YouTube, regarding the pulse frequency changing with the decreasing fluid level in the electrosiliconchip.com.au Repairing A Kenwood Mixer I discovered your website when I was attempting to find a place in Australia where I could buy a new circuit board for our Kenwood mixer. Not being technical, I just try to look for the obvious when working on broken things. We brought this mixer with us from the UK and hardly ever use it. Recently, my children were using it (I wasn’t watching at the time) and they called out because there was smoke billowing from the machine. As far as I can determine though, it was still working. As there isn’t too much to the machine I started looking at the motor and discovered that one of the components had blown out and was the cause of the burning smell. It is labelled “Rifa PME 271 M” on one side and on another, it says, “0.15µF X2”. Can you firstly tell me if I should consider replacing it as I don’t know what caused the problem, or is it that these modules lyser bottle, this has been fixed by the addition of a fluid level sensor and a reservoir with a pump so that the fluid level can remain constant. I am hoping that you can look at Stan’s circuit which drives his electrolyser and make any modifications needed to get this kit ready for manufacture through Jaycar or any one else that wishes to take it on. (S. W., Murray Bridge, SA). • Leo Simpson comments: virtually all the claims made with regard to “Browns Gas” are fallacies. I first became aware of Yull Brown some 30 years ago (he wasn’t claiming to be a Doctor then) when “Electronics Australia” featured an article on “the oxy-hydrogen economy” in the March 1978 issue. I was sceptical even then. I can go at any time and for no reason? Secondly, what is this part called? Is it possible to buy a replacement circuit board in Australia as the plastic back on the board appears to be moulded on. (D. S., via email). • The component that has evidently failed is a capacitor. It is possible that it failed on its own or maybe because some other component also failed. However, since the mixer is still working, it is likely that the capacitor is the only device to have failed. X2 capacitors can be purchased from Jaycar or Altronics but they do not have that specific value. You could try a value of 0.22mF (which they do stock) or you could probably purchase a 0.15mF X2 capacitor from Farnell Electronic Components (see www.farnellinone.com). Local service agents should be able to obtain the complete speed control module although the cost may make the repair uneconomic. was working for EA at the time. Subsequently, I was invited to Mr Brown’s home workshop at Auburn in Sydney to do a follow-up story on another application for oxy-hydrogen, as it was then called. However, the meeting did not last long. When I raised questions about the efficiency of the electrolysis process, Yull Brown became angry and ordered me off the premises. Let’s list the facts about electrolysis of water and the use of the resultant gas as a fuel: (1) Yes, water can be electrolysed and the resultant oxygen-hydrogen mixture burns very cleanly and with high calorific value to give pure water as the combustion product – no argument there. Issues Getting Dog-Eared? Keep your copies safe with these handy binders 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. REAL VALUE AT $13.95 PLUS P&P Buy five and get them postage free! September 2008  89 Problem With Vehicle Multi-Voltage Monitor I have recently constructed the Vehicle Multi-Voltage Monitor kit (SILICON CHIP, May 2006) and have a minor problem you may be able to assist with. I have configured the board to display a voltage between 10V and 15V in dot mode. The problem is that as the voltage increases past the lowest reading red LED (the one fed from pin 1 of the LM3914), it does not fully extinguish. The higher LEDs illuminate and extinguish as expected. When the voltage is decreased below the lowest LED value the offending LED extinguishes fully. I have tried another LM3914, with the same result. (2) Electrolysis is a very energy intensive process. Just as the burning of the hydrogen-oxygen mixture gives off lots of heat (an exothermic reaction), reversal of the process to split water into hydrogen & oxygen needs a lot of energy input (an endothermic reaction). It requires even more energy if platinum is not used as a catalyst. The popular internet process using stainless steel tubes is far less efficient. (3) Using a car’s electrical system to electrolyse water and inject the resultant gas into the cylinders to “improve” combustion is just silly. The energy to electrolyse the water has to come from the engine (to drive the alternator, etc) and there are losses at every stage in the process. Just as an aside, water injection can still be worthwhile in some engines. (4) Yull Brown’s idea to power cars from water fuel was never practical. Apart from the large amount of energy required to electrolyse water, the means of storage was always going to be heavy and difficult. At one stage Queensland’s premier Joh Bjelke-Petersen helped promote the idea of a hydrogen car (in association with Steven Horvath) – it never came to anything. (5) It is interesting that the process is now called “Browns Gas”, as if Yull Brown had invented it. Nonsense. The process for electrolysis of water was known for at least a century beforehand. Nor is the hydrogen and oxygen 90  Silicon Chip The voltage being monitored is the same as that supplying the board, ie, I have the input line connected to the +12V supply line. In all other respects the circuit appears to be fine. (D. W., via email). • Place a 10kW resistor between the anode and cathode of the first LED (the one that connects to pin 1). This will shunt the residual current that is supplied to this pin 1 output to prevent the LED glowing. When the LM3914 was introduced more than 20-years ago LEDs were not as efficient as they are today and the LED at pin 1 did not tend to remain lit. But now with modern highefficiency LEDs, the residual current causes the LED to glow faintly. so produced monatomic (HHO), as is claimed by the promoters. At normal temperatures and pressures (as produced in the electrolysis process) hydrogen and oxygen can only exist in the molecular state, ie, as H2 and O2. (6) Any use of hydrogen as a fuel, whether to be directly burnt in an engine to produce power (inevitably an inefficient process) or in a fuel cell to drive an electric motor in a car as promoted by Honda, BMW and other companies, is never likely to come to anything. The process for turning ordinary hydrocarbons into hydrogen is too inefficient and leads to high carbon dioxide emissions. (7) The suggested schemes and circuit for controlling the field windings of an alternator to somehow increase the electrolysis process are also nonsense. The circuits themselves (based on a 555 timer and a Mosfet) are suspect since they have no protection against transient voltages. Switchmode control of alternator windings has been in use for at least 25 years and does nothing to increase the output of the alternator – it is just an effective means of control compared to the old electromechanical voltage regulators. (8) Mention is made in quite a few internet posts about tests done by “Electronics Australia” magazine which purport to validate Browns gas, etc. No such tests were ever done and apart from the article mentioned above, there was never any association between Yull Brown and his Water Fuel Holdings and “Electronics Australia” magazine. Timed lamp dimmer wanted I would like to create a switch for a standard light globe that operates off a timer and when activated, dims slowly from low to high brightness. Do you know of any suitable kits? (U. M., Ocean Grove, NSW). • We published a remote controlled table lamp dimmer that can dim automatically (SILICON CHIP, July 2005). We have not produced a timer that works with the dimmer but you may be able to use a timer that has low voltage relay contacts to activate the automatic dimming on the remote control for the table lamp dimmer. Substitute battery for old transistor radio I have just purchased an old HMV Little Nipper Rangemaster portable transistor radio. Inside there is a little sticker stating that it requires an Eveready 276-P battery. I don’t think those batteries are available any longer and I was wondering if you could tell me the specifications, (volts, amps) of that battery so I can use a modern equivalent. I was thinking about one of those little gel cells that you can get in electronics stores or perhaps a combination of NiMH cells. I suspect that the modern equivalent would not actually fit in the case of the HMV but an external supply would be OK. (B. H., via email). • The Eveready 276-P was a 9V 5000mAh battery. There is no current equivalent that could be used. To make a suitable substitute, you could use a 9V pack made up with six NiMH AA cells in a holder. Jaycar sell six-AA cell holders, Cat PH-9206. Electric fence has voltage limits I have built the Jacobs Ladder kit from the April 2007 issue and it works fine. However, could I adapt it to power an electric fence to deter wildlife from eating my gardens? I believe it would have plenty of energy but I notice the article suggests not running the kit siliconchip.com.au Notes & Errata Ultra-LD Mk.2 200W Power Amplifier, August 2008: the 470mF 63V capacitor on the -55V rail is shown with reversed polarity on the circuit diagram (Fig.1), ie, its negative lead should go to the -55V rail. As well, the voltages marked across the 0.1W resistors are out by a factor of 10. They should be 7-10mV, not 70100mV. In addition, the 68W resistor in series between the +55V rail and Q7’s collector has been reduced to 47W, while a 22kW resistor has been added in series between Q8’s collector and ground (this change has been incorporated onto the PC board patterns sent to the parts retailers). Finally, the following changes should be made to the parts list: add 1 x 22kW 0.25W resistor, add 1 x 47W 0.25W resistor, add 1 x 10W 0.25W resistor, delete 1 x 68W 0.25W resistor and change the two 470W 5W test resistors to 68W 5W. There should also be 5 x 100nF 63V MKT polyester capacitors (not four). without some discharge in case it internally arcs in the ignition coil. What component changes are suggested? (P. C., via email). • The high voltage produced by the Jacob’s Ladder is far too high for an electric fence. It could easily put out 20kV to 25kV whereas the Australian standard (AS3129) calls for a maximum voltage of 5kV into a 1-megohm load. Nor would it be practical to throttle the circuit back enough to make it suit. In the past, we produced a similar Water Tank Level Meter, November and December 2007: the transmission repeat periods for the telemetry version for positions 4-7 and 8-B of the BCD switch (BCD2) do not run at the designated 33s and 67s respectively. The software has been updated (rev2) to fix this bug and is available for free download from our website. Infrared Rolling Code Receiver, October 2007: the A & K labelling on diodes D1-D4, shown at the top righthand corner of the circuit, is incorrect. It should be as shown for diode D5 at the top left corner of the circuit. DSP Musicolour, July & August 2008: in the component overlay of the DSP Musicolour display board shown on page 26 of the July 2008 issue, the labelling on the ICs is incorrect. IC1 should be IC3, IC2 should be IC4, IC3 should be IC5 and IC4 should be IC6. circuit with a conventional ignition coil which would be suitable for short fence runs (see SILICON CHIP, July 1995). Alternatively, we produced a high-output electric fence in the April 1999 issue. We can supply photostat copies of the articles for $9.50 including postage. Query on dimmable CFLs I was planning to replace three incandescent globes in a pendant light Want a real speed controller kit? If you need to control 12 or 24 volt DC motors and want a speed controller that will easily handle 30 amps, then this is the kit for you. This controller allows you to vary the speed of DC motors from 0 to 100%. It is also ideal for controlling loads such as incandescent/halogen lamps and heating elements. This kit makes a great controller for use on small electric vehicle projects, such as electrically assisted bikes and go-carts. We have tested it to over 30 amps without problems—it barely gets warm! Item code: SPEEDCON. We also have solar maximiser kits, Luxeon LEDs, and lots of interesting products and publications. Go to shop.ata.org.au or call us on (03)9639 1500. fitting with cooler CFLs because after 30 years some plastic and wiring was heat-affected. You state that GE dimmable CFLs tend to fail at 60°C. What is the likelihood of reaching this temperature? (H. W., via email). • We have never made any specific comment on lamp failure with respect to GE dimmable CFLs. We do not know. Provided CFLs are not totally enclosed in a lamp fitting, they should have good life, especially if they are normally left on for long periods. SC 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. 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Card expiry date: Signature_____________________________ SUBSCRIBERS QUALIFY FOR 10% DISCOUNT ON ALL SILICON CHIP PRODUCTS* * except subscriptions/renewals Qty Item Description Subscribe to SILICON CHIP on-line at: www.siliconchip.com.au Both printed and on-line versions available Total TO PLACE Phone (02) 9939 3295 OR Fax this form to OR 9am-5pm Mon-Fri (02) 9939 2648 YOUR Please have your credit with your credit card details card details ready 24 hours 7 days a week ORDER 92  Silicon Chip Item Price P&P if extra Total Price BUY MOR 10 OR ISSU E BACK ES A 1 0 & G ET DISC % OUN T $A Mail this form, with your cheque/money order, to: Silicon Chip Publications Pty Ltd, PO Box 139, Collaroy, NSW, siliconchip.com.au Australia 2097 08/08 MARKET CENTRE Cash in your surplus gear. Advertise it here in SILICON CHIP CLASSIFIED ADVERTISING RATES Advertising rates for these pages: Classified ads: $29.50 (incl. GST) for up to 20 words plus 85 cents for each additional word. Display ads: $54.50 (incl. GST) per column centimetre (max. 10cm). Closing date: 5 weeks prior to month of sale. To book your classified ad, email the text to silicon<at>siliconchip.com.au and include your name, address & credit card details, or fax (02) 9939 2648, or post to Silicon Chip Classifieds, PO Box 139, Collaroy, NSW, Australia 2097. FOR SALE TECH REPAIRS SERVICE MANUALS www.techrepairs.org Thousands of downloadable service manuals for all brands, makes and models including PDP, LCD, VCR, DVD, CTV, Vintage Radio, Laptops, Monitors, Sewing Machines, Washing Machines, Dryers, Fridges and many more. An absolute must have website for any Tech! FACTORY OUTLET: flexible neon wire. Sheet (Backlight cuttable) flower. LGP Backlight. EL products. Phone 041 771 8607 Fax (07) 3397 5787. Email: cjappliance<at>gmail.com 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 LEDs! Nichia superbright oval LEDs and 5mm Agilent (HP) LEDs - brandname quality LEDs at Chinese LED prices! Osram surface mount range and other NOS standard and superbright brand name LEDs from just a few cents each. Cree XR-E LEDs, LED drivers, kits and other interesting stuff. www. ledsales.com.au PCBs MADE, ONE OR MANY. Any format, hobbyists welcome. Sesame Electronics Phone (02) 9593 1025. sesame<at>sesame.com.au www.sesame.com.au CUSTOMERS: Truscotts Electronic World – large range of semiconductors and passive components for industry, siliconchip.com.au AT LAST! Quality batteries for power tools at prices you CAN AFFORD! CALL: PREMIER BATTERIESPTY LTD (02) 9755 1845 email: malcolmw<at>premierbatteries.com.au web: www.premierbatteries.com.au hobbyist and amateur projects including Drew Diamond. 27 The Mall, South Croydon, Melbourne. (03) 9723 3860. electronicworld<at>optusnet.com.au KIT ASSEMBLY KEITH RIPPON KIT ASSEMBLY & REPAIR: * Australia & New Zealand; * Small production runs. Phone Keith 0409 662 794. keith.rippon<at>gmail.com WANTED WANTED: EARLY HIFIs, AMPLIFIERS, Speakers, Turntables, Valves, Books, Quad, Leak, Pye, Lowther, Ortofon, SME, Western Electric, Altec, Marantz, McIntosh, Tannoy, Goodmans, Wharfedale, radio and wireless. Collector/ Hobbyist will pay cash. (07) 5471 1062. johnmurt<at>highprofile.com.au SOS COMPONENTS See Tomorrow’s Products Today – 3D Printing Rapid Prototyping Silicone Keypads SOS Components develops silicone moulds using Rapid Prototyping techniques. Also available in colour. Gold Medal Performance Vacuum metallising produces high gloss gold, silver and bronze products. SOS Components provides a “gold class service”, says Frank Downes from Grabba International. DIY Option You would rather produce the parts yourself? We are also the distributor for Z Corporation 3D Colour Printers throughout Australia. SOS Components www.3dprinting.com.au sales<at>3dprinting.com.au Ph: (07) 3267 8104 September 2008  93 ELNEC IC PROGRAMMERS High quality Realistic prices Free software updates Large range of adaptors Windows 95/98/Me/NT/2k/XP 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 Degen 1103 Pocket Receiver Range 100kHz - 29,999kHz, direct entry, digital display. Listen to SSB, amateur radio, marine weather, HF aircraft, shortwave and many more. Supplied with rechargeable AA batteries, approved charger, 10m longwire, carry case and earphones. $159.00 + P/H. Contact Av-Comm Pty Ltd Tel: (02) 9939 4377; www.avcomm.com.au IMAGECRAFT C COMPILERS ANSI C compilers, Windows IDE AVR, TMS430, ARM7/ARM9 68HC08, 68HC11, 68HC12 GRANTRONICS PTY LTD www.grantronics.com.au C O N T R O L S You get results faster with the world’s easiest controllers! best v alue! MS120OEM216 $149 1-off Developer’s Kit $193 includes programming cable & software Must-have books for the hobbyist “Will fascinate, captivate” FROM A.R. Winstanley, Electronics Editor $2.95 http://stores.lulu.com/thomasscarborough VIDEO - AUDIO - PC distribution amps - splitters digital standards converters - tbc's switchers - cables - adaptors genlockers - scan converters bulk vga cable - wallplates Made in Australia - enthusiastic users world-wide DVS5c & DVS5s High Performance Video / S-Video and Audio Splitters splat-sc.com ISM ISM Tx/Rx + 8051 Modules eRF-PoB. 433, 868 or 915MHz Programmable On Board Via RF Do you have wireless problems? Telelink has wireless solutions! MD12 Media Distribution Amplifier Use any 8051 Assembler/Compiler Nordic Semiconductors nRF9E5 8051 Processor: 32K Eeprom: 8 I/O:SPI:RS232:16MHz XTL etc. 01010101 Telelink Communications www.telelink.com.au e-mail Jack Chomley – jack<at>telelink.com.au or call (07) 4934 0413 or 0428 199 551 94  Silicon Chip HQ VGA Cables Come to the specialists... ellert-technologies.com.au SPK360 3/5/06 1:10 PM Page 1 HI-FISPEAKER REPAIRS Products, Specials & Pricelist at www.questronix.com.au fax (02) 4341 2795 phone (02) 4343 1970 email: questav<at>questronix.com.au www.excesselectronics.com.au Excess Electronic Components PO Box 2417 Rowville Vic 3178 Tel: 041 567 7761 Fax: 03 9755 8280 FREE MONTHLY MAILER Please Enquire 30mcd Dark Blue SMD Led (Pk-100) YOUR EXPERT SPEAKER REPAIR SPECIALISTS tel: 03 9647 7000 www.speakerbits.com ® Quest Electronics® Pty Limited abn 83 003 501 282 t/a Questronix Surplus Electronic Components ABN: 38 445 311 223 20 years experience! 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! VGA Splitter VGS2 AWP1 A-V Wallplate AB687 $ 3.00 SPK360 At Telelink we sell solutions, not problems! Quest AV® Mini RF Programmer Development Platform 1 off Module Price $59.00 Plus GST If you want the right ‘wireless’ ingredients for a successful project recipe, THINK Telelink! Don’t want to be confused by wireless gobbledegook and confusing buzz words? TALK to Telelink! We will give you honest advice so that you can make the right purchase decision for your OEM low power wireless requirements. Browse our website for more information about our products. If you have any questions speak with a Telelink Communications representative. QUEST ® On-line Shopping Range Of Excess Electronic Parts sales<at> excesselectronics.com.au FREE FREIGHT FOR ORDER OVER $100 siliconchip.com.au 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 50 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. Why not do something you love and get paid for it? Please write or email us with your details, along with your C.V. and any qualifications you may have. We pay a competitive salary, sales commissions and have great benefits like a liberal staff purchase policy. Send to: Retail Operations Manager - Jaycar Electronics Pty Ltd PO Box 107, Rydalmere, NSW 2116 Email: jobs<at>jaycar.com.au Jaycar Electronics is an equal opportunity employer and actively promotes staff from within the organisation. RFMA RF Modules Australia Low Power Wireless Connectivity Specialists Applications: Parani-SD100 Laptop/PDA Bluetooth Serial Adapter OEM Bluetooth Module comms, control In Stock NOW! In Stock NOW! AT Interface & measurement. Range 100m to 1Km Rural No drivers Power: +18dBm Class 1 Industrial Range of upto 1Km Data rate: upto 115200bps Bluetooth Spec: V2.0+EDR Commercial SENA: OEM Bluetooth Modules and Serial Adapters Parani-ESD1000 RF Modules Australia. P.O. Box 1957 Launceston, TAS., 7250. Ph: 03-6331-6789. Email: sales<at>rfmodules.com.au. Web: rfmodules.com.au HIGH QUALITY VALVE/TUBE KITS MUDLARK VALVE AMP KITS THE A205 a u d i o NX-14 RETRO NIXIE CLOCK s y s t e m s IMPROVED VERSION EVEN BETTER SOUND & LOOKS SC July-Aug 2007 Kit: $899.00 Built: $1299.00 New Models The A2.1 Series Stereo Valve + Subwoofer Amp The best of SE triode sound with a built-in powerful bass subwoofer amp. Total 60W power! 3 KIT VERSIONS FROM $399.00 With genuine NOS valves. Ask for the A2.1 brochure. LIMITED PRODUCTION These amazing clocks are loved by technical and non-technical people alike. Features retro vintage Nixie tubes & crystal control for accurate time. FULL KIT: $259.00 with transparent housing & blue LED uplighting. LESS HOUSING: $199.00 GLESS AUDIO: 7 Lyonsville Ave, Preston 3072. Phone: (03) 9442 3991   Mob: 0403 055 374   Email: glesstron<at>msn.com DOWNLOAD OUR CATALOG at www.iinet.net.au/~worcom Battery Packs & Chargers WORLDWIDE ELECTRONIC COMPONENTS PO Box 631, Hillarys, WA 6923 Ph: (08) 9307 7305 Fax: (08) 9307 7309 Email: worcom<at>iinet.net.au Advertising Index Alternative Tech. Association.......... 91 Altronics............................................ 7 Aztronics......................................... 43 Av-Comm........................................ 94 CJ Appliance................................... 93 Computronics.................................. 94 Dick Smith Electronics............... 20-21 Dontronics....................................... 41 Ecowatch........................................ 93 Ellert Technologies.......................... 94 Emona Instruments......................... 12 Force Electronics............................ 43 Furzy Electronics.............................. 4 Gless Audio..................................... 95 Grantronics..................................... 94 Harbuch Electronics........................ 39 Hare & Forbes..............................OBC High Profile Communications.......... 93 Instant PCBs................................... 95 Jaycar..............................IFC,45-52,96 JED Microprocessors........................ 5 Keith Rippon................................... 93 LED Sales....................................... 93 Microgram Computers...................... 3 MicroZed Computers..................... 8,9 Ocean Controls............................... 10 Ozitronics........................................ 39 Premier Batteries............................ 93 Prime Electronics............................ 11 Quest Electronics............................ 94 RCS Radio...................................... 93 RF Modules..................................... 95 Rockby Electronics......................... 94 Sesame Electronics........................ 93 Silicon Chip Back Issues............ 86-87 Silicon Chip Binders................... 70,79 Silicon Chip Bookshop....83,85,96,IFC SC Perf. Electronics For Cars......... 57 Silicon Chip Subscriptions.............. 92 Siomar Battery Industries............... 95 SOS Components........................... 93 Soundlabs Group.............................. 6 Speakerbits..................................... 94 Splat Controls................................. 94 Tech Repairs................................... 93 Tekmark Australia............................. 6 Telelink............................................ 94 Tenrod Pty Ltd................................. 75 Thomas Scarborough..................... 94 Truscotts Electronic World............... 93 Trusys.............................................. 94 Wagner Electronics......................... 41 Worldwide Elect. Components........ 95 PC Boards Siomar Battery Engineering www.batterybook.com Phone (08) 9302 5444 siliconchip.com.au Printed circuit boards for SILICON CHIP designs can be obtained from RCS Radio Pty Ltd. Phone (02) 9738 0330. Fax (02) 9738 0334. September 2008  95 ALL S ILICON C HIP SUBSCRIBERS – PRINT, OR BOTH – AUTOMATICALLY QUALIFY FOR A REFERENCE $ave 10%ONLINE DISCOUNT ON ALL BOOK OR PARTSHOP PURCHASES. CHIP BOOKSHOP 10% (Does not apply to subscriptions) SILICON For the latest titles and information, please refer to our website books page: www.siliconchip.com.au/Shop/Books PIC MICROCONTROLLERS: know it all SELF ON AUDIO Multiple authors $85.00 The best of subjects Newnes authors have written over the past few years, combined in a one-stop maxi reference. Covers introduction to PICs and their programming in Assembly, PICBASIC, MBASIC & C. 900+ pages. PROGRAMMING and CUSTOMIZING THE PICAXE By David Lincoln (2nd Ed, 2011) $65.00* A great aid when wrestling with applications for the PICAXE See series of microcontrollers, at beginner, intermediate and Review April advanced levels. Every electronics class, school and library should have a copy, along with anyone who works with PICAXEs. 300 pages in paperback. 2011 PIC IN PRACTICE by D W Smith. 2nd Edition - published 2006 $60.00* Based on popular short courses on the PIC, for professionals, students and teachers. Can be used at a variety of levels. An ideal introduction to the world of microcontrollers. 255 pages in paperback. PIC MICROCONTROLLER – your personal introductory course By John Morton 3rd edition 2005. $60.00* A unique and practical guide to getting up and running with the PIC. It assumes no knowledge of microcontrollers – ideal introduction for students, teachers, technicians and electronics enthusiasts. Revised 3rd edition focuses entirely on re-programmable flash PICs such as 16F54, 16F84 12F508 and 12F675. 226 pages in paperback. A collection of 35 classic magazine articles offering a dependable methodology for designing audio power amplifiers to improve performance at every point without significantly increasing cost. Includes compressors/limiters, hybrid bipolar/FET amps, electronic switching and more. 467 pages in paperback. SMALL SIGNAL AUDIO DESIGN By Douglas Self – First Edition 2010 $95.00* The latest from the Guru of audio. Explains audio concepts in easy-to-understand language with plenty of examples and reasoning. Inspiration for audio designers, superb background for audio enthusiasts and especially where it comes to component peculiarities and limitations. Expensive? Yes. Value for money? YES! Highly recommended. 558 pages in paperback. AUDIO POWER AMPLIFIER DESIGN HANDBOOK by Douglas Self – 5th Edition 2009 $85.00* "The Bible" on audio power amplifiers. Many revisions and updates to the previous edition and now has an extra three chapters covering Class XD, Power Amp Input Systems and Input Processing and Auxiliarly Subsystems. Not cheap and not a book for the beginner but if you want the best reference on Audio Power Amps, you want this one! 463 pages in paperback. DVD PLAYERS AND DRIVES by K.F. Ibrahim. Published 2003. $71.00* OP AMPS FOR EVERYONE By Bruce Carter – 4th Edition 2013 $83.00* This is the bible for anyone designing op amp circuits and you don't have to be an engineer to get the most out of it. It is written in simple language but gives lots of in-depth info, bridging the gap between the theoretical and the practical. 281 pages, PROGRAMMING 32-bit MICROCONTROLLERS IN C By Luci di Jasio (2008) $79.00* Subtitled Exploring the PIC32, a Microchip insider tells all on this powerful PIC! Focuses on examples and exercises that show how to solve common, real-world design problems quickly. Includes handy checklists. FREE CD-ROM includes source code in C, the Microchip C30 compiler, and MPLAB SIM. 400 pages paperback. PRACTICAL GUIDE TO SATELLITE TV By Garry Cratt – Latest (7th) Edition 2008 $49.00 Written in Australia, for Australian conditions by one of Australia's foremost satellite TV experts. If there is anything you wanted to know about setting up a satellite TV system, (including what you can't do!) it's sure to be covered in this 176-page paperback book. NEWNES GUIDE TO TV & VIDEO TECHNOLOGY By KF Ibrahim 4th Edition (Published 2007) $49.00 It's back! Provides a full and comprehensive coverage of video and television technology including HDTV and DVD. Starts with fundamentals so is ideal for students but covers in-depth technologies such as Blu-ray, DLP, Digital TV, etc so is also perfect for engineers. 600+ pages in paperback. RF CIRCUIT DESIGN by Chris Bowick, Second Edition, 2008. $63.00* The classic RF circuit design book. RF circuit design is now more important that ever in the wireless world. In most of the wireless devices that we use there is an RF component – this book tells how to design and integrate in a very practical fashion. 244 pages in paperback. A guide to DVD technology and applications, with particular focus on design issues and pitfalls, maintenance and repair. Ideal for engineers, technicians, students of consumer electronics and sales and installation staff. 319 pages in paperback. See Review March 2010 See Review Feb 2004 SWITCHING POWER SUPPLIES A-Z by Sanjaya Maniktala, Published April 2012. $83.00 Thoroughly revised! The most comprehensive study available of theoretical and practical aspects of controlling and measuring EMI in switching power supplies. ELECTRIC MOTORS AND DRIVES By Austin Hughes & Bill Drury - 4th edition 2013 $59.00* This is a very easy to read book with very little mathematics or formulas. It covers the basics of all the main motor types, DC permanent magnet and wound field, AC induction and steppers and gives a very good description of how speed control circuits work with these motors. Soft covers, 444 pages. AC MACHINES By Jim Lowe Published 2006 $66.00* Applicable to Australian trades-level courses including NE10 AC Machines, NE12 Synchronous Machines and the AC part of NE30 Electric Motor Control and Protection. Covering polyphase induction motors, singlephase motors, synchronous machines and polyphase motor starting. 160 pages in paperback. PRACTICAL VARIABLE SPEED DRIVES & POWER ELECTRONICS Se e by Malcolm Barnes. 1st Ed, Feb 2003. $73.00* Review An essential reference for engineers and anyone who wishes to design or use variable speed drives for induction motors. 286 pages in soft cover. Feb 2003 BUILD YOUR OWN ELECTRIC MOTORCYCLE PRACTICAL RF HANDBOOK by Ian Hickman. 4th edition 2007 $61.00* by Douglas Self 2nd Edition 2006 $69.00* by Carl Vogel. Published 2009. $40.00* A guide to RF design for engineers, technicians, students and enthusiasts. Covers key topics in RF: analog design principles, transmission lines, couplers, transformers, amplifiers, oscillators, modulation, transmitters and receivers, propagation and antennas. 279 pages in paperback. Alternative fuel expert Carl Vogel gives you a hands-on guide with the latest technical information and easy-to-follow instructions for building a two-wheeled electric vehicle – from a streamlined scooter to a full-sized motorcycle. 384 pages in soft cover. *NOTE: ALL PRICES ARE PLUS P&P – AUSTRALIA ONLY: $10.00 per order; NZ – $AU12.00 PER BOOK; REST OF WORLD $AU18.00 PER BOOK PAYPAL (24/7) INTERNET (24/7) MAIL (24/7) PHONE – (9-5, Mon-Fri) eMAIL (24/7) FAX (24/7) To ilicon Chip Use your PayPal account www.siliconchip. Call (02) 9939 3295 with silicon<at>siliconchip.com.au Your order and card details to Your order to PO Box 139 Place96  S com.au/Shop/Books silicon<at>siliconchip.com.au Collaroy NSW 2097 with order & credit card details with order & credit card details (02) 9939 2648 with all details Your You can also order and pay for books by cheque/money order (Mail Only). Make cheques payable to Silicon Chip Publications. Order: ALL TITLES SUBJECT TO AVAILABILITY. PRICES VALID FOR MONTH OF MAGAZINE ISSUE ONLY. ALL PRICES INCLUDE GST ALL S ILICON C HIP SUBSCRIBERS – PRINT, OR BOTH – AUTOMATICALLY QUALIFY FOR A REFERENCE $ave 10%ONLINE DISCOUNT ON ALL BOOK OR PARTSHOP PURCHASES. CHIP BOOKSHOP 10% (Does not apply to subscriptions) SILICON For the latest titles and information, please refer to our website books page: www.siliconchip.com.au/Shop/Books PIC MICROCONTROLLERS: know it all SELF ON AUDIO Multiple authors $85.00 The best of subjects Newnes authors have written over the past few years, combined in a one-stop maxi reference. Covers introduction to PICs and their programming in Assembly, PICBASIC, MBASIC & C. 900+ pages. PROGRAMMING and CUSTOMIZING THE PICAXE By David Lincoln (2nd Ed, 2011) $65.00* A great aid when wrestling with applications for the PICAXE See series of microcontrollers, at beginner, intermediate and Review April advanced levels. Every electronics class, school and library should have a copy, along with anyone who works with PICAXEs. 300 pages in paperback. 2011 PIC IN PRACTICE by D W Smith. 2nd Edition - published 2006 $60.00* Based on popular short courses on the PIC, for professionals, students and teachers. Can be used at a variety of levels. An ideal introduction to the world of microcontrollers. 255 pages in paperback. PIC MICROCONTROLLER – your personal introductory course By John Morton 3rd edition 2005. $60.00* A unique and practical guide to getting up and running with the PIC. It assumes no knowledge of microcontrollers – ideal introduction for students, teachers, technicians and electronics enthusiasts. Revised 3rd edition focuses entirely on re-programmable flash PICs such as 16F54, 16F84 12F508 and 12F675. 226 pages in paperback. A collection of 35 classic magazine articles offering a dependable methodology for designing audio power amplifiers to improve performance at every point without significantly increasing cost. Includes compressors/limiters, hybrid bipolar/FET amps, electronic switching and more. 467 pages in paperback. SMALL SIGNAL AUDIO DESIGN By Douglas Self – First Edition 2010 $95.00* The latest from the Guru of audio. Explains audio concepts in easy-to-understand language with plenty of examples and reasoning. Inspiration for audio designers, superb background for audio enthusiasts and especially where it comes to component peculiarities and limitations. Expensive? Yes. Value for money? YES! Highly recommended. 558 pages in paperback. AUDIO POWER AMPLIFIER DESIGN HANDBOOK by Douglas Self – 5th Edition 2009 $85.00* "The Bible" on audio power amplifiers. Many revisions and updates to the previous edition and now has an extra three chapters covering Class XD, Power Amp Input Systems and Input Processing and Auxiliarly Subsystems. Not cheap and not a book for the beginner but if you want the best reference on Audio Power Amps, you want this one! 463 pages in paperback. DVD PLAYERS AND DRIVES by K.F. Ibrahim. Published 2003. $71.00* OP AMPS FOR EVERYONE By Bruce Carter – 4th Edition 2013 $83.00* This is the bible for anyone designing op amp circuits and you don't have to be an engineer to get the most out of it. It is written in simple language but gives lots of in-depth info, bridging the gap between the theoretical and the practical. 281 pages, PROGRAMMING 32-bit MICROCONTROLLERS IN C By Luci di Jasio (2008) $79.00* Subtitled Exploring the PIC32, a Microchip insider tells all on this powerful PIC! Focuses on examples and exercises that show how to solve common, real-world design problems quickly. Includes handy checklists. FREE CD-ROM includes source code in C, the Microchip C30 compiler, and MPLAB SIM. 400 pages paperback. PRACTICAL GUIDE TO SATELLITE TV By Garry Cratt – Latest (7th) Edition 2008 $49.00 Written in Australia, for Australian conditions by one of Australia's foremost satellite TV experts. If there is anything you wanted to know about setting up a satellite TV system, (including what you can't do!) it's sure to be covered in this 176-page paperback book. NEWNES GUIDE TO TV & VIDEO TECHNOLOGY By KF Ibrahim 4th Edition (Published 2007) $49.00 It's back! Provides a full and comprehensive coverage of video and television technology including HDTV and DVD. Starts with fundamentals so is ideal for students but covers in-depth technologies such as Blu-ray, DLP, Digital TV, etc so is also perfect for engineers. 600+ pages in paperback. RF CIRCUIT DESIGN by Chris Bowick, Second Edition, 2008. $63.00* The classic RF circuit design book. RF circuit design is now more important that ever in the wireless world. In most of the wireless devices that we use there is an RF component – this book tells how to design and integrate in a very practical fashion. 244 pages in paperback. A guide to DVD technology and applications, with particular focus on design issues and pitfalls, maintenance and repair. Ideal for engineers, technicians, students of consumer electronics and sales and installation staff. 319 pages in paperback. See Review March 2010 See Review Feb 2004 SWITCHING POWER SUPPLIES A-Z by Sanjaya Maniktala, Published April 2012. $83.00 Thoroughly revised! The most comprehensive study available of theoretical and practical aspects of controlling and measuring EMI in switching power supplies. ELECTRIC MOTORS AND DRIVES By Austin Hughes & Bill Drury - 4th edition 2013 $59.00* This is a very easy to read book with very little mathematics or formulas. It covers the basics of all the main motor types, DC permanent magnet and wound field, AC induction and steppers and gives a very good description of how speed control circuits work with these motors. Soft covers, 444 pages. AC MACHINES By Jim Lowe Published 2006 $66.00* Applicable to Australian trades-level courses including NE10 AC Machines, NE12 Synchronous Machines and the AC part of NE30 Electric Motor Control and Protection. Covering polyphase induction motors, singlephase motors, synchronous machines and polyphase motor starting. 160 pages in paperback. PRACTICAL VARIABLE SPEED DRIVES & POWER ELECTRONICS Se e by Malcolm Barnes. 1st Ed, Feb 2003. $73.00* Review An essential reference for engineers and anyone who wishes to design or use variable speed drives for induction motors. 286 pages in soft cover. Feb 2003 BUILD YOUR OWN ELECTRIC MOTORCYCLE PRACTICAL RF HANDBOOK by Ian Hickman. 4th edition 2007 $61.00* by Douglas Self 2nd Edition 2006 $69.00* by Carl Vogel. Published 2009. $40.00* A guide to RF design for engineers, technicians, students and enthusiasts. Covers key topics in RF: analog design principles, transmission lines, couplers, transformers, amplifiers, oscillators, modulation, transmitters and receivers, propagation and antennas. 279 pages in paperback. Alternative fuel expert Carl Vogel gives you a hands-on guide with the latest technical information and easy-to-follow instructions for building a two-wheeled electric vehicle – from a streamlined scooter to a full-sized motorcycle. 384 pages in soft cover. *NOTE: ALL PRICES ARE PLUS P&P – AUSTRALIA ONLY: $10.00 per order; NZ – $AU12.00 PER BOOK; REST OF WORLD $AU18.00 PER BOOK PAYPAL (24/7) INTERNET (24/7) MAIL (24/7) PHONE – (9-5, Mon-Fri) eMAIL (24/7) FAX (24/7) To siliconchip.com.au September Use your PayPal account www.siliconchip. Call (02) 2008  97 9939 3295 with silicon<at>siliconchip.com.au Your order and card details to Your order to PO Box 139 Place com.au/Shop/Books silicon<at>siliconchip.com.au Collaroy NSW 2097 with order & credit card details with order & credit card details (02) 9939 2648 with all details Your You can also order and pay for books by cheque/money order (Mail Only). Make cheques payable to Silicon Chip Publications. Order: ALL TITLES SUBJECT TO AVAILABILITY. PRICES VALID FOR MONTH OF MAGAZINE ISSUE ONLY. ALL PRICES INCLUDE GST