Fullscreen HTML5Med Res (??MB)HTML4

SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings.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.18, No.4; April 2005 www.siliconchip.com.au FEATURES   8 Install Your Own In-Car Video Want a reversing monitor and/or an in-car navigation system? Or how about a back-seat screen for entertainment video? Here’s how to do-it-yourself and save money – by Gary Rollans 15 Atlas SCR – Thyristor & Triac Tester You just connect the test leads to the device in any order and press the test button for go/no-go indication – by Peter Smith 36 The Start Of Colour TV In Australia, Pt.2 The sets that we bought 30 years ago and their problems – by Keith Walters Build A MIDI Theremin – Page 24. PROJECTS TO BUILD 24 Build A MIDI Theremin, Pt.1 Connect it to your PC or to a MIDI synthesiser for a truly awesome array of sound possibilities – by John Clarke 60 Bass Extender For Hifi Systems Want an extra octave of bass response from your loudspeakers? This simple circuit will get them pumping – by Rick Walters 70 Build A Professional Sports Scoreboard, Pt.2 Second article has the Control Console assembly plus the control board assembly for the main display unit – by Jim Rowe 78 SMS Controller Add-Ons Install Your Own In-Car Video System – Page 8. Here are three handy add-ons for your SMS Controller: a simple test jig, a PIR sensor interface and a low battery alarm – by Peter Smith SPECIAL COLUMNS 44 Serviceman’s Log Tempest tortures Turkish Teac – by the TV Serviceman 66 Circuit Notebook (1) Automatic Security Lights; (2) Op Amp Auto-Zero Circuit; (3) Synthetic Floating Negative Inductor; (4) Plugpack Checker 80 Vintage Radio The mysterious Monarch D671/32 from Astor – by Rodney Champness Bass Extender – Page 60. 88 Salvage It! A $5 variable voltage power supply – by Julian Edgar DEPARTMENTS   2   4 57 90 Publisher’s Letter Mailbag Product Showcase Order Form siliconchip.com.au 94 97 100 103 Ask Silicon Chip Notes & Errata Market Centre Ad Index $5 Variable Voltage Power Supply – Page 88. April 2005  1 SILICON CHIP www.siliconchip.com.au Publisher & Editor-in-Chief Leo Simpson, B.Bus., FAICD Production Manager Greg Swain, B.Sc.(Hons.) Technical Editor Peter Smith Technical Staff John Clarke, B.E.(Elec.) Ross Tester Jim Rowe, B.A., B.Sc, VK2ZLO Reader Services Ann Jenkinson Advertising Enquiries Lawrence Smith Benedictus Smith Pty Ltd Phone (02) 9211 8035 Fax: (02) 9211 0068 lawrence<at>benedictus-smith.com Publisher’s Letter Reader feedback is welcome This month, as in all months, we have some very good letters from readers, on a diverse range of topics. As you will see in the Mailbag pages starting on page 4, some are very complimentary and others, well . . . you can see for yourself. In particular, my answer to David Millist last month on the topic of current transformers brought forth a torrent of letters, both by email and by post. David Millist can take a bow because all the letters rushed to his defence. I must admit to being taken aback by the vehemence of some of the letters – we have only included a selection – and I thought “Oh dear, what have we unleashed this time?” As I went through the letters and talked to a few older readers, I realised that in stating that we failed to see how a current transformer can generate lethal voltages, I had completely overlooked the common type of current transformers widely used in power distribution systems. If an open-circuit occurs in the secondary winding, such transformers can be very dangerous indeed. Regular Contributors Brendan Akhurst Rodney Champness, VK3UG Julian Edgar, Dip.T.(Sec.), B.Ed, Grad.Dip.Jnl Mike Sheriff, B.Sc, VK2YFK Stan Swan And of course, after we ran a few current monitoring lashups, I had to admit an error in the operation of toroids. Expletive deleted. 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. I particularly like the fact that so many readers comment on the answers in “Ask SILICON CHIP”. Readers enjoy most sections of the magazine, but “Ask SILICON CHIP” consistently generates far more correspondence than any other section, both in questions asked and comments on the resulting answers. Printing: Hannanprint, Noble Park, Victoria. Distribution: Network Distribution Company. Subscription rates: $83.00 per year in Australia. For overseas rates, see the subscription page in this issue. Editorial office: Unit 8, 101 Darley St, Mona Vale, NSW 2103. Postal address: PO Box 139, Collaroy Beach, NSW 2097. Phone (02) 9979 5644. Fax (02) 9979 6503. E-mail: silchip<at>siliconchip.com.au On reflection, I realise that such rapid feedback from readers, immediately after an issue has gone on sale, is a good thing. Many thousands of readers take SILICON CHIP very seriously indeed and are anxious that we continue to maintain a high standard. We like getting the compliments and therefore we must also accept the criticisms when they come. We have always known that our readers are vigilant, which is why I hate it when errors do appear in the magazine. That is one of the drawbacks of a print magazine – when an error occurs, it is there for all time. We can and do publish Notes & Errata but the error still remains on the printed pages. An on-line publication is different; if an error occurs, you can do a quick up-load and presto, it might never have happened. But our long-term destiny appears to be with the print magazine. While the on-line version of SILICON CHIP is popular with many people, the vast majority appear to favour the printed edition. It is so much easier to read, to digest and refer back to, and to spot those loathsome errors! Leo Simpson ISSN 1030-2662 * Recommended and maximum price only. 2  Silicon Chip siliconchip.com.au For more ideas, greater choice & better service, try MicroGram Product of the month Windows Based Terminal Supports Windows Terminal Server with Microsoft RDP & Citrix ICA protocols. Also emulates SCO, DEC, Wyse terminals. Cat 1239-7 $649 A basic cash register suitable for small retail outlets. Cat 1008129-7 $289 Highpoint SATA RAID VPN Server Provides 48 digital I/O lines on a PCI PnP interface card. Has three 16bit counters with a maximum count rate of 10MHz. Cat 17053-7 $249 • Designed specifically for Skype. • Make free phone calls world wide - Skype to Skype • Ridiculously cheap phone calls to any fixed line phone in Australia for approx. 3 cents/min NO FLAG FALL Cat 10165-7 Desktop Style $129 Cat 10166-7 Mobile Style $119 IP KVM Attach this unit and access all the machines on your existing KVM remotely with a web browser. Even allows you to reload the OS on the remote computer using your local CD drive. Cat 11674-7 $1099 Wireless Keypad for Notebook Digital I/O to Ethernet This unit allows the user to remotely control 7 Digital I/O ports and 1 RS232/422/485 port over LAN or WAN. Cat 15157-7 $329 Zebra LP2844 Barcode Printer LCD with Terminal USB Barcode Scanner 17" LCD with a Windows Control one computer from A reliable thermal printer that is based termitwo different locations (not at great for retail outlets or small nal built in. the same time). Uses standard warehouses. Print width of Has Win CE keyboards, monitors & PS/2 with IE. 28mm to 104mm. Serial, Cat 1236-7 mouses Parallel and USB interface. Cat 11667-7 $139 $1849 Cat 5751-7 $799 Serial Over wLAN Use any serial device over a 4 port SATA RocketRAID card. wireless connection. A higher Supports RAID 0,1,5,10 and gain antenna can be attached JBOD. to cover longer distances. Cat 2906-7 $249 Cat 15155-7 $529 Digital I/O Card Internet Phones This keypad is the same as a numpad on a full size keyboard. It also has 14 multimedia keys. Cat 1008153-7 $69 Provides up to 100 VPN tunnels for secure access over wLAN or WAN links. Cat 10164-7 $849 Computer Sharer Sharp Cash Register What’s new? Extend USB 50m Use inexpensive UTP cable (not included) to extend any USB 1.1 device up to 50m from the PC. Cat 11666-7 $105 SMS I/O Controller Symbol LS-2208 CCD Barcode scanner. Comes with a stand and attaches to a USB port. Cat 8614-7 $499 USB Temp and Humidity Sensor 64Bit 3.3v PCI-X Serial Card Wireless Hotspot Allow users to access the Internet over a secure wireless link. Great for cafes, libraries, conference rooms etc. Cat 11451-7 $1199 Switch any electrical device on or off by sending an SMS from any mobile phone. Cat 17087-7 $1029 Measures the relative humidity and temperature and can graph the results on the included software. Cat 17090-7 $319 Cash Drawer 64Bit 3.3v PCI-X Parallel Card Fingerprint Reader Serial Over Bluetooth Can be attached to Epson/Star/Citizen/Posiflex parallel receipt printers. Cat 8897-7 $199 Compatible with both 32 and 64bit PCI slots. Single DB25 connector Cat 2871-7 $119 Provide secure access to your PC using this USB fingerprint reader. Cat 9237-7 $199 Turn any serial device into a cordless device over a Bluetooth link. Cat 11908-7 $459 Compatible with both 32 and 64bit PCI slots. Two DB9 connectors. Cat 2870-7 $149 USB to 8 Port Serial Attach up to 8 serial devices to one USB port. Cat 2936-7 $459 Wireless LAN Equipment! We’ve got the lot - antennas, cards, pigtails, converters, cables! MicroGram Computers Ph: (02) 4389 8444 FreeFax: 1800 625 777 Vamtest Pty Ltd trading as MicroGram Computers ABN 60 003 062 100, info<at>mgram.com.au 1/14 Bon Mace Close, Berkeley Vale NSW 2261 All prices subject to change without notice. For current pricing visit our website. Pictures are indicative only. See all these products & more on our website...www.mgram.com.au A 2005  3 siliconchip.com.au pril SHORE AD/MGRM0405 Dealer inquiries welcome MAILBAG Desalination water costs are wrong The costs you quoted in the March editorial for WA’s desalinated and piped water were surely not as shown? They correspond to about 50c and $1.50 per litre! This is as high as the bottled water racket charges on our supermarket shelves. On the subject of loud DVD background music, my thanks to Graham Johnston (Mailbag, March 2005). I do not use an amplifier but I find that by connecting the centre audio channel to one of the TV speakers and making no connection to the other, nearly all the music is suppressed and the dialog is very clear. Robin Stokes, Armidale, NSW. Comment: three people proof-read that March editorial – they must be blind! The figures should have related to a kilolitre of water! Disagreement on current transformers David Millist wrote regarding current transformers (March 2005, page 6) and I wish to disagree with your comment on this matter. Referring to open circuit secondary voltages being dangerous, I enclose a copy of a relevant page from a text book used in gaining the Electrical Engineering Certificate from NSW TAFE during the 1960s, which included the Electrical Measurements option. It does indicate some danger to persons and equipment and the reasons behind it. With regard to the one conductor through the core being considered as a full turn, many students question this but the lecturers were adamant that it was correct and that it definitely could not be treated as a “half turn”. Unfortunately, age has blunted the memory and I am unable to elucidate the theory. Nor can I find any clear reference in the several texts which I have retained covering the subject. In my work with current transformers used in test equipment, it was usual for there to be a link or simple switch provided on the transformer to facilitate short circuiting the sec4  Silicon Chip ondary and the work instructions were quite clear “DON’T FORGET TO SHORT BEFORE OPENING THE SECONDARY CIRCUIT”. Peter Grout, Forestville, NSW. Current transformers generate high voltage I must agree with David Millist – current transformers (Instrument Type at least) must never have an open secondary as they generate high voltages. This was one of the first things I was taught as an apprentice in the electrical generation/distribution industry some 35 years ago. I have checked various reference books, such as Newnes Electronics Engineer’s Pocket Book 1996, and page 16 carries that very warning! It also explains why! It is a shame your “comment author” did not check the facts before commenting! Another electrical hand book clearly states: “The secondary must be shortcircuited if the ammeter is removed for servicing”. What a shame they have made such a basic uninformed mistake! Michael Abrams, Capalaba, Qld. Current transformers can be lethal I read the letter from David Millist on current transformers and your reply. I am inclined to agree with Mr Millist. The secondary voltage of any transformer is (if I’ve got it right) actually proportional to the time rate of change of the flux – ie, d(f)/dt – which most of the time is proportional to the primary voltage. The output voltage of a current transformer loaded with a resistor is proportional to the product of the secondary current and the load resistance, so in the extreme case when the load resistance becomes infinite, one might expect the secondary voltage to become infinite as well. Of course, this won’t happen in the real world as other effects come into play. Furthermore, the burden of a current transformer will increase if it is not terminated, so the primary voltage will increase in such circumstances, and less voltage will be dropped across the load whose current is being measured. So high voltages can be generated at the secondary terminals of a current transformer if it is not terminated with a low enough impedance. Whether they are lethal will depend on the particular circumstances. I reckon that in many cases the shock might be unpleasant at least. The source impedance of a current transformer (essentially the secondary winding impedance) is pretty low, so one would expect that they could deliver currents that might be lethal. The issue is whether enough voltage can be sustained long enough for a lethal current to be delivered. Lethality of a current depends on its magnitude and the length of the exposure. On the issue of full or half turns in a toroid, David Millist is quite correct. It is not possible to use a genuine toroid core with anything but an integer number of turns. The wire through the centre might appear as half a turn but the turn is completed in the outside world. Non integer turns are only possible in cores with more than one hole (such as the E-I form common in mains power transformers). Two holes can give half turns, three holes could give a third of a turn, etc. Phil Denniss, University of Sydney. Comment: ahem, hmm (gulp – large slice of humble pie required to be eaten here). OK, since people have been so adamant about this, we had to go and do some actual tests. Never mind theory – what happens in practice? siliconchip.com.au We did a number of tests with toroidal power transformers to simulate the effect of a straight wire carrying 1A through the centre of the core. These tests were quite unequivocal – a straight wire is exactly equivalent to full turn, not a half turn. We repeated the tests with a clamp meter and again, the result was exactly the same. So yes, we were wrong! On the question of current transformers though, we plead not (so) guilty. Our answer is still essentially correct. It appears that readers have assumed that we are talking about current transformers used in power distribution systems whereby very high currents are monitored by a moving iron ammeter in the secondary of the current transformer. Certainly, these transformers can be very dangerous if the ammeter is disconnected while current flows in the primary. In fact, the voltages can be high enough to destroy the transformer itself. In really big current transformers, there is even the risk of a violent explosion if the ammeter connection in the secondary is inadvertently broken. But in our reply to David Millist, we did not think about such large current transformers. After all, not many electronic enthusiasts have access to such beasts! Our original answer relates to a letter on page 98 of the January 2005 issue and is about a flea-power transformer to drive a high impedance multimeter. Nor did we suggest the specific figure of 1000 turns, just many turns. However, as part of our tests, we measured the voltage from the 240VAC primary of a 160VA transformer which actually had 1024 turns. With the same 1A wire through the centre of the toroid and using the 240VAC primary as the secondary, the output voltage was 18.5VAC into a 10MW load – ie, a digital multimeter – and 6.2VAC when loaded with a 10kW resistor. From that, if the wire carried 10A, you could expect 185VAC into 10MW and 62VAC into a 10kW load. So yes, the voltage into an open circuit is much higher, as we would expect, but again even this is a much bigger current transformer than our original answer suggested. In hindsight, we should have been siliconchip.com.au more specific in our original answer. If we had suggested, say, 50 or 100 turns on the secondary, it would have been quite sufficient to drive a high impedance (10MW) digital multimeter. Current transformers operate in a different mode In your reply to the letter on Current Transformers in the March 2005 issue, you state that you cannot “see how a current transformer can generate a dangerous voltage unless it has a significant voltage across its primary”. The problem with current transformers is that they operate in a different mode to the basic voltage transformer that most people are used to – and the expected transformer ratio rules simply don’t apply! For a current transformer, the core flux depends on the primary current (as per a voltage transformer) and also on the flux, generated by the secondary current that, according to Lenz’s Law, cancels out most of the primary flux, leaving the core with a low level of total flux, and a low generated EMF in the secondary winding. (CTs typically run with low core flux levels compared to voltage transformers, and so generate no more than 5 -15V at maximum primary and secondary current.) CTs with no load have a primary flux but do not have an opposing secondary flux, so the basic voltage transformer operation, as well as the normal transformer rules cannot be applied to them. This occurs because, if you open the secondary and power up the CT primary, the primary current will drive the core flux to quite high values, as there is no secondary flux to oppose and reduce the primary flux, and these high flux levels in the core generate high EMFs in the secondary winding, which may have hundreds of turns in larger (commercial) CTs. In many instances, low ratio CTs – 50:5 (ie, 50A primary to 5A secondary), or 100:5 – can yield over 100V across the secondary terminals and in the case of high ratio CTs (2000:5 or 5000:5), several thousand volts are common. This can cause flashovers and in the case of oil-filled CTs used by the supply authorities, has led to explosions and fires on occasions. Although the CT in the project mentioned is not capable of these 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 outs, LCD/ Kbd, 2xRS232, 1xRS485, 1-Wire, power reg. etc. See www.jedmicro.com.au/avr.htm $330 PC-PROM Programmer This programmer plugs into a PC printer port and reads, writes and edits any 28 or 32-pin PROM. Comes with plug-pack, cable and software. Also available is a multi-PROM UV eraser with timer, and a 32/32 PLCC converter. JED Microprocessors Pty Ltd 173 Boronia Rd, Boronia, Victoria, 3155 Ph. 03 9762 3588, Fax 03 9762 5499 www.jedmicro.com.au April 2005  5 Mailbag: continued effects, it may generate voltages that do exceed Extra-Low Voltage (32V AC) and so may present a hazard to electronic devices to which they connect or they may “bite” an incautious service person hard enough to cause dropped tools, with possible short-circuit problems and naughty sailor-type words from the lips of the startled technician. So David Millist’s statement that CTs can and will generate lethal voltages with an open circuit secondary is quite correct. The “lethal” applies mainly to commercial CTs as you know but you cannot apply the “logical” voltage transformation rules to a CT to understand the reason for those high voltages! Secondly, a “half-turn” through a CT core is effectively a single turn – if you draw a sketch of a single turn passing through a toroid, all of that turn’s flux expands out and enters the core, and generates an EMF. The permeability of the core, with no air gaps, gives up to 2000 times the flux in the core that a conductor surrounded by air would generate, so any conductor inside the core is very effective. But if you place the same conductor outside the core and sketch its flux path, the flux may enter the core on the side nearest the core but it must leave the core before passing all the way round and has to expand away from the core, through air, on the side remote from the core. That means there’s a very large air gap in the magnetic path outside the core, which gives a low relative permeability (typically slightly more than unity) for the flux path and hence low flux generated in the turn outside the core. That, in turn, means that the side of the turn outside the core has almost no effect in generating voltages in a core with a “closed” flux path! Only an E-I core or double C-core will use both sides of a turn and hence have “half-turn” capability. Toroids or single C-cores only use the part of the turn inside the core to generate useful flux, generally, so a “half-turn” counts as one turn, really! Of course, this doesn’t apply to air-core inductors (RF transformers, etc) where the absence of the iron 6  Silicon Chip core means all core permeabilities are unity. Nor does it apply to RF and IF transformer “rod-type” ferrite cores. This is because this type of construction always has large air gaps around the coils, with the core inside the turns and no “easy” flux path. This means that all flux paths have about the same (low) permeability, and “partial” turns do have a proportional effect. Brian Spencer, Seaford, SA. Comment: oh, well – see our previous comment. Thanks from East Hills Girls Just a short email to thank Ross Tester and the staff at SILICON CHIP for your excellent article on the PEDX project in the February 2005 Issue. The article has provided the greatest boost for both our students and the school community. It has show-cased what a small group of our students are capable of achieving with very limited resources, especially time. They were particularly proud to have their photo in print and also on the internet. This year is also the first time that the school has run a year 9 electronics class. It is proving to be quite a success. We were surprised just how many girls are involved in electronics in one form or another, outside of school. Steve Sharp, Head Teacher, Information & Communications Technology, East Hills Girls Technology High School, NSW. Better method for setting amplifier quiescent current I wish to comment about the setting of quiescent current (Iq) in audio amplifiers. I never set it up by the book – ie, adjust the trimpot for XmA or YmV across the emitter resistors. I have found that to get it right, you connect a dummy load to the output of the amplifier, connect your CRO across the load, connect your signal generator to the amplifier input and set it to say 30kHz. With an output of full screen on the CRO with the attenuator set to 0.5V/ DIV, probes on X1 setting (a total of about 4V p-p), you then adjust the Iq pot for no crossover distortion. With amplifiers that I know will run OK with more Iq, I give them say, an extra 10-15mA – it depends on the heatsink size and thermal feedback arrangements. Leaving them to soak for an hour or so and then giving them a power/cool down test usually lets you know if it’s set too high. Many years ago, a Leak Delta 70 came across my bench. When repaired, set up as above and returned to its owner, I received a phone call from him. “Oh-oh what’s wrong?” was my initial reaction. As it turned out there was nothing wrong. He rang to say that he had had the unit repaired before and when he received it this time it “sounded” so much better. He had not really been happy with the sound since new but he was really pleased this time. Brad Sheargold, Collaroy, NSW. Comment: we are not keen on your method for setting Iq. In our experience, at 30kHz, secondary crossover distortion becomes quite significant and usually is not greatly affected by the amount of quiescent current. In any case, trying to judge crossover distortion just by looking at a sinewave is very difficult. Most good amplifiers will show no visible crossover distortion, even at high frequencies and low power. The only sure way to judge the setting is with the benefit of a harmonic distortion analyser which can display the distortion products on an oscilloscope. That is not to say that some amplifiers might not benefit from a small increase in quiescent current. However we would not recommend increasing the quiescent current setting for any of our designs, unless the builder has access to the above test equipment. Positive feedback on audio projects This is just some feedback about very positive results I have had from several SILICON CHIP projects. The first is the 175W power amplifier (SILICON CHIP, April 1996) built for my brother who is a musician. I matched it to a version of the JC-80 loudspeakers (October 2003). I used the same drivers and crossover but changed the shape (not the volume) of the speaker box. siliconchip.com.au In the setup, a balanced microphone signal is fed into a preamp, (SILICON CHIP, April 1995) and then fed to the amplifier via a 5-Band Graphics Equaliser, (SILICON CHIP, December 1995). The results are very pleasing, with plenty of power and excellent quality sound. The other success is a Sub Bass Processor described in “Electronics Australia” (September 1999), feeding into an SC480 amplifier (SILICON CHIP, January & February 2003), driving the subwoofer described in March 2003. The Sub Bass Processor is connected to the speaker output lines of a Pioneer stereo hifi amplifier (about 30W RMS per channel). The results were very pleasing indeed, especially playing older tapes and LPs that could only supply a rather poor bass signal. Joe Kelly, via email. Tektronix TPS2000 The New Isolated Channel Battery Operated Scope. Ratting old headlamp globes Thanks for that great Salvage It! article on pages 90 & 91 of the February 2005 issue. Headlight globes usually fail when the low-beam filament blows before the high-beam filament. This leaves us with a globe that can’t be used in a vehicle. In the circuit on page 91, a resistor is used to limit the current to the maximum of the plugpack. By replacing the resistor with the high-beam filament of an old headlamp globe, we can utilise a globe that would normally be thrown out. Not only does this recycle an old globe but it also acts as a constant current source, while still allowing the battery voltage to rise with time. Let us assume that a high-beam filament is rated at 100W. Using the formula R = V x V divided by P, then the resistance of the hot filament would be about 1.44W. Assuming a 13.5V DC plugpack and that the battery is at about 11V when flat, there would only be a maximum of 2.5V across the globe, so it would never get hot. The resistance of a headlight filament varies with current, thus acting as a constant current source while still charging the battery. In the case where a headlight globe was passing too much current, an 18W stoplight globe could be used. Chris Potter, Kilsyth, Vic. Cheap checker for remote controls Using the Remote Control Checker kit (January 2005) or a video camera (February 2005) to check if your remote control is working are both effective. If you can’t afford the above methods, try my (poor man’s) version: grab the nearest broadcast trannie, tune between stations, increase volume and place the remote control within a couple of centimetres of the end of its ferrite rod antenna and press a button. Norman Ratcliffe, Toorbul, Qld. Comment: your method using an AM broadcast radio works extremely well. Thanks. siliconchip.com.au Do you face these Power Measurement Challenges? • Make multi-channel floating measurements • Measure current and voltage distortion and their spectral content • Measure harmonics, instantaneous power, power factor, switching loss to characterise power electronics circuitry • Measure 3-phase currents & voltages • Validate compliance to regulatory standards • Work in an environment without AC Power • Document and Save your measurement results For more information about the TPS2000 family... Talk to NewTek Instruments: Ph: 02 9888 0100 email: info<at>newtekinstruments.com NewTek Instruments Pty Ltd - Sydney - Melbourne www.newtekinstruments.com April 2005  7 $ave BIG money: Install Your Own In- Now you can install your own in-car video system at a fraction of the cost of the ones you’ve seen in those fancy luxury cars. Jaycar Electronics has everything you need to put together a system for fitting a reversing monitor and/or in-car navigation system to your dashboard, or even a back-seat screen for the kids to watch DVDs, TV or playing their PS-2 on those long, boring trips. You have the choice of a rear-view “mirror” display, as shown here, or you could add a GPS unit and an old laptop computer for a highly useful “Sat Nav” unit. Both are perfectly legal to use while driving along but you cannot mount the screen in this position for “entertainment” video – for that, the driver must not be able to view the screen while driving. 8  Silicon Chip siliconchip.com.au By Gary Rollans -Car Video! T HE BASIC installation we are going to describe here is a really useful rear-view video system that takes the guesswork out of reversing 4WDs, vans, trucks and buses, etc. We’ll even show you how to extend it to cover caravans, large trailers and even semi-trailers, B-doubles and road trains! Where you take it from there depends entirely on your requirements: keeping the kids entertained on long trips with games or a mobile DVD player, finding your way around Australia (or a strange city!) with GPS sat nav . . . it really is an open-ended equation. But back to the basic system: a dash-mounted video screen and a rear-of-vehicle mounted colour video camera which gives you a much better view behind your vehicle than you can achieve with mirrors. The camera is designed for exactly this purpose, producing a reversed output so that picture you see on the screen is just like the one you see in an ordinary rear-view mirror – ie, reversed. However, if you already have a standard camera (ie, right-reading), it’s possible to use that as well. We’ll explain how shortly. Mounted in the dash, the video display doesn’t stand out as anything special . . . But press the button (left top) and it pops out, ready to be . . . The screen type There are currently three types of screen available from Jaycar: ceiling mounted, in-dash mounted and ondash mounted. The hardest thing about installing one of these is choosing which one you want to use. Each has its own merits but for simplicity, we chose the QM-3753 in-dash model. This compact unit will slip into a standard DIN dashboard slot and can be folded away when not in use to minimise attention from prying eyes. That’s pretty important these days, siliconchip.com.au . . . tilted vertical and twisted left or right for the right viewing angle. April 2005  9 as “obvious” in-car video screens can be tempting items for thieves. Apart from losing the screen, there’s all the damage created as they break in. We mentioned the reversed image before. Most screens, this one included, can reverse the image if required (it’s most disconcerting looking at a “right reading” image behind you!). If you are using a standard (right-reading) camera, this particular monitor can reverse the image by connecting one wire. But it’s more convenient to use a wrong-reading camera and a right-reading screen, because you can then use it “as is” for GPS/Sat Nav, entertainment, etc. Screen installation To install the screen, you will first need to remove the dashboard console panels to gain access to the CD-radio cradle assembly. On some vehicles, this is not as easy as it sounds because hidden screws may be used, air/heater/ air conditioner control knobs are often difficult to remove without damage, etc, etc. We’re not going to try to advise you here – there are simply too many variables. If in doubt, try to get the workshop manual for your car or perhaps ask for advice from a car repairer or auto electrician. Next, remove the assembly retaining screws. Most systems use some form of cradle – it should slide forward, enabling you to unplug the power and speaker connections and remove the assembly from the console. Before taking the assembly to your workspace, check the wires as you take them off. In some vehicles, they will be tagged, telling you what is what. But if they’re not, tag the wires as you take them off so that they can be put back in the correct places. Next, you will need to mount the video screen into the spare DIN mounting space of the cradle. This will vary from vehicle to vehicle so again we won’t go into detail here. It would be a good idea at this point to extend the video input connection. Jaycar have a cable (Cat. WV7316) specifically made for the task. This will let you easily connect to the screen once the CD and screen assembly is fitted back into the car. It might also be helpful to wrap a turn or two of insulation tape around the A/V connections while the assembly is out of the car. The tape will help prevent the connectors from being pulled out later when you are scratching around under the dash. Before reinstalling the CD player and video assembly back into the dash, you will need to provide a power line for the screen and camera. This is best achieved by splicing into the CD player’s power line using crimp connectors, rather than cutting and soldering, which makes later removal difficult. This splice should be made on the CD-player side of the fuse. If you choose to run a separate power line for the screen and camera, don’t forget to include an in-line fuse. Once the power lines are in place, you can re-install the CD/video cradle assembly back into the dashboard, plug their associated connectors back in and replace the console panels. The video input leads to the screen should be positioned where they will be easily accessible when you are ready to connect the camera cable from the back of the car. Checking the unit Before going any further, plug the video camera into the 10  Silicon Chip You’re going to need a spare DIN space in your dashboard (the black panel underneath the radio/CD in this picture hides the space). Virtually all car stereo systems these days are made to standard DIN dimensions. First step: uscrew/unclip the trim/fascia and carefully remove it, then disconnect the car radio/CD/cassette. Most have one or two plugs which disconnect everything. Don’t forget the antenna! Most vehicles these days have some form of frame or carrier which itself can be unscrewed and removed (makes life a lot easier!). Remove the faceplate covering the empty DIN space and slide the video screen into position in the cradle. Fasten the appropriate screws in place. siliconchip.com.au How do you know if it’s legal? The following is an extract from the Australian Road Rules, which apply in all states. We believe NZ rules are the same or similar. Specifically, this is: Part 18, Section 299 – Television receivers and visual display units in motor vehicles Replace the cradle in the dashboard and screw it back into position. Temporarily push the trim/fascia over the radio/ CD/cassette to make sure it still fits, then reconnect all radio cables (don’t forget the antenna!). (1) A driver must not drive a motor vehicle that has a television receiver or visual display unit in or on the vehicle operating while the vehicle is moving, or is stationary but not parked, if any part of the image on the screen: (a) is visible to the driver from the normal driving position; or (b) is likely to distract another driver. Offence provision. Note: Motor vehicle and park are defined in the dictionary, and vehicle is defined in rule 15. (2) This rule does not apply to the driver if: (a) the driver is driving a bus and the visual display unit is, or displays, a destination sign or other bus sign; or (b) the visual display unit is, or is part of, a driver’s aid; or Work out which of the radio/CD/cassette cables are +12V and ground and splice the video power cables into the appropriate ones AFTER the fuse(s). It may be that there is no ground wire as such because the radio grounds via the frame. If so, you’ll need to connect the video ground cable also to a good ground. (c) the driver or vehicle is exempt from this rule under another law of this jurisdiction. Examples of driver’s aids 1 2 3 4 5 6 Closed-circuit television security cameras. Dispatch systems. Navigational or intelligent highway & vehicle system equipment. Rear-view screens. Ticket-issuing machines. Vehicle monitoring devices. The blue italics emphasis is ours, to highlight the uses which are permitted, in moving vehicles in view of the driver. Needless to say, anything which is NOT mentioned – eg, DVDs, video games, TV, etc – is prohibited. Our advice is that it is possible you could be fined or your vehicle defected if you have a screen which is capable of displaying prohibited images while mobile, even if it is also used for driver’s aids. Sometimes, it’s necessary to run new power cables if the radio cables are inaccessible or they won’t handle the extra current. If so, it’s usually best to go back to the battery and fasten a suitable fuse/terminal block (such as this Jaycar model) to the firewall. siliconchip.com.au Therefore, if the display is fitted where the driver can view it, we would suggest a lockout system be used on the device (eg, a relay powered from the ignition switch) to prevent prohibited inputs when the ignition switch is turned on. April 2005  11 display video input, power up and check that all is OK. Better to find any problems now than later on when all the wiring is in place! Installing the camera This is a fairly simple task with the hardest part deciding where and how you wish to mount it. Some prefer to have the camera mounted inside, viewing through the back window, to give a “high” image. The alternative position is mounted inside your rear bumper – adjustable collars are actually supplied with the Jaycar QC-3452 camera for this purpose. If you decide to fit the camera inside the vehicle, you will need to find a suitable mounting position which not only gives a clear view but minimises the danger of the camera being damaged by anything moving around the back of the vehicle. You may also need to make a small “L” bracket to mount the camera or you can do as we did and mount the camera inside a Jaycar HB-6080 flanged jiffy box and use double-sided foam pads to stick the box to the roof lining at the rear of the vehicle. That way, there are no holes to drill and no damage when it comes to disposing of the vehicle, The hardest part about the bumper-mounted camera is drilling the 25mm hole in your rear bumper. It’s easy if you have plastic bumper bars; not so easy if they are steel! You will need a 25mm hole-saw to do the job. Once the hole has been cut and de-burred, you can fit the camera into the bumper and adjust its mounting angle using the collars supplied for the purpose. The rear of the camera has two orientation marks to help get the picture the right way up. To get the video signal to the front of the car and power back to the camera, you will need to run a pair of cables through the cabin. These should be tucked away under the carpets, out of sight and harm’s way. You can either make your own video cable or use a ready-made one, such as the Jaycar WQ-7224. Ready-made is the quickest and easiest option – and probably the cheapest as well. One alternative for power is to use the parking light circuit. Admittedly, this means you’ll need to have your parkers on whenever the system is in use but that’s no big deal these days – and it might make your vehicle just that much more visible. Getting the cables to the outside of the car can usually be achieved by routing them through one of the access bungs in the floor of the rear cargo area in a 4WD or the boot in a sedan. Typically, these are in the lowest areas such as under the spare tyre. Alternatively, you could use the same access bung which encases the cables to the number plate lamps or trailer plug. Once the cable has been run, you can connect the power and video lines. Turn on the ignition and check that power is available at the camera. If all is OK, turn the ignition back off and plug the cables into the camera. Now you can unfold the screen turn it on and turn your ignition on. If you have wired up everything correctly, you should have a nice rear-view picture on the screen. Road testing As soon as our newest toy was installed, we were eager to get out and see how it performed on the road. The first thing we noticed was the significantly better view of the 12  Silicon Chip The Jaycar QC-3452 Reversing Camera is especially made for our application, providing the “mirror image” picture you’re used to seeing in the rear view mirror. It is also very easy to mount – just one 25mm hole is required. The red lead is 12V CD power, while yellow is video out. Here’s the camera mounted in a Jaycar HB-6080 jiffy box (a nice, neat fit!), itself mounted on the roof of the 4WD. Different vehicles will have different mounting arrangements. An alternative is to mount the camera low down, even through the bumper bar (it is waterproof!) for an excellent reverse parking indicator. Another view of the mounting arrangement for the camera. This gives an excellent “high up” view through the rear window when the rear door is closed. The cable can be routed above the headlining and down one of the pillars for a nice, neat installation. siliconchip.com.au The “low down” camera position, inside the rear bumper, makes parking a breeze! Fortunately, this bumper is plastic – drilling metal is much more difficult. The angle can be adjusted via the use of supplied collars. Cabling can go via the rear number plate wiring “boot” or a cargo area drainage plug. It’s not hard to see why they’re called a GPS “Mouse” but there is no mouse function at all. Inside the waterproof case, here magnetically mounted on the vehicle roof, is a GPS antenna and receiver – this particular one is a USB device but there are PC card, CF, serial and Bluetooth varieties. Here’s a demo screen from one of the freeware packages we found on the ’net. There are others which offer street-level resolution but generally you have to pay for the better ones. You don’t need too much in the way of computer grunt to run them – a good use for that old laptop, maybe? siliconchip.com.au area behind the vehicle. The camera’s wide-angle lens provides a 92° field-of-view and practically eliminated the blind spots in the rear quarters. The system also provided an easy means of judging the distance to objects behind the vehicle. We had decided to mount our camera on the ceiling at the top of the rear window, in a mid-size 4WD. From this position, we were able to see the roadway as close as one metre behind the vehicle. If mounted at bumper level, the view would be much closer. Four-wheel-drives have great forward visibility but it’s difficult to judge just how close you are to objects at the back. With our new system we were able to reverse into tight parking spaces with ease and there was no doubt how close objects were. The screen was easy to see, even in full sun and needs no skill to operate. Other options There are a host of useful possibilities that can be added once the basic system is installed. These include a TV tuner or a DVD player for passenger entertainment, or even a low-cost GPS navigation system utilising an obsolete notebook computer, low-cost GPS module and shareware mapping software. You could even extend the reversing camera to a caravan by using a standard audio/video sender. If you have ever tried to reverse a caravan down a narrow driveway, you’ll know how useful that can be! Note, however, that Australian road rules prohibit any “entertainment” type video – that is from a TV tuner, DVD, game, etc, being displayed while the vehicle is in motion if the driver can view the screen. Common sense suggests this anyway – you can imagine just how dangerous it would be trying to watch a TV screen and driving at the same time! It wouldn’t be too hard to knock up some form of interlock which prevents the wrong video being displayed while the ignition is turned on. Power supply preparation If you are going to install more than one extra device in your system, it’s probably a good idea to have extra power readily available. The best way to do this is run heavy-duty cables directly from the battery – fitting a good quality distribution block such as the Jaycar HC-4020 and a suitable automotive relay (such as the Jaycar SY-4068) and matching base (SY-4069) in the engine bay is the best way to achieve this. First, mount the terminal block and power relay in an easily accessible place with metal screws and lock washers. Then run a length of heavy gauge cable from the terminal block via the relay and in-line fuse to the positive battery terminal. Make sure you allow enough extra cable to neatly secure the wire to the existing cable loom in the engine bay. The cable should be terminated with a suitable connector and already connected to the terminal block before it is connected to the battery terminal. This will prevent any accidental short circuits when you are running the cable. Power to the relay should come from the accessory side of the ignition so that the auxiliary systems only operate when the car is running or the key is in the accessory position. This is easily obtained by tapping into the supply line to the existing CD player or even the cigarette lighter April 2005  13 Par t s Lis t: Reversing Video In-dash TFT monitor (QM-3753) Reversing camera (QC-3452) Camera power connector (PP-0510) Crimp connectors (WV-7316) Video extension cable (WQ-7224) 6m length of Fig-8 cable (WB-1710) Hook-up wire, cable ties, heatshrink tubing, etc For higher capacity supply: Distribution block (HC-4020) Horn relay (SY-4068) Relay base (SY-4069) In-line 60A fuse (SZ-2065) Hook-up wire, cable ties, heatshrink tubing, etc Note: all part numbers refer to catalog numbers for Jaycar Electronics. socket, which is normally switched on by the ignition switch in most cars. When this is complete you will have a convenient point to run the power lines to from the extra equipment. Adding GPS navigation Now that you have a video screen installed in your car, there are lots of other applications. One of the easiest is an in-car GPS navigation system. Commercial units cost $1500 or more but you can cobble one together for just a few hundred dollars using a notebook computer, a “mouse” GPS receiver and free software readily available from the Internet. There are plenty of older laptops lurking around and they don’t need to be very powerful to do the job. The system described here runs on a Toshiba 600MHz Celeron but the development was done on an old Pentium 100 with 16Mb of RAM! The only reason we ended up using the Toshiba was because it has on-board composite video out, so was a bit easier to interface to the screen (ie, it plugged straight in!). But even the old P-100 worked fine with the addition of a VGA to composite converter – these are readily available from Jaycar Electronics and cost around $100. There are many ways to put this system together and once you have started to poke around the Internet, you will doubtless find a few more. The GPS receiver While this system will work with the majority of GPS receivers that have a data (computer) output, our system utilises a low cost “mouse” GPS receiver that we bought brand new on Ebay for about $110. In fact, we bought this about a year ago and it’s been sitting around waiting for a use such as this. Currently on Ebay, the same devices are selling for about $75.00 – you might even do better! There’s no screen, buttons, switches, or anything else that the dearer, self-contained GPS units have but it is perfectly suited to our task. The device consists of a matchbox-sized module with a USB (or serial) connector on the end of two metres of cable. It is waterproof and has a strong magnetic base to secure it 14  Silicon Chip to the roof of the vehicle. The unit could easily be left on the dashboard (for better security) but the roof mounting gives the receiver a better view of the sky (ie, more satellites to view) and therefore better accuracy. Be careful when buying a GPS receiver that you get one that is NMEA-compatible. Most are but for some unbelievable reason, a few recent models have gone their own way and use their own non-compatible software. If you want to use the GPS with mapping software, for example, it will almost certainly need to output using NMEA code. Also be careful about the interface between the GPS receiver and the computer. As mentioned above, most are USB or RS-232C serial and so plug straight into most laptops. Some are PC-slot (once called PCMCIA) compatible and most laptops and notebooks, even low cost and relatively elderly ones, have at least one PC slot. There are some otherwise fine GPS receivers available which are ONLY CF-slot compatible. These plug into a compact flash card (CF) slot on a PC but until fairly recently, few laptops had one of these built in. Fortunately, CF-toUSB adaptors are very commonly available and are also cheap (for example, $10 on EBAY will get you a multi-card adaptor). You can also get cheap CF to PC-slot adaptors. Installation What installation? It could hardly be easier. Simply plonk the GPS receiver on the vehicle roof, plug it into the notebook, plug the composite video output from the notebook into the monitor and load the software. OK, so you might need to add a VGA-to-composite video converter if your laptop doesn’t sport composite video out but that’s it. Software GPS software is readily available on the Internet and we have tried three different versions. Two are freeware and one has to be paid for. Two of them follow the normal Windows style with tool bars at the top of the screen and the selected map below. The third version operates under Windows but has a full screen display. It also has a number of interesting features including a speech option that gives you a commentary as you drive along, telling you how fast you are travelling, which direction you are travelling in and how far you are from your destination. The program can also be used with voice recognition software to produce a voice-driven system that talks back to you. None of these have turn-by-turn directions but this will undoubtedly be available before too long. In fact, there’s probably freeware or shareware out there which does it already – it’s just a matter of searching. All three programs we looked at allow you to scan your own paper maps and calibrate them for use with the system You can also download digital maps from the Internet SC for free. Where To Get Software www.oziexplorer.com – this costs around $110 and is locally written. www.gpss.co.uk – this site is free and has all the speech stuff. www.gpstm.com – this Brazilian site is also free (in English). siliconchip.com.au Atlas SCR Thyristor & Triac Analyser This latest in-your-palm tester from Peak will reliably check all thyristors and Triacs that you are likely to encounter. Just connect the mini-hook leads (in any order) and press “test”! You might be surprised to learn that hand-held semiconductors testers often do not have the capability to accurately test “sensitive gate” thyristors and Triacs. Typically, these instruments provide only one gate current level regardless of device. Although a higher than specified current would fire a sensitive gate device, there’s no guarantee that it will operate normally when in circuit. Paradoxically, many testers do not provide high enough gate current to reliably trigger some larger devices. The test current used (anode to cathode or MT1 to MT2) may also be too low, particularly as the instrument’s battery voltage declines. Reliable testing Peak has addressed these issues and eliminated the guesswork with the Atlas SCR. Devices are tested with up to eight discrete gate current levels (100mA, 500mA, 2.5mA, 10mA, 25mA, 50mA, 75mA & 90mA). Naturally, testing starts at the lowest level and progress towards the higher levels, ensuring that the minimum necessary trigger current is used. Note: Triacs are tested in both quadrants 1 and 3 but only the gate current for quadrant 1 is displayed. To ensure consistent results, test current is fixed at 100mA (nominal) regardless of battery condition and is applied as 100ms pulses. This eliminates the possibility of damage to sensitive devices. Rocket science? The Atlas SCR works the way all test instruments should (we think). Just connect the three mini-hook leads in any order and press “test”. The tester then automatically determines Main Features • • • • • • • • Automatic identification of component type (thyristor or Triac) Automatic lead identification (just connect any way around!) Categorisation of gate sensitivity (100µA, 500µA, 2.5mA, 10mA, 50mA, 75mA or 90mA) Load test conditions of 12V <at> 100mA (regardless of battery condition) Test pulse durations less than 200ms minimises possibility of damage Fault identification (shorted junctions, faulty operation) Clear and user-friendly scrollable display Supplied with detachable micro-hook probes siliconchip.com.au device type and pin-out and displays the results on its 16-character x 2-line LCD. The device type (thyristor or Triac) is displayed first up. Alternatively, if the device has an internal short or open circuit or fails to trigger, an appropriate message is displayed instead. Three more informative screens are accessible by pressing the “scroll” button. The first of these displays the pin-out details. Another press brings up the trigger current, with a third displaying the test current. As this value is fixed at 100mA, it serves only as a reminder. After a short delay, the instrument switches itself off or you can press and hold the “scroll” button to save even more battery power. There’s little more to tell you about this useful little device. If you’re in market for a hand-held “go/no-go” thyristor and Triac tester, you won’t find a better deal anywhere! Where to get yours As well as the Atlas SCR Thyristor and Triac Analyser, Peak offers a number of other useful test instruments in the same handy form-factor – eg, the Atlas LCR Passive Component Analyser (see Circuit Notebook). Peak Electronic Design is situated in Derbyshire, UK. You can purchase their products on-line at this site: www.peakelec.co.uk. Current price for the Atlas SCR including airmail delivery is $227.20, subject to exchange rate variations. Their products are also available locally through Farnell, although the Atlas SCR is not currently listed. See www.farnellinone.com.au or phone SC 1300 361 005 for availability. April 2005  15 SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: dicksmith.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: dicksmith.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: dicksmith.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: dicksmith.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: dicksmith.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: dicksmith.com.au 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 Connect it to your computer (with sound card) or a MIDI synthesiser for a truly awesome array of sound possibilities. Using a computer, you can even record, save and playback your compositions. MIDI THEREM THERE Move over “Theremin” . . . the “MIDI Theremin” is here. While it’s based on the original concept of producing sounds using hand movement, it has now gone digital, taking the Theremin from the 20th to the 21st century! T he original Theremin, with a foot pedal to control volume and a switch mechanism to control pitch, was invented during World War One – in 1917, to be exact – in St Petersburg, Russia. It was named after its inventor, a young cellist and physics student, Lev Sergeivitch Termen. (It was also known as the Aetherophone or Etherphone, meaning “sound from the ether”). Termen’s life story is a kaleidoscope of intrigue itself. After demonstrating and playing his device throughout Russia and Europe (Lenin was said to have been very impressed), he travelled to the USA in 1927 and decided to stay, and married . . . much later, it was claimed he was in the US as a Russian spy. 24  Silicon Chip Lev Termen “playing” the RCA Theremin, first produced in 1929. But in 1938 he was kidnapped by the Russian NKVD (which later became the KGB) and clandestinely spirited back to Russia, where he was sentenced to a Siberian labour camp for “anti-Soviet propaganda”. After his “rehabilitation”, he apparently again found favour with Russian authorities and taught at the Moscow Music Conservatory up until his death in 1993, aged 97. In his later years he was again allowed to travel to the USA where he was introduced to the Beach Boys, who themselves made the Theremin famous in one of the most famous tracks of all time – Good Vibrations. We’ve immortalised Lev to some degree (who incidentally was known siliconchip.com.au Features • Sound outpu t via a compute r and speakers • Selection of 1 or a synthesiser 5 instrument ty pes with 8 vari • Record, save ations of each and playback u sing a compute • Volume plate r and pitch anten na • Auxiliary inpu t for pitch or no te change • Back-lit LCD shows instrum ent selection, vo • Selection of su lume, note and stain on or off pitch or setting • Adjustment fo s r discrete note or pitch glide ef • Selection of n fect between no ormal or wide n tes ote range • Selection of n otes with or wit h out sharps • Selection of an tenna operation from note chan and auxiliary in ge to pitch chan put from pitch ge glide to note ch • Midi out, gam ange es port or serial connections (U • Plug-pack po SB via a conve wered rter) MIN EMIN Part 1: by John Clarke siliconchip.com.au April 2005  25 This close-up of the completed MIDI Theremin shows the various controls on the front panel (fully explained in the text), along with the volume level plate (left) and the telescoped whip antenna (top), here shown in the “transport” position. in the west under the Gallic form of his name, Léon Théremin) by including a stylised image of him on the front panel of our design! The Theremin version we know today, using a volume plate and pitch antenna, was developed and first produced in 1920. A commercial Theremin was built by RCA in 1929 and comprised a large wooden box to house the valve electronics and included the volume plate (actually a wire loop) and pitch antenna. Moving the left hand closer to the sensor would reduce the volume level; conversely, taking the hand away would increase the level. Similarly, pitch could be controlled using hand movement around the antenna. The thinness of the antenna allowed for very fine pitch adjustment by only moving the fingers while keeping the hand still. Larger pitch changes could be accomplished by moving the hand inward to decrease the pitch and away from the antenna to increase the pitch. Somewhat unsuccessfully marketed as a replacement for a piano, RCA’s Theremin sold for $US175 in 1929. Oh, you wanted tubes (valves) and a loudspeaker with that? Another $71.50, please! (That was, of course, a lot of money in 1929). The sound produced by that Theremin (or by modern versions) is similar to the eerie sounds heard in many science fiction movies. In fact, it is the eerie sound heard in many science fiction movies! Although some may consider the Theremin to be just an electronic toy, it’s also regarded by others as a legitimate musical instrument. There have been countless professional performances using the Theremin , either alone or as part of an orchestra. From Theremin to synthesiser The Theremin concept lead to the development of electronic music, starting with the Moog (pronounced mogue, as in vogue) synthesiser (invented by Robert Moog in the 1960s). Today we have fully digital synthesisers and samplers that can produce just about any type of sound imaginable. Incidentally, any idea where Robert Moog got his interest in electronic music from? You guessed it, a home-made Theremin he built from a magazine article when he was 14 years old. The Theremin itself has also been updated in many forms over the past 80+ years to use transistors in the electronics instead of bulky and What is MIDI? MIDI is an acronym for Musical Instrument Digital Interface. It is a system for communicating between synthesiserequipped electronic musical instruments and PC-based sequencers. The communication is a series of codes that can control the synthesiser. Control codes can for example be sent to set the instrument sound, start or stop a note being played, vary the pitch of the note and set the volume. The code is sent as 10-bits with one start bit, eight code bits and a stop bit at a rate of 31.25k baud. The communication is asynchronous and is provided using a 5mA current loop. In more detail, a MIDI message can be defined as either a channel or system message. The channel message applies to a specific synthesiser channel from 1 to 16, while 26  Silicon Chip the system message applies to all channels. System messages include resetting, tuning and timing codes. Channel messages can be further broken down into voice or mode messages. The voice messages include turning a note on or off, the pressure (how hard a key on a keyboard is pressed), pitch blend (where the note frequency changes off key) and program change (to alter instrument). Mode messages affect the way the synthesiser will respond to a note being played. For example, the sustain effect can be switched on or off and the note can be selected to pan between the left, centre or right channels siliconchip.com.au power-hungry valves. Later designs used both transistors and then ICs – a design using ICs was published in the August 2000 issue of SILICON CHIP (the article is available via www.siliconchip.com.au). That design replicated the original Theremin in the way it produced sounds, using the pitch antenna and volume plate approach. The project remains very popular to this day, with Jaycar Electronics and Dick Smith Electronics still selling it as a kit. Although the August 2000 Theremin works well, it is only able to produce the original, characteristic Theremin sound – an almost pure sine wave, which is not overly musical. We reasoned that the Theremin would be more interesting to play and use if it could produce different sounds. So why not merge the old and the new and use a digital synthesiser to produce the sounds while keeping the original Theremin control format with the pitch antenna and volume plate? And that is exactly what we have done – produced a MIDI Theremin that has the volume plate and the antenna for volume adjustment and pitch control as in the original Theremin – but instead of providing an internal sinewave oscillator to produce the basic sound, we control an external synthesiser instead. Use of the synthesiser allows a huge selection of different instrument sounds that can be played, all under the control of the MIDI Theremin. And just in case you are wondering where you get a synthesiser from, it is available in just about every home in the developed world – in your personal computer. We take advantage of a now-universal standard, the Musical Instrument Digital Interface or MIDI and the myriad of software available for MIDI on the PC. More on this shortly! Accompany the computer with multimedia loudspeakers and you can begin to realise the possibilities of the sounds produced by the MIDI Theremin. And for even greater sound levels and deeper bass, connect the computer’s audio output to an amplifier and high fidelity speakers. In fact, if you want to reproduce the very low frequencies that can be generated via the MIDI Theremin setup, hifi speakers are a must. The MIDI Theremin is easy to siliconchip.com.au Specifications Note Range with Sharps (#) (reference: middle C is designated as C3 (261.626Hz): Wide C#-2 to G8 (126 notes, over 10 octaves) (8.662Hz to 12.544kHz) Normal C1 to C6 (61 notes, 5 octaves) (65.406Hz to 2.093kHz) Note Range without sharps (Natural or C Major scale): Wide D-2 to G8 (74 notes, over 10 octaves) (9.177Hz to 12.544kHz) Normal C1 to C6 (36 notes, 5 octaves) (65.406Hz to 2.093kHz) Pitch glide: 8 steps between notes for wide note range 16 steps between notes for normal note range Compensation of pitch between notes when there is no sharp in between the note (i.e. between E and F and B and C) Pitch glide range (calibration is synthesiser dependent): 0 to 255 for between notes that include a sharp 0 to 511 for between notes without sharps Pitch range when antenna is selected set for pitch variation: -500 to +500 (not calibrated) in steps of 1 Volume steps: >1000 steps from maximum level to off Volume display: 0 to 500 in steps of 1 (500 is maximum volume) Current consumption: 135mA with 9V DC in MIDI out: 5mA loop, galvanic isolation for games port (31.25k baud) Serial out: RS232 levels (38.4k baud) use. A liquid crystal display (LCD) screen shows what is happening. In fact, when the display is showing the volume level, note and pitch, it is possible to play the MIDI Theremin even without listening to it. Perhaps Beethoven would have appreciated the visual feedback of this unit, being totally deaf in his latter years! Sound differences The sound produced by the MIDI Theremin and synthesiser combination is not exactly the same as the original Theremin. While the original Theremin could produce a virtually infinite number of tones over its frequency range, a synthesiser can only play discrete notes. This effect goes against the Theremin “continuous frequency” concept, so we have incorporated a pitch glide feature where the pitch of a note changes for in-between note positions on the antenna. The glide feature is implemented in such a way that the change from note to note is less noticeable than without the pitch glide effect. There is still a distinct level change when another note begins but the effect is very good at simulating a continuous variation in tone. In particular, this is true when specific instruments are selected and if the hand movements are not extremely slow. The accompanying instrument table shows the instruments that can be used to best effect with this pitch glide feature to simulate the continuous tone variation of the original Theremin. The designated instruments are marked with an asterisk. Presentation The MIDI Theremin is housed in a small plastic box which is mounted on a sloping stand. The stand acts to raise the hand plate and antenna above the desktop (or wherever it is placed) so that the hand controls are not affected by the proximity to the mounting surface. The sloping face of the box also improves visibility of the LCD screen and the operation of the hand plate. The hand plate and antenna are spaced as far apart as possible and oriented so that the left and right hands operate in different planes. This prevents any interaction between the two controls. By the way, the antenna is normally used in its retracted, or closed, posiApril 2005  27 Instruments Instruments that thatcan can be be selected selected with the MIDI Theremin PIANO 1.Acoustic 5.Electric #1 2.Bright Acoustic 6.Electric #2 3.Electric Grand 7.Harpsichord 4.Honky Tonk 8.Clavichord 2.Glockenspiel 6.Xylophone 3.Music Box 7.Tubular Bells 4.Vibraphone 8.Dulcimer 2.Percussive 6.Accordian 3.Rock 7.Harmonica 4.Church 8.Tango Accordion 3.Electric Jazz 7.Distortion 4.Electric 8.Harmonic 2.Electric (Finger) 6.Slap #2 3.Electric (Pick) 7.Synth #1 4.Fretless 8.Synth #2 2.Viola 6.Pizzicato 3.Cello 7.Harp 4.Contra Bass 8.Timpani CHROMATIC PERCUSSION 1.Celesta 5.Marimba ORGAN 1.Drawbar 5.Reed GUITAR 1.Acoustic 2.Steel Acoustic 5.Electric Muted 6.Overdriven BASSapart 1.Acoustic 5.Slap #1 STRINGS 1.Violin 5.Tremolo* Synthesiser ENSEMBLE 1.String #1* 5.Choir Aahs* 2.String #2* 6.Voice Oohs 3.Synth Strings #1* 4.Synth Strings #2* 7.Synth Voice* 8.Orchestra Hit 2.Trombone 6.Brass Section 3.Tuba 7.Synth #1 4.Muted Trumpet 8.Synth #2 2.Alto Sax 6.English Horn 3.Tenor Sax 7.Bassoon 4.Baritone Sax 8.Clarinet 2.Flute 6.Shakuhachi 3.Recorder 7.Whistle 4.Pan Flute 8.Ocarina 2.Sawtooth 6.Voice 3.Calliope 7.Fifths Sawtooth 4.Chiffer 8.Bass 2.Warm 6.Metallic* 3.Polysynth 7.Halo* 4.Choir 8.Sweep* 2.Soundtrack 6.Goblins* 3.Crystal 7.Echoes* 4.Atmosphere 8.Science Fiction* 2.Banjo 6.Bagpipe 3.Shamisen 7.Fiddle 4.Koto 8.Shahnai 2.Agogo 6.Melodic Drum 3.Steel Drums 7.Synth Drum 4.Woodblock 8.Reverb Cymbal BRASS 1.Trumpet 5.French Horn REED 1.Soprano Sax 5.Oboe PIPE 1.Piccolo 5.Blown Bottle SYNTHESISER LEAD 1.Square 5.Charango SYNTHESISER PAD 1.New Age 5.Bowed* SYNTHESISER EFFECTS 1.Rain 5.Brightness ETHNIC 1.Sitar 5.Kalimba PERCUSSIVE 1.Tinker Bell 5.Taiko Drum Those marked with a * produce eerie sounds characteristic of the original Theremin, particularly when the pitch glide control is set correctly. 28  Silicon Chip tion. Extending it has the same effect as bringing the hand closer to the antenna. The LCD becomes the “window” to view the MIDI Theremin’s operation. It can show the selected instrument, effects settings, volume, note and pitch being played, plus other settings. Nine pushbutton switches are used to change the instrument, the effects and other settings. An auxiliary potentiometer control (used for different effects) is mounted on the righthand end of the box. You can make this an external control (eg, used with a foot pedal) via the stereo jack socket at the rear of the box. Other connectors at the rear of the box are the MIDI out, the serial connector, the games port connector and the DC power socket for the 9V DC plugpack attachment. A power switch selects power and the LED adjacent to the MIDI socket is for the MIDI invalid indication. More on this later. As mentioned, the MIDI Theremin cannot be used on its own; it needs to be connected to a synthesiser. By far the most common source of a synthesiser is inside a standard personal computer or laptop using the soundcard’s synthesiser. However, as MIDI itself is a standard, another source for a synthesiser is in a MIDI electronic instrument such as a MIDI keyboard. The MIDI Theremin can be used on either of these two synthesisers. Signals from the MIDI Theremin are sent as a series of codes in MIDI format that command the synthesiser to produce sounds. More detail on MIDI can be seen in the accompanying “What is MIDI” section. To connect the MIDI Theremin to a MIDI instrument you use a purposemade MIDI lead between the two. When connecting to a computer, you have the option of using either the games port outlet (which connects directly to the computer’s sound card), or to the serial outlet that connects to a serial port on the computer. The sound card input on the computer will accept MIDI signals directly and uses a DB15 connector. Many modern computers do not have a games input and so you will need to use a serial port instead. If you do not have a serial port or siliconchip.com.au effects are also available. We used a freely available sequencer program that can be downloaded from the Internet. The software works with Windows 3.1, 95, 98, Me, 2000, NT and XP. We will explain how to download, install and use the software in Part 2. Software for the serial port driver works with Windows 95, 98, Me, 2000, NT and XP. Presumably, if you are using Windows 3.1, this serial port driver will not be required since you will have the games port available. The serial-to-USB port driver works with Windows 98 through to XP. MIDI Theremin controls This inside shot gives a good idea of how it all goes together. There are two PC boards, the main one mounting in the case and the display board in the lid. They’re connected by an IDC cable. You’ll find construction details next month. games port, then the only way to use the MIDI Theremin is via the USB port on the computer. In this case, you will need to use a MIDI to USB converter or a serial port to USB converter. MIDI to USB converters currently cost around $140, while serial to USB converters are only around $40, so if you need to use USB ports on the computer we recommend the serial to USB option. In both cases, software will need to be installed in order for the USB ports to respond to the signals sent by the MIDI Theremin. program. This accepts the MIDI signal sent by the MIDI Theremin and directs it to the sound card’s synthesiser. The sequencer also provides many other functions such as the ability to record the music, store it and play it back. You can also multi-track record for up to 32 tracks and mix these together using individual volume level settings. Panning from left to right, instrument change, looping and quantisation By far the most-used control on the MIDI Theremin will be the Instrument/Note switch. This switch selects whether the display will show the current instrument selection or the volume, note and pitch value. Each pressing of the switch will toggle the selection from one to the other. To select an instrument, you press the Instrument/Note switch to bring up the word “INSTRUMENT” on the top line of the LCD. The second line will show the current instrument selection. Instruments are selected using one of four switches. To change the in- Houston, we have a problem! The signal at the MIDI Theremin’s serial (computer) output is not genuine MIDI standard. It’s 38.4k-baud vs MIDI’s 31.25k-baud. Consequently, this can only be used to drive a computer, NOT a MIDI instrument. In this case, a LED lights to indicate that the MIDI output is invalid. The oscilloscope waveforms of Fig.2 show the difference. At the top is the genuine MIDI signal with 31.25k-baud rate codes, while the lower trace shows the same code transmission at the 38.4k-baud rate suitable for the serial port computer connection. The lower trace also shows how the signal transmission is completed over a shorter time. Software Software is required when using the computer as the synthesiser source. The main software is the sequencer siliconchip.com.au Fig.2: these oscilloscope waveforms show the difference between a genuine MIDI signal (yellow trace) operating at a 31.25k-baud rate and a serial output signal (white trace) with the same code transmission but operating at a 38.4k-baud rate. The lower trace shows that the signal transmission is completed in a considerably shorter time than for the top trace, which is why this serial output is not MIDI compatible. April 2005  29 PLATE AMPLIFIER & LEVEL SHIFTER VARIABLE OSCILLATOR T1, Q1 BANDPASS FILTER T2, Q2 DETECTOR & LOWPASS FILTER D1, C1 IC1a, VR1 LCD AN0 ANTENNA AMPLIFIER & LEVEL SHIFTER VARIABLE OSCILLATOR T3, Q3 BANDPASS FILTER T4, Q4 Fig.1: the various functions are explained in detail in the text but in a nutshell, two separate variable oscillators change in frequency with hand movement. This change is converted to a DC level. The microcontroller monitors the hand plate and antenna voltage changes and converts these to MIDI signals. strument selection you can press the Instrument Up or Instrument Down switch to single step to the next instrument. Alternatively, you can use the step up or step down switches to select one of 15 various instrument groups. The Instrument Up or Down switch can then be used to select one of the eight variations available within the selected group. The instrument types available are Piano, Chromatic Percussion, Organ, Guitar, Bass, Strings, Ensemble, Brass, Reed, Pipe, Synthesiser Lead, Synthesiser Pad, Synthesiser Effects, Ethnic and Percussive. The LCD will show the selected instrument with these names, although some abbreviations are used for the DETECTOR & LOWPASS FILTER D2, C2 +5V 5k FOOT CONTROLLER (OPTIONAL) IC1b, VR2 SWITCHES S1 – S9 MICRO CONTROLLER IC2 AN1 +5V 5k OUT TO GAMES PORT MIDI OUT VR3 RS-232C CONVERTER IC4 AN2 AUX POTENTIOMETER CONTROL longer names. For example, synthesiser is abbreviated to “Synth”. Within each instrument group, the eight types are labelled from #1 to #8. There is a subtle difference between some of these types, particularly the piano selections. The full list of instruments, including the types and their numbers (from 1 to 8) that can be selected is shown in the table on page 28. For each instrument you can select the sound to come from the left channel (shown on the display as an <L>), the centre channel (both left and right channels), shown as a <C>, from the right channel as an <R>, or off <OFF>. These are selected using the < or > switches. The off position is useful when This rear-panel photo shows the telescopic whip antenna (top) and volume plate (right) but more importantly (left to right) the external foot switch jack socket, DC power socket, games port, RS-232C (serial) port with its non-MIDI warning LED and the MIDI socket. 30  Silicon Chip OPTO COUPLER IC3 SER OUT 6 SERIAL PORT OUT MIDI λ INVALID LED testing the Theremin response to the hand controls by using the LCD to show what is happening rather than listening to the synthesiser. Note that the < and > bracketing is an indication that the labelling within these can be changed using the < or > switch. These brackets are shown where you can change other settings available on the MIDI Theremin. The Note display is selected when the Instrument/Note switch is pressed again. The top line display shows the volume level setting, the note that is being played at the time and in which octave it is positioned. Volume is indicated with a loudspeaker cone and sound wave icon and the volume level as a number from 0-500, with 500 representing maximum. Notes are shown with a stylised notes icon and A to G labelling. Sharps are indicated with # to conform to musical labelling convention. The current octave being played is shown, with the lowest octave labelled as -2 through to the highest octave at number 8. The lower line on the LCD shows the pitch or pitch glide value but more about this later. The table opposite shows the possible notes that can be played using the MIDI Theremin. It shows the octave, siliconchip.com.au note and frequency for each. Middle C is defined as C3. Effects There are several note effects available when playing the MIDI Theremin. These include the pitch glide, sustain, and note range, sharps and inputs usage. The pitch glide controls the degree of pitch change between notes. It is adjustable from 0, when there is no pitch change between notes, up to 255 between a note and a sharp and up to 511 between standard notes. The actual pitch change depends on the synthesiser but in general the amount of pitch change adjustment is beyond the difference in pitch between notes. This means that it is possible to set the pitch range at less than maximum so that the pitch glides smoothly between notes, making note changes less abrupt. The pitch glide control is the auxiliary potentiometer. For knob settings between fully anticlockwise and halfway, the Note display will show the Pitch Glide as 0 – ie, no pitch glide – so the notes produced are discrete and distinct from one another. As the auxiliary control is turned further clockwise, the degree of pitch glide increases. The display shows the actual pitch being introduced as you play the Theremin. You will see the pitch value change as you sweep between notes. Setting the pitch glide to maximum will cause the pitch to change beyond that of the next note to produce a snap-on effect as the note changes. The sustain setting is selected by pressing the Effects switch. This brings up the word SUSTAIN on the top line and <ON> or <OFF> on the lower line. The setting is changed from on to off to on by pressing the < or > switch. After selecting the required sustain A screen grab of the software we use to drive the MIDI Theremin. The sequencer software can show the sequence of notes that were played during recording. They are displayed in the standard 5-line music format. setting, the Instrument/Note switch must be pressed before the MIDI Theremin can be played. Note that the “Sustain On” effect can only be used with naturally decaying note instruments, such as piano, guitar, bass and percussive, as well as some strings and others. Sustain causes the note to take a longer time to decay. Naturally note-sustaining instruments such as violin, organ, ensemble, brass, reed and effects types should not be set to include the sustain effect. If sustain is set for these instruments, then the notes played will continue until there is a crescendo of notes and the synthesiser becomes overloaded. Pressing the Effects switch and returning sustain to off will stop this if it happens. A second pressing of the Effects switch will show NOTE RANGE on the top line and <NORMAL> or <WIDE> on the lower line. You can select either of these using the < or > switches. The normal note range extends from C1 to C6. The wide note range is from D-2 to G8 when no sharps are selected and from C#-2 to G8 when sharps are selected. The normal note range when sharps are included corresponds to a standard 61-note organ keyboard. This covers the frequency range from 65.41Hz to 2,093.0Hz and should be adequate for most playing purposes. The wide note range is good for reproducing very wide-frequency range instruments (such as a pipe organ), as well as reproducing the high frequencies of instruments such as tubular bells. The next selection with the Effects switch is the note effects. In this case, NOTE EFFECTS will be displayed on the top line and <INC. SHARPS> or <NO SHARPS> will be shown on the second line. You can select one of these with the < or > switches. The NO SHARPS selection is some- Notes available with the MIDI Theremin (frequency in Hz). Middle C is C 3. Sharps are labelled with a #. Octave -2 -1 0 1 2 3 4 5 6 7 8 C 16.35 32.70 65.41 130.81 261.53 523.25 1,046.50 2,093.00 4,186.01 8,372.02 C# 8.66 17.32 34.65 69.30 138.59 277.63 554.36 1,108.74 2,217.46 4,434.92 8.869.84 siliconchip.com.au D 9.18 18.35 36.71 73.42 146.83 293.66 587.33 1,174.66 2,349.32 4,698.64 9,397.27 D# 9.72 19.45 38.89 77.78 155.56 311.13 622.25 1,244.51 2,489.02 4,978.03 9,956.06 E 10.30 20.60 41.20 82.41 164.81 329.63 659.25 1,318.51 2,637.02 5,274.04 10,54808 F F# G 10.91 11.56 12.25 21.83 23.12 24.50 43.65 46.25 49.00 87.31 92.50 98.00 174.61 185.00 196.00 349.23 370.00 392.00 698.46 739.99 783.99 1,396.92 1,479.98 1,567.98 2,793.83 2,959.96 3,135.97 5,587.65 5,919.91 6,271.03 11,175.30 11,839.82 12,543.85 G# 12.98 25.96 51.91 103.83 207.65 415.30 830.61 1,661.22 3,322.44 6,664.88 - A 13.75 27.50 55.00 110.00 220.00 440.00 880.00 1,760.00 3,520.00 7,040.00 - A# 14.57 29.14 58.27 116.54 233.08 466.16 923.33 1,864.66 3,729.31 7,458.62 - B 15.43 30.87 61.74 123.47 246.94 493.88 987.77 1,975.53 3,951.07 7,902.13 - April 2005  31 32  Silicon Chip siliconchip.com.au SC 2005 4 2 1 68pF 100k G Q1 2N5484 68pF 100k G Q3 2N5484 MIDI THEREMIN 390pF A K 100nF CERAMIC 100Ω 100nF CERAMIC 390pF 1N4148 S D S D 100Ω (ANALOG/USER INTERFACE CIRCUITRY) VARIABLE OSCILLATOR 3 2 1 ANTENNA VARIABLE OSCILLATOR 3 6 T3: WHITE 4 6 T1: WHITE HAND PLATE 680Ω 100k B 220k 680Ω 100k B 220k G E C E C 100Ω 100nF CERAMIC 2 1 D 2N5484 E T4: BLACK BANDPASS FILTER 560pF Q4 BC547 S 100nF CERAMIC 2 1 T2: BLACK BANDPASS FILTER 560pF Q2 BC547 100Ω B C 4 6 4 6 SLOPE DETECTOR 10k K 10k K SLOPE DETECTOR BC547 A D2 1N4148 A D1 1N4148 VR2 2k VR1 2k 2.2k 6.35mm STEREO SWITCHED JACK SOCKET TP3 TP GND EXTERNAL INPUT C2 2.2 µF C1 2.2 µF TP1 2.2k 10 µF 1k +5V 10 µF 1k +5V 100nF 220k IC1a 8 1 4 IC1b 100nF 220k 7 VR3 5k LIN 100nF LEVEL SHIFTER & AMPLIFIER 6 5 IC1: LM358 LEVEL SHIFTER & AMPLIFIER 2 3 10 µF TP4 TP2 C AUX INPUT +5V B A +9V SC 2005 2.2k A 2.2k 3 x 10k 33pF X1 8MHz A K 5 16 15 1 18 17 Vss (DIGITAL CIRCUITRY) S5 S6 S2 S3 4 RB5 RB0 RB1 RB4 RB3 RB7 RB6 11 6 S9 S8 S7 DB4 DB5 DB6 DB7 Rs E S10 POWER 12 7 11 13 10 14 4 13 9 6 100F 12 100nF 9V DC INPUT (150mA) S4 3 2 RA5 S1 RA4 IC2 PIC16F88 Vdd 14 RA3 OSC1 OSC2 AN2 AN1 AN0 MIDI THEREMIN +5V 33pF A K A K 470F D6 1N4004 +9V 220  GND OUT REG1 7805 IN K MIDI OUT INVALID A GND DB3 DB2 DB1 DB0 R/W CONT LED1 LCD MODULE V+ 1 2 10 9 8 7 5 3 10F 10F +5V 10k VR4 LED 220 Figs.3 & 4: the complete circuit for the MIDI Theremin. Because it occupies two pages it looks daunting but in reality it can be broken down into a few functional elements. The opposite page (Fig.3) has all the “analog” circuitry while this page (Fig.4) has the PIC microcontroller, the LCD module and the output devices. C B A 2.2k D3qD5 1N4148 K +5V 100k A K 1F 1F  6 5 4 3 1 11 5 6 8 15 1F 14 470 K A K 1N4148 A 1N4004 2 220 220 IC4 MAX232 16 7 IC3 6N139 +5V 1F 3 2 +5V 4 2 5 10F 1F 5 4 15 9 8 OUT GND IN 7805 5 8 7 6 4 1 2 DB9 SOCKET MIDI OUT TO SYNTHESISER 100nF 1 16-PIN IDC HEADER TO GAMES PORT TO SERIAL PORT siliconchip.com.au April 2005  33 The RS-232 converter changes the 0-5V signal from the microcontroller to a nominal ±10V signal for the serial port. When using the serial port connection, the MIDI invalid LED lights to indicate that the MIDI signal on the serial MIDI socket is not able to drive a synthesiser. The microcontroller also drives the LCD and monitors switches S1-S9. Oscillators The MIDI Theremin display board, which we will construct next month. times called the Natural or C Major scale. It has an effect similar to running your fingers up and down the white keys on a piano. Selecting sharps (the black keys on an organ or piano) increases the number of notes and reduces the distinctiveness between each note. There are no sharps between the B/C and the E/F notes. The final selection with the Effects switch is to change the function of the antenna and auxiliary input. The normal setting is shown as PLATE/ ANT./AUX. on the top line, indicating the hand plate, antenna and auxiliary inputs. The second line shows <VOL/ NOTE/PITCH>. This shows that the hand plate is for volume, the antenna for note and the auxiliary pot is for pitch glide adjustment. Pressing the < or > switch will change the settings to <VOL/PITCH/ NOTE>. The top line will remain as before with PLATE/ANT./AUX. shown on the top line. For this setting, the hand plate remains as the volume control, but the auxiliary potentiometer is now used to select the note. The antenna controls pitch over a small range. This is indicated when the Instrument/Note selection is showing Volume, Note and Pitch. Pitch can be varied over a -500 to +500 range in steps of 1. The actual values do not mean much since synthesisers are not calibrated as far as the pitch adjustment range is concerned. In practice, pitch varies by more than one note above and below the currently set note. It is important to set 34  Silicon Chip the auxiliary control so that the note will not skip to the next note. Port selection The Set Port switch is recessed within the box and needs to be accessed using a pen or similar object. It allows the MIDI Theremin to be set up to provide MIDI signals from the MIDI outlet and the games port or a pseudo-MIDI signal via the serial outlet. You can press the switch when the MIDI Theremin display is showing the instrument or note. The display will then show <DRIVE> VIA MIDI OUT & GAMES PORT or VIA SERIAL PORT ONLY. You can select one or the other using the < or > switches. The MIDI Invalid LED will light when the serial port is selected. Press the Instrument/Note switch to exit from the port setting mode. Block diagram Fig.1 shows the block diagram for the MIDI Theremin. A PIC microcontroller is used to monitor signals from the hand plate control section at its AN0 input, the antenna control section at its AN1 input and the auxiliary control at the AN2 input. In response to these signals, the micro produces a MIDI signal which is applied to an optocoupler (IC3), the MIDI output socket and the RS-232 converter. The optocoupler provides isolation between the MIDI Theremin and the computer connection via the games port. This prevents hum loops if the MIDI output is also connected to a synthesiser. There are two identical variable oscillators, one for the hand plate control and the other for the antenna control. The oscillators run at a nominal 455kHz, reducing in frequency as your hand moves closer to the plate or antenna. The frequency reduction is due to extra capacitance from your hand being applied to the oscillator circuit. The oscillator output is fed to a bandpass filter. When the frequency drops as your hand moves closer to the plate or antenna, the filter begins to attenuate the signal because the frequency moves out of the filter’s pass-band. The signal is detected (rectified) and filtered so that the bandpass filter output is converted to a voltage. This voltage is then amplified and level-shifted so that the amplifier output covers a 0-5V range. This voltage is then applied to the microcontroller. An auxiliary control can alter the voltage from 0-5V using potentiometer VR3. Alternatively, an external (eg, foot-controlled) potentiometer can be plugged in. If this is used, VR3 is automatically disconnected. Circuit details The circuitry for the MIDI Theremin can be divided into two sections: the hand interface circuit (Fig.3) comprising the hand plate, antenna and auxiliary sections; and the digital circuitry (Fig.4) comprising the microcontroller, LCD, switches and the MIDI output sections. Let’s start with Fig.3, the hand interface circuit. Both the hand plate and antenna control sections are identical and use standard intermediate frequency (IF) transformers as used in low-cost AM radios. Each transformer has a tapped winding with a capacitor connected in parallel, forming a tuned circuit. The variable oscillator for the hand plate comprises T1 and Q1 (a JFET), plus associated resistors and capacitors. The JFET drives the portion of the siliconchip.com.au coil between pin 2 and ground. The full winding signal is applied back to the gate of Q1 via a 68pF capacitor (positive feedback) to ensure oscillation. The hand plate is connected directly to the top of the T1 tuned circuit winding. As you move your hand near the plate, the extra capacitance across the tuned circuit reduces the oscillator frequency. A second winding on IF transformer T1 couples the oscillator signal to the base of transistor Q2, via a 390pF capacitor. Q2 drives IF transformer T2 to provide a bandpass filter centred on 455kHz. Because it has a sharp rolloff above and below 455kHz, it provides a signal output level that varies widely in response to small changes in input frequency. The 455kHz signal from T2 is rectified by diode D1 and filtered with the 2.2mF capacitor. This produces a DC level that is proportional to the hand plate oscillator. At this stage, the voltage levels are around 0.9V, dropping to around 0.83V when your hand is near the plate. This is amplified by op amp IC1a to give a 5V swing. Trimpot VR1 adjusts the output from IC1a so that it covers the range from above 5V down to 0V. The antenna circuit operates in exactly the same way as the hand plate section, using op amp IC1b, together with trimpot VR2. The auxiliary input is provided by potentiometer VR3, which is connected directly across the 5V supply. Therefore, the wiper of this pot can produce a variable DC level anywhere MicroVGA: between 0V and 5V, depending on its setting. VR3 is normally internal but can be made external (eg, used like a wahwah pedal) via a 6.35mm switched stereo jack socket. When the plug for the external potentiometer is inserted into the jack socket, the internal pot is switched out of circuit. Digital circuitry The digital circuitry comprises IC2, IC3, IC4 and the LCD module, as shown in Fig.4. IC2 is a PIC16F88 microcontroller from Microchip. It is a direct replacement for the PIC16F628A, with more memory and a 10-bit multi-channel analog-to-digital converter (ADC), making this device ideal for our MIDI Theremin. It also has a serial output that can produce MIDI format signals at a 31.25kHz baud rate, with the required stop and start bit. The serial output can also be set to provide the 38.4kHz signal suitable for the serial port on a computer. Either of these two baud rates is accurate when the microcontroller operates at 8MHz, as set by crystal X1, between pins 15 and 16. IC2 monitors the sensor signals from the hand plate, antenna and auxiliary potentiometer control, at its AN0, AN1 and AN2 inputs. Diodes D3, D4 and D5 are included to add to the existing internal clamp protection for these inputs, while the 2.2kW resistors provide input current limiting. The Enable and Register Select an idea whose time has come! You often wonder “Why hasn’t someone thought of that before . . .” MicroVGA is such a product: a graphics adaptor which allows you to display text and graphic patterns on any standard VGA monitor without the need to have a computer attached! Wonder no more: 4D Systems have done it! MicroVGA can be interfaced to any host microcontroller, embedded device, or a PC with a serial port. Predetermined programming commands can perform a multitude of tasks with high quality imagery in 64 colours, not just for graphics and text characters but also for the entire screen (background). If your application – consumer, industrial, control, in fact just about anything at all – calls for displayed text, graphics or a combination of both you must have a look at what 4D Systems’ MicroVGA can do for you! Call 4D Systems now for more information or a PDF of the User Manual! Features:  64 colours  252 (H) x 192 (V) pixel resolution  15pin standard VGA connector interface  128 standard ASCII built in character set  64 user defined (8 x 8) bitmapped characters siliconchip.com.au inputs on the LCD module are driven from IC2 using the RB6 and RB7 outputs. The data input lines are also driven by the RB0 to RB3 lines from IC2. The LCD module has eight data lines but we are only driving the upper four bits (DB7-DB4). This means that the data must be sent as two 4-bit blocks in order to drive the display. The Enable input and the Register Select input are control lines to place characters on the display and to set the character position. When the RB0 line is not driving the display, it drives the MIDI Invalid LED1 either on or off. If the LED is set to off, then the fact that the DB4 data line to the display is also being driven does not light LED1, since it happens in short bursts. RB5 from IC2 is the serial output. This provides the MIDI signal for optocoupler IC3 and the MIDI output socket. When the circuit is connected to the games port on a computer, pin 8 of IC3 is connected to the computer’s own 5V supply. IC4 provides the RS232 conversion for the serial signal. In short, the MIDI Theremin is a very powerful instrument in its own right and we imagine it will become very popular indeed with bands, orchestras and anyone interested in either playing or experimenting with synthesised music and sound effects. That’s enough to for this month. Next month, we’ll give the construction details and describe how the Midi Theremin is set up and used. SC  31 x 24 Text (8 x 8 font)  42 x 24 Text (5 x 7 font)  RS-232 serial interface  Auto Baud Rate detect, speeds from 300baud to 19.2kbaud Two versions of MicroVGA available: “Bare bones” version consisting of assembled PC board with all sockets and drivers. Ideal for $ embedding into other applications +GST 90 “Consumer” version with above PC board, complete in small (9 x 5 x 2cm) case, includes driver. Ideal for all end$ user applications. +GST 120 Proudly designed and manufactured by 4D Systems AND NOW AVAILABLE FROM: Dontronics (Melbourne): www.dontronics.com Optek Enterprises (Sydney) Ph: (02) 9979-2777 April 2005  35 A nostalgic look Colour TV in Aus Last month, we looked at some of the interesting changes that the introduction of colour TV brought to the service industry some 30 years ago. This month, we’re looking at some of those “interesting” locallymade colour TV sets . . . then again, for those in the industry at that time (and since), the word “interesting” is not the first adjective you’d use! B EFORE THE WHITLAM Labor government announced sweeping changes to the tariff systems covering imported manufactured goods and components, there was a general agreement in the industry that colour TV sets would cost somewhere between $1200 and $1500 (ie, approximately 10 times the average gross weekly wage!). Moreover, there would probably be no more than five basic chassis designs: Philips, Sanyo, Panasonic, Thorn and Pye. Of course, the changes to the tariff structure changed this drastically and these prices were drastically revised. In a bid to level the playing field a bit, Telefunken, the owners of the PAL patents, enforced a 6-month moratorium on the direct importation of colour sets with screen sizes of 51cm or less, from the date the first official “limited” broadcasts started in late 1974. 36  Silicon Chip The locally manufactured line-up for 1974 consisted of the Philips K9, the Kriesler 59-01 (basically an electronic clone of the K9 but with different board layouts), the AWA/Thorn 4KA (an antipodean-ised version of the UK “hot chassis” Thorn 4000 series), the Panasonic 2000 chassis, the Sanyo CTP7601, the HMV C210, the PYE CT25 and the Rank Arena (NEC) 2601 and 2201. Notably absent were any locallymade models with remote control, absurd though that may sound now. The problem was that remote control necessitates a varicap tuner and because Australia has a number of “oddball” TV channel frequencies that are not used anywhere else in the world, there was nothing available that could tune in all the Australian channels. There were some up-market fully-imported European models that did offer remote control but sales-wise they were problematic, because you couldn’t guarantee they would work everywhere. The first remote controls used ultrasonic transducers and were big, clumsy and unreliable. It wasn’t until the appearance of infrared models in the 1980s that they started to become standard equipment. Philips/Kriesler The Philips K9 was a fascinating mixture of the antiquated and the futuristic. It featured a choice of 56cm and 66cm 110° delta-gun tubes, with an incredibly comprehensive convergence panel. When this worked, it gave very good results indeed and in fact K9s were widely used in TV studios as inexpensive substitutes for “studio” monitors. Sadly, its very complexity was also its downfall. It was the same siliconchip.com.au at the start of P a r t 2 : B y K e i t h W a l ters stralia old story – the more things you put in, the more things there are to go wrong! Nonetheless, a fully-working 66cm K9 forms part of my “living museum”! The video drive to the picture tube used the “colour difference principle” – ie, a high-voltage luminance signal was fed in parallel to the three cathodes, while separate R-Y, G-Y and B-Y signals were fed to the appropriate control grids. Although this was common practice with earlier all-valve colour TV sets overseas, the K9 was the only mass-market all-solid state design I am aware of that used this technique. Some time before this, Philips had decreed that the way of the future was highly “modular” chassis design, with most of the active circuitry contained in small plug-in units reminiscent of the “motherboard/expansion board” approach of PCs. You weren’t supposed to try to repair them and none of the Philips circuit manuals included schematics of any modules used. The K9 used a large number of these modules and naturally they wanted to charge an arm and a leg for replacements! Fortunately, Kriesler (owned by Philips) used a similar module system with almost identical circuitry and pin layout but their modules were physisiliconchip.com.au cally larger and meant to be serviced. More importantly, Kriesler included the module circuits in their manuals, which were “close enough” to the Philips ones! Like many of the other locallymade designs, the K9 also featured something else new and frightening: a switchmode power supply. Although all TV sets made these days (as well as VCRs and DVD players) use that technique, in 1974 this was something we’d only read about in English TV servicing magazines and then with reference to only one TV chassis – the Thorn 3000 series! When it’s all said and done, the Philips engineers got it mostly right with the K9, since as far as the power supply and deflection systems go, modern colour TV sets are remarkably similar to the classic Philips design, albeit with most of the discrete transistors now packaged into ICs. The Australian version of the K9 was unusual in that, while the power supply itself was “hot”, it had an isolated secondary winding, which meant the rest of the chassis was “cold”. With the modern requirement for direct A/V inputs, this is standard practice now but the original Dutch version of the K9 had a hot chassis. The Kriesler models were basically very similar to the K9, although they’d dispensed with the colour difference drive and just used direct RGB drive to the tube. Kriesler also specialised in the manufacture of “prestige” models with elaborate teak veneer cabinets. Some of these cabinets were so good that a friend of mine used to make extra money “refurbishing” them for a large department store, basically by “retro-fitting” them with the innards of a modern plastic-cabinet TV! And now for something completely different . . . Then I suppose if you want to go from the sublime to the ridiculous, we also had the HMV C210. Unlike the K9, this was a veritable tour de force of dead-end design, in particular the use of a Thyristor-based horizontal deflection system. The story behind this technique is quite fascinating and not terribly well known. First of all, in most countries, the bulk of valve TV sets did not use power transformers, a tradition the manufacturers were keen to maintain with their solid-state designs. The valve heaters were connected in series directly to the mains through a suitable “ballast” resistor and (usually) April 2005  37 Many of the early colour TV sets were real pieces of furniture, built to quite high standards of joinery. This AWA set (sorry, AWA Deep Image Colour set – what ever that meant!) was typical of the genre. the 200V or so main HT line was derived by half-wave rectification on the mains. (You may have read about valve radios being configured the same way in the vintage radio column). With any “conventional” horizontal deflection system, (ie, using either a pentode valve or a bipolar transistor as a 15,625Hz switch), there is an approximate 10:1 correspondence between the HT rail voltage used and the flyback pulse generated across the switching device. For example, a 100V supply rail will produce 1000V flyback pulses, 120V will produce 1200V flyback pulses and so on. It’s no trouble to produce power valves with breakdown voltages of thousands of volts, so they could be run more or less directly off rectified 240V mains. In fact, most valve horizontal stages used a so-called “HT Boost” circuit where the input HT voltage was stepped up to 500V or so by the horizontal damper diode. This had a number of advantages but in particular, manipulation of the grid bias of the output valve allowed the boosted HT rail voltage to be regulated by a feedback loop, which both stabilised the width and filtered out any residual mains ripple. They were in fact an early form of switchmode power supply. Unfortunately, this approach is not possible with transistors. There is a definite technological brick-wall you run into with silicon which makes it impractical to manufacture transistors with breakdown ratings much above 1500V. This means that the maximum sup38  Silicon Chip ply rail voltage is limited to around 150-160V. This was all perfectly splendid with the US 117V AC mains, since that voltage could be directly rectified and filtered to produce around 150V DC, which could then be regulated down to 110-120V, giving a comfortable 1200V flyback. Thus most US and Japanese sets were “hot chassis” designs, often using a simple linear series regulator. With European 220/240V mains voltages, this was not possible. The raw rectified DC would be something over 300V; getting this down to 150V or so with a linear regulator at the typical current of 1A would give a dissipation of around 150W! Some manufacturers experimented with using two 1500V horizontal output transistors in series but this was a tricky and expensive option. The most common approach in Europe was to use a single thyristor as both half-wave mains rectifier and voltage regulator, which worked on much the same principle as a light dimmer. The thyristor simply held off conducting until the positive mains cycle had passed its peak and dropped back to around 170V or so. Although these worked well enough, the various electrical authorities weren’t too thrilled about the way they chopped up the mains waveform, and so the manufacturers, particularly those with a sizeable export market, began to look for alternatives. The Japanese for the most part took a pragmatic approach and simply fitted their European export models with stepdown transformers. This allowed them to retain their tried and proven series regulators and in fact, their European designs weren’t all that different from their NTSC models. Philips, as mentioned earlier, went for the new-fangled switchmode power supply, while others tried a more exotic approach, using a Thyristorbased horizontal deflection developed by RCA in the mid 1960s. The full operation of a Thyristor (SCR) based horizontal deflection system is extremely complex but essentially, the energy is fed into the deflection yoke during the flyback period, something in the manner of a Capacitor Discharge Ignition system. The yoke winding then essentially “coasts” through the visible scan period, using a network of switching diodes and a second SCR to produce an approximation of a sawtooth scanning current. In the 1960s, there was considerable doubt over whether it was even possible to manufacture silicon transistors with a breakdown rating of much over 500V, so for a while it seemed that the only practical way of making an allsolid-state colour TV chassis was to use a big (and heavy) mains stepdown transformer. RCA’s SCR horizontal deflection system was first demonstrated in 1967, as a possible solution to this problem. An unregulated +140V HT line derived directly from the 117V mains was fed to the flyback Thyristor via a saturable reactor, which basically formed the control element of an electronic regulator system. Without going into too many details, flyback pulses of about 120V amplitude were applied to the horizontal deflection yoke, resulting in a peak-to-peak scan voltage of about 24V. This operation is basically the reverse of that of a conventional line output stage. Although the system did work, it never caught on for a number of reasons. First of all, although the basic principle was simple enough, the actual circuitry needed was quite complex, requiring several large ferrite inductors and high-value polyester capacitors. Because of the very low scanning voltage used, the yoke current peaked at over 100A in large-screen sets, which meant extreme care was needed in manufacture to avoid dry solder joints, as the slightest resistance would result in major burn-ups. There were siliconchip.com.au also severe problems with “spooks” (line frequency harmonics) causing interference on the screen. Ironically, it was RCA themselves who finally sealed the fate of the original system, when in the late 1960s their semiconductor division managed to produce power transistors with a 1500V rating, using a design not all that different from what is still standard today. US (and Japanese) solid-state designs thereafter tended to use bipolar transistors with a linear regulated power supply. However in Europe, the SCR line output stage was re-invented in the early 1970s, with a new three-SCR design. This also was designed to run from filtered but unregulated mainsderived DC (this time from 220-240V mains) but in this case, a special flyback circuit stepped this voltage up to somewhere between 450V and 600V. The third SCR regulated this boosted voltage by bleeding a variable proportion of it back into the main unregulated supply during the horizontal scanning period. The revised system worked on much the same principle as the earlier RCA one but because it applied higher voltage flyback pulses, a more conventional (cheaper) yoke design could be used. However, the Australian HMV C210 would have to take the biscuit as an example of taking the worst features of two technologies and combining them! The C210 used the old-fashioned two-SCR design but they also used a switch mode power supply, which meant the main feature of the SCR design – the built-in voltage regulator function – wasn’t actually used! The lack of a boosted HT rail also meant that they had to revert to a special low-impedance scanning yoke, with all the inherent problems of heavy circulating scan currents, dry joints and so on. Worse still, for the switchmode power supply, they chose a peculiar self-oscillating design which, while economical to build, was barely good enough to drive a set with a conventional transistor horizontal output stage. SCR line output stages are notorious for occasionally drawing unpredictable and extremely heavy supply currents during start-up; in fact many sets that used them were equipped with mechanical circuit breakers as an afterthought! The C210 power supply siliconchip.com.au This 1975 26-inch Lowboy Thorn 9064 also boasted “twin hi fidelity speakers” and a quality timber cabinet. As with most sets at the time, it was VHF-only. was one of the least reliable on the market; it just couldn’t cope with that sort of hammering. To be fair, when the C210 chassis worked, it was quite a good set but they were hopelessly unreliable and easily the worst set on the Australian market in this regard. The new “Euro-version” three-SCR line output stage fared somewhat better but manufacturers very quickly dropped the technique, out of simple economics if nothing else! When it was all said and done, it was simply cheaper to use a switchmode power supply and a transistor horizontal output stage and a damned sight more reliable! But then a strange thing happened. Just when we thought the SCR line output stage had been relegated to the industrial bin of history, the Japanese cottoned onto the idea! After a fairly uneventful start with quite conventional designs, in 1975 Sharp started the ball rolling with a truly awful chassis called the C1831X. These were smart-looking little sets with state-ofthe art 18-inch 110° inline-gun tubes, and performed very well. But after a year or so (presumably as the electrolytics started to dry out), they started to fall over like flies. And they were just about unfixable! It was the same sad story as with many other SCR designs: you replace everything, and it still blows up at switch on! Apart from that, they had appalling chassis access, making them almost impossible to service in the home. From memory, I think they were the only colour sets we wouldn’t accept under service contract! But to give them credit, Sharp quickly realised the error of their ways and went over to the tried and proven switchmode power supply/transistor line output system. However, just when we thought it was safe to go back into the workshop, National (now Panasonic) decided to have a go, or show Sharp how it was done, or something! It was the same story – plagued by dry joints, blown up by even slightly tired electrolytics and “spooks” on Channel 0. Well, the flirtation didn’t last loo long there either and the SCR line output stage finally bit the dust! The C210 was such a disaster that HMV soon started selling fully imported British-made sets using the “Decca 33” chassis. This had the distinction of being the only mass-market colour TV sold in Australia with valves in it! After their flirtation with “hi-tech” SCRs, obviously HMV weren’t about to take any more chances! Ironically, they were damn good sets! In a store display, the Decca 33 would always stand out for picture quality and they were considerably more reliable than many of their all-solid-state competitors. This was April 2005  39 The C2201 was the first Rank Arena set available in Australia, along with the C2601. They were very successful and “The Bulletin” magazine reported that Rank Arena had 17% of the colour TV market in 1976. probably at least partly due to the fact that they were fitted with power transformers with a special winding that provided the exact voltage needed for the series heater string, rather than a dodgy dropper resistor. Their presence in the market also provided a handy source of valves for all the “odds and sods” colour TVs brought in to Australia by European migrants! The Thorn 4KA This chassis was almost as unreliable as the C210 but at least there was a reasonable possibility of fixing the 4KA and having it keep working long enough to get it out the door! I think the 4000 chassis would have to be a leading contender for the most over-designed set in television history! Admittedly, the K9 was a pretty complex beast but at least they mostly used common parts and they didn’t break down all that often. In fact, while there are quite a few K9s still working even to this day, I don’t know of anybody who had a working 4KA past 1990! The 4KA was the “Ocker-ised” version of the English Thorn 4000 chassis. The UK version had a live chassis and used a full-wave rectifier (ie, it was “hot” which ever way round the 40  Silicon Chip mains Active and Neutral leads were connected). For Australia, they simply fitted it with an isolation transformer, a move which was adopted by a number of European manufacturers as the easiest way to make their sets meet local safety standards. It’s interesting to ponder just what went through the designers’ heads when they came up with the 4000. Like most of the locally-made sets, it came with a choice of 56cm or 67cm 110° picture tubes but unlike most of the other manufacturers’ offerings, these were a special RCA narrow-neck delta gun tube (which didn’t seem to work any better than the standard wide-neck Philips tubes). The matching deflection yoke was also from RCA and was originally designed for use with a Thyristor line output stage. That plus the fact that the 4000 uniquely had separate horizontal output and EHT generating transistors strongly suggests that it was originally meant to use SCRs in the horizontal deflection section. The 4000 also had an incredibly comprehensive set of convergence controls, all brought out via a monstrous cable to a paperback-book-sized hand-held control box that could be unclipped and brought round to the front of the set. Instead of the usual conglomeration of variable inductors and wire-wound pots, the controls were all thumbwheels similar to those on a pocket radio. They were clearly marked with their functions and were a delight to use when the thing was working properly which sadly, wasn’t all that often! Thorn had developed an unfortunate fixation with thick-film modules, which still live on today in the form of the ubiquitous “Sanken” audio amplifier modules. The notion was fine in theory: a resistor network could be formed onto an insulating ceramic substrate, trimmed with a laser, connecting wires, transistors and other components soldered on, and then the whole assembly dipped in epoxy. The idea was that complete circuit modules could be built this way and the heat-conductive ceramic substrate would ensure that all the components were kept at the same temperature and so avoid thermal drift problems. There were several of these in the 4000 chassis and they were all hopelessly unreliable. Towards the end of the 4KA’s production life, AWA-Thorn started substituting small circuit boards which were far more reliable but suffered horrendous thermal drift problems. The static convergence would often drift 5mm during warmup! The 4KA also had tremendous problems with its chroma decoding circuitry. This must have started fairly early in the piece because the subcarrier oscillator and chroma processing circuitry were all located on a small plug-in board and several different boards were used, none being particularly reliable. I think the original idea was to have an elegant state-of-the-art two-chip colour processing system: a TBA395 for the chroma processing and subcarrier oscillator and an MC1327 for the decoder and output, but Thorn just couldn’t get it to work properly. The 4KA was so unreliable that, in 1975, following HMV’s lead, AWAThorn started importing British-made 56cm and 67cm sets using the older Thorn 3500 chassis. Although this seemed like a huge step backwards for many, at least these sets with their antediluvian 90° delta gun tubes and strange transistor types were reliable and properly set up, they gave an excellent picture. The Australian version of siliconchip.com.au the 3500, (dubbed the 3504) was fitted with an isolation transformer and a standard 13-channel VHF tuner. The above three models were probably the most noteworthy/notorious. Most of the other brands simply behaved themselves and so there’s not much to say about them really. That is, while there were certainly a lot of these sets sold, they were not, as the police might put it, “models of interest” to us! National National’s (Panasonic) first entry was a chassis known locally as the 2000 (also “M4”), which appeared in several screen sizes and models. This chassis was actually the very first locally manufactured colour set I ever saw and I still have a working 56cm sample in my collection! It seemed the Matsushita designers didn’t want to miss out on anything, since this chassis had a mains stepdown transformer, an SCR voltage regulator and a bipolar transistor as an electronic filter, which sadly, were the only unreliable parts of these otherwise excellent sets. Our first reaction was one of abject horror when we saw how the chassis was constructed though, with quite poor service access! Pye For a home-grown effort, the Pye CT25 was quite well-designed and relatively trouble free and unlike many of its “countrymen”, these sets tended to stay the distance. Unusually for a “Euro-centric” design, it used a simple mains stepdown transformer and a Japanese-type series regulator for its 120V HT rail. Pye were also unusual in using an inline gun picture tube from the start; other manufacturers took a couple of years to catch up. Otherwise, there was nothing whatever unusual about its circuitry, which is probably why so many of them lasted so long! Sanyo Another chassis that was “underrepresented in crime statistics”, the Sanyo was another fairly conservative effort, with a simple linear regulator power supply using two transistors in parallel. There are still a few of these in operation today, although at some siliconchip.com.au One of the early Philips colour sets – this was taken from an advert at the time complete with the then-standard “simulated picture” disclaimer . . . did they think that viewers would complain if the yacht sail did not poke out of the top of the television when it was installed in their loungeroom? point they would be in need of a bulk electrolytic transplant! Rank Arena These sets were basically a locally assembled version of an NEC chassis. The story went that a consortium of local manufacturers was offered the choice of the British-designed “true” Rank chassis or a badge-engineered NEC chassis. Legend has it that they took one look at the British effort and took the NEC option! Although the NEC chassis worked reasonably well, construction-wise they were a bit of a mess, the earlier designs being pretty much an NTSC chassis with extra circuitry tacked on for PAL decoding. They were less reliable than most of the fully-imported Japanese sets, but they were cheap and cheerful and most customers were satisfied with their purchases. Their only real vice was that the insulation around their EHT triplers often used to fail without warning, unleashing a noisy fireworks display that traumatised many a snoozing household pet (and its owner!) The Japanese invasion To give the local manufacturers a sporting chance, Telefunken, the owners of the PAL patents, enforced a 6-month moratorium on the importation of sets with screen sizes 51cm and under, until the actual commencement of full-time colour broadcasts in March 1975. As I said, we had good reason to fear an onslaught of cheap Japanese-made sets, in light of our experiences with their monochrome efforts! I was working for AWA-Thorn when the imports began and we were frankly left open-mouthed when the first container of 1000 AWA-branded (and Thorn) 34cm Mitsubishi portables duly arrived – not with horror but rather with amazement. Every single one of them worked! OK, a couple of them had purity errors that needed a touch of the degaussing wand and one or two of them had minor static convergence errors, but compared to what we’d been used to, this was unbelievable! With the 4KAs, as each shipment arrived from Sydney, it had become standard practice to take them all out of their cartons, sit them on top, and let them run without antenna input for about two weeks! Out of every lot of 100, after the first day there’d typically be 10-15 blank screens (some of which responded to switching off and then on again) and an equal number of screens with snow some colour other than white! Each day, the number of duds was a little bit April 2005  41 the life of the cathodes, it seems to have done them a power of good! Bypass operation A view inside a Ferguson set (actually a 7C06) of the period – they sure knew how to fit a lot in in those days! Of course, most of what you see in today’s sets would be replaced by a couple of large ICs and a few other components. smaller, until eventually a week could go by without failures. Of course, then we’d go round plugging in an antenna, and the fun would start again! The story was the same with just about every Japanese import: for sheer reliability and price, the Japanese were simply unbeatable. If I had to make a choice, I’d say that JVC gave the best all-round package of appearance, image quality, reliability and value for money. Apart from a couple of notable exceptions, you really couldn’t go wrong! Actually, “Dad’s TV” is a bit of a family joke that is a case in point. My father turned 70 in July 1975 and so my brother and I decided we’d go halves in buying him one of the new “AWA” 34cm portables. I actually paid the “dealer price” of $333, which in those days was a ludicrously low price for a working colour TV set! He was as pleased as punch and as he was bedridden a lot of the time. He didn’t expect to be with us much longer and so he kept remarking that the little set would “see him out!” However he got over that illness but true to his word, when he finally passed on 28 years later in September 2003, aged 98, the set was still going, with the picture tube as good as the day 42  Silicon Chip we bought it! What’s most remarkable is that it only ever broke down once in all that time (after 22 years). Recently I saw an identical set at a flea market for the princely sum of $5 and I bought it for spare parts. Would you believe that when I got that set home, I found it was also still in working order? After a few minor adjustments, it is also producing as good a picture as it did the day it was made – just like the 56cm version of the same chassis which I found during a council clean-up 10 years ago and fixed for a few dollars! There’s another bit of irony here too. Many of the first wave of imported sets had the “instant picture” facility, where about 4V (“standby”) was applied to the CRT heater while the rest of the set was off. This heater voltage was then increased to the normal 6V when the set was switched on. Grave concerns were raised as to the effect this “convenience” feature might have on the longevity of the picture tube cathodes, particularly if the set was to be taken under service contract. Well now we know! All of the sets I’ve seen with tubes still in perfect condition after 30 years were the ones with this feature! Far from shortening One of the weirder aspects of the Telefunken’s attempts to regulate the market via their control of the PAL patents was the “PAL bypass” fiasco. In 1968, Sony announced the development of their revolutionary Trinitron picture tube. It certainly produced the best pictures available at the time, and Sony caused a lot of concern with their announcement that they would not be licensing the technology to any other manufacturer, presumably hoping to corner the market. However, in retaliation, Telefunken refused to issue Sony with a license to manufacture PAL receivers, effectively locking them out of the lucrative European market. Sony then announced that they had developed a chroma decoder that didn’t actually infringe on the PAL patents, because it essentially turned the PAL signal into NTSC. The upshot of this was there were a few fully-imported sub-51cm sets imported into Australia before March 1975, some by Sony and a few from Mitsubishi. Because they didn’t actually use PAL decoding, they were prone to the “green faces” problem of NTSC, although properly set up, I doubt that too many people would have noticed the difference. However Telefunken insisted that these decoders did in fact infringe on the PAL patents, as they relied on certain characteristics of the PAL signal to determine which lines held PAL encoding and which held NTSC encoding. In the end, Telefunken relented, after experience with the US NTSC market showed that consumers weren’t all that impressed with the Trinitron tube, not if it meant paying substantially more for the technology! Apart from that, neither the Sony sets nor the Trinitron tubes turned out to be particularly reliable, and even after the Trinitron patents lapsed, no other manufacturer seemed interested. It’s rather sad now after all this time to see “Badge Engineered” Sony-branded TV sets with ordinary tubes in them. One of the minor mysteries of all this carry-on cropped up when HMV started selling small Japanese-made “General” colour sets under the HMV and Healing brands. There was nothing particularly noteworthy about these sets except that they used a siliconchip.com.au These two Toshiba sets from 1978 show just how far TV sets progressed in three years. The set at left was a basic VHF/UHF model, while the unit at right featured an ultrasonic remote control! “weirdo” two-crystal PAL chroma decoder system that would almost certainly have successfully sidestepped the Telefunken patents but they also used a perfectly standard PAL delay line system that most emphatically would not! It seems almost as though they changed their minds half way through! The beginning of the end The start of unrestricted importation of cheap colour sets pretty much marked the beginning of the end for the larger TV service companies. When colour was first on the horizon, the local manufacturers began to work out warranty service deals with the service companies and prices were agreed and so on, but this was on the basis of the original estimates of colour set prices before the tariff cuts were announced. With their prices effectively cut in half, the manufacturers naturally wanted to halve the service contract prices as well – but of course, it doesn’t work like that. For all practical purposes, the service cost was the labour cost, which remained stubbornly the same! The result was that most of the manufacturers decided it would be more cost-effective for them to provide their own service departments and that was how I came to be working for AWA-Thorn. Unfortunately, most of them badly overestimated the reliability of their own products, and so their service departments became hopelessly overloaded. The problems were massively complicated by the actions of certain smaller concerns siliconchip.com.au who suddenly started offering cut-rate service contracts to some of the big retailers, who had no way of knowing that these outfits hadn’t spent a cent on staff training or upgrading their equipment. It was pretty much a case of “take the money and run”, leaving the manufacturers (ie, us) to face the angry customers. In the current climate of consumer protection laws for everything, it’s hard to imagine what it was like back then. In those days it was perfectly normal for a customer to spend up to a thousand dollars on a colour TV set, have it fail the very first night, and then have to wait days or weeks for someone to even come and look at it! I had to make many a late-night house call with a 4KA chassis on the back seat of my car! Of course, with the wafer-thin profit margins involved with the new cheap imports, the importers/manufacturers were obviously keen to screw an even lower service contract price out of the service companies, which was generally greeted with statements like “Yeah, right!” This was well before anybody realised how reliable the Japanese sets actually were. If the service companies had known that, they could have cleaned up with low-price contracts on sets that never broke down. So in the end, the importers realised that it was probably going to be cheaper to simply keep a supply of spare sets on hand for replacement purposes or spare parts, which is pretty much the practice today. By the early 1980s, TV set manufacture had pretty well ceased in Australia, although some manufacturers maintained a “screwdriver industry” presence, basically assembling some of their larger models locally from fully imported components. The arrival of VCRs and things like personal computers revived the fortunes of the servicing industry to a certain extent but slowly it regressed to the “Mom and Pop” style of independent operators typical of the 1950s. Much the same thing happened in New Zealand, incidentally, although things happened a little differently there. What used to be one very large service organisation with branches in most of the larger towns, became a sort of “McDonalds franchise” operation, with independently owned branches supplied by a centralised parts buying agency. It’s hard to know where the future lies. In this era of $95 34cm portable TVs, $98 VCRs, $50 DVD players and $495 2.5GHz PCs, obviously it’s going to be a lot cheaper to throw things away than get them fixed. Nonetheless, as “Serviceman’s Log” can attest, people are still sometimes willing to pay an over-the-top price to get something fixed, purely on the basis of: “well, I know how to operate that set!” Organisations like WES Components do a sterling job of keeping small servicing companies in business, combining an enormous parts inventory with fast delivery. It’s truly amazing what you can still get parts for! Having said that, my local electronics repair shop has just closed down for good and that’s something that’s occurring far too often these days! SC April 2005  43 SERVICEMAN'S LOG Tempest tortures Turkish Teac Lightning can cause all sorts of damage to a TV set and fixing the problems is sometimes a complicated process. It gets even more complicated when you have to reprogram the EEPROM as well. I was called to Andrew Twist’s 2002 Teac CTW3250S (using the Turkish Vestel 11AK19PRO chassis), which was dead. This is a 76cm widescreen TV and I knew that if the fault wasn’t simple, it would have to go to the workshop. And that would be difficult considering the size of the small hatchback I was driving. Apparently, Andrew had decided to switch the set off and disconnect it from the mains just as a storm was beginning. However, before he could get to the set, a nearby lightning strike did the job for him! I removed the back and checked the power supply. Ironically (and typically these days), the 3.15A mains fuse (F801) hadn’t failed but R817 (2.2W, 5W) had. The bridge rectifier was OK but FET Q802 was short circuit. Items Covered This Month • Teac CTW3250S TV set (Turkish Vestel 11AK19PRO chassis) • Teac EU-80ST TV set (Vestel 11AK19) • Sanyo CP14SR1-50 TV set (AC5-G14 chassis • Panasonic Series II Inverter Microwave Oven NN-T790SF • Panasonic TX51P800H Rear Projection Television (chassis GP1VP) • Orion 32 DVA TV set (T7800 PRO Series chassis) 44  Silicon Chip Because this FET is DC-coupled to IC802 (MC44604P), the question was had that also blown, along with anything else? Anyway, that was as far as I was prepared to go in Andrew’s home. And having informed him of the facts, I suggested that he contact his insurance assessors. Unfortunately, he had been going through a rough trot and was only just beginning to get back on his feet. He wasn’t insured and really couldn’t afford to spend any money. Instead, he simply paid for the service call and told me he would wait until he could afford to have it fixed. Three months later, he finally dropped the set around to the workshop. Unfortunately, luck hadn’t been on his side during the storm. Not only had the control IC been destroyed but also D827 (BA159) which connects to the source of the FET. This was rather puzzling. D827 is in series with D826 and both are identical BA159 diodes but only D827 had short circuit. I cannot really imagine why – I guess it’s just part of the rich tapestry of life and chaos theory. After replacing D827, the power supply came on but was now pulsating slowly, with a low output. In addition, the red LED wasn’t lighting. I checked for shorts in the six secondaries but could find none. Next, I turned my attention to the +150V rail to the line output stage, where I checked D816 BYM26D (now BYM36D), the line output transistor Q605 and transformer TR602 (which was unlikely to have failed in this instance). I then shorted Q605’s base and emitter and hung a 60W globe from its collector to ground. However, this globe merely blinked gently when the power was applied. Further checking showed that there were low pulsating outputs on all the rails, even when I disconnected them one at a time. This meant that it was time to take a close look at the control circuitry in the switchmode power supply and at microprocessor IC501 – in particular, the circuitry to pin 22 (ST-BY) and pin 33 (RESET). The supplies to the microprocessor are 3.3V and 2.5V and both these were extremely low. Disconnecting the links to the microprocessor brought these voltages up but still there was no life. Furthermore, shorting one side of R831 to ground should turn the power supply on from standby but it made no difference. Next, I checked the optocoupler and its control IC zener (TL431), as well as IC804, C818, C704 and C829. However, I wasn’t really getting anywhere. Biting the bullet It was time to bite the bullet and replace microprocessor IC501 and the EEPROM (IC502). This was all rather confusing, as the service manual lists not one but two different part numbers – neither of which bore much resemblance to the one fitted in the set, the one on the circuit diagram or the ones supplied. I tried them one at a time until I found, naturally, that the most expensive part worked! I now had some control of the set. The red LED would come on in Standby and flash four times when the set was on and I could do this with the remote. The voltage rails were up a little as well, especially the low 2.5V, 3.3V and 5V rails. However, the 150V rail was still pulsating around the 80V level. Well, where to next? There was only the line driver and the jungle IC (IC401) left. The latter device is a TDA88441NZ, a big 56-pin device with high-density pins. I had already checked the voltages into this IC and siliconchip.com.au the clock crystals, so it now had to be changed. Replacing this IC finally brought the set to life, with picture and sound, but the geometry and picture were all over the place. Just in case I had misdiagnosed, I refitted the old micro and EEPROM which were socketed but it was obvious that these had been destroyed. Now all I had to do was reprogram the EEPROM. First, you have to get into the Service Mode by pressing the blue INSTALL button and then 4, 7, 2, 5 and go to the Options menu. Once again, the inadequate service manual (which, I might add, lists the CTW3250S as an 11AK19P3 – not an 11AK19PRO as written on the back of the set – and the CTW32505-1 as an 11AK33) does not have a list of option codes for each model. Instead, it has a list of 60 options with eight bits each and you have to work out what is appropriate for your TV. Fortunately, or unfortunately, options 30-37 and 39-49 are missing, so what do you do about these? And the manual refers to each bit as having a value of 1, 0 or X – X presumably being “I’m not sure?” (many of the choices you have to make from this total lack of information would surely come under this category). The only siliconchip.com.au thing is, the TV won’t let you put in X as an option. For example, Option Ø, Bit B4 Akb = 0 ) )0x02) Hue B6 (Black Current Stabilisation)? and Option 01 Bits B7 & B6 Forf = Fors = 1 (Forced Field frequency auto) (50Hz when line not synchronised)? As you can see, it’s not easy to make decisions based on these criteria! However, I did the best I could, making intelligent guesses, before moving onto the adjustment menus. Here we now have 65 controls to align for 4:3, 16:9, Cinema, Sub-title and Super Zoom settings, again with no real specification to compare with. Ironically, you cannot use a colour bar generator connection to an AV input as AV is not selectable in the Service Mode. Instead, you have to tune it in first on an RF channel and store it as a program number. For each of the aspect ratios, it doesn’t make it clear whether you need a generator that can give signals other than 4:3, nor does it make it clear whether and by how much you must overscan the picture. By trial and error, I managed to get what I thought was the correct geometry for each size but found the S-correction (adjust 14, 26, 37, 48 and 59) made no difference and I assume that Vertical Slope (adjust 14, 25, 36, 47 and 58) means Vertical Linearity and that EW Parabola Width (adjust 18, 29, 40, 51 and 62) means pincushion. When it came to setting up “Y” delay for SECAM, NTSC and others, as well as IF-PLL negative adjustment with PLL tuner, I chickened out and left the default values that were already there. Adjust 03 is AGC and was set to 015. After that, I tuned in all the local stations and was quite happy with the results while it was on test. Andrew managed to con me into redelivering the set and reinstalling it. No sweat – I felt that this shouldn’t be too difficult. All I had to do was retune the NEC VCR and connect his Foxtel box. It all initially went well, despite the millions of stairs and the hassle of moving his other 68cm set out of the way. However, when it came to tuning the set, I ran into all sorts of grief. I selected the Foxtel MENU setting so that I could easily identify it and that went into the pre-tuned VCR (on which I also selected its own menu) and into the Teac. I was expecting it to come up in two places on the TV and sure enough, it came up fine on Ch65 for the VCR (too close for comfort for Channel 10 on UHF Ch66) and Ch55 for the April 2005  45 Serviceman’s Log – continued – hey presto – the remote control was back in business and the set could be switched on again. The front control buttons still couldn’t be used but I didn’t care (it was probably due to a hairline crack). After all, the client was happy and if he was happy, Mrs Serviceman would be happy and perhaps I would get something special for dinner that night! Microwave ovens too! Foxtel. However, when I turned off the menu, the picture was shocking, with severe herringbone patterning on both locations. Andrew kept assuring me that all had been perfect before and that the reception was also perfect on the temporary set he had been using. The only thing I could think of was that perhaps the AGC hadn’t been set correctly and that it might be critical in this location. I went back into the Service Menu and spent what seemed like hours messing with the tuner options and adjustments – all to no avail. In the end I did the “De Bono thing” and thought laterally – if the tuner/tuning is crook, connect everything via the AV sockets. This meant supplying extra AV leads and a SCART adaptor – but it was worth it if would save time to fix the fault. Well, I did that but Foxtel was still showing a terrible picture. But why? Well, the first thing I noticed was that the simple blue and white menu was fine. It was only while actually watching Foxtel Ch13 that the problem occurred, so I changed the channel and found that almost 90% the other channels were perfect. It had to be a cable fault! Luckily, Andrew rarely watched Ch13 and someone must have selected it by chance. Anyway, he was delirious and so was I that at last I was out of this particular nightmare. Another Teac Later that week, I was forced into attending (for political reasons, to do with Mrs Serviceman) a Teac EU-80ST 46  Silicon Chip (Vestel 11AK19) for another client. This was dead and stuck in standby, with the red standby LED on and no other functions working. As luck would have it, the 80cm set was wedged into an entertainment centre that had to be unscrewed before it could be moved! I can’t tell you how much I didn’t want to be there but there are times when you just have to do jobs you don’t want to do, whether you like it or not (it’s called appeasement)! Anyway, after a struggle, the client and I eventually managed to dismantle his elaborate entertainment centre console and place the TV on a coffee table. I then removed the back and took a “peek-a-boo” inside. The first thing I noticed was that, despite the furniture looking pristine, the cabinet of this 4-year old TV had been badly scratched. When I looked at the chassis, I also noticed a large number of cracks in the PC board that someone had bridged with jumpers. Faced with this evidence, the client finally cracked (excuse the pun!) and admitted that the set had been dropped some time ago – but it had been working perfectly for a very long time since (where does Mrs Serviceman pick up these people?). He also admitted that the front controls had not been working for a very long time. However, the remote was fine so he hadn’t worried about this. Well, careful examination of the main chassis and the front control board, which also carried the infrared remote control receiver, showed that plug PL502 had a series of very bad dry joints. I resoldered these and Our amazing technician Michael was telling me about an interesting problem he had with a Panasonic Series II Inverter Microwave Oven NN-T790SF. This problem involved the display. When the START button was pressed, the word prompting display would sometimes show “Welcome to Panasonic”, as though the power had been switched off and the microprocessor reset. He traced this to the mounting screw for PC board 4W7QPT, which had failed to make a good ground connection. The circuit diagram shows pin 2 (centre) of plug CN4 as an alternate ground lead (yellow) but, in fact, the matching pin hadn’t been fitted to the PC board in the factory. The fix was to cut and solder the yellow lead directly to D27 instead. Stubborn Sanyo Sometimes, the problems I encounter are straightforward and sometimes they are extremely complex. Unfortunately, when a set first comes in, you can never tell which category the problems are going to be in. Recently, I had a “newish” Sanyo CP14SR1(G)-50 (AC5-G14 chassis) come in with the complaint that there was no colour when a DVD or VCR was plugged into it. Well, straight away, I thought that this was going to be easy – the wrong colour format must have been selected for the AV input. I pressed the Menu button, picture and tuning menus but nowhere could I find a system menu. OK, this isn’t unreasonable – after all, this is only a cheap 34cm portable so perhaps it doesn’t have this feature. Next, I had a good look for dry joints, especially around the crystal, and looked for a reference oscillator control that might be slightly out. I couldn’t find anything. Eventually, I noticed that if I ran my fingers down the pins of the jungle IC siliconchip.com.au (IC201, LA76818A), the colour appeared but I couldn’t pinpoint the problem. In the end, I assumed that it was probably the IC, so I ordered a new one. I fitted it as soon as it arrived but “quelle horreur”! – there was no change! A service manual for this chassis had been ordered at the same time but I could find nothing in it that gave me a clue. The oscilloscope showed the full colour waveform arriving on pin 42 of the chip and the reference oscillator was spot on. Fortunately, by mistake, an instruction booklet had also been supplied with the Service Manual. And page 17 (near the very back) had the solution! What you have to do is select the AV input and then the RECALL button on the remote control. This button is marked with a symbol of a TV screen and a bar in the bottom righthand corner and it reveals an AV system menu offering AUTO, PAL and NTSC. Of course, NTSC had been selected and changing this to AUTO fixed the colour problem. Husband bashing A husband and wife were having a domestic dispute that began to get a bit out of hand. In frustration, she picked up a glass and threw it at her husband (as you would expect) and naturally he ducked. The glass continued its trajectory unhindered until it came into contact with their brand new Panasonic TX51P800H Rear Projection Television (GP1VP chassis). It hit the middle of the set’s 130cm diffuser, severely cracking it. The diffuser is made of two layers: a front lenticular lens that’s worth $300 and a rear Fresnel lens that’s worth $400. Add in an extra $220 for the labour charge and . . . OUCH! Anyway, they lived with this for a while until the set blacked out into Service Mode, with the red LED flashing. This problem was even more severe. The red picture tube had been broken in two when the EHT arced through the neck and onto the deflection yoke winding. Fortunately, these latter items could be fixed under war- ranty but they had to cough up just under a grand for the diffuser lenses! Dead Orion A dead Orion 32 DUA TV set (T7800 PRO series chassis) was delivered to my workshop without its instruction booklet or remote control, which I always request for MicroZed.com.au MELBOURNE VISIT OUR WEBSITE FOR ALL THE DETAILS OF THE UPCOMING P ICA X E FA I R SATURDAY APRIL 30TH - 10AM to 4PM VICTORIA UNIVERSITY, BALLARAT ROAD, SUNSHINE Bring your PICAXE project along (complete, or even incomplete if you’re looking for help with hardware or programming techniques). YOU COULD WIN A PRIZE! MicroZed.com.au PHONE (02) 6772 2777 9-5 FAX (02) 6772 8987 24 Hours altronics.com.au VIC: School Electronic Supplies STOCKISTS WA/NSW: NZ: sicom.co.nz NSW: austeksecurity.com.au (John - 03 8802 0628) NSW: oatleyelectronics.com (chips only) (south island) surplustronics.co.nz (north island) siliconchip.com.au April 2005  47 Serviceman’s Log – continued obvious reasons. The fault was fairly easy to diagnose – the line output transistor had gone short circuit due to an arcing flyback transformer. Both were replaced but on switch-on, there was just a black screen with the program number “PO2” displayed and “Child Security Active”. I couldn’t get into the menu to unlock this as only the remote control works in this mode. That meant a delay of a couple of days while I contacted the client, to ask him to drop the remote in. When I finally got the remote, I found I could activate the menu and go to child safety but I still couldn’t remove the message. It was only when I went I went into the service mode (press menu and –vol and switch on with the remote control) and entered the VG2 set-up that I saw “error” next to it. Adjusting the screen control of the flyback transformer changed this message from “increase” to “OK” to “decrease”. Leaving it on “OK” finally removed the “Child Security Active” message. It’s easy once you know why and how! An expensive repair A dead Sony KV-PF21L70 (BG-3S chassis) was brought in and I immediately thought “piece of cake”. Its line output transistor (Q511, 48  Silicon Chip 2SD2578-CA) was short circuit. I replaced it, resoldered the line drive transformer (T501) to eliminate any potential dry joints and checked C528 which is across transistor Q511. I then switched the set on, thinking that that would be the end of the matter. So much for my confidence – the new (and rather expensive) transistor failed again and I was back to square one! This time, I removed the flyback transformer (T503) and checked it with a shorted turns tester. It checked OK but just to be sure, I substituted a flyback transformer from a similar set with a broken tube. I then shorted out the base and emitter terminals of the line output transistor and hung a 60W globe on its collector, along with a DVM. When I applied power, the globe lit and the DVM measured +135V. I then touched the CRO probe on the collector of line driver transistor Q506 and momentarily saw a good waveform appear. Suitably encouraged, I removed the globe and the base-emitter short from the line output transistor, attached the CRO probe to its collector and set the DVM for maximum hold on the 135V rail. Once again, the set tried to fire up but after an initial rush of static, it immediately died. The second replacement transistor had also failed. Both the waveform and voltage were correct, so I checked for shorts on the secondary of the flyback transformer, replaced the transistor again and tried another deflection yoke. This third transistor also failed when power was applied. By now I was beginning to feel that excessive EHT was killing these expensive transistors. I had already used up my entire stock, so I switched temporarily to cheaper BU2508DF transistor equivalents. Unfortunately, the failed start-ups were also causing further damage. D504 and Q505 (an IRF614 FET in the east-west circuit) had gone short circuit and IC301 CXA21395 jungle had also been damaged. This latter IC is extremely expensive, costing just over $110. Even worse, I still I hadn’t got within cooee of solving this but my pride wouldn’t let me stop. As a last-ditch effort, I started removing and checking all the capacitors in Q511’s collector circuit. Fortunately, the third one I checked, C538 (8.5nF), was faulty, measuring just 1nF. This is a critical capacitor and as the EHT is inversely proportional to its value, it’s a wonder the tube hadn’t been damaged by flashover. I fitted a new capacitor and switched on with some trepidation. This time the picture and sound came on perfectly. However, I wasn’t completely out of the woods because there was still one more fault. On high-contrast pictures (ie, high beam current), the picture would pull to the left and the set would switch off with the red LED flashing twice, denoting overcurrent protection. The self-diagnosis showed errors 002, 003 and 004 as all being 001. I spent a lot of time analysing and measuring the ABL (Automatic Brightness Limiter) circuit, especially D315, D316 and Q312, before finally concluding there was nothing wrong with it. Eventually, I realised that it was a protection fault and that Q604 and Q503 were being switched on. It was then that the penny dropped – R615 (1.2W) had gone high due to the repeated excessive current being drawn by the short-circuit horizontal output transistors. I replaced it and this time the set performed correctly – but was this all really worth it? Oh, well – you win some and you SC lose some. siliconchip.com.au NEW CATALOGUE OUT NOW new products and great bargains [ April 2005 ] MPEG4 Media Player Great for the car or home! Here is a great way to enjoy movies, music, and picture slide shows on your TV or PC monitor. It accepts many common memory cards so all you need to do is load the files on the card, pop it in and you're away! The IR remote control operates all functions, including great features such as image zoom, image rotate, slide shows, and various other great functions. It supports MPEG4 encoded files in MPG, DAT, and AVI format, and Cat. XC-4865 $ .00 can also play music and image files. See our website for full details. Measures 125(W) x 22(H) x 83(D)mm. 199 40 Channel UHF CB Band Transceiver Cheap short distance communication! They operate up to 5km in an open field, or 1km in the city. Lots of accessories available, see our website for details. Cat. DC-1010 FREE MAINS $ .00 39 CHARGER* WITH EVERY PURCHASE! While stocks last. or 2 for $69.90 New Store in ALEXANDRIA! 647 Botany Rd., ROSEBERY NSW 2018 Ph: (02) 9699 4699 Fax: (02) 9699 4966 Opens Mid April Kodak™ Digital Camera Power Supply BARGAIN! Get ‘em quick! We have a limited quantity of Kodak™ switchmode power supplies that were intended for use with digital cameras. They have an Cat. MP-3234 output of 7VDC <at> 2.1A, and are $ .00 terminated to a 1.3mm DC plug. Ltd qty. COSTS MORE THAN $60 ELSEWHERE Available Mid April Gear Shift Indicator Kit Double moulded housing! It features large digits, Cat III 600V certification, and is designed for the professional and serious enthusiast. •Capacitance. Cat. QM-1539 •Frequency. .95 •Relative measurement. $ Faster gear shifts for faster acceleration! Ref: Silicon Chip April 1999. Many performance cars use "shift lights" to indicate when their car is reaching red-line, giving them a clear indication when it is time to change gears. This project has three lamps to illuminate close to, very close to, and at red-line. With the use of our Engine Immobiliser Kit (KC5255), it can also perform a rev-limiter Cat. KC-5265 function. Kit includes PCB, and all $ .95 electronic components. 69 Digital Optical Tachometer Non-contact! It measures up to 99,999RPM, and can be used to measure RPM or simply count revolutions. It has a large LCD display, laser pointer, and min/max recall. Great for the mechanics workshop or Cat. QM-1448 handyperson. $ .95 34 2.4GHz Wireless Colour LCD Receiver 69 Roam while monitoring! Now you can take your surveillance monitor with you to watch the kids, or keep a lookout for potential thieves. It has a 65cm LCD and a speaker for audio. See our 2005 catalogue page Cat. QC-3596 312 for compatible cameras. $ .00 Mini AC/DC Current Clamp Meter Includes voltage detection! Rated at Cat II 600V, this clamp meter can measure AC or DC current up to 200A, and features an integrated non-contact voltage sensor. Supplied with a leather like belt pouch. Illuminated Multimeter Probes Cat. KC-5408 $ .00 799 Additional Scoreboard Expand the possibilities! The control console can operate more than one scoreboard, so you can have one on each end of the court. Additional scoreboards contain everything included in the original kit, without parts Cat. KC-5409 for the control console. $ .00 649 Memory Card Type MP3 Player A cheap alternative! It uses standard SD memory cards (available separately), giving you a cheap, high capacity MP3 player. Measures just 57(W) x 45(H) x 12(D)mm. Cat. GE-4003 $ .95 Was $69.95 49 SAVE $20 128MB MP3 Player with LCD Screen Great music portability! It can store up to two hours of MP3 or four hours of WMA Great Savings on music. Five built-in EQ settings, it can also operate as a USB Selected Ni-MH Batteries! Save a bundle! By using rechargeable batteries, you flash disk. Ltd qty. Cat. GE-4001 SAVE $ .00 Was $149.00 $30 not only reduce waste, you save yourself money! Ni-MH capacities now rival alkaline counterparts, so you get long run times from each charge. Limited 128MB MP3 Player Backphones quantity available. See our website for battery Great at the gym! They look chargers. like regular headphones, but 299 Cat. QM-1564 $ .95 99 119 Type Nipple AAA 650mAh Tag AAA 650mAh Nipple AA 1650mAh Nipple AA 1800mAh 4Pk Nipple AA 2300mAh FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 EXCLUSIVE TO JAYCAR! This kit enables you to make a full-sized electronic scoreboard, in particular for Basketball but also adaptable for netball and other games. Ref: Silicon Chip March/April/May 2005. It can be built for a fraction of the cost of commercial equivalents and has a completely wireless scoring console that can control one or multiple scoreboards. You can mount the scoreboards high up in a court and all you need is a convenient 240V power point. You can then control them from a table courtside with no messy wiring. It features Home/Away team scores 0 to 199, Game period, and Countdown time. The scoreboard measures 900 x 600mm. •The Jaycar kit comes complete with all pre-cut scoreboard woodwork, screen printed face, display filters, mounting plates, pre-programmed microcontroller, printed circuit boards, 2.4GHz transmitters and receivers, pre-punched control console with special piezo end-of-game/quarter sounder, and all electronic components to make one scoreboard. KIT OF THE MONTH Cat III Auto Ranging DMM 39 Get it with April Silicon Chip Magazine or at your local store for just $3.95! 15 *Rechargeable batteries sold separately Not as extravagant as you think! They make light work of taking measurements in dark places and crowded cabinets. An LED in the tip is powered by an internal rechargeable battery and charger supplied. 800mm Cat. WT-5300 long. $ .95 Wireless Basketball Scoreboard Kit 2005 Catalogue Out Now! INTERNET> www.jaycar.com.au Cat SB-2444 SB-2446 SB-1702 SB-1712 SB-1726 Was $2.95 $3.25 $4.25 $15.95 $6.25 Now $1.95 $2.25 $2.75 $11.95 $3.75 Save $1.00 $1.00 $1.50 $4.00 $2.50 actually contain an MP3 player! Great to eliminate headphone cables when jogging etc. Ltd qty. Cat. GE-4002 $ .00 Was $149.00 99 SAVE $50 1 Laser Pointer with Presentation Control PC interaction! Eliminate timing hassles when giving PC assisted presentations. It has a regular laser pointer as well as a wireless IR transmitter / receiver to control the PgUp / PgDn functions on your computer. Works Cat. ST-3108 over $ .95 15m! 49 2.5" IDE - USB 2.0 Hard Disk Drive Case Massive portable storage! Instantly add gigabytes of storage to your PC or notebook. You can use any 2.5" IDE HDD, and then plug it into your USB 2.0 port for super fast backup, transfer, and Cat. XC-4678 $ .95 storage. Includes carry pouch, cable, and drivers (only required for Win98). 49 CPU Ventilation Duct Highly efficient cooling! Achieve up to 14°C better cooling by using this air duct to pipe fresh cool air to your CPU. It is flexible and extendable between Also 90 and 300mm suitable for long. Suitable Amplifiers! for 80mm fans. Cat. XC-5028 $ .95 19 Extremely versatile memory device! As well as having 64MB of on-board storage, this flash disk also has a card reader for use with SD, MMC, and Memory Cat. XC-4768 Stick (including Pro and $ .95 Duo). Full speed USB 2.0 data transfer and a compact 28(W) x 80(H) x 20(D)mm package. 64 USB Power Booster Cable Jaycar carries a range of wireless networking devices to get you connected without wires. It is becoming increasingly common for homes and even offices to be networked without wires, and it is now very affordable. Wireless Network Adaptors A range of cards to suit all computers and provisions. Common specifications: Cat. YN-8066 •IEEE 802.11g wireless network compatible. •Interoperation with IEEE 802.11b 11Mbps networks. Cat. YN-8067 •64 / 128 Bit WEP encryption. •54Mbps high speed transfer rate. •40 - 100m indoor range. •100 - 300m outdoor range. •Low power consumption. Cat. YN-8068 •Plug and Play compatible. •Compatible with Win98/SE/2000/ME/XP PCI Wireless Network Cat. YN-8066 SAVE $ .95 Adaptor Was $89.95 $20.00 69 USB 2.0 Wireless Network Cat. YN-8067 $ .95 Adaptor Cat. WC-7750 $ .95 14 300k Pixel SurfCam USB Web Camera Video conferencing and more! It uses a 300k pixel colour CMOS sensor with auto exposure and white balance for optimum performance. Software included for creating Cat. QC-3223 greeting cards and $ .00 photo albums. PCMCIA Wireless Network Cat. YN-8068 $ .95 Adaptor Was $89.95 69 Wireless Access Point with 4 Port Router Allows communication with up to four wireless network computers. It includes support for WAN, web based and remote management, auto detection and configuration of ISP, built in firewall, and more! See website for details. •IEEE 802.11g and IEEE 802.11b compatible. •Up to 54Mbps data rate. Cat. YN-8086 $ .00 •Static and dynamic routing. •VPN pass through. 179 Quick and easy! Test UTP, STP, Coaxial, and Modular network cables by automatically scanning the wires for continuity, mis-wiring and polarisation. It uses a remote terminator for testing of installed or uninstalled Cat. XC-5075 network cables. $ .95 Was $69.95 39 CD Destroyer 2.4GHz Wireless Antennas Cat. AR-3270 $ .95 2.4GHz Yagi Antenna 8dB gain! If features high gain for excellent transmission range. 129 SAVE $10.00 29 SAVE $30.00 Network Cable Tracer Invaluable for technicians! This tone generator is a highly practical network installation and troubleshooting tool. The insulated inductive pickup amplifies the tone signal, SAVE $70.00 and the tracer can also be used to check telephone line status (ring, Cat. XC-5083 busy, idle). $ .00 Was $199 129 SAVE $50.00 Powered Multimedia Speakers Great sound! Boasting a power output of around 4WRMS, and bass reflex enclosures, these PC speakers sound great. They are shielded to prevent damage to CRT monitors, and are mains powered. Cat. XC-5160 Was $23.95 $ .95 19 SAVE $4.00 2 Port Automatic KVM Switch Improved range! Increase the effective range of your wireless network or AV sender transmission. They are supplied with mounting hardware and SMA connection. There are two types available: Cat. AR-3272 $ .95 99 It makes dimpled tracks over your CDs to stop them from being read. Was $39.95 Cat. YS-2832 $ .95 Cheap protection! Connect this unit inline with your antenna to stop lightning strikes on the antenna reaching your valuable equipment. "N" plug to socket connection. 5dB gain! It features a 700mm lead and a magnetic base. 179 CD/Media/Paper Shredder 49 2.4GHz Lightning Protector HDTV on your computer! Watch either high or standard definition TV on your PC! It supports wide-screen (16:9) and standard (4:3) Cat. XC-4819 $ .00 aspect ratios. It shreds up to 15 sheets of paper at a time, as well as CDs, floppy disks, and credit/ATM cards. Cat. YS-2830 SAVE Was $129.95 $ .95 $30.00 Visual indication! Suitable for use with UTP, STP, Coaxial, and Modular network cables, it features two LED bar-graphs to indicate pin connection. You can then quickly see any incorrect connections. Cat. XC-5076 Was $99.95 $ .95 2.4GHz Dipole Antenna 249 Protect sensitive data! Make sure you destroy your sensitive data so it doesn’t fall into the wrong hands. Multi-Network Cable Tester with Pin-Out Indication 69 SAVE $20.00 Top quality reception! No need for physical hardware installation, just plug it into your USB 2.0 port for HDTV. It operates in enhanced 16:9 format with software supplied for DVD making and manipulation. See our website for Cat. XC-4814 $ .95 system requirements. Destroy CDs with Ease! 35 Cat. AR-3278 $ .95 89 USB 2.0 HIGH DEFINITION Terrestrial TV Tuner for PCs HIGH DEFINITION Digital Terrestrial TV Card for PCs Simple, but effective! This cable connects to two USB A ports, effectively doubling the current available to the peripheral device. It has a USB B plug on the end, and is 1m long. Multi-Network Cable Tester The Wireless Network Revolution! 2 64MB USB 2.0 Flash Disk with Built-In Card Reader 19 Simple switching! This KVM switch allows you to connect one keyboard, monitor, and mouse to two PCs, and switch between them with the use of "hot keys". See website for details. Cat. YN-8095 Was $89.00 $ .00 75 SAVE $14.00 Keyboard / Monitor / Mouse Lead for Switch Boxes No tangles! It is fully moulded, and is much better than using individual cables. 1m long, Cat. WC-7570 colour coded connectors. $ .95 Was $22.95 19 SAVE $3.00 FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 INTERNET> www.jaycar.com.au Speaker / Source Control Wall Plates S-Video Cat5 Video Balun Source and Speaker Switch Long range! Send S-Video signals over UTP Cat5 cabling for transmission distances of up to 300m with far less signal loss than coaxial cable. One required at each end. Measures 69(W) x Cat. QC-3423 $ .95 25(D) x 22(H)mm. Control the music around your home! With these inexpensive units, you can control volume, select speakers, and even sources! It allows you to wire your home with sound, while maintaining flexibility. See website for full details. 39 Select between two sources Cat. AC-1677 $ .95 and distribute to one or both pairs of speakers. VGA Cat5 Video Balun 19 Unbeatable! Send VGA signals up to 135m without hassle! Ideal for auditoriums, lecture halls, tradeshows, and more. Supplied as a transmitter and receiver pair. Measures 110(W) x 77(D) x 24(H)mm. 2 Way Speaker Switch Switch between two speaker Cat. AC-1679 $ .95 pairs quickly and easily. 19 70W 12-Step Stereo Loudspeaker Attenuator Attenuates by 46dB on an 8-ohm system for tailored listening Cat. AC-1685 $ .95 levels. Ideal for home theatre! Send RGB signals over UTP Cat5 cable up to 300m! This is much further than is possible with coaxial cable. One required at each end. Measures 110(W) x 77(D) x 24(H)mm. Noise Cancelling Headphones Sleep soundly! They are designed for use in noisy environments such as an aircraft or cars reducing background noise by as much as 15dB. Powered by two AAA batteries (included), they come with a 1.8m lead terminated with a 3.5mm stereo plug. Cat. AA-2054 $ .95 2.4GHz Wireless Audio Video Sender Watch cable TV all over the house! Send a signal from a DVD player, set-top box etc., to another room, without the use of any cables! You can use as many receivers as you like, without degrading signal quality. Each unit comes supplied with stereo audio and video transmitter and receiver, mains plugpacks & RCA cables. Transmission range is up to 100m, but depends on the type of construction materials used. Was $99 Cat. AR-1832 SAVE $ .95 $24.05 74 Extra receiver to suit Cat. AR-1833 .95 Cat. AR-1833 Was $69 $ SAVE $19.05 49 2.4 GHz Wireless A/V Sender with Remote Control Extender With the addition of an IR remote control repeater you can change the channel of the source device etc from the other room. Cat. AR-1830 $ .95 Was $139 Extra receiver to suit Cat. AR-1831 Cat. AR-1831 $ .95 Was $89 94 SAVE Great versatility! It offers wide viewing angles, image reverse, and more! Was Cat. QM-3752 $399 $ .00 SAVE $100 149 Ideal for rear seat viewing! It has integrated dome lights in the console, so you can replace your factory interior light. Was $419 Cat. QM-3751 SAVE $ .00 $90 329 Dash Mount 7" Monitor Cat. QC-3429 $ .95 79 Reversing made safe! With the use of a screen or monitor, you can obtain much better vision than otherwise possible. It mounts flush into your bumper bar or similar, and is powered straight from 12VDC. See SPECIAL OFFER! installation article in Purchase a Reversing Camera with any of our April Silicon Cat. QC-3452 LCD screens for just Chip. $ .00 $99. Save $50! 149 SAVE $80 Retractable! This unit folds down to store into a single DIN space (standard car stereo space) so it will go unnoticed. Cat. QM-3753 Was $ .00 $449 369 VHS Head and DVD / CD Lens Cleaners Keep it clean! If you experience problems with playback, distortion in the audio, or DVD skipping etc., it is quite possible that it is simply dirt causing the problem. These cleaners will take care of that, and get you the picture quality you want. See website for details. DVD Lens Cleaner with Voice Guide Wall Mount Speaker Brackets Cat. AR-1410 $14.95 VHS Head Cleaner with Solution Suits Lifestyle series! Ideal for mounting home cinema effects speakers. Maximum capacity of 5kg, and fully adjustable. Cat. CW-2820 Sold as a pair. $ .95 Cat. AR-1412 $9.95 CD / DVD Lens Cleaner Cat. AR-1416 $19.95 19 In Wall Speakers SAVE $44.05 Standard Mount 7" Monitor Roof Mount 7" Monitor Cat. QC-3428 $ .95 Weatherproof Colour Reversing Camera for Cars 49 See our website for full features & specs 299 RGB Cat5 Video Balun 39 7” Widescreen TFT LCD Monitors for Cars Radial CD / DVD Disc Cleaner Cat. AR-1414 $17.95 A great mounting solution! If space is limited, or you simply don’t want free standing speakers, then these are a great option for you. 8 ohm impedance allows them to be used in an array of applications. Supplied with attractive white baffle covers. 2 Way Cat. CS-2440 $99.00 3 Way Cat. CS-2442 $149.00 2 Way Ceiling Speakers Great quality sound! Most ceiling speakers are just simple single speaker designs. These dual cone speakers are superior, suitable for a wide range of applications. Supplied with attractive white baffle covers. Two way 6.5" drivers Cat. CS-2446 Two way 8" drivers Cat. CS-2448 Techstore only specials have extremely limited quantities available. They are only available from our Australian Techstore, not our "Bricks and Mortar" stores, or from New Zealand. Please check with mailorder staff for stock availability. Cat No JS-0570 JT-1895 JJ-0012 JJ-0013 JJ-0014 JJ-0015 JW-7235 JM-3110 JM-3118 JM-3121 JM-3523 Description SPST Standard Toggle Switch 3A/125V Copper Cable Shears Speaker Port 72 x 145mm Flared Speaker Port 50 x 130mm Flared Crossover 2Way with Speaker Terminal Speaker/Woofer 8” 8Ω 30oz Magnet 3 x RCA Plugs to 3 x RCA Plugs HQ 10m 150W 12.5A 12VDC Switchmode PSU 240W 18A 13.8VDC Switchmode PSU 120W 8.5A 12VDC Switchmode PSU 1.8Amp 6/12V SLA Battery Charger Was $2.00 $15.00 $4.50 $3.50 $4.95 $23.95 $39.95 $55.00 $110.00 $45.00 $39.95 Now $0.50 $5.00 $0.75 $0.50 $2.00 $10.00 $15.00 $38.00 $55.00 $25.00 $10.00 Save $1.50 $10.00 $3.75 $3.00 $2.95 $13.95 $24.95 $17.00 $55.00 $20.00 $29.95 Cat No JM-5080 JM-5088 JM-5090 JM-5095 JQ-3051 JQ-3360 JQ-3361 JQ-3363 JQ-3489 JQ-3496 JX-5087 Description 150W Pure Sinewave Inverter 1000W Economy Pure Sinewave Inverter 1000W Pure Sinewave Inverter 1500W Pure Sinewave Inverter 36Hour Time Lapse Video Recorder 4 Ch B/W Digital Video Camera Processor B&W Low-Cost Quad Processor 4 Channel Colour Quad Video Processor Dome Style Colour CCD Camera 380TVL Colour Pinhole CCD Camera in Metal Case Terminator Set For Cable Tester Was $129.00 $599.00 $709.00 $859.00 $500.00 $185.00 $95.00 $225.00 $150.00 $150.00 $25.00 Now $60.00 $450.00 $600.00 $750.00 $250.00 $100.00 $50.00 $120.00 $50.00 $50.00 $15.00 Save $69.00 $149.00 $109.00 $109.00 $250.00 $85.00 $45.00 $105.00 $100.00 $100.00 $10.00 NOT AVAILABLE SPECIALS - NOT $89.95 $19.05 69 $119.95 TECHSTORE SPECIALS - NOT AVAILABLE IN SHOPS TECHSTORE SPECIALS IN SHOPS TECHSTORE SPECIALS - NOT AVAILABLE IN SHOPS TECHSTORE FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 INTERNET> www.jaycar.com.au 3 Intelligent Automatic Rubbish Bin Air Powered Jet Hawk Glider Hands full? No worries! Just wave your hand, foot, or whatever you can, in front of the intelligent rubbish bin and the lid will open automatically! It will also close back up again, so you never need to touch it. Cat. GG-2315 $ .95 23L capacity. Launch it like a rocket and watch it soar like a hawk! Pump up the air powered launcher and send your Jet Hawk glider soaring 500 feet (150m) into the wild blue skies! It includes a safety feature to disable launching in horizontal or vertical positions. 610mm wing-span. 39 Pedometer with FM Radio and Calorie Counter Keep track of your calories! You can input the food you have eaten, and it will count down how far to go until you have walked it off. Many other functions, see our website. Cat. XC-0267 19.95 $ Don’t be late! This watch announces the time at the touch of a button. It is great for young children to help read the time, or the vision impaired. It has various alarm sounds to get you out of bed including a rooster crow. Cat. XC-0258 LED Velcro Safety Band Be safe, be seen! Use this LED safety band when you are out jogging, walking the dog, on your bike, and more. It consists of four red LEDs in an adjustable 30mm wide Velcro band that can be set to flashing or Cat. ST-3026 steadily on. Battery included. $ .95 9 New “Nite Ize” Maglite/Torch Accessories Nite Ize accessories suit AA Maglites and small torches (not included). Bite Light Adaptor Simple but effective! This attachment fits over the end of your torch with a patented mouth piece to allow you to safely bite down on it to hold the torch in place. It also includes a neck lanyard. Cat. ST-3405 7.95 $ Belt Pouch Not your average belt pouch! Not only can you store your torch on your belt, but with real world use in mind it has a small pouch to carry two spare AA or AAA batteries. Made from strong Nylon. Cat. ST-3408 6.95 $ Thin and flexible! Light only travels in straight lines, but you can make it bend with this Fibre Optic adaptor. A small attachment fits right over the head of your torch to give you a flexible light source for inspecting in tight places. 3mm diameter cable. 14.95 $ 4 Get this! Not only a normal flashlight but 8 extra buttons generate those weird sounds you hear in the "Addams Family" or a fairground Ghost Train! You get: evil laugh, wolf howl, creaky door hinges, thunder storm, Witches cauldron, Jacobs’ ladder etc. Cat. GH-1550 Colour filters clip over the light to add $ .95 atmosphere! 24 Great for emergencies! It contains a hand pump, puncture repair kit, two-piece tyre lever, Allen keys and a stainless steel multi tool, all stored in a nylon pouch. Great for on the road, or general maintenance at home. 19 Cat. ST-3410 59.95 $ 5Pc Bicycle Tool Set with Carry Bag .95 7" Fibre Optic Adaptor Cat. GT-3440 "Fright Night" Torch Talking Digital Watch with Alarm $ Portable Plasma Ball Cat. TH-2137 29.95 $ A sphere of magical plasma light that you can take anywhere! It creates a dramatic display of multicoloured light under a hand-blown glass dome. Requires 2 x AA batteries and measures Cat. GH-1527 $ .95 135(Dia) x 145(H)mm. 39 Plasma Clock Stylish and functional! With the option of table or wall mounting, the cool electric blue glow of the plasma will add a new dimension to your décor. It measures 291(H) x 177(W) x 107(D)mm, and a mains adaptor is included. Cat. GH-1525 59.95 $ Interactive Plasma Disk A great light show! This flat panel plasma disk produces an amazing display of blue light which will respond to your touch, voice or music. It measures 152(dia)mm, Cat. GH-1530 and includes a mains adaptor. $ .95 49 Camera and Equipment Cases How’s your green thumb? A must-have item for any keen gardener! It contains high quality stainless steel pieces including a mini hand trowel, mini rake and multi tool featuring secateurs, knife, 2 serrated knives Cat. TH-2139 and weeder. See $ .95 website for details. A worthwhile investment! Protect your valuable camera, mobile phone, or PDA with a tough carry case. The outer case is made from semi-hard PVC with soft fabric lining, this case is able to be attached to almost anything using the carabineer. Three sizes available: Small: 85(L) x 37(H) x 115(D)mm $8.95 Cat. AR-1440 Medium: 80(L) x 35(H) x 131(D)mm $8.95 Cat. AR-1442 Large: 105 (L) x 60(H) x 130(D)mm $9.95 Cat. AR-1444 Slimline 3 LED Book Light 11 Language Translator 3Pc Mini Gardening Tool Set 19 Over 700 phrases! It can cross translate between eleven languages on its own, and by using the optional voice cards, it can play them at the touch of a button. It has a host of other functions and is a must-have for overseas Cat. XC-0186 travellers. Compact and portable! While providing adequate light for reading, it is soft enough to not disturb your sleeping partner. It measures just 40(W) x 105(L) x 10(D)mm, and Cat. ST-3980 requires two $ .95 CR2450 batteries. 9 Bookmark Electronic Dictionary So slimline it’s a bookmark! Holding a vocabulary of over 50,000 words, this dictionary’s vocabulary is about five times better than the average human. The flexible keypad fits neatly between pages, and it even has calculator Cat. XC-0185 and alarm functions. $ .95 29 Animated Lightshow Fans Cooling and entertaining! Each fan features 5 super bright LEDs. When they spin, they display 64 incredible patterns and effects. The blades are made from soft foam, so they are safe for kids. Three types available: Desktop Fan GH-1077 Requires 2 x AA batteries. Car Fan with Suction Base GH-1078 Powered by car’s 12V supply. Gooseneck Fan GH-1079 Requires 4 x C and 4 x AA batteries. Cat. GH-1077 14.95 $ Cat. GH-1078 17.95 $ Cat. GH-1079 29.95 $ Optional Voice Cards (not required for text translation) English, French, & German XC-0187 $24.95 English, Spanish, & Italian XC-0188 $24.95 Mandarin & Japanese XC-0189 $19.95 Electronic Toy Safes Ideal protection against… siblings! Features an illuminated keypad and programmable combination, with voice or sound effects. Pink Cat. GH-1310 Blue Cat. GH-1311 •185(H) x 135(W) x 125(D)mm. BOTH COLOURS 19.95 $ Multi-Currency Coin Bank Count your savings! The counter can be set to one of 37 different countries, including the European Union. It then displays the total amount of money on the LCD screen. Measures 125(H) x 95(Dia.)mm. 24.95 $ Cat. GH-1315 14.95 $ FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 INTERNET> www.jaycar.com.au OGGZ - Colour Morphing Mood Lights Remote Controlled Massage Seat Cover Pad with Built in Heater Set a romantic atmosphere! These rechargeable wireless lights slowly change from one colour to the next, and have a soft glow for romantic or mystical effects. They are charged on their base, and run for up to 6hrs. 1 Piece Set Cat. GH-1047 Includes 1 OGGZ, charging base, and mains adaptor. 3 Piece Set Cat. GH-1048 Includes 3 OGGZ, charging base, and mains adaptor. Get a great massage on the go! It fits over most seats with the use of elastic straps, and the built in heater has three different heating levels. Three independent motors target the upper back, lower back, and thighs. Cat. GH-1753 Supplied with car and $ .95 mains adaptors. 49 Cat. GH-1047 34 $ .95 Cat. GH-1048 69.95 $ Alcohol Breath Tester with LCD Readout Cat. QM-7294 69.95 $ Electronic Body Fat Scales Are you overweight? These scales calculate your body fat content using the body mass index. They also give you your weight, and can store up to 6 profiles for different people in the family. Was $129.95 Cat. QM-7249 89.95 $ 29 Cat. XC-0375 19 $ .95 Anti-Fog 5" Shaving Mirror with FM Radio Shave in the shower and save time! This 'anti-fog' mirror won't get steamed up, has a digital clock, and an AM/FM radio. Supplied with handy razor holder, suction cups, screen hook and hanger cord. Cat. GH-1057 SAVE $40.00 Radio Controlled Submarines Great underwater fun! They have full manoeuvrability with forward, reverse, left and right, and a power dive function. Was $29.95 ea Two types available: 27MHz Yellow Cat. GT-3044 40MHz Blue Cat. GT-3045 SAVE $5.00 Both types 24.95ea $ Chemical free Flea killing! The comb emits an electronic charge to kill fleas on contact. It is suitable for use on cats and short-haired dogs, and requires 2 x AA batteries. Measures 155(L) x 45(D) x 90(H)mm. Going On Holidays? Use our Automatic Pet Feeder! Ideal for the kitchen or tackle box! The EL backlit LCD display indicates weight with a resolution of 1g and accuracy of +/-2g. They are highly sensitive and suited to a wide range of Cat. QM-7230 applications. $ .95 12V Camping Shower A touch of luxury! Wash away the cares of the day no matter how far from civilisation you are! The camping shower allows you to take a shower wherever you are. Cat. YS-2800 Powered by your $ .95 vehicle’s 12V battery. 34.95 Anti-Fog Shaving Mirror with FM Radio Shave in the shower and save time! It won’t fog up, and it tunes into your favourite station too. Was Cat. GH-1059 $ .95 $29.95 High Resolution 5kg Hanging Scales 39 $ Flea Exterminating Pet Comb 19 SAVE $5 Musical Bathtub Novelty 24 4 in 1 Mars Rover, Boat & Submarine Your heart will go shala-la-la-la! Sing along with these sound activated, animated characters enjoying a vigorous bathtub romp. Sure to put a smile on everyone’s face. Cat. GH-1090 24.95 $ Novelty Boss Voodoo Doll Cat. GH-1202 29.95 $ SAVE $10.00 Don’t worry about troubling your neighbours! Just put the food in and program the timer for 8, 12, or 24hrs. It will then slide open the lid and play your recorded voice Cat. GH-1190 message so your pet knows it’s dinner $ .95 time! Three separate compartments. Was $49.95 39 This thing will go anywhere! Whether it is driving over rough terrain, crossing water, or diving deep into it, this great craft will do it. It uses a skid steer drive system, or detach the wheels for full use of the props. Cat. GT-3420 Approx 180mm long. $ .95 Radio Controlled Boat Great fun on the water! This little beauty speeds around the bathtub or pool with full manoeuvrability. Uses an internal battery that is recharged with the battery pack. Cat. GT-3410 29 $ FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 A must have for every recreational fisherman! It includes a 14 in 1 multi tool, 0 - 6kg scales, and an LED hand torch, all in a convenient Cat. TD-2053 belt pouch. $ .95 Digital Map Distance Calculator How far is the next turn off? Automatically convert a map’s scale distance to real distance by rolling the small wheel along the desired route. It works with any map scale and displays in kilometres or miles. 199 Fishing Tool Set 7 Stay safe and under the limit on the roads! This unit is very compact & features an integrated LCD to give you an actual readout of your blood alcohol content.. While providing a good indication of BAC, it should not be relied on for precise results, and you should never drink and drive. The Amazing Flygun! Keep the kids entertained! The Amazing Flygun is a safe, fun, and effective method of killing flies and mosquitoes. Launch the spring powered swatter at your target! It is safe, fun and really does work! Cat. YS-5545 KILLS $ .95 COCKROACHES TOO! Mini Digital Video Camera Fantastic price! New This easy to use camera fits improved model with 32MB in the palm of your hand! internal memory The recorded video can be transferred to a computer for editing, or simply viewed directly on any TV with AV inputs. Supplied with camera bag, cables and software. •3.1 mega pixel software resolution for stills. •1.5" colour LCD screen. •5 layer glass lens. •32MB internal memory SAVE Was $249 •SD/MMC expansion slot $50 Cat. QC-3230 •4x digital zoom $ .00 •Internal microphone and lots more! INTERNET> www.jaycar.com.au .95 49 Show your boss what you really think! Twist his arms, break his legs, and he will be begging for you to come back to work with a pay rise. Great fun for every Cat. GT-3104 one. $ .95 24 IOUS! Animated Pen Stand Your Grandmother won't like it, but you will! It lets out a series of amusing sounds and lifts its head when you insert a pen into the rear-facing rectal receptacle. HILAR ted! R-Ra Cat. GT-3110 19.95 $ 5 New Pan / Tilt / Zoom Camera Controllers Pan / Tilt / Zoom Controller Expandable performance! When this unit is combined with the control receivers shown below. You can control up to 100 receivers, so it can provide the base to a very sophisticated and elaborate surveillance setup. It also has support for control of focus and iris controls, and Cat. QC-3213 uses PELCO D control protocols for $ .95 reliability. See website for details. 249 Pan / Tilt / Zoom Control Receivers Telescopic CCTV Bracket Quad Output Video Distributor No video loss! Suitable for small scale video distribution applications, you can view or record the video from any or all four outputs at any time. Includes mains Cat. QC-3439 plugpack. $ .95 Versatile mounting! Made from a strong metal, it features a telescopic section to adjust the mounting height perfectly to suit your requirements. Adjustable height 305 465mm height with a Cat. QC-3319 $ .95 10kg max payload. 24VAC to 12VDC 300mA Power Adaptor Two Channel 6" B&W Surveillance Monitor 39 99 Simple power distribution! Tap into your low-loss 24VAC professional wiring to power 12VDC cameras and equipment. Input voltage can Cat. MP-3069 range from 20-28VAC or $ .95 16-30VDC. Very versatile! They interface with the controller above to control Pan / Tilt / Zoom cameras, as well as focus and iris 2 Channel Video Web Server controls when required. They can be Cat. QC-3212 with Email Alert .95 used up to 2km away from the controller, $ Remotely monitor your system! and also have a relay output for IP (Internet Protocol) surveillance has revolutionised controlling lighting or locks etc. See website for details. the way we monitor and record in many surveillance situations. This web server can be connected to an Cat. QC-3214 existing setup, and transmits up to 12fps at 640 x IP-65 Weatherproof $ .95 480 resolution. It has two video inputs Receiver and four alarm inputs to email you when one is Video / Power / Data Cable for triggered. Cat. QC-3394 Pan / Tilt / Zoom Cameras $ .00 Long distance communication! Send your video, power, and data Realistic Dummy Dome Cameras over Cat5 UTP cable up to 300m (colour) or 600m Cat. QC-3431 Extremely realistic! $ .95 (B&W). Both models can have standard board cameras fitted to make them real working cameras. CCD Colour Dome Camera LA-5312 Corner Mounting Cat. with Pan / Tilt / Function $ .95 Dummy Camera Versatile monitoring! This camera is integrated Metal mounting for stability. into a weatherproof dome housing, suitable for ceiling mounting. Just use the remote control to Dome Dummy Camera with follow the action! It uses a 1/3" Panasonic Right Angled Bracket colour CCD sensor to provide Cat. QC-3497 Highly noticeable for Cat. LA-5311 quality 420TV line resolution $ .00 .95 maximum deterrent. $ video. 19 149 189 399 39 29 499 19 Small and compact! Ideal for small surveillance setups such as shop-front monitoring. It has two video inputs with a manual switch for input selection. It weighs just 1.5kg, and is powered by an external mains plugpack. Cat. QM-3409 $ .95 89 14" B&W Video Surveillance Monitor with Audio Programmable switching! While the large 14" CRT ensures that your video is displayed properly, the internal switcher is not your average source switcher. It features the ability to have the channel sequence manually programmed, with the audio synchronised with the input channel. It also features alarm inputs, and a whole lot more. Cat. QM-3411 $ .00 299 14" B&W 4 Channel Switching Monitor with Quad Processor and Audio Versatile monitoring! Your monitoring requirements are fulfilled with the option of a switching or four-way quad display. A number of advanced features are available including freeze frame, image zoom, and picture in picture (PIP). Video inputs are via RCA/BNC or 4 pin mini DIN. Cat. QM-3418 $ .00 599 Fantastic Reductions on Sur veillance Cameras! Colour CMOS Pinhole Camera B&W CCD Pinhole Camera in with Audio and Power Supply Metal Case with Audio Colour CCD Pinhole Camera with Audio Colour CCD Mini Pinhole Camera with Audio •380TV line resolution. SAVE •1/3" CMOS sensor. $50 •20(W) x 20(H) x 15(D)mm. Was $139.95 •380TV line resolution. •1/3" CCD Panasonic sensor. •36(W) x 36(H) x 14(D)mm. Was Cat. QC-3496 $ .95 $199.00 •380TV line resolution. •1/4" CCD Sony sensor. •22(W) x 25(H) x 35(D)mm. Was Cat. QC-3493 $259.00 $ .00 Cat. QC-3454 $ .95 89 •420TV line resolution. •1/3" CCD Samsung sensor. •25(W) x 25(H) x 20(D)mm. Cat. QC-3473 Was $ .00 $149.00 129 SAVE $20 Colour CCD Camera with Audio Colour CCD Dome Camera •380TV line resolution. •1/3" CCD Panasonic sensor. •100(W) x 60(D)mm dome. Was $219.00 Cat. QC-3489 $ .00 •380TV line resolution. •1/3" CCD Panasonic sensor. •36(W) x 36(H) x 16(D)mm. Was $199.00 Cat. QC-3494 SAVE $ .95 169 199 $29.05 SAVE $20 Flickerless Colour Pro Style Colour Pro Style CCD Camera CCD Camera with Auto-Iris with Auto-Iris Control Control and and Audio Audio •420TV line resolution. SAVE •1/3" CCD $50 Panasonic sensor. Cat. QC-3314 •63(W) x 52(H) x .00 120(D)mm. Was $249.00 $ 199 6 •420TV line resolution. SAVE $70 •1/3" CCD Panasonic sensor. Cat. QC-3309 •56(W) x 52(H) x 95(L)mm. $ .00 Was $319.00 249 169 SAVE $29.05 199 SAVE $60 Colour CCD Dome Camera with B&W Pro Style CCD Camera Variable Focus with Auto Iris Control and Audio •380TV line resolution. •1/3" Panasonic sensor. •39.4° to 92.6° lens angle. Cat. QC-3295 Was $279.00 $ .00 229 SAVE $50 •380TV line resolution. •1/3" CCD Samsung sensor. •63(W) x 52(H) x 120(D)mm. Cat. QC-3310 Was SAVE $ .00 $10 $109.00 99 Colour Pro Style CCD Camera High Resolution Colour Pro with IR & AI Control and Audio Style CCD Camera with Auto •420TV line resolution. •1/3" CCD Panasonic Iris Control sensor. •62(W) x 50(H) x 108(D)mm. Was Cat. QC-3321 $329.00 $ .00 269 SAVE $50 •1/3" CCD Panasonic sensor. •420TV line resolution. •118(L) x 62(W) Cat. QC-3307 x 50(H)mm. $ .00 Was $349.00 299 SAVE $50 FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 INTERNET> www.jaycar.com.au NEW HARDCORE ELECTRONICS! 20A Solar Charging Controller with LCD Protect your batteries! This microprocessor controlled unit is capable of handling all of your solar charging requirements. It has an array of features including adjustable charging voltage, automatic dusk-till-dawn on/off, overload protection, and a whole Cat. MP-3129 .95 lot more. See our website for full details. $ This section is dedicated to what’s new for the Hardcore Enthusiast. Dune Tube with Insertion Shuttle Silver Conductive Pen Easy repairs! It is quick drying with a high silver content for superior corrosion resistance. 1.6mm trace width, 10 min drying time (typ). Tidy cables with ease! Unlike regular spiral binding, cables can be put in and out of the tubing with ease, using the included insertion Cat. HP-1235 shuttle. Made from flexible black plastic. $ .95 9 Cat. NS-3032 $ .95 15(dia)mm x 2.5m Cat. HP-1235 33 169 20(dia)mm x 2.5m Cat. HP-1237 Temperature Controlled Soldering Station Digital PH Meter with LCD Great value! It features a high quality ceramic heating element for accurate temperature control, adjustable between 200 and 480°C. The soldering pencil is lightweight, (45g excluding cable), so it is comfortable for long periods. It is a great station, so check out our website for details. In Stock Now 99 Quick and easy! Checks AAA, AA, C, D, and 9V(N) type batteries, and indicates their power level on the easy-to-read, colour-coded analogue display. Also checks bulbs and fuses giving a "good" Cat. QP-2252 or "replace" indication. $ .95 150mm long. 9 Battery / Charger / Alternator Tester 10mW Green Laser Module Extremely bright! Multi Function ESD Safe This laser module consists of a 10mW laser diode, lens, SMD Rework Station and driver PCB. Simply Complete SMD working at your fingertips! connect a 3VDC supply, This robust unit features a soldering pencil, and hot blower for all rework applications. The soldering pencil and you have a great high power laser. Datasheet included. and hot blower have individual temperature Cat. ST-3117 $ .95 •Measures 65(L) x 11(dia)mm. adjustment, and the air flow can also be varied. It is ESD safe for sensitive components, and is ready to tackle a myriad of tasks. See our website for details. 149 IDEAL Non-Contact 60 - 400VAC Tester In Stock Now Great for every tradesman’s pocket! Gives an audible and visual indication on energised circuits. It has an unlimited lifetime warranty, and is rated at CAT III 600V. Cat. TS-1570 $ .00 449 Non-Contact Digital Thermometer with Laser Sighting Extremely versatile! Now there is no need to touch the object you would like to take the temperature of. Simply point and pull the trigger to take the surface temp quickly and easily. Was $149.95 129 Carbon Monoxide Meter Protect from the hazards of CO! This meter detects concentrations as low as 1ppm, up to 1000ppm, with 5% accuracy. Was $229.00 SAVE $30.00 Cat. QM-1665 $ .00 199 GPO Mains and Earth Leakage Tester Make GPO installation and checking a breeze! Identifies problems with wiring, and checks earth leakage circuit breakers using selectable trip Cat. QP-2000 current. $ .95 19 29 Quality Rechargeable Cordless Screwdriver Top quality! This unit features a high torque motor, to drive screws harder and faster than those cheap units. Beware of inferior lower priced units - they do not have the Cat. TD-2495 SAVE same power as this unit. $ .95 $8.00 Was $19.95 Precision Mini Metal Lathe Deal Industrial quality on a budget! This fantastic unit has a FULL cast iron bed, frame, and head stock assembly, just like industrial lathes. It bristles with safety features including a plastic chuck cover which must be down for the machine to operate. This prevents you from starting the lathe with the chuck-key in! We have not seen a product of this quality, at this price. See website for details. The cutting tools, drill chuck, and live centre and all usually sold extra, costing over $100 more, but are included in $107.80 the price! worth of parts Was $899 already included! Simple but effective! It uses three LEDs to indicate battery voltage, and another three to indicate over-voltage, max voltage, and charging status. It includes 600mm leads and a magnetic base to secure it while testing. Cat. QP-2258 $ .95 9 High Quality CAT III Multimeter Probes A must for the professional! They are made from strong silicon rubber for durability and flexibility, with adequate strain relief and finger guards. Rated at CAT III to pass 15A of current. 900mm Cat. WT-5335 Cat. WT-5335 120mm Cat. WT-5337 $ .95 24 Cat. WT-5337 $ .95 29 Portasol 50 Gas Soldering Iron Great entry level iron! With a fixed tip temperature of 350°C, it is suitable for a range of applications. 35W approximate electrical equivalent, with a 30min run-time from a refill. Was $39.95 SAVE $10.00 Cat. TS-1300 $ .95 29 Portasol Pro Piezo Gas Soldering Iron For the avid enthusiast! It has an adjustable tip temperature of up to 580°C, with equivalent electrical power of approximately 15 – 75W. 45min run-time on a 20 second refill. Was $89.95 SAVE $5.00 Cat. TS-1310 $ .95 84 Portasol Super Pro Gas Soldering Iron The big brother of ‘em all! With massive power equivalent to up to 125W, this iron will tackle anything. It runs for 2hrs on a 30 second refill, and is ideal for the technician on the road. Was $109.00 SAVE $10.00 Cat. TL-4000 $ .00 799 FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 Cat. QP-2274 $ .95 11 SAVE $20.00 Cat. QM-7222 $ .95 39 Battery Bulb and Fuse Tester 79 Cat. TS-1560 $ .00 9 Cat. HP-1239 $ .95 20(dia)mm x 10m Cat. HP-1239 Simple and accurate! Useful for checking pH levels in water, fish tanks, swimming pools, and more! It is great in a chemical lab for testing and checking solutions, and the large LCD is easy to read. It has a range of 1 – 14pH, 0.1pH resolution, and +/-0.2pH accuracy. Cat. QM-1670 $ .95 Cat. HP-1237 $ .95 INTERNET> www.jaycar.com.au SAVE $100 Cat. TS-1320 $ .00 99 7 SMS Controller Kit Bass Extender Kit 19 A must for car enthusiasts! Ref: SC Jan 2004. Be the envy of you mates as they hear the rumble when they press your doorbell. You may have seen commercially available units, but nothing like this. It sounds just like a V8, and has variable background noise for tappets and valves etc, for an even more realistic effect. Two versions available: Supplied with PCBs, silk-screened and machined case, push button bell switch, speaker, hook-up wire, and all electronic components. Includes the optional 120mm length of 100mm Cat. KC-5405 $ .95 diameter pipe for that extra rumble! Short Form V8 Doorbell Kit 79 Contains the working electronics only. Supplied with PCBs, and all electronic components. Cat. KC-5406 No case, speaker, or pushbutton etc $ .95 supplied. 49 YOUR LOCAL JAYCAR STORE NEW SOUTH WALES Albury Ph (02) 6021 6788 Alexandria Ph (02) 9699 4699 Bankstown Ph (02) 9709 2822 Bondi Junction Ph (02) 9369 3899 Brookvale Ph (02) 9905 4130 Campbelltown Ph (02) 4620 7155 Erina Ph (02) 4365 3433 Hornsby Ph (02) 9476 6221 Newcastle Ph (02) 4965 3799 Parramatta Ph (02) 9683 3377 Penrith Ph (02) 4721 8337 Silverwater Ph (02) 9741 8557 St. Leonards Ph (02) 9439 4799 Sydney City Ph (02) 9267 1614 Taren Point Ph (02) 9531 7033 Wollongong Ph (02) 4226 7089 VICTORIA Coburg Ph (03) 9384 1811 Frankston Ph (03) 9781 4100 Geelong Ph (03) 5221 5800 Melbourne Ph (03) 9663 2030 Ringwood Ph (03) 9870 9053 Springvale Ph (03) 9547 1022 QUEENSLAND Aspley Ph (07) 3863 0099 Brisbane - Woolloongabba Ph (07) 3393 0777 Gold Coast - Mermaid Beach Ph (07) 5526 6722 Townsville Ph (07) 4772 5022 Underwood Ph (07) 3841 4888 AUSTRALIAN CAPITAL TERRITORY Canberra Ph (02) 6239 1801 TASMANIA Hobart Ph (03) 6272 9955 SOUTH AUSTRALIA Adelaide Ph (08) 8231 7355 Clovelly Park Ph (08) 8276 6901 WESTERN AUSTRALIA Perth Ph (08) 9328 8252 NORTHERN TERRITORY Darwin Ph (08) 8948 4043 NEW ZEALAND Hamilton Ph (07) 846 0177 Newmarket - Auckland Ph (09) 377 6421 Glenfield - Auckland Ph (09) 444 4628 Wellington Ph (04) 801 9005 Christchurch Ph (03) 379 1662 Freecall Orders Ph 0800 452 9227 8 Radio Frequency Identity (RFID) is a contact-less method of controlling an event such as a door strike or alarm etc. An ‘RFID Tag’ transmits a unique code when energised by the receiver’s magnetic field. As long as a pre-programmed tag is recognised by the receiver, access is granted. RFID Security Module Receiver Kit Ref: Silicon Chip June 2004. Provides normally open, normally closed electrically switched outputs. Supplied PCB will mount behind standard wall plate. Kit supplied with PCB, tag, and all electronic components. 49 V8 Sounding Doorbell Kit Full V8 Doorbell Kit RFID - Secure Access Without Keys! Control appliances from anywhere! Ref: Silicon Chip Nov 2004. The SMS controller kit works with Nokia 3210, 3310, 5110, and 6110 models to control electronic outputs, and gives you a host of control options. The possible uses are almost endless! Kit includes PCB, pre-programmed micro, and all Cat. KC-5400 electronic components. Requires $ .50 Nokia data cable. An extra octave of bass response! Ref: Silicon Chip April 2005. This project boosts the level of bass to counteract the frequency roll-off of your loudspeaker enclosures, effectively giving you an extra octave of bass response. Kit includes PCB and all electronic components. Cat. KC-5411 $ .95 Valve Audio Preamp Kit Experience the warmth from a valve preamplifier! Ref: SC Nov 03, Feb 04. Valve amplifiers are said to have a ‘warmer’ sound than transistor counterparts. Now you can find out for yourself. Includes PCBs, case, 12AX7WA valve, bobbin, core and Cat. KC-5370 clips, and all electronic components. $ .95 See website for extra channel. EXCLUSIVE: The Jaycar kit includes a specially modified PCB that is designed to fit within an Aust/NZ standard Clipsal / HPM type wall plate. Beware of inferior kits that do not have this valuable feature. This is in addition to the high quality parts like machined pin IC sockets, silk screened PCB and more that may not be included in our competitors kits. 89 Transmit quality audio to your FM stereo! Ref: Silicon Chip Dec 2002. Crystal locked to a preset frequency to eliminate frequency drift. Kit includes PCB, case, silk screened front panel, and all electronic components. Cat. KC-5341 $ .95 49 A must have! Ref: EA March ’91. Using just a handful of components, it can accurately time intervals to trip the relay. Cat. KA-1732 $ .95 Includes PCB and all electronic components. 18 Car Turbo Timer Kit Save your turbo! It idles you car for a set time after ignition switch-off to aid in turbo cooling. Includes PCB, case, relay, and all electronic components. RFID Tags Keyfob Style Cat. ZZ-8950 These tags $ .95 transmit a 40 bit unique Credit Card Style code and are Cat. ZZ-8952 EM-4001 $ .95 compliant. Three styles Clear Style - NEW available: Cat. ZZ-8954 $ .95 9 5 4 The SHORT CIRCUITS LEARNING SYSTEM The Short Circuits learning system is a great way to learn electronics. It is fun, informative, and you build great projects along the way. Here is just one from Short Circuits 2… LED Audio Level Display Kit Make your music visual! Connect it to the output of your CD, tape, or MP3 player to see the lights dance up and down. Just like on DJ mixing desks! Kit supplied with PCB and all electronic components. Instructions are in the Short Circuits 2 book. AC/DC Current Clamp Meter Kit for DMMs Cat. KC-5254 $ .95 29 A cheap alternative! Ref: SC Sept ’03. It works with your DMM just like a professional clamp meter. Kit includes PCB, case, hall Cat. KC-5368 $ .95 effect sensor, pre-cut core, and electronic components. 34 High Energy Ignition Kit Less emissions! Ref: SC June ’98. A high energy 0.9ms spark burns fuel faster and more efficiently to give you more power! Cat. KC-5247 Includes PCB, case, and all $ .95 electronic components. 52 IR Remote Control Extender Kit A low cost solution! Ref: SC July ’96. It receives the IR signal, then re-transmits it in another room. Much cheaper than commercial units. Includes PCB, case, and electronic components. Cat. KC-5209 $ .95 22 Performance Electronics for Cars Book Over 160 pages! The Performance Electronics for Cars Book from Silicon Chip publications has chapters on modification and theory, as well as the 16 projects. Here is just one… Cat. BS-5080 $19.80 Intelligent Turbo Timer Save your Turbo! This project actually senses how hard you are driving, and then selects the most appropriate cool down period after ignition switch-off. Kit includes PCB and all electronic components. PRICES VALID TO END APRIL 2005 89 Includes 1 Keyfob RFID tag worth $9.95 absolutely FREE! See below for extra tags. Micromitter Stereo FM Transmitter Kit The "Flexitimer" Kit Cat. KC-5393 $ .95 Cat. KJ-8212 $ .95 12 PC IR RX/TX Kit Quick and easy! Ref: SC Dec ’01. Adapts to PC motherboards that have provisions for on-board IR support. Includes PCB and all electronic components. Cat. KC-5323 $ .95 21 Theremin Synthesiser Kit Far cheaper than commercial units! Ref: SC Aug ’00. The Theremin Synthesiser produces those familiar science fiction movie sound effects when you move your hand between the metal plate and antenna. It has an amazing range from shrieks to growls, and is not just entertaining. The Beach Boys used a Theremin in their classic hit "Good Vibrations"! Kit supplied with PCB, silkscreened and machined case, metal plate, antenna, speaker, and all electronic components. Cat. KC-5383 $ .95 44 Also available pre-built and tested Cat. AM-4025 - $99 Cat. KC-5295 $ .95 49 FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 INTERNET> www.jaycar.com.au PRODUCT SHOWCASE Programming bigger PICs? SILICON CHIP published a Portable PIC Programmer back in September 2003 and it continues to enjoy popularity. However, it is limited to 18-pin PICs. What if you want to program a 28pin or 40-pin device such as the larger PICs now becoming quite common? We described a small circuit in the article which showed you how but Altronics’ Cameron Costigan has taken this one step further by designing two separate add-on boards based around Peter Smith’s original Portable PIC Programmer design. Both kits retail for $24.95 and include a bonus PIC chip. The 28-pin kit (K9506) includes a Pic16F767 while the 40-pin kit (K9507) has a Pic16F877. Each board has a universal Zero-Insertion-Force (ZIF) socket, which means that you can program both narrow and wide-spacing PICs. The Altronics Portable PIC Programmer Kit (K9505) itself includes a fully pre-made DB9 cable, 18-pin ZIF socket and a Pic16F84A. Construction is very straightforward as there are only four parts to solder to the PC board. For this month only, you can get all three kits (the original Portable PIC Programmer and both add-on kits) for $79.95, a total saving of almost $30.00. Contact: Altronics Distributors Box 8350, Perth Business Centre 6849 Tel: 1300 797 007 Fax: (08) 9428 2187 Website: www.altronics.com.au Melbourne PICAXE fair Text/graphics on VGA monitor – without a PC Following the success of the Sydney PICAXE fair, Microzed’s Bob Nichol has decided it’s time for Melbourne to have a go. The Melbourne PICAXE fair will be held at Victoria University, Ballarat Rd, Sunshine on Saturday, April 30th from 10AM to 4PM. “While I was very happy with the attendance at the Sydney fair, a lot of people said that they couldn’t make it on a weekday,” said Bob. “So the Melbourne fair will be on a Saturday.” Microzed expects a similar range of trade suppliers to exhibit at the Melbourne fair, along with more than a few PICAXE specialists. Anyone with a PICAXE project is invited to bring it along, even if it is unfinished, and show it off. There is a prize for the best PICAXE project. At time of going to press, “Mr PICAXE”, Stan Swan, from Massey University in NZ, was trying to adjust his impossible schedule to allow him to come to Melbourne. To display text and graphics on a VGA monitor you need a PC with a video card, correct? Until now, yes. But there are many applications where you want the text and graphics but don’t want to lug a PC around to drive it. 4D Systems has come up with rather clever module called MicroVGA which enables text and an unlimited variety of graphics to be generated from a host microcontroller or embedded device with RS-232 output. Of course, this also includes the vast majority of PCs. The baud rate is auto-detected. The signal generating circuitry can output in up to 64 colours, setting not only text and graphics colours but also the screen background colours. You can address the full ASCII character set. Once set up, there is no need for the source to remain connected. Typical applications include a wide variety of consumer display and information systems, process and industrial Contact: MicroZed PO Box 634, Armidale NSW 2350 Tel: (02) 6772 2777 Fax: (02) 6772 8987 Website: www.microzed.com.au siliconchip.com.au control systems; in fact just about anything where text and graphics need to be delivered. Contact 4D Systems for more information or a PDF of the manual. Contact: 4D Systems Tel: (02) 9673-2228 or 0433 198 874 email: atilla<at>4dsystems.com.au TOROIDAL POWER TRANSFORMERS Manufactured in Australia Comprehensive data available Harbuch Electronics Pty Ltd 9/40 Leighton Pl. HORNSBY 2077 Ph (02) 9476-5854 Fx (02) 9476-3231 April 2005  57 Jaycar’s WiFi Spy finds hotspots, hidden cameras There are huge numbers of WiFi hotspots (802.11 wireless LANs) around these days and finding them is often as simple as walking around with your notebook computer searching for wireless LAN activity . . . But who wants to walk around the streets carrying an open notebook? Jaycar Electronics have a much simpler way with their new WiFi-N-Spy Finder. It’s tiny enough to fit in the palm of your hand (it even has a lanyard so you can wear it around your neck) and when it finds either a WiFi hotspot or RF-equipped surveillance camera it there is a hotspot/camera present but you can then decide if you want to further investigate the source (eg, to determine if is open access or WEP, etc encrypted) by opening the computer and searching it out. The WiFi-N-Spy retails for $39.95 (Cat XC4885) and is available from all Jaycar Electronics stores, resellers or through their web techstore. Contact: Jaycar Electronics lights up and beeps. Of course, the WiFi-N-Spy can’t tell you any more than the fact that PO Box 6424, Silverwater NSW 1811. Tel: 1800 022 888 Fax: (02) 9741 8500 Website: www.jaycar.com.au DIY Amplifier chassis, panels First BTX form-factor PC released Design Build Listen, the Kiwi makers of ezChassis pre-punched cabinets for DIY amplifier builders, have announced a raft of new cosmetic options. These will help DIY enthusiasts to build the amplifiers of their dreams. Moving beyond “any colour you like as long as it’s black” ezChassis panels are now available in anodised silver or gold. Wood panels are also offered for front or side panels, supplied ready for oiling or staining. Finally for the Contact: DIY enthusiast who Design Build Listen is proud of their PO Box 5415, Dunedin, New Zealand handiwork, clear Tel/Fax: +643 477 3817 acrylic top panels Website: www.designbuildlisten.com are available. Hallmark Computer International Pty Ltd has released of Viewmaster Advantage 6000 Series, a high-performance desktop computer claimed to be the first to take advantage of Intel’s latest Balanced Technology Extended (BTX) design concept. The BTX design concept greatly improves the cooling efficiency and significantly reduces the noise of the entire system. The user of today wants a faster and faster machine in a smaller and smaller chassis. In reality, this causes a higher and higher thermal envelope, which ultimately results in premature failure of components. Acoustically, a typical classroom is rated at 45dBA; a quite office at 40dBA. Given that a decrease of 3dBA means that the volume has halved, the 30dBA approximate level produced by the Viewmaster Advantage 6000 series BTX system equates to about a 90% noise reduction of the quietest office. BTX aligns the hottest components – CPU, chipset and graphics controller such that they are cooled by the front-toback airflow produced by a single large, slow RPM fan that also acts as the CPU fan. The result is a de- Contact: sign which no longer Hallmark Computer International requires multiple PO Box 5415, Dunedin, New Zealand chipset, graphics card Tel/Fax: +643 477 3817 and chassis fans. Website: www.hallmark.com.au SILICON CHIP WebLINK How many times have you wanted to access a company’s website but cannot remember their site name? Here's an exciting new concept from SILICON CHIP: you can access any of these organisations instantly by going to the SILICON CHIP website (siliconchip.com.au), clicking on WebLINK and then on the website graphic of the company you’re looking for. It’s that simple. 58 Silicon 58  S ilicon C Chip hip Our website is updated daily, with over 5,500 products available through our secure online ordering facility. Features include semiconductor data sheets, media releases, software downloads, and much more. JAYCAR JAYCAR ELECTRONICS ELECTRONICS Tel: Tel: 1800 1800 022 022 888 888 WebLINK: WebLINK: www.jaycar.com.au www.jaycar.com.au siliconchip.com.au Compact wind speed and direction display A new wind speed and direction display from Amalgamated Instrument Co Pty Ltd (AIC) shows wind direction is on a circular LED display, while wind speed, scaled to desired units (m/s, km/h, knots, etc) is indicated in a 5-digit LED numerical display. The entire unit is housed in a 1/8 DIN panel mount enclosure (bezel size 96mm x 48mm) with IP65 environmental protection options available. Wind sensor input can be in either a 4-20mA format or NEMA serial data stream. Wind direction can be displayed as degrees on the numerical display as well, at the push of a button. The display includes alarm annunciators for quick warning of “out of line” situations. This unit is ideal for applications where an accurate, easily visible dis- Greener chips from Linear Technology play is required and where space is at a premium. Contact: Amalgamated Instrument Coy P/L 5/28 Leighton Pl, Hornsby NSW 2077 Tel: (02) 9476 2244 Fax: (02) 9475 2902 Website: www.aicpl.com.au Ah! Three into one does go! With a home theatre setup or even a reasonable selection of video/audio devices and games, it seems that you are always plugging and unplugging leads these days to watch/listen to what you want! This A/V switch box from Microgram can switch three different devices (3 in, 1 out) with lots of connectors including optical audio, so its perfect for switching between DVD’s, satellite receivers, pay TV, games consoles, CD’s and other digital audio/ video equipment. It is really well built and has a remote control, so you can switch programs from your armchair! Each channel has S-VHS, compos- ite, audio and optical audio inputs to a single output also with S-VHS, composite and optical audio. Recommended retail price is $149.00. Linear Technology Corporation, a leading supplier of high performance analog integrated circuits, has announced that all of the company’s products are available in lead-free versions as an ordering option. This is part of the company’s commitment to meeting the European Community’s Reduction of Hazardous Substances (RoHS) guidelines and represents the latest step in Linear Technology’s ongoing commitment to excellence and leadership in protecting the environment. After evaluating various lead-free alternatives, Linear Technology selected matte tin as the optimal plating for leadfree products. The company believes that this provides the best drop-in replacement since it has the lowest reflow temperature of the lead-free alternatives, has excellent solderability performance and provides excellent quality and reliability. In order to ensure a smooth transition for customers, Linear Technology will continue to offer solder-plated products as well, with unique part numbers for both the lead-free and solder-plated versions. In addition to offering lead-free plating, Linear Technology will also provide by mid-2005 an improved plastic mold compound that eliminates antimony trioxide and elemental bromine for a more environmentally-friendly packaging alternative. The company’s goal is to replace these flame retardants with environmentally friendly alternatives that meet flammability standards, while improving the product reliability. Contact: Contact (Australian agents): 1/14 Bon Mace Cl, Berkeley Vale 2261 Tel: (02) 4389 8444 Fax: (02) 4389 8388 Website: www.microgram.com.au D1, 3-9 Birney Ave, Lidcombe NSW 2141 Tel: (1300) 889 883 Fax: (02) 9741 0155 Microgram Computers Soanar Inc (Mayer Krieg Components) Website: www.linear.com This valuable WebLINK Space for Rent! JED designs and manufactures a range of single board computers (based on Wilke Tiger and Atmel AVR), as well as LCD displays and analog and digital I/O for PCs and controllers. JED also makes a PC PROM programmer and RS232/RS485 converters. Jed Microprocessors Pty Ltd Tel: (03) 9762 3588 Fax: (03) 9762 5499 WebLINK: jedmicro.com.au siliconchip.com.au A 100% Australian owned company supplying frequency control products to the highest international standards: filters, DIL’s, voltage, temperature compensated and oven controlled oscillators, monolithic and discrete filters and ceramic filters and resonators. Hy-Q International Pty Ltd Tel:(03) 9562-8222 Fax: (03) 9562 9009 WebLINK: www.hy-q.com.au We specialise in providing a range of Low Power Radio solutions for OEM’s to incorporate in their wireless technology based products. The innovative range includes products from MK Consultants, the worldrenowned specialist manufacturer. TeleLink Communications Tel:(07) 4934 0413 Fax: (07) 4934 0311 WebLINK: telelink.com.au Want to be NOTICED? Without costing you a fortune? To reserve your place in SILICON CHIP WebLINK, email BENEDICTUS SMITH Pty Ltd info<at>benedictus-smith.com December 2004  59 April 2005 59 April 2005  59 Get an extra octave of bass with this . . . Bass Extender This Bass Extender circuit can give you as much as an extra octave of bass response from your existing hifi speakers, as long as you are not running them near full power. Design by RICK WALTERS T HIS MAY SOUND like black magic. Just how is it possible to get an extra octave of bass response from a hifi loudspeaker? Well, the theory supporting this idea originates from Neville Thiele’s 1961 paper (1) on loudspeakers and vented enclosures. He postulated that the response of a loudspeaker in a vented enclosure was similar to a fourth-order high-pass filter, rolling off in the bass region at -24dB per octave. For a sealed enclo- Fig.1: the response in a vented enclosure is similar to a fourth-order high-pass filter, rolling off in the bass region at -24dB per octave (red trace). Similarly, the response in a sealed enclosure rolls off at -12dB per octave (green trace), much like a second-order filter. This graph plots the response of hypothetical speakers with a cutoff frequency of 70Hz. 60  Silicon Chip sure, the response was similar to a second order high-pass filter, rolling off at -12dB per octave. Fig.1 shows this for hypothetical speakers that are -3dB down at 70Hz (the cutoff frequency), in each type of enclosure. Now if we apply bass boost with an amplitude of +3dB at 70Hz, rising to a maximum boost of around 11dB or so (for a sealed enclosure), it will partially compensate for the speaker’s rolloff and thus extend the bass response by as much as an octave. As we’ll see later, the Bass Extender can be tailored for either type of enclosure, applying less boost to a vented enclosure than a sealed enclosure. This is the opposite of what you might expect but is necessary because the speaker cone in a vented enclosure has little loading below the box resonance. There is a limit to the amount of bass compensation we can apply anyway. A speaker’s cone excursion increases as frequency decreases, so large bass boost levels would test the mechanics of the speaker as well as the damping ability of the enclosure. Also, it is likely that some power amplifiers would run into clipping. Even with all these limitations, we can usually gain an extra octave without major problems. This is much more precise than merely boosting the bass with your amplifier’s tone controls, as it’s compensating for the loudspeaker’s natural rolloff. Note this does not mean that the overall bass from the speaker will increase for all music. Since the bass response will be extended to a lower siliconchip.com.au Fig.2: the circuit includes two identical channels, each consisting of an input buffer followed by an equal component Sallen-Key filter. As shown, the circuit is configured for vented enclosures but will also work with sealed enclosures by changing the indicated resistor values. frequency (say, 35Hz instead of 70Hz) you will only hear the difference if the music signal includes bass content at these low frequencies. Incidentally, if your loudspeakers have a response down to 50Hz or better, there is no point in building the Bass Extender. Speaker specifics The catch in this process is that you need to know the rated cutoff frequency for your speakers. Once you know this, you need to calculate a particular resistor value for the bass boost circuit. Apart from that, the circuit is simple and foolproof. So, what is the rated cutoff frequency for your hifi loudspeakers? If you have the manufacturer’s original specs, it is easy. They should give a frequency response curve and you just look to see where the bass response is 3dB down siliconchip.com.au Fig.3: the cutoff frequency of your speakers can be determined from the manufacturer’s data sheets. Here, the frequency response curve from a VAF DC-7 G4 shows a -3db point around 25Hz. In this case, there is absolutely no point in building the Bass Extender! April 2005  61 Fig.4: the performance of the prototype when set up for speakers with a 70Hz cutoff frequency. The green trace shows the boost curve for a sealed enclosure, whereas the red trace is for a vented enclosure. with respect to the output at a higher reference frequency, say 200Hz. An example frequency response curve is shown in Fig.3 (this example has a very good low-frequency response). Failing that, have a look at the speaker’s impedance curve, if you have it. For a bass reflex (vented) enclosure, the impedance curve will have a double hump in the bass region. The -3dB point is usually to be found in the dip between the two humps. Similarly, if you have a sealed enclosure, the impedance curve will have a single peak (the system resonance) in the bass region and the -3dB point will be about 10% below that. For example, if the system resonance for a sealed enclosure is at 80Hz, the -3dB point will be around 70Hz. If we wanted to compensate a vented enclosure, we need to boost the bass by 3dB at 70Hz, rising to a maximum of 6dB at around 35Hz. Circuit details Fig.2 shows the circuit details. It uses two op amps per channel, all in a TL074 quad op amp package. We will discuss only one channel, since both channels are identical. The input signal for the left channel is fed through a 1mF capacitor and a resistive attenuator to the noninverting input (pin 5) of op amp IC1a, which is wired as a unity gain buffer. The 68kW and 39kW resistors at pin 5 result in a loss of 2.74 times (-8.76dB). To compensate for this loss, op amp IC1c provides a gain of 2.74 (+8.76dB) so that the overall circuit gain is unity; ie, zero gain. Apart from providing some gain, IC1c is configured as an equal compo- SPECIFI CATION S Frequency response................... -3dB <at> 61kHz (see graph for bass response) Signal to noise ratio....................... -70dB unweighted, -83dB A-weighted (with respect to 1V, 20Hz - 20kHz bandwidth) Total harmonic distortion........................ 0.02% at 1kHz and 20kHz (1V input) Signal handling....................... 2.5V RMS maximum input level (12V DC supply) Crosstalk................................................................................ 60dB (typical) 62  Silicon Chip nent Sallen-Key filter. How it works is quite complex but in simple terms, the resistors from the output (pin 8) to the junction of the two 100nF capacitors provide positive feedback below a certain frequency. Thus the gain increases to provide the bass boost characteristic we want. This is shown in Fig.4. Naturally, the shape of the bass boost curve will need to vary, depending on whether we are compensating for a sealed enclosure or a vented enclosure (bass reflex) and the rated cutoff (-3dB point) of the loudspeaker system. Accordingly, the values of resistors R1, R2 & R3 on the circuit are for vented enclosures. If you have sealed enclosures (bass reflex), R1 should be changed to 27kW, R2 to 47kW and R3 to 39kW. Similarly, the value of the four resistors marked RS depends on your speaker’s cutoff frequency and this is calculated using the formula: RS = RT - 33kW where RT = 3,180,000 ÷ fc and fc = speaker cutoff frequency. This formula applies to both sealed and vented enclosures. For example, if your speakers have a cutoff frequency (-3dB point) of 70Hz, RT = 3,180,000 ÷ 70 = 45.4kW. Subtracting 33kW from this figure gives a value of 12kW for RS. You will have to do the calculations for your own system before you can assemble this project. Power supply The circuit can be powered from 12-20V DC. Diode D1 provides input polarity protection. Two 10kW resistors divide the supply rail in half (VCC/2). This is used as a bias voltage for IC1, necessary to allow the op amp to work with AC signals when running from a single supply rail. Provision has been made for a power indicator (LED1) but we expect that most readers will not install this. It should not be installed if the board is to be powered from a DC plugpack, as the extra current drain will increase supply hum. Construction All parts for the Bass Extender mount on a small PC board, measuring 74 x 56mm (code 01104051). As usual, begin by checking the PC board for defects. Now is also a good time to enlarge the mounting holes for the siliconchip.com.au Par t s Lis t 1 PC board, code 01104051, 74 x 56mm 1 UB3 size plastic case (Jaycar HB-6013 or similar) (optional) 2 dual PC-mount RCA sockets 1 2.1 or 2.5mm PC-mount DC socket 2 6G x 6mm self-tapping screws for RCA sockets 1 16-pin IC socket Fig.5: use this diagram as a guide during assembly. Take care with the orientation of the diode (D1), op amp (IC1) and the 100mF & 330mF capacitors. The 1mF & 2.2mF capacitors are nonpolarised and can go in either way. Semiconductors 1 TL074 op amp (IC1) 1 3mm or 5mm red LED (optional; see text) 1 1N4004 diode (D1) Capacitors 1 330mF 25V PC electrolytic 1 100mF 16V PC electrolytic 2 1mF 16V non-polarised PC electrolytic 2 2.2mF 16V non-polarised PC electrolytic 4 100nF 50V metallised polyester (MKT) 1 100nF 50V monolithic ceramic 2 10pF 50V disc ceramic Right: this view shows the prototype PC board assembly. Note that there are some minor differences between this prototype and the final version shown in Fig.5 above. Resistors (0.25W 1%) 2 1MW 2 27kW 2 68kW 2 22kW 2 47kW 2 10kW 2 39kW 1 1.5kW 6 33kW 2 100W RCA sockets and/or power socket, if required. Next, install the single wire link, diode (D1) and all of the resistors, using the overlay diagram (Fig.5) as a guide. It’s a good idea to check resistor values with a multimeter before installation. Note that the banded (cathode) end of the diode must be oriented as shown. Follow up with the IC socket and all of the capacitors. The larger 100mF and 330mF electrolytic capacitors are polarised and must be inserted with their positive leads oriented as indicated by the “+” markings on the overlay. The two RCA sockets and power socket can be left until last. Push them all the way down on the PC board before soldering them in position. That done, plug in the TL074 (IC1), watch- Table 1: Resistor Colour Codes o o o o o o o o o o o siliconchip.com.au No.   2   2   2   2   6   2   2   2   1   2 Value 1MW 68kW 47kW 39kW 33kW 27kW 22kW 10kW 1.5kW 100W 4-Band Code (1%) brown black green brown blue grey orange brown yellow violet orange brown orange white orange brown orange orange orange brown red violet orange brown red red orange brown brown black orange brown brown green red brown brown black brown brown 5-Band Code (1%) brown black black yellow brown blue grey black red brown yellow violet black red brown orange white black red brown orange orange black red brown red violet black red brown red red black red brown brown black black red brown brown green black brown brown brown black black black brown April 2005  63 DIY Loudspeaker Measurements H ow do you measure your speaker’s resonance in its enclosure? For both types of enclosures, you will need an audio oscillator, an analog multimeter, AC millivoltmeter or oscilloscope and a 47W resistor. A frequency counter can be used to set your oscillator’s output if it lacks an accurately calibrated scale. Bass reflex (ie, with a vent): connect the oscillator’s output to the speaker terminals, running one of the connections via the 47W resistor. That done, monitor the voltage across the speaker terminals (set your meter to its lowest AC range) and slowly reduce the oscillator frequency, starting off at about 200Hz. The reading should rise to a maximum then fall then rise again. The middle of the dip is the resonant frequency of the speaker and enclosure combination. Sealed (closed box or infinite baffle): the same setup is used as for a bass reflex design but instead of a dip between two peaks, your meter should rise to a maximum then fall. The peak is the resonant frequency of the system. In most cases, the system resonance will be near your speaker’s free-air resonance but can be a little higher or lower depending on the enclosure size. If you cannot get a reasonable reading on your multimeter, perhaps due to the low output level from your oscillator, you will have to feed the oscillator into an audio amplifier. Place the resistor (preferably 5W or so) in series with the ungrounded output of the amplifier and the speaker. Connect the multimeter across the speaker terminals and set the oscillator output to give about 1V on the multimeter at 200Hz (with the amplifier turned on, naturally). Then follow the relevant procedure above. ing that you have the notched (pin 1) end around the right way. Testing Fig.6: this is the full size etching pattern for the PC board. To test the Bass Extender you will need an audio oscillator and a multimeter or oscilloscope. Start with the oscillator set to about 1kHz, with 450-500mV RMS output. Check the output of the oscillator with your multimeter (or millivoltmeter) if it doesn’t have a calibrated amplitude scale. Apply power and connect the oscillator to the left and right RCA inputs in turn. Measure the amplitude of the signals at the corresponding RCA outputs; they should be almost identical to the inputs. Now set the oscillator to your speaker’s resonant frequency; eg, 80Hz. Fig.7: if you’re installing your board into a case, a photocopy of this drilling guide will make life much easier. 64  Silicon Chip siliconchip.com.au The PC board can either be mounted inside an existing stereo amplifier or it can be mounted inside a small “UB3” size plastic instrument case as shown here. You will need to drill holes in one side of the case for the RCA sockets and to provide access to the DC power socket (see Fig.7). Measure each channel again and this time you should find that the outputs read about 40% higher (+3dB). Finally, measure each channel while tweaking the oscillator frequency to obtain the maximum possible reading. For a bass reflex (vented) enclosure, the maximum output should be around twice the input (+6dB), while for a sealed enclosure it should be about 3.5 times higher (+11dB), in line with the performance of our prototype (see Fig.4). If the results aren’t what you expect, then go back and re-check your resistor calculations. If you don’t get any bass boost, it is likely that the value calculated for RS is much too large. For those without the appropriate test gear, a listening test will quickly tell whether the Bass Extender is doing its job. Simply hook the project into one channel of your hifi system and listen to the bass with a suitable music program; the difference between channels should be noticeable. Housing The Bass Extender could be used in a variety of ways. For example, it could be installed inside a stereo amplifier and patched into a tape loop or inserted between the preamp and power amplifier stages. It could also be used in a car sound system. siliconchip.com.au Where a separate enclosure is required, the board can be installed inside a small “UB3” size plastic instrument case. Mounting details for this option are as follows: Photocopy the drilling template (Fig. 7) and place it centrally along the open edge of the plastic case, fixing it in place with adhesive tape. Mark and drill the holes, starting with small pilot holes and working up to the final size in several steps. A tapered reamer can also be used to enlarge the holes. The three ribs on the inside of the case should be removed with a sharp knife or chisel to allow the power socket to fit flush with the inside. The bottom 5mm or so of the three ribs on the other side may need to be removed if the board is reluctant to fit. Drop the PC board into the case and then slide the board backwards. The sockets will drop into their holes and the two self-tapping screws can then be fitted to hold the RCA sockets and PC board in place. References (1). A. Neville Thiele, “Loudspeakers in Vented Boxes,” Proceedings of the IRE Australia, August 1961; reprinted Journal of Audio Engineering Society, SC May & June 1971. Select your microcontroller kit and get started... From $295* Fax a copy of this ad and receive a 5% discount on your order! Feature rich, compiler, editor & debugger with royalty free TCP/IP stack RCM3400 • Prices exclude GST and delivery charges. Tel: + 61 2 9906 6988 Fax: + 61 2 9906 7145 www.dominion.net.au 4007 Ozitronics www.ozitronics.com Tel: (03) 9434 3806 Fax: (03) 9011 6220 Email: sales2005<at>ozitronics.com PC Printer Port Relay Board Put that old PC to good use. Direct connection to printer port. Eight relays with LED indicators. DOS and Windows software. 12VDC. K74 - $53.90 Also available assembled K74A - $70.40 Prices include GST – shipping extra. Full documentation available from website. April 2005  65 CIRCUIT NOTEBOOK Interesting circuit ideas which we have checked but not built and tested. Contributions from readers are welcome and will be paid for at standard rates. Automatic security lights Combination PIR sensor and floodlight units are cheap but rather inflexible if you want to locate the sensor and light in different places. In my case, I wanted to detect movement on the driveway and switch on the lights in the carport around the corner. Yet another job for the ubiquitous PICAXE-08 microcontroller! A standard PIR sensor is used as the movement detector. The sensor interfaces to the PICAXE (IC1) on input 2 (pin 5). This pin is pulled low via isolation diode D3 and the normally open (NO) output of the sensor whenever movement is detected. It can also be pulled low by transistor Q1, which acts as a simple inverter for sensors with normally closed (NC) outputs. So that the lights aren’t needlessly switched on during the day, a light-dependent resistor (LDR) 66  Silicon Chip is used as an ambient light sensor. Together with a 100kW resistor, the LDR forms a simple voltage divider, which converts its changing resistance to a changing voltage at the micro’s analog input (pin 6). As light falling on the sensor decreases, its resistance increases, resulting in less voltage at the analog input. Below a preprogrammed threshold voltage, it is assumed to be nighttime. When movement is detected, a program timer is started and the relay is energised via Q2, switching on the lights. If no further movement is detected, the lights will turn off after about 10 minutes. However, if movement is detected within this period, the timer is reset, extending the on period a further 10 minutes. The on time is easily modified to suit your installation (see program listing). As shown, power comes from a small 9VAC transformer, bridge rectifier (BR1) and a 2200mF filter capacitor. A 9V DC plugpack could also be used; just omit the transformer and BR1 and substitute a 100mF 25V capacitor for the 2200mF unit. A polarity protection diode (eg, 1N4004) in series with the positive plugpack input is also a good idea. A 7805 low-power regulator provides a stable +5V supply for the PICAXE and associated circuitry. Note that a diode (D2) is included in series with the regulator output to reduce the supply voltage to about 4.4V, which improved system reliability in hot weather. All 240VAC wiring should be properly terminated and insulated, and the project housed in a suitable plastic instrument case that is protected from the elements. Modifications to fixed mains wiring will require the services of a licensed electrician. Jeff Monegal, North Maclean, Qld. ($50) siliconchip.com.au ' Security Lights Controller ' Jeff Monegal 18 May 2004 ' PICAXE-08 symbol timer = w6 'used as a lights on timer Silicon Chip Binders REAL VALUE AT '----------------------------------------------------------------------------------------------' The value in the B0 register from the readadc command below may need to be ' changed to suit different types of LDR. Use the debug command to monitor ' the value given by your particular LDR. Don’t forget to change the rest of ' the readadc values throughout the program. '----------------------------------------------------------------------------------------------start: readadc 1,b0 debug b0 if b0 < 140 then night_time goto start $12.95 PLUS P & P 'read the LDR ‘look at the value given by your LDR 'if less than 140 then it is night time These binders will protect your copies of S ILICON CHIP. They feature heavy-board covers & are made from a dis­ tinctive 2-tone green vinyl. They hold up to 14 issues & will look great on your bookshelf. night_time: if input2 = 0 then detect readadc 1,b0 if b0 > 140 then maybe_daytime goto night_time detect: pause 100 'short delay then look at the PIR again to confirm if input2 = 0 then yes_detect ‘a movement detection and not just noise goto night_time H 80mm internal width yes_detect: timer = 0 high 4 H Buy five and get them postage free! time_loop: readadc 1,b0 if b0 > 140 then maybe_daytime timer = timer + 1 if timer > 3000 then time_out pause 100 if input2 = 1 then time_loop pause 100 if input2 = 1 then time_loop timer = 0 goto time_loop time_out: low 4 pause 3000 goto night_time 'clear timer counter 'turn on the lights 'add one to the time counter 'change to suit your installation '(3000 x 200mS = 600s) 'short delay then look again for movement 'reset timer if movement detected H SILICON CHIP logo printed in gold-coloured lettering on spine & cover Price: $A12.95 plus $A7 p&p per order. Available only in Aust. Silicon Chip Publications PO Box 139 Collaroy Beach 2097 Or fax (02) 9979 6503; or ring (02) 9979 5644 & quote your credit card number. Use this handy form Enclosed is my cheque/money order for 'turn the lights off '3s before lights can be triggered again $________ or please debit my  Bankcard  Visa    Mastercard Card No: _________________________________ maybe_daytime: pause 2000 readadc 1,b0 if b0 > 140 then is_daytime goto night_time Card Expiry Date ____/____ Signature ________________________ Name ____________________________ is_daytime: low 4 goto start siliconchip.com.au 'turn lights off in case they are on Address__________________________ __________________ P/code_______ April 2005  67 Circuit Notebook – Continued Op amp auto-zero This auto-zero circuit was developed to simplify setting up an instrument with a large background signal that needed to be zeroed out. It uses two CA3140 op amps, which themselves could be trimmed out for a smaller final offset value if required (see device datasheet for more details). The input signal is applied to IC1, which is configured as an inverting buffer. When momentary switch S1 closes, IC1’s output voltage charges the low-leakage 1µF capacitor via the 10kW resistor. When S1 subsequently opens, this voltage (buffered by IC2) is subtracted from the input signal to IC1, thus zeroing the output. If desired, IC1 could be followed by a second stage to restore the original signal polarity. Switch S2 can be used to discharge the capacitor and cancel the zero. Switches S3 and S4 are included to allow fine adjustment of the output voltage. A smaller resistor (4.7MW) in the positive charge circuit versus the negative circuit (22MW) allows for finer control. Slower adjustment can be arranged by returning these resistors to a lower voltage. Graham Jackman, via email. ($30) Synthetic floating negative inductor This circuit is a floating negative inductor using only two op amps. It obviates use of a GIC (General Impedance Converter), which would require more than four op amps for the same purpose. It requires two matched capacitors and three matched resistors. The relevant equations are as follows: (1) i1 = (V1 - V3)/R; (2) i2 = (V2 - V4)/R; and (3) (V2 - V4). Cs = (V3 - V1). Cs      = (V1 - V2)/R From (1), (2) and (3): (4) V1 = -i1. CsR² + V2 (5) i1 = - i2 Comparing (4) and (5) with the transmission matrix: V1 = A.V2 - B.i2 i1 = C.V2 - D.i2 68  Silicon Chip Now -B is the short circuit transfer impedance, hence equivalent floating impedance is given by Z = -CR², which is equivalent to a negative inductor. Saumitra Raj Mehrotra, New Delhi, India. ($30) siliconchip.com.au Plugpack checker This simple circuit lets you quickly determine the relative amount of ripple from a DC plugpack. Two test currents are selectable via toggle switch S1. For the 120W and 47W resistor values shown, this corresponds to 100mA and 250mA of load current when testing 12V plugpacks. A good-quality 12V plugpack will measure up to about 100mV ripple with a 250mA load. Up to 200mV ripple may be regarded as good, while a budget plugpack may measure up to 500mV. Anything above this can be considered abysmal. The circuit uses no voltage regulation or supply decoupling to suppress ripple. Therefore, a fraction of the ripple from the power supply appears at the non-inverting input (pin 3) of the op amp (IC1) via the 500kW pot (VR1). In contrast, the voltage at the op amp’s inverting input (pin 2) is filtered via two low-pass filters, consisting of the two 470kW resistors, CONTRIBUTE AND WIN! As you can see, we pay good money for each of the “Circuit Notebook” contributions published in SILICON CHIP. But there’s an even better reason to siliconchip.com.au 100kW potentiometer VR1, a 1MW resistor and two 100nF capacitors, which effectively removes most of the ripple. When the voltage at the inverting input dips below that of the non-inverting input, the op amp’s output swings towards the positive rail, illuminating LED1. The 100kW potentiometer (VR1) acts as a sensitivity adjustment, allowing you to dial up the amount of ripple present before LED1 illuminates. This makes it possible (with a calibrated dial) to determine just how much ripple a plugpack is generating. Since the two 100nF filter capacitors are initially discharged, LED1 immediately illuminates when a plugpack is connected, then fades (within two seconds) if the ripple rating is within the selected margin. LED2 provides a simple “voltage present” indication. IC1 has a limited voltage swing at its output, so D1 is included in series to prevent the LED from glowing when it should be off. Bridge rectifier BR1 ensures that the checker works regardless of input polarity. Before use, the circuit must be calibrated to suit a particular input voltage. We chose 12V, as most (adjustable) plugpacks have a 12V maximum setting. However, the Plugpack Checker may also be calibrated for use with other voltages between about 5.6V and 18.6V. Initially, turn VR1 fully anticlockwise (wiper towards 0V) and then connect a 12V battery or other well-regulated (no ripple) 12V DC source. LED2 should illuminate immediately and LED1 may illuminate only briefly, or it may stay illuminated. If it stays illuminated, turn VR2 anti-clockwise (wiper towards 0V) until it just extinguishes, otherwise turn it clockwise until it just illuminates. With the circuit values shown, you should be able to measure approximately 0-1000mV of ripple. For greater sensitivity but reduced range, the value of VR1 can be scaled downwards. For example, to measure approximately 0-200mV, use a 20kW pot instead. Thomas Scarborough, South Africa. ($40) send in your circuit idea: each month, the best contribution published will win a superb Peak Atlas LCR Meter valued at $195.00. So don’t keep that brilliant circuit secret any more: sketch it out, write a brief description and send it to SILICON CHIP and you could be a winner! April 2005  69 Build Your Team A Professional Sports Scoreb Because of its modular construction, our new Electronic Scoreboard is easy to build. This month, we describe the assembly of the Control Console and the main control board in the display unit. I N ALL, THERE are some seven modules to build for the Electronic Scoreboard – two for the control console and five for the main display unit. We’ll start with the assembly of the control console modules. As shown in the photos, the Scoreboard’s control console is built into a compact sloping-front ABS plastic case. This case measures 189 x 134 x 70  Silicon Chip 32/55mm and is listed in the Jaycar catalog as HB-6094. Inside the case, most of the circuit components are mounted on a PC board measuring 178 x 111mm and coded BSBKYBD1. This fits snugly into the lower half of the case. The only remaining components are the keyswitches and the two indicator LEDs, which mount on a second smaller PC board measuring 163 x 100mm and coded BSBKYBD2. This switch board fits inside the top of the case, behind the front panel, and the two boards are connected together via a short length of 16-way ribbon cable fitted with IDC connectors. The switch board is the easiest to assemble, so it can be built first. Fig.6 shows the parts layout diagram and siliconchip.com.au Pt.2: By JIM ROWE board as you can see, there is very little involved. Start by fitting the seven wire links. These all run vertically down the centre of the board and can be made using tinned copper wire or resistor lead offcuts. That done, fit the 90° 16way DIL connector (CON3) (the other vertically mounting header goes on the main console control board). The 13 key switches can go in next. These all have four connection pins, plus two moulded plastic locating pins near diagonal corners, so they can only be fitted one way around. The main thing to watch is that you fit the correct This view shows the completed switch board that’s used in the control console. Follow this to install the correct keytop colour in each location. colour keytop to each switch – just use the photo as a guide. Note that the keytops are fitted by holding them at about 40° to the top of the switch body, so the two rear “hinge tabs” will slip down evenly into the recesses on each side of the rear of the switch. The keytops are then pushed down until the hinge pins click into place and the actuator rods also click in. That done, check that the switches operate correctly. They should operate with a distinct click each time you press the keytops. Once the switches are in, the only Fig.6: check that the switches are seated properly on the switch board before soldering their leads. siliconchip.com.au April 2005  71 Fig.7: follow this diagram carefully when installing the parts on the main console board. Note that the two DIP switches must be fitted with their “ON” sides to the left. remaining components to fit to this board are the two indicator LEDs. These mount vertically, with the lower surface of each LED body about 10mm above the PC board itself. Use a green LED for LED1 and a red LED for LED2 and make sure they are orientated correctly. Main console board The next step is to assemble the main console board – see Fig.7. Begin by fitting the two wire links, followed by the resistors and the small non-polarised ceramic, monolithic and MKT capacitors. The three larger electrolytic capacitors are fitted after these, making sure they go in the correct way around. Note that all three electros must be mounted on their side as shown in Fig.7, to ensure adequate clearance between them and the keyswitch board when the console is later assembled. Now for the semiconductors. Begin 72  Silicon Chip by fitting the four diodes (D1-D4), taking care to ensure that a 1N4004 power diode is used for D1 (D2-D4 are all 1N4148 signal diodes). Make sure you fit all four with the orientation shown in the diagram. Follow these with the seven transistors and again check Fig.7 carefully to ensure each one has the correct orientation. Note also that the two PN200 transistors go in the Q1 and Q3 positions, while the five PN100 transistors go in the remaining positions. The two 14-pin ICs – IC2 (74HC132) and IC3 (74HC74) – can go in next. Install them with their notched ends orientated as shown on Fig.7. They are both CMOS devices, so take the usual precautions to prevent damage due to static electricity – ie, earth the barrel of your soldering iron and solder their power supply pins (7 & 14) to the board pads before the remaining pins. The 4MHz crystal (to the right of IC1 is next on the list. It should be pushed right down onto the PC board, before soldering its leads. Be careful not to overheat the leads, to prevent damage to the crystal inside the metal case. Now fit the two 4-way DIP switches. These must both be installed with their “On” sides to the left. Note, however, that only one switch in each group should actually be slid into the “On” position. In the case of DIP switch S1 (the frequency channel select switches), we suggest that you initially set the “1” switch on, so that you can try using this frequency channel first. However, when it comes to S2 (the basketball code select switches), you will have to move either the 1, 2 or 3 switch to “On”, according to the basketball code you’ll be playing (see Table 1 last month). CON1, the 2.5mm concentric power input socket, can go in next. Note that you may need to enlarge the mounting slots slightly with a jeweller’s needle siliconchip.com.au The completed console control board is secured in the bottom half of the case using self-tapping screws. Take care with the DIP switch settings, otherwise the unit won’t function correctly – see text. file, so the socket lugs will slip through them. That done, fit the 16-way DIL header (CON2). It must be mounted with its centre-locating slot towards the left, as shown in Fig.7. Next, fit the 18-pin DIL socket for the PIC microcontroller (IC1). This should be fitted so that the end recess is at the top, near DIP switch S2 (so that you will later install the IC the right way around). Now for the +5V regulator REG1. This is fitted by first bending all three of its leads down by 90° 6mm from the regulator’s body. That done, the regulator and its matching U-shaped heatsink (6073B type) can be attached to the PC board using an M3 x 6mm machine screw, nut and lock washer. Check carefully that everything is correctly aligned before soldering the three leads. That done, the AWM609TX data transmitter module can be installed. Again, you may need to enlarge the siliconchip.com.au mounting slots in the board slightly, so that the mounting lugs will all slip through. The lugs are then soldered to the copper underneath to secure the module to the board, after which its 10 connection pins can be soldered to their respective pads. Once the transmitter module is in place, solder a 31mm length of 1mm brass wire to the centre pad at the top left. This serves as the module’s transmitting antenna (31mm corresponds to a quarter of a wavelength at 2.4GHz). The main console board can now be completed by plugging the programmed PIC16F84A microcontroller (IC1) into its socket. Be sure to install it with its notched end towards DIP switch S2. Console assembly The completed console control board can now be mounted inside the bottom section of the console case. This is done by first slipping the an- tenna wire through a matching hole in the rear and then lowering the board until it’s sitting neatly on the moulded plastic mounting pillars. Four 4G x 9mm self-tapping screws are then used to secure it in place. A short length of 16-way ribbon ca- Where To Buy A Kit Jaycar Electronics has sponsored the development of this project and they own the design copyright. A full kit of parts will be available from Jaycar in due course – Cat. KC5408. This kit includes a pre-built wooden display frame with screenprinted lettering and individual Perspex covers for the displays; screen-printed and solder-masked PC boards; all on-board parts; and a control console case with a prepunched front panel and screened lettering. April 2005  73 The 16-way ribbon cable should be plugged into the switch board before mounting the latter in the top section of the case. As with the control board, it’s secured using selftapping screws. ble is used to connect the two console boards together. This is only about 70mm long and is fitted with two 16way IDC line sockets. These sockets must be fitted as shown in Fig.8, so that the cable can link the two board headers without problems when the case is assembled. Once the cable has been made up, plug its end socket into the 16-way DIL header on the keyswitch board. That done, place this board inside the top section of the case, with its switch keytops passing through the matching rectangular holes in the front panel and the two LEDs passing through the round holes. The board can then be secured using five 9mm x 4g selftapping screws. Finally, plug the socket at the other end of the 16-way ribbon cable into its header on the main console board and dress the cable so that the two halves of the case can be swung together. The two case sections can then be fastened together using the four self-tapping screws supplied with it. That’s it – the control console is now ready for use. Main control board Fig.9 shows the assembly details for the main control board used in the scoreboard. Begin by fitting the 14 wire links which can be made from resistor lead offcuts or tinned copper wire. The only exception is the first link immediately to the left of IC2 and IC3. This link should be run using insulated The 31mm-long brass antenna wire protrudes through a hole in the side of the console case. This photo shows the top half of the console case, prior to installing the switch board. 74  Silicon Chip siliconchip.com.au Fig.8: here’s how the sockets are fitted to the 16-way ribbon cable that connects the console boards. hookup wire, so there is no chance of it being able to contact either the adjacent IC pins or the equally long link on its left. Once the links are in place, fit the single PC board terminal pin. This goes near the centre right of the board, to provide test point TP1. That done, you can install all the smaller components, including the resistors, diodes, crystal X1 (10MHz) and the capacitors. Be sure to fit the tantalum capacitors and the diodes with the correct orientation, as shown on Fig.9. Similarly, take care with the orientations of the transistors. In particular, Brand New From SILICON CHIP note that Q11 is a PN200 PNP transistor, while Q1, Q9, Q10 & Q12 are all PN100 NPN transistors. Q2-Q8 are all MTP3055 power Mosfets. Each device is installed by first bending its leads down by 90° 7mm from its body and then fastening the device to the PC board using an M3 x 6mm screw and nut. Attach all the devices to the board in this manner, then solder the leads and trim the excess lead lengths. Don’t solder the leads before bolting the device tabs to the PC board. If you do, it could place strain on the solder joints when the mounting screw is installed, which could then crack the copper pads. The 5V regulator (REG1) is installed is exactly the same way, except that it’s fitted with a 6021 type U-shaped heatsink. Before assembly, apply a thin smear of heatsink compound to the underside of the regulator, to ensure that there’s a good thermal bond between it and the heatsink. The four CMOS ICs – IC2, IC3, IC4 & IC5 – can go in next. These are all CMOS devices, so be sure to observe the usual anti-static precautions (ie, 160 PAGES 23 CHAPTE RS Mail order prices: Aust: $A22.50 (incl. GST & P&P) Overseas: $A26.00 via airmail From the publishers of Completely NEW projects – the result of two years research & development • • • • Learn how engine management systems work Build projects to control nitrous, fuel injection and turbo boost systems Switch devices on and off on the basis of signal frequency, temperature and voltage Build test instruments to check fuel injector duty cycle, fuel mixture and brake and coolant temperatures Available from selected newsagents Or order by phoning (02) 9979 5644 & quoting your credit card number; or fax the details to (02) 9979 6503; or mail your order with cheque or credit card details to Silicon Chip Publications, PO Box 139, Collaroy, NSW 2097. siliconchip.com.au Intelligent turbo timer I SBN 095852294 - 4 9 780958 522946 $19.80 (inc GST) NZ $22.00 (inc GST) TURBO BOOST & nitrous fuel controllers How engine management works April 2005  75 Fig.9: follow this diagram to build the main control board in the display unit. Note that DIP switch S1 (channel select) must be set to match DIP switch S1 in the control console. earth the barrel of your soldering iron and solder their supply pins first (pins 7 & 14 for IC4 & IC5, pins 8 & 16 for IC2 & IC3). Make sure that these devices are all correctly orientated 76  Silicon Chip and that the correct device is used at each location. As on the main console board, the PIC microcontroller (IC1) is installed in an 18-way DIP IC socket. Install this now, with its notch at the bottom end, to indicate the correct orientation when the microcontroller is later plugged in. You can now fit the larger hardware siliconchip.com.au Silicon Chip Binders REAL VALUE AT $12.95 PLUS P & P H SILICON CHIP logo printed in gold-coloured lettering on spine & cover H Buy five and get them postage free! Price: $A12.95 plus $A7.00 p&p per oder. Available only in Australia. Just fill in the handy order form in this issue; or fax (02) 9979 6503; or ring (02) 9979 5644 & quote your credit card number. Your fully-assembled control board for the display unit should look like this. Observe all the usual precautions with component polarity. items, starting with the 26-way DIL header (CON1), the 2.5mm concentric power connector (CON2) and the 2-way terminal block (CON3). Be sure to fit CON1 with its side locating slot towards the left, as shown on Fig.9. Next, fit the AWM608RX data receiver module and the adjacent 4-way DIP switch (S1). Be sure to orientate the latter with the “On” side uppersiliconchip.com.au most, as shown. Assuming you have set the console to channel 1, now is a good time to set this switch to the same setting – ie, set switch 1 in S1 to “On” and set the other three switches to “Off”. This ensures that the transmitter and receiver both operate on the same frequency. LED1, the power/carrier-present LED, is next on the list This goes near the centre of the board and is mounted vertically with its cathode (flat) side facing the receiver module. It’s fitted with its leads left at full length, so that it’s body will pass through a matching hole in the Scoreboard front panel when it’s all finally assembled. Before mounting the LED, fit both leads with 25mm lengths of 3mm varnished cambric sleeving (for insulation and support). That done, the leads can be passed through the board holes and soldered to the pads. As in the control console, a 31mm length of 1mm brass wire is used as an antenna. This antenna is soldered to the centre pad of the AWM608RX data receiver’s antenna terminals. Finally, plug the PIC16F84A-20P microcontroller (programmed with SCORDISP) into its socket, making sure that the notched end faces towards the adjacent 47W resistor. And that’s it – the display control board assembly is now complete and you can start building the four display boards. That’s all we have space for this month. Next month, we’ll describe the display board assembles and give the SC wiring and check-out details. April 2005  77 SMS Controller Add-ons by PETER SMITH Did you build the SMS Controller published in the October & November 2004 issues? The universal nature of the design means that it can be used in a huge variety of applications. As a result, external interface circuits will sometimes be required. Here are three handy add-ons that we’ve devised after reading a lot of your emails! O UR THREE ADD-ON circuits for the SMS Controller are as follows: (1) a test jig; (2) a PIR sensor interface; and (3) a low-battery alarm. Let’s start with the test jig. Test jig After suitable message programming, all of the controller’s inputs and outputs can be tested with little more than a length of wire and a multimeter. However, if you want to do some serious bench testing or just want to demonstrate your completed project, a simple test jig with LED indicators can be constructed to make life easier. As shown in Fig.1, push-button or toggle switches can be connected between each of the inputs and ground. Closing any switch pulls that input down to a logic low (0V) level. When the switch is opened again, the input returns to a logic high. On the output side, the LEDs are used to provide a visual indication of the state of each channel. All LEDs are powered from +12V via individual 1kW current-limiting resistors. When any output is programmed to be “low”, the open-collector driver for that channel is switched on, illuminating the respective LED. PIR sensor interface To eliminate the need for a fullblown alarm system, some constructors have asked if it would be possible to connect the output terminals of a PIR sensor (or similar) directly to one of the SMS Controller’s digital inputs. While a typical sensor can be connected directly to the controller, its output will trip many times when an intruder is detected, causing the controller to send multiple messages. A simple solution to this problem is to connect a monostable circuit between the sensor’s output and the controller’s input. The circuit shown in Fig.2 provides a 114s (approx.) positive pulse at its output, measured from the time of the last pulse at the input. Additional input pulses that occur within this period retrigger the monostable via transistor Q1, discharging the timing capacitor (C1) and restarting the timer. The effect is to produce one long positive pulse for the controller, meaning just one alarm message. R1 and C1 can be altered to change the pulse width for your particular application. The additional circuit in Fig.3 can be inserted ahead of the power supply inputs of the monostable (or any other add-on interface that you devise) to protect against transient voltages when reliability is important. Fig.1: this simple test jig uses four pushbutton switches, eight LEDs and eight resistors to demonstrate that the SMS Controller is working correctly. 78  Silicon Chip siliconchip.com.au Fig.2: you can use this circuit to interface the output of a PIR sensor (or some other sensor) to the SMS Controller’s digital inputs. Note that the jumper for the associated 3.3kW pull-up resistor on the controller input should be removed, as it is not required when driven from the 555’s totem-pole output. Low-battery alarm Several constructors have requested a low-battery alarm add-on for the SMS Controller. Although a number of circuits would be suitable for this job, perhaps the easiest approach is to modify the Micropower Battery Protector, published in the July 2004 edition of SILICON CHIP. The original project is designed to disconnect a battery from its load when the terminal voltage drops below a preset value. In this case, we require only the voltage monitoring circuit and can dispense with the Mosfet switch (Q1) and a few other components (see Fig.4). The circuit is based around the MAX8212 Voltage Monitor (IC1), which compares a scaled-down version of the input voltage (set by R1, R2 & VR1) on the THRESH pin with an internal 1.15V reference. When the input (battery) voltage is above the Fig.3: this circuit can be inserted between the power supply and the supply rails to Fig.2 to protect against transient voltages. preset value, the open-drain output on pin 4 is grounded. Conversely, when the input voltage falls below the preset value, the output goes open circuit. Although the circuit could be constructed on a prototyping board, the easiest route would be to partly assemble the original Micropower Battery Protector PC board. A matching overlay diagram appears in Fig.5, showing how to populate the PC board for the low-battery alarm function. The fuse (F1), Mosfet (Q1), 220nF capacitors and zener diode (ZD3) that were part of the original design are all omitted. Two links are added in place of the fuse and Mosfet and a 100W resistor is substituted for the 1MW value to the left of the existing 100W resistor. The battery to be monitored connects to the input terminals and the “+” output connects to one of the inputs of the SMS Controller. The jumper for the associated 3.3kW pull-up resistor on the controller input should remain in place, as the low-battery alarm’s output is open-drain. Where to get stuff Copies of the July 2004 issue are available from our subscription department. A kit of parts for the Micropower Battery Protector is available from Dick Smith Electronics (Cat. No. K3132). Alternatively, blank PC boards can be obtained from RCS Radio (board no. 11107041) while MAX8212 ICs are available from Wiltronics, on the web SC at www.wiltronics.com.au Fig.5 (below): the original PC board for the Micropower Battery Protector can be used to build the low-battery alarm. This diagram shows the revised parts layout. Fig.4: a low-battery alarm add-on is a handy feature. This circuit is based on the Micropower Battery Protector (SILICON CHIP, July 2004). When the battery voltage falls below a preset value, pin 4 of IC1 goes open circuit. siliconchip.com.au April 2005  79 Vintage Radio By RODNEY CHAMPNESS, VK3UG The mysterious 32V DC Monarch D671/32 from Astor It’s not often that I come across an Australianmade set for which I have no information. Made by Astor, the 32V DC Monarch D671/32 falls into that category and may have been a pre-production model. Every so often, I come across a radio for which I am unable to find any information. Perhaps it’s an orphan from a particular radio manufacturer’s family or for some reason, the manufacturer omitted it from the list of receivers published in the Australian Official Radio Service Manuals (AORSM) or other trade publications. These omissions make it just that much harder to service the “unknown” set – particularly if it has been modi- fied (or “improved”) since manufacture. How often have you obtained a set that has been modified and have had to resort to the published information to restore the receiver to its original specifications? The Monarch brand is one of several Astor clones – like Peter Pan, National and Airchief, etc. However, I looked through all the Monarch information for this particular set without success. Because it is a 32V DC operated set, This view shows the fully restored set. Note the polarity discs fitted to the power leads. 80  Silicon Chip I then searched for any Monarch that had a similar valve line-up that used 32V high tension (HT), still without success. My next step was to check all Astor clones in my various books and service manuals but that didn’t turn up anything either. I had hoped that I would at least find a receiver with a nearly identical circuit but I had no luck at all. Astor circuits Astor sets and Astor clones that use 32V for the heaters and HT supply (late 1940s and early 1950s) usually have a multi-band radio frequency (RF) stage, a converter and two IF stages. This is then followed by a detector and first audio stage, a 25L6 audio driver feeding a push-pull inter-stage audio transformer, and a pair of 25L6 valves in push-pull feeding the loudspeaker. The RF section tunes the broadcast band and three bandspread shortwave bands. However, it was obvious to me that this receiver’s circuit was quite different. It has no RF stage and is a conventional dual-wave set tuning the broadcast band and the 6-18MHz shortwave band. The audio section is also noticeably different and uses a 6G8-G as the detector and first audio stage. This feeds one section of a 6SN7-GT as the second audio stage. This stage acts as a phase splitter and feeds two 25L6 audio output valves in push-pull. Another obvious difference is that this set has negative feedback from the speaker voice coil winding to the grid of the first section of the 6SN7-GT. By contrast, the common Astor 32V (HT) sets don’t use negative feedback. siliconchip.com.au It really is rather puzzling as to why this circuit differs so much from the one almost universally used by Astor for 32V radios. Perhaps this was an experimental, limited production run, economy model receiver? Its circuit is certainly simpler than Astor’s other 32V receivers. However, it’s still quite a complex receiver when compared to sets like the Diason described back in the February 2002 issue. Tracing out the circuit Before tracing out the circuit, I did what I normally do – I dusted the chassis and then cleaned it using kerosene on a kitchen scouring pad. This not only makes the set a lot more pleasant to work on but also makes the job easier. It’s got to be done sooner or later, so why not when the chassis is first removed from the cabinet? Unfortunately, it’s not a particularly easy circuit to trace, as most of the wiring has been run in a single colour – in this case, rubber-coated wire that’s a faded yellow colour. However, armed with a valve data book and circuits of similar 32V radios, I set to and traced out the circuit. Lots of components had been replaced in this set during its life, so a complete circuit would quickly reveal if any “strange” circuit alterations had been done. As it turned out, it proved to be almost original, the main exception being that the previous owner had rewound the shortwave coils (and altered the padder to suit the new band), so that it tuned from 2.6-7.5MHz. He had even painted the new dial calibrations on the dial scale! There was a reason for this – the original owner (now deceased) had The chassis layout of the Monarch D671/32 is quite conventional (photo taken before restoration). It’s a 32V set that covers both the broadcast and shortwave bands and uses seven valves. been a radio amateur and had wanted to tune the 3.5MHZ and 7.0MHz amateur bands plus the two bushfire brigade frequencies he was licensed to use (2692kHz and 2836kHz). Circuit overview Fig.1 shows the circuit details of the Monarch D671/32. It’s really quite conventional for a receiver using a 32V HT rail. However, it did surprise me that the screens of all the RF valves were fed through resistors, to reduce the screen voltages below the already low 32V on the plates. The similar Astor clones also did this but they also had an extra valve in the RF chain which meant that more care was necessary to ensure stable operation. As shown on Fig.1, automatic gain control (AGC) is applied only to the converter and first IF stage. AGC is not applied to the second IF valve as a strong signal would push the valve into a non-linear amplifying condition near cut-off and cause distortion. This occurs because with such a low HT voltage, the valve has a very narrow The old Monarch D671/32 was fitted with a gear driven tuning capacitor, as shown in the photo at left. The close-up above shows an overheated 0.47mF paper capacitor that’s located too close to a high-wattage resistor. siliconchip.com.au April 2005  81 Fig.1 (left): the complete circuit for the Monarch D671/32 receiver. Note that the audio output stage employs two 25L6 valves operating in push-pull configuration. operating range over which it amplifies linearly. If the valve had a normal HT voltage of around 200V applied to it, this would not be a critical concern. The audio amplifier is similar in design to many medium-power public address amplifiers of the era. What makes it different is that it uses a HT voltage of just 32V. So why use two 25L6 valves in a push-pull configuration? With only 32V HT, the valves draw very little current, so two are necessary to get reasonable output from the speaker. Because they are in push-pull, the valves can be driven a bit harder than otherwise, to give more output before distortion becomes objectionable. In this case, the audio output is about 300mW, hence the use of a 6-inch (150mm) loudspeaker to ensure a reasonable audio level. Normally, 25L6 valves are designed to work effectively with a HT voltage of about 110V, whereas valves like a 6V6G are designed for HT voltages of 200-250V. This means that a 6V6G would not work well in this set, as it would draw very little plate current. Power supply The 32V power supply is connected to the receiver via a 2-core lead and each lead is identified by a small brass label which indicates whether it is positive or negative. This is a useful feature that I haven’t seen on other DC-powered radios. Typically, this set would have been run from a 32V lighting plant and this may have either been fully floating above earth or the negative side may have been earthed. Both the positive and negative power leads are switched, so that the receiver is completely isolated from the power supply when it’s turned off. This prevents current from flowing through the set’s earth to the batteries when the set is off, which could cause electrolysis effects in the whole 32V system. Wasteful circuits The way in which the heaters and dial lamps are wired to work off 32V is 82  Silicon Chip siliconchip.com.au There are lots of components under the chassis but this is still an easy set to service. There are lots of factors which indicate that this was probably an experimental model which never went into full production – see text. quite wasteful, both in parts and power consumption. First, the 6SN7GT valve draws 0.6A of heater current but its heater is wired in series with the other 6V valve heaters which draw just 0.3A. As a result, 20W 5W equalising resistors are wired in parallel with these latter valve heaters, to draw the extra 0.3A required – ie, to bring the total current drain up to 0.6A. Similarly, the heater wiring to the two 25L6 valves is hardly efficient. These valves each draw 0.3A of heater current and are wired in parallel. They are also wired in series with an 11.5W resistor which drops the voltage across the heaters from 32V to around 25V. In practice, it would have made more sense to wire the 6SN7GT’s heater in place of the 11.5W resistor, remove all the 20W resistors across the heaters, and install a 20W resistor in place of the existing 6SN7GT heater. The dial light is a 6V 300mA unit which is fed from the 32V rail via a 100W 20W resistor. However, by using a 12V 150mA dial lamp (available when this set was built) and changing the series resistor to 170W, the current would have been halved. In addition, the amount of under-chassis heating siliconchip.com.au would have been substantially reduced. The result of this heating can be seen in one of the photographs, which shows a 0.47mF capacitor with the 100W 20W resistor immediately above it. Using the original heater and diallamp supply circuitry, the total current is 0.6A (25L6 line) + 0.6A (6SN7GT line) + 0.3A (dial lamp) = 1.5A. With my suggested heater and dial-lamp modifications, this current would be reduced to 1.05A, which is a considerable saving. On a 32V system, a kilowatt-hour of energy would have cost at least $2 (as opposed to around 15c today), so saving power was important. The HT current in this receiver does not exceed 50mA, so this is inconsequential when calculating the receiver’s total current drain. One curiosity is that the power switch has three positions: (1) “off”, (2) “on” and (3) “on with top cut of audio frequencies”. I believe that it would have been better if this had been changed to: (1) “off”, (2) “charge” and (3) “on”. To explain, when the batteries in a 32V home lighting plant were being charged, the voltage could reach as high as 40V if the normal 16-cell bank of batteries was used. And if an extra cell or two had been added to the bank to overcome voltage drops in the cables, the battery voltage could rise to as much as 45V during charging. Clearly, this is not good for the valve heaters. As a result, some 32V receivers have a “charge” position to reduce the voltage to the valve heaters to somewhere near their rated voltage. This is achieved by installing a wirewound resistor in series with the supply line. The smoke test Armed with my hand-drawn circuit diagram, a 32V DC power supply and April 2005  83 Fig.2 (above): this amended oscillator circuit gives much improved performance on shortwave. Fig.3 (right): the amended AGC circuit. The added AGC diode is fed from the plate of the second IF amplifier (V3) and this gives higher AGC voltages than before. my trusty digital multimeter, I decided to give the set a thorough check out. Normally, in a mains-powered receiver, I would check the capacitors before applying power. However, because the voltages are so low in these 32V sets, there’s not much risk of damaging valves or other components due to faulty parts – at least, not in the short term. The dial lamp had obviously blown so a new one was installed, after which the set was connected to a 32V power supply and switched on. The dial lamp glowed nicely but there was no sign of life in any other sections of the receiver – in fact, the valve heaters didn’t appear to be lighting at all. As a result, I checked the valve heaters for continuity and found that they all had open circuit heaters, the only exception being the 6J8G which had at some time been replaced with a 6J8GA. So what had caused this catastrophic failure in the valves? To me, it indicated that someone had probably tested the set by connecting it to 240V AC and found that it produced nothing but smoke! And in the process, six out of the seven valves were ruined. If the set had been fitted with a fuse, little damage would have occurred, although it could have proved fatal had someone touched the chassis. In a 32V environment, the chassis is earthed and 32V is not usually considered lethal, although it can give you a nasty little surprise if you are perspiring profusely. But why was the 6J8GA’s heater still 84  Silicon Chip intact? The original valve used was a 6J8G which has a 0.3A heater, while the substituted 6J8GA has a 0.45A heater. This meant that it was better able to cope when the 240V was applied and the other heaters went open circuit before this one got to the point of burning out. This has also meant that I had to replace its 20W heater equalising resistor with a 47W resistor, so that around 6V is applied to the 6J8GA’s heater. With so many valves ruined, it proved to be a relatively expensive exercise to replace them. This time, when the power was reconnected, there was a dreadful hum from the loudspeaker. The volume control had no effect on this hum and, in addition, no stations could be heard. It didn’t take long to track down the problem – the 8mF capacitor in the decoupled HT supply to the 6G8G was faulty, with very low capacitance. I replaced it a 33mF 63V unit that I had on hand and that got rid of most of the hum. However, the set’s performance was very poor, the unit exhibiting poor sensitivity and a distorted audio output. I checked the voltages on various stages and soon found that the screen pins of the two 6U7G valves were at only 5V. This was due to two factors: (1) a leaky 270nF screen bypass capacitor; and (2) the 25kW screen dropping resistor intermittently going open circuit. They were both replaced and the performance was vastly improved. The receiver was now starting to show some promise. I checked the tuning range on the broadcast band and adjusted the oscillator padder at the low-frequency end of the dial and the wire trimmer at the high-frequency end, so that stations appeared in the correct places. I then adjusted the trimmer on the antenna coil towards the high-frequency end of the band for peak performance. Next in line was the IF amplifier stage and after making the necessary adjustments, the set really started to perform. These IF adjustments were carried out with the aid of a signal generator and an insulated alignment tool. Unwanted whistle Although it was now performing quite well, there was still an occasional “whistle” from the set. A few checks soon revealed that the IF amplifier stage was oscillating. The reason for this was straightforward – the closefitting metal shield (also known as a “goat” shield) on one 6U7G was loose, so I compressed the circlip that held it together. The shield now worked properly and no further whistles occurred. However, I did notice that the set oscillated weakly at the lowfrequency end of the broadcast band (more on this later). I next checked the shortwave band and found that it tuned as the altered dial-scale indicated – ie, from 2.67.5MHz. In practice, it worked quite well down to 3.3MHz but below that, it ceased to operate. I suspect siliconchip.com.au that the oscillator stops at about this frequency, which effectively kills the set’s operation. Some readers will be aware that I dislike having padder capacitors in the earthy end of the oscillator’s tuned winding. That’s because oscillators often have reliability problems when the padder is in this position. As a result, I decided to do as I’ve often done before and change the position of the padder on the shortwave band. This involves moving it to the other end of the oscillator coil. The amended circuit configuration is shown in Fig.2. When I did this, the shortwave operation improved noticeably and, what’s more, it now worked right across the band. That done, the receiver was aligned using a combination of the techniques described in the December 2002 and the January and February 2003 issues. Faulty capacitors Paper capacitors in particular have a reputation for becoming quite leaky. However, as explained in the articles in the October and November 2004 issues, not all leaky capacitors have to be replaced. Rather than describe every component that was replaced, I’ve marked them with an asterisk (*) on the circuit diagram (Fig.1). They either had too much leakage or in the case of the electrolytics, low capacitance. Several other paper capacitors were also leaky but their circuit locations meant that they didn’t cause any problems, so they were left in circuit. By contrast, all those capacitors marked with an asterisk were replaced and each gave further improvements in performance. Six out of the seven valves in the Monarch were faulty, probably because someone plugged it into 240V AC. AGC diode which is fed from the plate of the second IF amplifier. As an experiment, I altered the set’s AGC circuit to this system (see Fig.3) and the improvement was dramatic, with little remaining evidence of overloading. I suspect that Astor clones with an RF stage had better AGC control by having AGC applied to three stages instead of just two, as in this receiver. As mentioned earlier, the receiver oscillates weakly at the low-frequency end of the broadcast band. I checked the earthing of the valve shields and the IF transformer cans, looked at the bypassing around the RF/IF sections and even tried adding extra IF (455kHz) filters in the audio amplifier stage, all to no avail. However, any radio station worth listening to overcomes this problem. That’s because the AGC reduces the gain and hence the amount of feedback drops below the level that causes the oscillation. My conclusion is that it’s the receiver’s wiring layout that causes this problem. In this set, the detector is relatively close to the front-end circuitry. As a result, radiation of 455kHz IF energy from the detector is amplified sufficiently in the aerial circuit to cause oscillation when it’s tuned towards the low-frequency end of the band. It’s worth noting that aerial coils don’t have a particularly high “Q”, so they will respond slightly to signals around 455kHz when a set is tuned to low frequencies. Wiring & dial cord Most of the wiring has been left insitu, as it’s not causing any problems Subtle problems There is only one strong broadcast station where I live and I soon found that it overloaded the receiver quite noticeably. The strength of the signal is such that it drives the second IF amplifier into non-linearity. This is largely overcome by not applying AGC to the second IF amplifier – only to the two preceding stages. In practice, I have found that higher AGC voltages need to be applied to the controlled stages than can be achieved with the simple AGC system fitted to this set. However, higher AGC voltages can be derived by having a separate siliconchip.com.au Many of the paper and electrolytic capacitors had to be replaced, along with some of the wiring which had cracked insulation. April 2005  85 Photo Gallery: Astor Mickey Mouse Model EC of the labels, so they now look just like they did when they were first made. Next, the speaker cloth was removed from the cabinet, washed in soapy water and then laid out flat to dry. That turned out to be something of a disaster because it shrank too much to be refitted to the cabinet. As a result, a new piece of dark-brown speaker cloth was cut and glued into place. That done, the cabinet and knobs were brushed clean of all loose dust and then scrubbed using a nail brush and soapy water to get rid of the surface muck. Some more automotive cut and polish and a polishing cloth brought the cabinet to life and made it look almost new. Unfortunately, however, a few scratches were too deep to remove without damaging the cabinet itself. Summary Manufactured by Radio Corporation, Melbourne, in 1939, the “Mickey Mouse” EC was a 5-valve superheterodyne receiver fitted with metal valves. Using an output valve that gave good performance at relatively low operating voltages allowed the size of the power transformer to be reduced and also reduced the heat build-up in the small Bakelite cabinet (the white cabinet shown here was not common). The valves fitted were as follows: 6A8 frequency changer; 6K7 IF amplifier; 6Q7 audio amplifier/detector/AGC rectifier; 25A6 audio output; and 5Z4 rectifier. Photo: Historical Radio Society of Australia, Inc. and is unlikely to do so if left undisturbed. However, the insulation on some of the wiring had cracked and that meant it had to be replaced (see photo). But I wasn’t quite out of the woods yet – just as I was about to finish all the alignment and performance testing, the dial cord broke. Fortunately, its replacement wasn’t all that difficult. I followed the original layout and within a few minutes, the dial drive was back in operation. Performance This radio was obviously designed for use in locations that were somewhat remote from radio stations, as it is unable to handle strong signals from local stations. However, its sensitivity is extremely good and signals of the order of just a few microvolts are heard 86  Silicon Chip quite clearly on both the broadcast and shortwave bands. Cabinet clean-up Although rather grubby, the cabinet was in quite good condition. First, I removed the “Monarch” badge from the front of the cabinet by undoing the nut on the inside. This badge is in two sections: a “crown” which I cleaned with a small wire brush and a main section which was cleaned with automotive cut and polish. It now looks quite presentable. The polarity labels (mentioned earlier) were also cleaned with automotive cut and polish. This also removed the paint, so they were resprayed using black paint for the negative label and red paint for the positive label. Once the paint had dried, I used a razor blade to scrape it off the raised sections Because it isn’t described in any of my service manuals and because the model number doesn’t follow the normal Astor/clones sequence, I suspect that this receiver never went into full-scale production. Another pointer to this is that all the knobs on the set have extended sleeves. However, this is necessary only for those knobs that have to reach the recessed control shafts beneath the protruding dial scale. By contrast, the other two shafts protrude beyond the cabinet and so the two lefthand controls sit quite proud of the cabinet. In addition, the cabinet itself appears to have been designed for a different model. That’s because the chassis mounting holes are not all in the correct positions. These factors, together with the low-frequency instability and the inefficient valve heater circuits, all indicate that this might have been a pre-production receiver. It is similar to other 32V HT receivers from the same stable but it was obviously designed as an economy version. It doesn’t handle strong signals at all well but is very sensitive and quite suitable for remote rural areas. The supply line is also poorly filtered and ripple on the line when the batteries in the power plant were being charged could have cause a “whine” in the audio output. So the old Monarch has many design flaws, although these could have been addressed in a full production model. What a pity the manufacturer didn’t SC do the job properly. siliconchip.com.au Custom-made Lithium Ion, NiCd and NiMH battery packs NiCd/NiMH Smart Chargers www.batterybook.com (08) 9240 5000 Li-Ion Smart Chargers 2400mAh NiMH AA cells High-quality single cell chargers with independent channels. Charge any combination of NiCd & NiMH AA and AAA cells Ask for a free copy of the Battery Book catalogue or visit www.batterybook.com Brand New From SILICON CHIP 160 PAGES 23 CHAPTE RS From the publishers of Completely NEW projects – the result of two years research & development • Learn how engine management systems work • Build projects to control nitrous, fuel injection and turbo boost systems Intelligent • Switch devices on and off on the basis of signal frequency, temperature and voltage • Build test instruments to check fuel injector duty cycle, fuel mixture and brake and coolant temperatures turbo timer I SBN 095852294 - 4 9 780958 522946 $19.80 (inc GST) NZ $22.00 (inc GST) TURBO BOOST & nitrous fuel controllers How engine management works Available from selected newsagents or from SILICON CHIP Order by phoning (02) 9979 5644 & quoting your credit card number; or fax the details to (02) 9979 6503; or mail your order with cheque or credit card details to Silicon Chip Publications, PO Box 139, Collaroy, NSW 2097. Mail order prices: Aust. $A22.50 (incl. GST & P&P); Overseas $A26.00 via airmail siliconchip.com.au April 2005  87 Salvage It! BY JULIAN EDGAR A $5 variable voltage power supply Want to be able to dim lights in, say, a model rail layout? Or what about varying the speed of a low-powered motor or regulating the voltage going to a bike headlight, so that its brightness stays the same as the battery voltage falls? It’s all possible for less than $5.00. T HIS DESIGN uses a slightly modified car phone charger. The idea is based on a Circuit Notebook contribution from Timo Mahoney in the November 2003 issue of SILICON CHIP. Most car phone chargers use a DCDC switching power supply to reduce the voltage from the car’s 13.8V to what ever the phone requires. However, it’s easy to modify the PC board to give an adjustable voltage output. Apart from the car phone charger (the electronics are normally built into the cigarette lighter plug), all you need is a 10kW potentiometer. Car phone chargers are available in secondhand shops, at the tip and in the junk rooms out the back of phone retailers, while a 10kW pot can be scrounged from some old gear or purchased from your local electronics parts retailer. Building it Fig.1 shows a typical circuit for a car phone charger. The IC controls the output voltage, using voltage feedback provided by resistors R1 and R2. So if you change the values of R1 and R2, Inside each of these car phone chargers is a sophisticated DC/DC converter than can be easily modified to provide a variable output power supply. 88  Silicon Chip the voltage output will also change. However, rather than have a fixed output, we can vary the output at will by installing an adjustable pot in place of the two resistors. Then it’s just a case of measuring the output voltage and adjusting the pot until the required voltage is obtained. If you want the voltage to be set and then forgotten, use a trimpot. Alternatively, if you want to be able to vary the voltage at any time, wire a full-size pot to the board with flying leads. The most difficult part is finding the correct resistors to change. Individual chargers vary quite a lot, so the com- Rat It Before You Chuck It! Whenever you throw away an old TV (or VCR or washing machine or dishwasher or printer) do you always think that surely there must be some good salvageable components inside? Well, this column is for you! (And it’s also for people without a lot of dough.) Each month we’ll use bits and pieces sourced from discards, sometimes in mini-projects and other times as an ideas smorgasbord. And you can contribute as well. If you have a use for specific parts which can easily be salvaged from goods commonly being thrown away, we’d love to hear from you. Perhaps you use the pressure switch from a washing machine to control a pump. Or maybe you salvage the high-quality bearings from VCR heads. Or perhaps you’ve found how the guts of a cassette player can be easily turned into a metal detector. (Well, we made the last one up but you get the idea . . .) If you have some practical ideas, write in and tell us! siliconchip.com.au Silicon Chip Binders REAL VALUE AT $12.95 PLUS P & P Fig.1 – the circuit of a typical car phone charger. The output voltage is set by R1 and R2. If these are replaced with a 10kW pot, the output voltage can be adjusted over a wide range. H SILICON CHIP logo printed in goldcoloured lettering on spine & cover H Buy five and get them postage free! Price: $A12.95 plus $A7 p&p. Available only in Australia. Just fill in the handy order form in this issue; or fax (02) 9979 6503; or ring (02) 9979 5644 & quote your credit card number. The charger is modified to produce a variable output by substituting a pot (arrowed) for two resistors. If external adjustment is needed, a full-size pot can be wired to the board with flying leads. In this case, a multi-turn pot has been used, which allows for very accurate setting of the output voltage. ponent designations marked on the board (R1, R2, etc) will probably not coincide with Fig.1. Hmmm. So how do you find the right resistors? The answer is to closely look at the top and bottom side of the board. Somewhere, there will be two resistors that join to a common track at one end Each of these bike headlights is run from a modified phone charger. The chargers are used to drop the voltage from the available 12V (provided by sealed lead-acid batteries that also power the electricassist bike) to a regulated 6V. siliconchip.com.au but go to different tracks at their other ends. The track that both resistors join to will also connect to pin 5 of the IC. Given that there will only be three or (at most) four resistors on the board, it shouldn’t be all that hard to find the resistor pair in question. The next step is even easier – re- move these two resistors and solder the pot to the board in their place. The centre terminal of the pot goes to the track where the two resistors were originally joined together, while the outer pot terminals connect to the remaining two vacant pads. Note that it, in some cases, it’s easier to make the connections by soldering the pot to the track side of the board. Using it To test the modified power supply, you’ll need a source of 12V power and a multimeter. First, connect the power supply to the 12V source (eg, a plugpack), making sure that you get the polarity the right way around (the tip of the cigarette lighter plug is positive). That done, connect the multimeter to the output leads of the adaptor and measure the voltage as the pot is adjusted – the output voltage should vary. Finally, place a load on the output (eg, a small 12V bulb) and check that you can alter the brightness of the lamp over a wide range. Typically, you can draw about 0.5A from the unit (depending on the plugpack). If the output voltage is critical, the pot should be set SC with the load attached. April 2005  89 SILICON CHIP Order Form/Tax Invoice Silicon Chip Publications Pty Ltd ABN 49 003 205 490 www.siliconchip.com.au PRICE GUIDE: SUBSCRIPTIONS YOUR DETAILS (Note: all subscription prices include P&P). (Aust. prices include GST) Your Name________________________________________________________ (PLEASE PRINT) Organisation (if applicable)___________________________________________ Please state month to start. Australia: 1 yr ....................$A83 1 yr + binder .....................$A96.50 NZ (air): 1 yr .....................$A89 Overseas (air): 1 yr ...........$A135 2 yrs .....................$A160 2 yrs + 2 binders ..$A186 2 yrs .....................$A178 2 yrs .....................$A260 Address__________________________________________________________ __________­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­___________________­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­____________________________________ Postcode_____________ Daytime Phone No. ( )_____________________ Email address (if applicable) ___________________________________________ Method of Payment: PRICE GUIDE: OTHER PRODUCTS (all prices include GST on Aust. orders) *SILICON CHIP BACK ISSUES in stock: 10% discount for 10 or more issues or photocopies. Australia: $A8.80 ea (including p&p). Overseas: $A10 each (including p&p by air). *ELECTRONICS AUSTRALIA: project photocopies, limited back issues. 10% discount for 10 or more issues or photocopies. Australia: $A8.80 each (including p&p). Overseas: $A10 ea (including p&p by air). o Cheque/Money Order o Bankcard o Visa Card o Master Card *BINDERS: BUY 5 or more and get them postage free.   (Available in Aust. only): $A12.95 each plus $7 p&p per order. Card No. *ELECTRONICS PROJECTS FOR CARS, VOL.2: Aust. $A14.95; NZ/Asia/Pacific $A18.00 including p&p (air); elsewhere $21.50. (All prices include p&p). Card expiry date: Signature_____________________________ *PERFORMANCE ELECTRONICS FOR CARS: Aust. $A22.50; Overseas $A26.00. (Prices include p&p & GST where applicable). 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) 9979 5644 OR Fax this form to OR 9am-5pm Mon-Fri (02) 9979 6503 YOUR Please have your credit with your credit card details card details ready 24 hours 7 days a week ORDER 90  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, Australia 2097 04-05 siliconchip.com.au April 2005  91 ALL S ILICON C HIP SUBSCRIBERS – PRINT, OR BOTH – AUTOMATICALLY QUALIFY FOR A REFERENCE $ave 10%ONLINE DISCOUNT ON ALL BOOK OR PARTSHOP PURCHASES. CHIP BOOKSHOP 10% (Does not apply to subscriptions) SILICON For the latest titles and information, please refer to our website books page: www.siliconchip.com.au/Shop/Books PIC MICROCONTROLLERS: know it all SELF ON AUDIO Multiple authors $85.00 The best of subjects Newnes authors have written over the past few years, combined in a one-stop maxi reference. Covers introduction to PICs and their programming in Assembly, PICBASIC, MBASIC & C. 900+ pages. PROGRAMMING and CUSTOMIZING THE PICAXE By David Lincoln (2nd Ed, 2011) $65.00* A great aid when wrestling with applications for the PICAXE See series of microcontrollers, at beginner, intermediate and Review April advanced levels. Every electronics class, school and library should have a copy, along with anyone who works with PICAXEs. 300 pages in paperback. 2011 PIC IN PRACTICE by D W Smith. 2nd Edition - published 2006 $60.00* Based on popular short courses on the PIC, for professionals, students and teachers. Can be used at a variety of levels. An ideal introduction to the world of microcontrollers. 255 pages in paperback. PIC MICROCONTROLLER – your personal introductory course By John Morton 3rd edition 2005. $60.00* A unique and practical guide to getting up and running with the PIC. It assumes no knowledge of microcontrollers – ideal introduction for students, teachers, technicians and electronics enthusiasts. Revised 3rd edition focuses entirely on re-programmable flash PICs such as 16F54, 16F84 12F508 and 12F675. 226 pages in paperback. by Douglas Self 2nd Edition 2006 $69.00* A collection of 35 classic magazine articles offering a dependable methodology for designing audio power amplifiers to improve performance at every point without significantly increasing cost. Includes compressors/limiters, hybrid bipolar/FET amps, electronic switching and more. 467 pages in paperback. SMALL SIGNAL AUDIO DESIGN By Douglas Self – First Edition 2010 $95.00* The latest from the Guru of audio. Explains audio concepts in easy-to-understand language with plenty of examples and reasoning. Inspiration for audio designers, superb background for audio enthusiasts and especially where it comes to component peculiarities and limitations. Expensive? Yes. Value for money? YES! Highly recommended. 558 pages in paperback. AUDIO POWER AMPLIFIER DESIGN HANDBOOK by Douglas Self – 5th Edition 2009 $85.00* "The Bible" on audio power amplifiers. Many revisions and updates to the previous edition and now has an extra three chapters covering Class XD, Power Amp Input Systems and Input Processing and Auxiliarly Subsystems. Not cheap and not a book for the beginner but if you want the best reference on Audio Power Amps, you want this one! 463 pages in paperback. DVD PLAYERS AND DRIVES by K.F. Ibrahim. Published 2003. $71.00* OP AMPS FOR EVERYONE By Bruce Carter – 4th Edition 2013 $83.00* This is the bible for anyone designing op amp circuits and you don't have to be an engineer to get the most out of it. It is written in simple language but gives lots of in-depth info, bridging the gap between the theoretical and the practical. 281 pages, A guide to DVD technology and applications, with particular focus on design issues and pitfalls, maintenance and repair. Ideal for engineers, technicians, students of consumer electronics and sales and installation staff. 319 pages in paperback. by Sanjaya Maniktala, Published April 2012. $83.00 Thoroughly revised! The most comprehensive study available of theoretical and practical aspects of controlling and measuring EMI in switching power supplies. Subtitled Exploring the PIC32, a Microchip insider tells all on this powerful PIC! Focuses on examples and exercises that show how to solve common, real-world design problems quickly. Includes handy checklists. FREE CD-ROM includes source code in C, the Microchip C30 compiler, and MPLAB SIM. 400 pages paperback. By Garry Cratt – Latest (7th) Edition 2008 $49.00 Written in Australia, for Australian conditions by one of Australia's foremost satellite TV experts. If there is anything you wanted to know about setting up a satellite TV system, (including what you can't do!) it's sure to be covered in this 176-page paperback book. See Review Feb 2004 SWITCHING POWER SUPPLIES A-Z PROGRAMMING 32-bit MICROCONTROLLERS IN C By Luci di Jasio (2008) $79.00* PRACTICAL GUIDE TO SATELLITE TV See Review March 2010 ELECTRIC MOTORS AND DRIVES By Austin Hughes & Bill Drury - 4th edition 2013 $59.00* This is a very easy to read book with very little mathematics or formulas. It covers the basics of all the main motor types, DC permanent magnet and wound field, AC induction and steppers and gives a very good description of how speed control circuits work with these motors. Soft covers, 444 pages. NEWNES GUIDE TO TV & VIDEO TECHNOLOGY By KF Ibrahim 4th Edition (Published 2007) $49.00 It's back! Provides a full and comprehensive coverage of video and television technology including HDTV and DVD. Starts with fundamentals so is ideal for students but covers in-depth technologies such as Blu-ray, DLP, Digital TV, etc so is also perfect for engineers. 600+ pages in paperback. RF CIRCUIT DESIGN by Chris Bowick, Second Edition, 2008. $63.00* The classic RF circuit design book. RF circuit design is now more important that ever in the wireless world. In most of the wireless devices that we use there is an RF component – this book tells how to design and integrate in a very practical fashion. 244 pages in paperback. PRACTICAL RF HANDBOOK AC MACHINES By Jim Lowe Published 2006 $66.00* Applicable to Australian trades-level courses including NE10 AC Machines, NE12 Synchronous Machines and the AC part of NE30 Electric Motor Control and Protection. Covering polyphase induction motors, singlephase motors, synchronous machines and polyphase motor starting. 160 pages in paperback. PRACTICAL VARIABLE SPEED DRIVES & POWER ELECTRONICS Se e by Malcolm Barnes. 1st Ed, Feb 2003. $73.00* Review An essential reference for engineers and anyone who wishes to design or use variable speed drives for induction motors. 286 pages in soft cover. Feb 2003 BUILD YOUR OWN ELECTRIC MOTORCYCLE by Carl Vogel. Published 2009. $40.00* by Ian Hickman. 4th edition 2007 $61.00* Alternative fuel expert Carl Vogel gives you a hands-on guide with A guide to RF design for engineers, technicians, students and enthusiasts. the latest technical information and easy-to-follow instructions Covers key topics in RF: analog design principles, transmission lines, for building a two-wheeled electric vehicle – from a streamlined couplers, transformers, amplifiers, oscillators, modulation, transmitters and scooter to a full-sized motorcycle. 384 pages in soft cover. receivers, propagation and antennas. 279 pages in paperback. *NOTE: ALL PRICES ARE PLUS P&P – AUSTRALIA ONLY: $10.00 per order; NZ – $AU12.00 PER BOOK; REST OF WORLD $AU18.00 PER BOOK To Place Your Order: INTERNET (24/7) PAYPAL (24/7) eMAIL (24/7) www.siliconchip. com.au/Shop/Books Use your PayPal account silicon<at>siliconchip.com.au silicon<at>siliconchip.com.au with order & credit card details FAX (24/7) MAIL (24/7) Your order and card details to Your order to PO Box 139 Collaroy NSW 2097 (02) 9939 2648 with all details PHONE – (9-5, Mon-Fri) Call (02) 9939 3295 with with order & credit card details You can also order and pay for books by cheque/money order (Mail Only). Make cheques payable to Silicon Chip Publications. ALL TITLES SUBJECT TO AVAILABILITY. PRICES VALID FOR MONTH OF MAGAZINE ISSUE ONLY. ALL PRICES INCLUDE GST ALL S ILICON C HIP SUBSCRIBERS – PRINT, OR BOTH – AUTOMATICALLY QUALIFY FOR A REFERENCE $ave 10%ONLINE DISCOUNT ON ALL BOOK OR PARTSHOP PURCHASES. CHIP BOOKSHOP 10% (Does not apply to subscriptions) SILICON For the latest titles and information, please refer to our website books page: www.siliconchip.com.au/Shop/Books PIC MICROCONTROLLERS: know it all SELF ON AUDIO Multiple authors $85.00 The best of subjects Newnes authors have written over the past few years, combined in a one-stop maxi reference. Covers introduction to PICs and their programming in Assembly, PICBASIC, MBASIC & C. 900+ pages. PROGRAMMING and CUSTOMIZING THE PICAXE By David Lincoln (2nd Ed, 2011) $65.00* A great aid when wrestling with applications for the PICAXE See series of microcontrollers, at beginner, intermediate and Review April advanced levels. Every electronics class, school and library should have a copy, along with anyone who works with PICAXEs. 300 pages in paperback. 2011 PIC IN PRACTICE by D W Smith. 2nd Edition - published 2006 $60.00* Based on popular short courses on the PIC, for professionals, students and teachers. Can be used at a variety of levels. An ideal introduction to the world of microcontrollers. 255 pages in paperback. PIC MICROCONTROLLER – your personal introductory course By John Morton 3rd edition 2005. $60.00* A unique and practical guide to getting up and running with the PIC. It assumes no knowledge of microcontrollers – ideal introduction for students, teachers, technicians and electronics enthusiasts. Revised 3rd edition focuses entirely on re-programmable flash PICs such as 16F54, 16F84 12F508 and 12F675. 226 pages in paperback. by Douglas Self 2nd Edition 2006 $69.00* A collection of 35 classic magazine articles offering a dependable methodology for designing audio power amplifiers to improve performance at every point without significantly increasing cost. Includes compressors/limiters, hybrid bipolar/FET amps, electronic switching and more. 467 pages in paperback. SMALL SIGNAL AUDIO DESIGN By Douglas Self – First Edition 2010 $95.00* The latest from the Guru of audio. Explains audio concepts in easy-to-understand language with plenty of examples and reasoning. Inspiration for audio designers, superb background for audio enthusiasts and especially where it comes to component peculiarities and limitations. Expensive? Yes. Value for money? YES! Highly recommended. 558 pages in paperback. AUDIO POWER AMPLIFIER DESIGN HANDBOOK by Douglas Self – 5th Edition 2009 $85.00* "The Bible" on audio power amplifiers. Many revisions and updates to the previous edition and now has an extra three chapters covering Class XD, Power Amp Input Systems and Input Processing and Auxiliarly Subsystems. Not cheap and not a book for the beginner but if you want the best reference on Audio Power Amps, you want this one! 463 pages in paperback. DVD PLAYERS AND DRIVES by K.F. Ibrahim. Published 2003. $71.00* OP AMPS FOR EVERYONE By Bruce Carter – 4th Edition 2013 $83.00* This is the bible for anyone designing op amp circuits and you don't have to be an engineer to get the most out of it. It is written in simple language but gives lots of in-depth info, bridging the gap between the theoretical and the practical. 281 pages, A guide to DVD technology and applications, with particular focus on design issues and pitfalls, maintenance and repair. Ideal for engineers, technicians, students of consumer electronics and sales and installation staff. 319 pages in paperback. by Sanjaya Maniktala, Published April 2012. $83.00 Thoroughly revised! The most comprehensive study available of theoretical and practical aspects of controlling and measuring EMI in switching power supplies. Subtitled Exploring the PIC32, a Microchip insider tells all on this powerful PIC! Focuses on examples and exercises that show how to solve common, real-world design problems quickly. Includes handy checklists. FREE CD-ROM includes source code in C, the Microchip C30 compiler, and MPLAB SIM. 400 pages paperback. By Garry Cratt – Latest (7th) Edition 2008 $49.00 Written in Australia, for Australian conditions by one of Australia's foremost satellite TV experts. If there is anything you wanted to know about setting up a satellite TV system, (including what you can't do!) it's sure to be covered in this 176-page paperback book. See Review Feb 2004 SWITCHING POWER SUPPLIES A-Z PROGRAMMING 32-bit MICROCONTROLLERS IN C By Luci di Jasio (2008) $79.00* PRACTICAL GUIDE TO SATELLITE TV See Review March 2010 ELECTRIC MOTORS AND DRIVES By Austin Hughes & Bill Drury - 4th edition 2013 $59.00* This is a very easy to read book with very little mathematics or formulas. It covers the basics of all the main motor types, DC permanent magnet and wound field, AC induction and steppers and gives a very good description of how speed control circuits work with these motors. Soft covers, 444 pages. NEWNES GUIDE TO TV & VIDEO TECHNOLOGY By KF Ibrahim 4th Edition (Published 2007) $49.00 It's back! Provides a full and comprehensive coverage of video and television technology including HDTV and DVD. Starts with fundamentals so is ideal for students but covers in-depth technologies such as Blu-ray, DLP, Digital TV, etc so is also perfect for engineers. 600+ pages in paperback. RF CIRCUIT DESIGN by Chris Bowick, Second Edition, 2008. $63.00* The classic RF circuit design book. RF circuit design is now more important that ever in the wireless world. In most of the wireless devices that we use there is an RF component – this book tells how to design and integrate in a very practical fashion. 244 pages in paperback. PRACTICAL RF HANDBOOK AC MACHINES By Jim Lowe Published 2006 $66.00* Applicable to Australian trades-level courses including NE10 AC Machines, NE12 Synchronous Machines and the AC part of NE30 Electric Motor Control and Protection. Covering polyphase induction motors, singlephase motors, synchronous machines and polyphase motor starting. 160 pages in paperback. PRACTICAL VARIABLE SPEED DRIVES & POWER ELECTRONICS Se e by Malcolm Barnes. 1st Ed, Feb 2003. $73.00* Review An essential reference for engineers and anyone who wishes to design or use variable speed drives for induction motors. 286 pages in soft cover. Feb 2003 BUILD YOUR OWN ELECTRIC MOTORCYCLE by Carl Vogel. Published 2009. $40.00* by Ian Hickman. 4th edition 2007 $61.00* Alternative fuel expert Carl Vogel gives you a hands-on guide with A guide to RF design for engineers, technicians, students and enthusiasts. the latest technical information and easy-to-follow instructions Covers key topics in RF: analog design principles, transmission lines, for building a two-wheeled electric vehicle – from a streamlined couplers, transformers, amplifiers, oscillators, modulation, transmitters and scooter to a full-sized motorcycle. 384 pages in soft cover. receivers, propagation and antennas. 279 pages in paperback. *NOTE: ALL PRICES ARE PLUS P&P – AUSTRALIA ONLY: $10.00 per order; NZ – $AU12.00 PER BOOK; REST OF WORLD $AU18.00 PER BOOK To Place Your Order: INTERNET (24/7) PAYPAL (24/7) eMAIL (24/7) www.siliconchip. com.au/Shop/Books Use your PayPal account silicon<at>siliconchip.com.au silicon<at>siliconchip.com.au with order & credit card details FAX (24/7) MAIL (24/7) Your order and card details to Your order to PO Box 139 Collaroy NSW 2097 (02) 9939 2648 with all details PHONE – (9-5, Mon-Fri) Call (02) 9939 3295 with with order & credit card details You can also order and pay for books by cheque/money order (Mail Only). Make cheques payable to Silicon Chip Publications. ALL TITLES SUBJECT TO AVAILABILITY. PRICES VALID FOR MONTH OF MAGAZINE ISSUE ONLY. ALL PRICES INCLUDE GST 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 Soldering surface mount ICs I was interested in the Serviceman’s technique for removing and replacing a surface-mount IC using a “flow soldering” approach (February 2005, page 50). Would it be possible for someone to spell out exactly how you do this? There are a few SILICON CHIP projects which interest me but which I have so far not had the courage to attempt after reading the recommended way of soldering an SM IC. The first problem I foresee is holding the IC in place while making the first soldered joint. Could this be done with a very temporary, quite weak, adhesive such as BluTak? What about then following this by “flow soldering” as described, followed by desoldering braid? (J. N., via email). • First, we should mention that the Serviceman uses this “flow soldering” technique because he lacks the correct tools for the job, which would be prohibitively expensive if rarely used. The technique will work on all fine-pitch surface-mount chips that have rows of pins on only two sides. The idea is actually quite simple, as follows: (1). Short all the pins on one side together by bridging them with solder. This is done by applying a lot more solder than is normally necessary to each pin. (2). Heat the IC to soften the glue that is used during assembly to hold it in place. Heat should also be applied to the opposite side of the PC board, under the IC. A hair dryer might be suitable for the job. (3). Slip a fine-bladed instrument under one side of the IC and apply light upwards pressure. (4). Heat the solder bridge formed in step (1), which should simultaneously melt the solder on all pins on that side. (5). Lever the IC up to lift the pins away from their pads, just clear of the solder. The second side can be removed in a similar manner. A desoldering tool or fine desoldering braid can then be used to remove excess solder. Note that two disadvantages to this Improving A 240VAC Inverter’s Output I have a question or two for an expert in electricity. Recently, I have been powering my 240VAC 0.9A 50Hz freezer from a modified sinewave inverter (12V DC input, 1500W continuous). I also have an 8mF 400VAC capacitor from an old water pump (240VAC 2.5A 50Hz). Would there be any advantage in making a junction box with the above capacitor connected to the Active (as it was with the water pump) to: (1) Reduce the surge maximum on the inverter, therefore making 1200W available for other applications during fridge start up? (2) Improve the quality of the modi94  Silicon Chip fied square wave supply by smoothing out the signal? I don’t have an oscilloscope! (A. M., via email). • We would strongly recommend against connecting any capacitor across the output of your inverter. It will increase the harmonic currents from the inverter and will actually increase the total load current. It will also increase the initial surge current, if it is installed as part of the freezer. It may smooth the waveform somewhat but there will be no benefit since your freezer motor naturally blocks the harmonics of the waveform and draws current mainly at the fundamental frequency. method are the possibility of damage to the PC board due to lifted pads as well as pin malformation of the IC itself. We don’t describe many projects employing SMD ICs because they can be very difficult to hand solder. In fact, most manufacturers do not recommend hand soldering for finepitched devices. We described how to solder a 0.5mm-pitch device in the “High Efficiency Power Supply For 1W Luxeon Star LEDs” project in the January 2004 edition. As you point out, one of the more difficult parts of the job is locating and holding the IC precisely over its pads. Unfortunately, short of using commercial rework gear, we know of no easy way this can be achieved. Marine TV antenna I have a question which relates to life on-board a yacht. How can I automatically keep the TV antenna pointing at the transmitter while the boat yaws about from the influence of winds and tides? I guess if cost is no problem, that a kind of auto-pilot arrangement with fluxgate compass, feedback unit and motor would do it? Or maybe some kind of gyro? Any ideas? (P. R., via email). • We are not sure how you would solve that problem. You would first have to find the correct heading for the antenna (could be difficult, if you don’t know where the transmitter is) and then maintain it. A servo circuit controlled by an electronic compass would do the job but we have not published anything in this area. Ozone generator wanted I am trying to find an ozone generator kit, to produce ozone. I understand that SILICON CHIP or EA did one a long time ago. (K. R., via email). • No magazine that we know of has ever produced an ozone generator. We siliconchip.com.au assume you are referring to a negative ion generator. These had the undesirable side-effect of producing ozone which is why EA and SILICON CHIP never produced one. ETI magazine did produce a negative ion generator in the April 1981 issue, however if you wanted it specifically to produce ozone, say for a sterilisation application, it would not be very effective. To produce reasonable amounts of ozone in a corona discharge, you would need much higher voltages than the 3kV generated by a negative ion generator. We can supply the negative ion generator article if you want it. Photocopies of SILICON CHIP, “Electronics Australia” and “ETI” articles are available from Silicon Chip Publications for $8.80 each including GST and P&P (Australia) or $A10.00 each including airmail P&P (outside Australia). It is the same price for a back issue if we have it in stock. Lost RFID tags require system reprogramming I want to build two RFID units (SILICHIP, June 2004) for our shop to activate and deactivate our alarm system and as an automatic door lock for our rear door. As we share the premises with a Subway store, there would be around 15 tags in circulation. The question is, if a tag was lost (very likely to happen) is there a way to eliminate that tag’s number from the RFID module? From what I can see, you need the tag to delete it from the module. (P. D., Marshall, Vic). • The only way to remove a lost tag is to erase the entire memory and reprogram the tags again. You may need a more comprehensive system for your application. Commercial units with keypads and/or computer connections that allow editing of tag codes are now available. You’ll find some examples at: www.microgram.com.au CON Magnetic field strength meter I am trying to find a kit that was available about eight years ago. It was a digital EMR meter kit which discriminated between 50Hz and 60Hz and measures in nanoteslas, microteslas and milliteslas. This instrument could also pick up harmonics and it factors in all radiation, not just primary siliconchip.com.au Concern about hot components in SC480 I recently constructed two of your SC480 amplifier modules (January & February 2003) and they sound great! However, after only perhaps half a minute of operation, Q4 and Q5 get very warm. For peace of mind, I have wedged a small heatsink between the two and affixed them using thermal compound (to the heatsink) and hot glue (to the PC board). Nevertheless, the transistors still remain hot at around 55°C (with the heatsink). I realise that this is within the operating limits of the transistor but such a temperature rise (in excess of 30°C) is much higher than I expected. Q6 also seems to get quite warm at around 60°C but according to your schematic, there is around 38V across it. In addition, the 1W resistors which are raised around 3-5mm off the PC board on the power supply board get very warm as well (around 60-65°C). I am not powering anything from this ±15V power supply. Is this temperature to be expected? The output transistors do NOT get hot. I know that most of these tem- frequencies. Can you help me? (P. B., via email). • The project was probably the Magnetic Field Strength Meter published in October 1991. No kit was produced but the parts should all still be available. PortaPal plagued with hum I have recently built the PortaPal portable PA system described in the February & March 2003 issues but have problems with it. With a good battery and mains plugpack connected, I get loud hum and “motor-boating”. If the plugpack is disconnected, the noise goes but of course, there is no earth and the (unbalanced) microphone produces bad hum. With the plugpack connected but with low battery volts (11V), I get no noise so the problem is voltagedependent. Has anyone else experienced problems with this circuit? Are there any notes/errata I should imple- peratures are (well) within devices’ operating limits, so perhaps the thought of the lot “blowing up” and the financial distress involved enforces this need for reconfirmation. I hope that you can tell me if these temperatures are to be expected. (Y. P., via email). • Q4, Q5 & Q6 have to dissipate about 0.33W and will therefore get quite warm in normal operation. As you point out, this is within the operating parameters of the transistors and therefore no heatsinking is required. The 2.2kW 1W resistors on the power supply board each dissipate about 0.28W. Again, these resistors will get quite warm. Check that the output voltages are correct (±15V), as overheating can be caused by accidental reversal of the zener diodes. Assuming that all of the DC voltages around the circuit approximate those shown on the circuit diagram, you can be reasonably confident that all is well and your investment is not about to disappear in a puff of smoke! ment? (J. W., Gladesville, NSW). • We published Notes & Errata in the April 2003 issue to the effect that the 10mF at the adjust terminal on the REG1 (charger circuit) should not be used in the PortaPal. This is because it can cause the problems you are experiencing. Also check the stability of the amplifier. It may have a faulty decoupling capacitor. High cost can make TV sets unrepairable Is it normal for TV sets which require a new yoke to be unrepairable? My NEC FS 6331 has a faulty yoke and I was told to throw it out and purchase a new TV as new yokes are not available without a new picture tube. If this is the case, could you please offer an opinion as to a brand and model of TV you consider reliable and well made, etc. (P. B., via email). • We ran your question past our Serviceman writer for his response and he April 2005  95 Solid-State Transformers No Good For DC Waveform A I have purchased a 240/12V solidstate transformer for use with a 50W halogen lamp. I want to rectify the output to give DC. I have used a 6A bridge rectifier but it gets extremely hot and drops about 5V across it. Is there some reason why the output of these power supplies cannot be rectified? (G. H., via email). • These so-called solid-state transformers are, in effect, highfrequency switchmode power supplies with an AC output. They are set to deliver 12V RMS to the halogen lamp but their peak output is a lot higher than that so you can’t use them to produce a given value replied, as follows: often, the deflection yoke is only sold as an integral custom-built part of the picture tube. In this case, this set uses a Thomson picture tube A63ADT10X505 which has the yoke (I believe!) cemented on to it (part no 33026904). I guess if you want to spend about $1000 on a 10+ year old TV, it can be repaired. I cannot guess which brand of TV currently on sale is the most reliable – only time can tell. Charging deep cycle batteries on a boat On my yacht, there are two deepcycle batteries that are charged by the diesel alternator. We stay away for periods of up to a week and when 96  Silicon Chip Waveform B of DC. Nor will ordinary rectifiers work with them, as you have found, as the switching frequency is very high at around 40kHz. Nor can they drive a standard rectifier/capacitor combination. The accompanying waveforms show the operation of a typical 50W solid state Halogen transformer. In waveform A, the scope sweep speed is set to 4ms/ div to show the 100Hz modulation of a high-frequency waveform. This has an RMS value of 11.9V – ideal for a halogen lamp but useless for anything else. at anchor, the internal system runs on one battery with the other held in reserve so that we are able to start the diesel. Looking at the circuitry in the Deep Cycle Charger (November & December 2004), it would seem that if two chargers were built with input from the rectified output of the alternator, the advantages of the designed charging cycle could be obtained. I assume that the display could be switched between the two controllers. I would be pleased to have your comments. (J. R., via email). • You can use the one alternator to drive both chargers. The display could be switched between chargers by switching the data and control lines. It would require a 6-pole 2-way rotary In waveform B, the scope sweep speed is set to 10ms/div so we can see the highfrequency waveform without the modulation. In this case it is running at about 38kHz. Note the peakto-peak voltage of 39.4V. So the unit is quite useless if you want to use it to produce a given value of DC. switch. It might be easier to have two displays to avoid the switching. Help needed with Speedo Corrector I have constructed a Speedo Corrector kit from your book “Performance Electronics for Cars” and cannot get it to work. Several experts have followed the decision diagram to no avail. We have installed LK1 at X, gone to procedure 2 and installed R2 and LK3 at Y. No output signal to the speedo results. The speedo and sender are from a 1991 Toyota Corolla Levin AE101 import. What is wrong? (J. O., via email). • First, make sure that the speedometer still works without the corrector. siliconchip.com.au Then, when the corrector is connected, check for voltage at the signal input and output. In your case, with LK1 at X and LK3 at Y and R2 installed, the voltage at the signal input should be around 6-7V (multimeter set to DC volts) and the same voltage should be at the output. If this is not the case, check through the procedure again. Make sure the correct resistor (R1 or R2) is installed and that the setting for LK3 is correct. How to motorise Santa We decorate our house at Christmas and have a motorised Santa that pops in and out of a chimney. This unit is home-made and is powered by a 12V DC windscreen wiper motor. I made this decoration some four years ago and it operated fine. It was run on a motor-bike battery that had some dead cells. However, this battery was totally “gone” by the next year and upon trying a car battery or even a good bike battery, the whole thing runs too fast. Can you suggest a circuit that will slow the motor’s speed while still leaving enough power for it to turn and lift the decoration? (P. M., Tuggerah, NSW). • Have a look at the 12/24V speed control from the June 1997 issue. It should do the job. NAND Schmitt gates explained I wish to know what the four lines in middle of a NAND gate symbol mean. When I did my amateur course, we were only informed of the four types of gates. So what is the significance of the NAND gate symbols featured on page 69 (Circuit Notebook) of the December 2004 issue? (G. A., via email). • The symbol you refer inside gates and inverters indicates that the device is also a Schmitt trigger. In fact, the symbol indicates the square hysteresis curve of the input signal. Different crystal for Big Digit Clock Can a 4.194304MHz crystal be substituted for the 4MHz crystal in the Big Digit Clock featured in the March 2001 issue? The way I read and look at it, in theory when the adjustment cycle is on zero, timekeeping with the 4.19MHz crystal would be nearly spot on. Not knowing the code inside the chip, I thought I would ask. (B. H., Creswick, Vic). • If you use a 4.19 MHz crystal, the time-keeping will be much too fast. Admittedly, the binary set crystal frequencies are easier to divide down to 1Hz using discrete logic but when using a microprocessor, the division can be done using standard crystals and dividing by non-binary numbers will obtain an exact 1Hz signal. The adjustment available in the clock is to allow for the crystal inaccuracy (typically 50 parts per million). Auto-start on deep cycle charger With reference to the Deep Cycle Battery Charger (November & December 2004), I would appreciate clarification of the auto-start function. Were I to build the charger, I would find this a useful facility as I would normally Notes & Errata Pool Lap Counter, March 2005: on the circuit diagram (Fig.1), the seven outputs from the 4511B (IC3) are shown connected to the LED array in reverse order. For example, pin 13 of IC3 should go to pin 7 (segment “a”) of the LEDs, pin 12 of IC3 to pin 6 (segment “b”) of the LEDs, etc. Also, the decimal point (pin 8) of DS1 is shown connected to ground via a 1.5kW resistor. Instead, this resistor should go to the +12V rail. The overlay diagram (Fig.2) and PC board (Fig.4) are correct. want to charge a deep-cycle battery but would occasionally want also to charge a starter battery (Specific #1) which I understand I can do with the link removed. However, does the PIC controller remember the last charging cycle selected or revert to “normal” parameters as distinct from Specific #1 on a future charging cycle? I would guess this comes down to whether the control out pin gets its data from EEPROM or RAM. (J. A., via email). • The charger remembers the last settings and uses these during the autostart feature. If you decide to change them, just press the set switch when power is first applied to the charger and change settings. The settings are in EEPROM and so are stored until SC changed. WARNING! SILICON CHIP magazine regularly describes projects which employ a mains power supply or produce high voltage. All such projects should be considered dangerous or even lethal if not used safely. Readers are warned that high voltage wiring should be carried out according to the instructions in the articles. When working on these projects use extreme care to ensure that you do not accidentally come into contact with mains AC voltages or high voltage DC. If you are not confident about working with projects employing mains voltages or other high voltages, you are advised not to attempt work on them. Silicon Chip Publications Pty Ltd disclaims any liability for damages should anyone be killed or injured while working on a project or circuit described in any issue of SILICON CHIP magazine. Devices or circuits described in SILICON CHIP may be covered by patents. SILICON CHIP disclaims any liability for the infringement of such patents by the manufacturing or selling of any such equipment. SILICON CHIP also disclaims any liability for projects which are used in such a way as to infringe relevant government regulations and by-laws. Advertisers are warned that they are responsible for the content of all advertisements and that they must conform to the Trade Practices Act 1974 or as subsequently amended and to any governmental regulations which are applicable. siliconchip.com.au April 2005  97 Silicon Chip Back Issues April 1989: Auxiliary Brake Light Flasher; What You Need to Know About Capacitors; 32-Band Graphic Equaliser, Pt.2. May 1989: Build A Synthesised Tom-Tom; Biofeedback Monitor For Your PC; Simple Stub Filter For Suppressing TV Interference. July 1989: Exhaust Gas Monitor; Experimental Mains Hum Sniffers; Compact Ultrasonic Car Alarm; The NSW 86 Class Electrics. September 1989: 2-Chip Portable AM Stereo Radio Pt.1; High Or Low Fluid Level Detector; Studio Series 20-Band Stereo Equaliser, Pt.2. October 1989: FM Radio Intercom For Motorbikes Pt.1; GaAsFet Preamplifier For Amateur TV; 2-Chip Portable AM Stereo Radio, Pt.2. November 1989: Radfax Decoder For Your PC (Displays Fax, RTTY & Morse); FM Radio Intercom For Motorbikes, Pt.2; 2-Chip Portable AM Stereo Radio, Pt.3; Floppy Disk Drive Formats & Options. January 1990: High Quality Sine/Square Oscillator; Service Tips For Your VCR; Active Antenna Kit; Designing UHF Transmitter Stages. February 1990: A 16-Channel Mixing Desk; Build A High Quality Audio Oscillator, Pt.2; The Incredible Hot Canaries; Random Wire Antenna Tuner For 6 Metres; Phone Patch For Radio Amateurs, Pt.2. March 1990: Delay Unit For Automatic Antennas; Workout Timer For Aerobics Classes; 16-Channel Mixing Desk, Pt.2; Using The UC3906 SLA Battery Charger IC. April 1990: Dual Tracking ±50V Power Supply; Voice-Operated Switch With Delayed Audio; 16-Channel Mixing Desk, Pt.3; Active CW Filter. October 1992: 2kW 24VDC - 240VAC Sinewave Inverter; Multi-Sector Home Burglar Alarm, Pt.2; Mini Amplifier For Personal Stereos; A Regulated Lead-Acid Battery Charger. February 1993: Three Projects For Model Railroads; Low Fuel Indicator For Cars; Audio Level/VU Meter (LED Readout); An Electronic Cockroach; 2kW 24VDC To 240VAC Sinewave Inverter, Pt.5. March 1993: Solar Charger For 12V Batteries; Reaction Trainer; Audio Mixer for Camcorders; A 24-Hour Sidereal Clock For Astronomers. April 1993: Solar-Powered Electric Fence; Audio Power Meter; ThreeFunction Home Weather Station; 12VDC To 70VDC Converter. July 1995: Electric Fence Controller; How To Run Two Trains On A Single Track (Incl. Lights & Sound); Setting Up A Satellite TV Ground Station; Build A Reliable Door Minder. August 1993: Low-Cost Colour Video Fader; 60-LED Brake Light Array; Microprocessor-Based Sidereal Clock; Satellites & Their Orbits. August 1995: Fuel Injector Monitor For Cars; Gain Controlled Microphone Preamp; How To Identify IDE Hard Disk Drive Parameters. September 1993: Automatic Nicad Battery Charger/Discharger; Stereo Preamplifier With IR Remote Control, Pt.1; In-Circuit Transistor Tester; +5V to ±15V DC Converter; Remote-Controlled Cockroach. September 1995: Railpower Mk.2 Walkaround Throttle For Model Railways, Pt.1; Keypad Combination Lock; Jacob’s Ladder Display. October 1993: Courtesy Light Switch-Off Timer For Cars; Wireless Microphone For Musicians; Stereo Preamplifier With IR Remote Control, Pt.2; Electronic Engine Management, Pt.1. December 1993: Remote Controller For Garage Doors; LED Stroboscope; 25W Audio Amplifier Module; A 1-Chip Melody Generator; Engine Management, Pt.3; Index To Volume 6. November 1990: Connecting Two TV Sets To One VCR; Build An Egg Timer; Low-Cost Model Train Controller; 1.5V To 9V DC Converter; Introduction To Digital Electronics; A 6-Metre Amateur Transmitter. January 1991: Fast Charger For Nicad Batteries, Pt.1; Have Fun With The Fruit Machine (Simple Poker Machine); Two-Tone Alarm Module; The Dangers of Servicing Microwave Ovens. February 1991: A Practical Approach To Amplifier Design; Synthesised Stereo AM Tuner; Three Inverters For Fluorescent Lights; Low-Cost Sinewave Oscillator; Fast Charger For Nicad Batteries, Pt.2. May 1991: 13.5V 25A Power Supply For Transceivers; Stereo Audio Expander; Fluorescent Light Simulator For Model Railways; How To Install Multiple TV Outlets, Pt.1. July 1991: Loudspeaker Protector For Stereo Amplifiers; 4-Channel Lighting Desk, Pt.2; How To Install Multiple TV Outlets, Pt.2; Tuning In To Satellite TV, Pt.2. September 1991: Digital Altimeter For Gliders & Ultralights; Ultrasonic Switch For Mains Appliances; The Basics Of A/D & D/A Conversion. October 1991: A Talking Voltmeter For Your PC, Pt.1; SteamSound Simulator For Model Railways Mk.II; Magnetic Field Strength Meter; Digital Altimeter For Gliders, Pt.2; Military Applications Of R/C Aircraft. January 1994: 3A 40V Variable Power Supply; Solar Panel Switching Regulator; Printer Status Indicator; Mini Drill Speed Controller; Stepper Motor Controller; Active Filter Design; Engine Management, Pt.4. February 1994:90-Second Message Recorder; 12-240VAC 200W Inverter; 0.5W Audio Amplifier; 3A 40V Adjustable Power Supply; Engine Management, Pt.5; Airbags In Cars – How They Work. March 1994: Intelligent IR Remote Controller; 50W (LM3876) Audio Amplifier Module; Level Crossing Detector For Model Railways; Voice Activated Switch For FM Microphones; Engine Management, Pt.6. April 1994: Sound & Lights For Model Railway Level Crossings; Dual Supply Voltage Regulator; Universal Stereo Preamplifier; Digital Water Tank Gauge; Engine Management, Pt.7. May 1994: Fast Charger For Nicad Batteries; Induction Balance Metal Locator; Multi-Channel Infrared Remote Control; Dual Electronic Dice; Simple Servo Driver Circuits; Engine Management, Pt.8. June 1994: A Coolant Level Alarm For Your Car; 80-Metre AM/CW Transmitter For Amateurs; Converting Phono Inputs To Line Inputs; PC-Based Nicad Battery Monitor; Engine Management, Pt.9. November 1995: Mixture Display For Fuel Injected Cars; CB Trans­verter For The 80M Amateur Band, Pt.1; PIR Movement Detector. December 1995: Engine Immobiliser; 5-Band Equaliser; CB Transverter For The 80M Amateur Band, Pt.2; Subwoofer Controller; Knock Sensing In Cars; Index To Volume 8. 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;. August 1996: Introduction to IGBTs; Electronic Starter For Fluores­cent Lamps; VGA Oscilloscope, Pt.2; 350W Amplifier Module; Masthead Amplifier For TV & FM; Cathode Ray Oscilloscopes, Pt.4. September 1996: VGA Oscilloscope, Pt.3; IR Stereo Headphone Link, Pt.1; High Quality PA Loudspeaker; 3-Band HF Amateur Radio Receiver; Cathode Ray Oscilloscopes, Pt.5. 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; 600W DC-DC Converter For Car Hifi Systems, Pt.2. 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. March 1992: TV Transmitter For VHF VCRs; Thermostatic Switch For Car Radiator Fans; Valve Substitution In Vintage Radios. November 1994: Dry Cell Battery Rejuvenator; Novel Alphanumeric Clock; 80-M DSB Amateur Transmitter; 2-Cell Nicad Discharger. April 1992: IR Remote Control For Model Railroads; Differential Input Buffer For CROs; Aligning Vintage Radio Receivers, Pt.1. 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. ORDER FORM October 1995: 3-Way Loudspeaker System; Railpower Mk.2 Walkaround Throttle For Model Railways, Pt.2; Nicad Fast Charger. April 1996: 125W Audio Amplifier Module; Knock Indicator For Leaded Petrol Engines; Multi-Channel Radio Control Transmitter; Pt.3. December 1991: TV Transmitter For VCRs With UHF Modulators; IR Light Beam Relay; Colour TV Pattern Generator, Pt.2; Index To Vol.4. June 1992: Multi-Station Headset Intercom, Pt.1; Video Switcher For Camcorders & VCRs; IR Remote Control For Model Railroads, Pt.3; 15-Watt 12-240V Inverter; A Look At Hard Disk Drives. May 1995: Guitar Headphone Amplifier; FM Radio Trainer, Pt.2; Transistor/Mosfet Tester For DMMs; A 16-Channel Decoder For Radio Remote Control; Introduction To Satellite TV. July 1993: Single Chip Message Recorder; Light Beam Relay Extender; AM Radio Trainer, Pt.2; Quiz Game Adjudicator; Antenna Tuners – Why They Are Useful. July 1990: Digital Sine/Square Generator, Pt.1 (0-500kHz); Burglar Alarm Keypad & Combination Lock; Build A Simple Electronic Die; October 1990: The Dangers of PCBs; Low-Cost Siren For Burglar Alarms; Dimming Controls For The Discolight; Surfsound Simulator; DC Offset For DMMs; NE602 Converter Circuits. 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. 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. June 1990: Multi-Sector Home Burglar Alarm; Build A Low-Noise Universal Stereo Preamplifier; Load Protector For Power Supplies. September 1990: 3-Digit Counter Module; Simple Shortwave Converter For The 2-Metre Band; Taking Care Of Nicad Battery Packs. 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. June 1993: AM Radio Trainer, Pt.1; Remote Control For The Woofer Stopper; Digital Voltmeter For Cars. November 1993: High Efficiency Inverter For Fluorescent Tubes; Stereo Preamplifier With IR Remote Control, Pt.3; Siren Sound Generator; Engine Management, Pt.2; Experiments For Games Cards. August 1990: High Stability UHF Remote Transmitter; Universal Safety Timer For Mains Appliances (9 Minutes); Horace The Electronic Cricket; Digital Sine/Square Generator, Pt.2. 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. 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: How To Network Your PC; Control Panel For Multiple Smoke Alarms, Pt.1; Build A Pink Noise Source; Computer Controlled Dual Power Supply, Pt.1; Digi-Temp Monitors Eight Temperatures. February 1997: PC-Con­trolled Moving Message Display; Computer Controlled Dual Power Supply, Pt.2; Alert-A-Phone Loud Sounding Telephone Alarm; Control Panel For Multiple Smoke Alarms, Pt.2. March 1997: 175W PA Amplifier; Signalling & Lighting For Model Railways; Jumbo LED Clock; Cathode Ray Oscilloscopes, Pt.7. April 1997: Simple Timer With No ICs; Digital Voltmeter For Cars; Loudspeaker Protector For Stereo Amplifiers; Model Train Controller; A Look At Signal Tracing; Pt.1; Cathode Ray Oscilloscopes, Pt.8. January 1995: Sun Tracker For Solar Panels; Battery Saver For Torches; Dual Channel UHF Remote Control; Stereo Microphone Pre­amp­lifier. May 1997: Neon Tube Modulator For Light Systems; Traffic Lights For A Model Intersection; The Spacewriter – It Writes Messages In Thin Air; A Look At Signal Tracing; Pt.2; Cathode Ray Oscilloscopes, Pt.9. June 1997: PC-Controlled Thermometer/Thermostat; TV Pattern Please send the following back issues:________________________________________ Enclosed is my cheque/money order for $­______or please debit my:  Bankcard  Visa Card  Master Card Card No. Signature ___________________________ Card expiry date_____ /______ Name ______________________________ Phone No (___) ____________ PLEASE PRINT Street ______________________________________________________ Suburb/town _______________________________ Postcode ___________ 98  Silicon Chip 10% OF SUBSCR F TO IB OR IF Y ERS OU BUY 10 OR M ORE Note: prices include postage & packing Australia ............................... $A8.80 (incl. GST) Overseas (airmail) ..................................... $A10 Detach and mail to: Silicon Chip Publications, PO Box 139, Collaroy, NSW, Australia 2097. Or call (02) 9979 5644 & quote your credit card details or fax the details to (02) 9979 6503. Email: silchip<at>siliconchip.com.au siliconchip.com.au Generator, Pt.1; Audio/RF Signal Tracer; High-Current Speed Controller For 12V/24V Motors; Manual Control Circuit For Stepper Motors. August 2000: Theremin; Spinner (writes messages in “thin-air”); Proximity Switch; Structured Cabling For Computer Networks. 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. September 2000: Swimming Pool Alarm; 8-Channel PC Relay Board; Fuel Mixture Display For Cars, Pt.1; Protoboards – The Easy Way Into Electronics, Pt.1; Cybug The Solar Fly. October 1997: 5-Digit Tachometer; Central Locking For Your Car; PCControlled 6-Channel Voltmeter; 500W Audio Power Amplifier, Pt.3. October 2000: Guitar Jammer; Breath Tester; Wand-Mounted Inspection Camera; Subwoofer For Cars; Fuel Mixture Display, Pt.2. 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. 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. 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. 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. January 1998: 4-Channel 12VDC or 12VAC Lightshow, Pt.1; Command Control For Model Railways, Pt.1; Pan Controller For CCD Cameras. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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; A PC To Die For, Pt.1. December 2003: How To Receive Weather Satellite Images; SelfDiagnostics Plug For Cars; 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. February 1998: Multi-Purpose Fast Battery Charger, Pt.1; Telephone Exchange Simulator For Testing; Command Control System For Model Railways, Pt.2; Build Your Own 4-Channel Lightshow, Pt.2. April 1998: Automatic Garage Door Opener, Pt.1; 40V 8A Adjustable Power Supply, Pt.1; PC-Controlled 0-30kHz Sinewave Generator; Understanding Electric Lighting; Pt.6. May 1998: 3-LED Logic Probe; Garage Door Opener, Pt.2; Command Control System, Pt.4; 40V 8A Adjustable Power Supply, Pt.2. June 1998: Troubleshooting Your PC, Pt.2; Universal High Energy Ignition System; The Roadies’ Friend Cable Tester; Universal Stepper Motor Controller; Command Control For Model Railways, Pt.5. July 1998: Troubleshooting Your PC, Pt.3; 15W/Ch Class-A Audio Amplifier, Pt.1; Simple Charger For 6V & 12V SLA Batteries; Auto­ matic Semiconductor Analyser; Understanding Electric Lighting, Pt.8. August 1998: Troubleshooting Your PC, Pt.4; I/O Card With Data Logging; Beat Triggered Strobe; 15W/Ch Class-A Stereo Amplifier, Pt.2. 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. 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. 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. January 1999: High-Voltage Megohm Tester; A Look At The BASIC Stamp; Bargraph Ammeter For Cars; Keypad Engine Immobiliser. July 2001: The HeartMate Heart Rate Monitor; Do Not Disturb Tele­phone Timer; Pic-Toc – A Simple Alarm Clock; Fast Universal Battery Charger, Pt.2; A PC To Die For, Pt.2; Backing Up Your Email. August 2001: DI Box For Musicians; 200W Mosfet Amplifier Module; Headlight Reminder; 40MHz 6-Digit Frequency Counter Module; A PC To Die For, Pt.3; 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 Tube Modulator For Cars; Audio/Video Distribution Amplifier; Build A Short Message Recorder Player; Useful Tips For Your PC. December 2001: IR Transceiver For PCs; 100W/Ch Stereo Amplifier, Pt.2; Pardy Lights Colour Display; PIC Fun – Learning About Micros. March 1999: Build A Digital Anemometer; DIY PIC Programmer; Build An Audio Compressor; Low-Distortion Audio Signal Generator, Pt.2. 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. 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. 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. May 1999: The Line Dancer Robot; An X-Y Table With Stepper Motor Control, Pt.1; Three Electric Fence Testers; Carbon Monoxide Alarm. 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. 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. November 1999: Setting Up An Email Server; Speed Alarm For Cars, Pt.1; LED Christmas Tree; Intercom Station Expander; Foldback Loudspeaker System; Railpower Model Train Controller, Pt.2. December 1999: Solar Panel Regulator; PC Powerhouse (gives +12V, +9V, +6V & +5V rails); Fortune Finder Metal Locator; Speed Alarm For Cars, Pt.2; Railpower Model Train Controller, Pt.3; Index To Vol.12. January 2000: Spring Reverberation Module; An Audio-Video Test Generator; Parallel Port Interface Card; Telephone Off-Hook Indicator. February 2000: Multi-Sector Sprinkler Controller; A Digital Voltmeter For Your Car; Safety Switch Checker; Sine/Square Wave Oscillator. March 2000: Resurrecting An Old Computer; 100W Amplifier Module, Pt.1; Electronic Wind Vane With 16-LED Display; 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. siliconchip.com.au 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. June 2002: Lock Out The Bad Guys with A Firewall; Remote Volume Control For Stereo Amplifiers; The “Matchless” Metal Locator; Compact 0-80A Automotive Ammeter; Constant High-Current Source. July 2002: Telephone Headset Adaptor; Rolling Code 4-Channel UHF Remote Control; Remote Volume Control For The Ultra-LD Stereo Amplifier; Direct Conversion Receiver For Radio Amateurs, Pt.1. August 2002: Digital Instrumentation Software For PCs; Digital Storage Logic Probe; Digital Therm./Thermostat; Sound Card Interface For PC Test Instruments; Direct Conversion Receiver For Radio Amateurs. September 2002: 12V Fluorescent Lamp Inverter; 8-Channel Infrared Remote Control; 50-Watt DC Electronic Load; Spyware – An Update. October 2002: Speed Controller For Universal Motors; PC Parallel Port Wizard; Cable Tracer; AVR ISP Serial Programmer; 3D TV. November 2002: SuperCharger For NiCd/NiMH Batteries, Pt.1; Windows-Based EPROM Programmer, Pt.1; 4-Digit Crystal-Controlled Timing Module; Using Linux And An Old PC To Share An Optus Cable Modem, Pt.1. 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; Using Linux To Share An Optus Cable Modem, Pt.2. 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; Using Linux To Share An Optus Cable Modem, Pt.3. February 2003: PortaPal PA System, Pt.1; SC480 50W RMS Amplifier Module, Pt.2; Windows-Based EPROM Programmer, Pt.3; Using Linux To Share An Optus Cable Modem, Pt.4; 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 Direct Digital Synthesis Generator; 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. 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 For Beginners, Pt.1; Simple Supply Rail Monitor For PCs; Studio 350W Power Amplifier Module, Pt.2; Fantastic Human-Powered LED Torches; Shorted Turns Tester For Line Output Transformers; PICAXE-18X 4-Channel Datalogger, Pt.2. March 2004: PC Board Design For Beginners, 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 For Beginners, Pt.3; Loudspeaker Level Meter For Home Theatre Systems; Shut That Mutt (Electronic Dog Silencer); Smart 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. June 2004: Dr Video Mk.2 Video Stabiliser; Build An RFID Security Module; 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. 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. September 2004: Voice Over IP (VoIP) For Beginners; WiFry – Cooking Up 2.4GHz Antennas; Bed Wetting Alert; Build a Programmable Robot; Another CFL Inverter. 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: Unwired Wireless Broadband; 42V Car Electrical Systems; USB-Controlled Power Switch (Errata Dec. 2004); Charger For Deep-Cycle 12V Batteries, Pt.1; The Driveway Sentry; SMS Controller, Pt.2; PICAXE IR Remote Control. December 2004: Build A Windmill Generator, Pt.1; Schoolies 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. 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. 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. PLEASE NOTE: issues not listed have sold out. All other issues are in stock. We can supply photostat copies from sold-out issues for $8.80 per article (includes 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 April 2005  99 MARKET CENTRE Cash in your surplus gear. Advertise it here in Silicon Chip. CLASSIFIED ADVERTISING RATES Advertising rates for this page: Classified ads: $22.00 (incl. GST) for up to 20 words plus 66 cents for each additional word. Display ads: $36.00 (incl. GST) per column centimetre (max. 10cm). Closing date: five weeks prior to month of sale. To run your classified ad, print it clearly in the space below or on a separate sheet of paper, fill out the form & send it with your cheque or credit card details to: Silicon Chip Classifieds, PO Box 139, Collaroy, NSW 2097. Alternatively, fax the details to (02) 9979 6503 or send an email to silchip<at>siliconchip.com.au Taxation Invoice ABN 49 003 205 490 _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ Enclosed is my cheque/money order for $­__________ or please debit my  Bankcard    Visa Card    Master Card Card No. Signature­­­­­­­­­­­­__________________________ Card expiry date______/______ Name _____________________________________________________ Street _____________________________________________________ Suburb/town ___________________________ Postcode______________ Phone:_____________ Fax:_____________ Email:__________________ 100  Silicon Chip FOR SALE ELECTRONIC ENGINEERING CONSULTANTS: Electronic Hardware and Embedded Software for Industrial Control and Commercial Communications. www.furzy.com.au New: Labjack Ethernet/USB Data Acquisition Module features 14 16bit analog inputs, 23 digital I/O, 2 analog outputs and 2 high speed counter. Free Daqfactory software, Labview driver and ActiveX component. New – Netiom Ethernet and Web I/O monitor and control I/O on the web and generate alarm emails Temperature and humidity sensors Proximity and Photoelectric sensors N1500 universal process indicator. Displays thermocouple, RTD, 4-20mA and 0-5V readings UHF 433MHz and Infra-Red remote relay controller cards Serial and Parallel port relay controller cards Pump and Alarm Controller cards. MicroProgrammers for Atmel and PIC chips. DAS005 Parallel Port Data Acquisition Module features 8 12bit Analog inputs, 4 Digital I/Ps & 4 Digital O/Ps. Free windows software and source code. Pixel Programmable Controller with 4 analog inputs, 8 digital inputs and 8 relay outputs. Uses a 28X Picaxe. Programmed in basic or Flow chart. 2, 4 & 8 Relay Cards suitable for TTL and Open Collector Outputs DC, Stepper and Servo Motor controller kits Switch Mode and Linear Power Supplies and DC-DC converters. Full details and credit card ordering available at: www.oceancontrols. com.au RCS RADIO/DESIGN is at 41 Arlewis St, Chester Hill 2162, NSW Australia and has all the published PC boards from SC, EA, ETI, HE, AEM & others. Ph (02) 9738 0330. sales<at>rcsradio. com.au, www.rcsradio.com.au siliconchip.com.au ELECTRONIC DESIGN Want cost-effective, professional design expertise “on call”, without having to employ new staff? Use ours! 4D Systems have extensive experience in hardware & software design, from component through to entire project. We will take your ideas from concept to completion, on time and on budget. Digital, analog, software: whatever your requirements, 4D Systems can do it! 4D Systems (02) 9673 2228 0433 198 874 Select your microcontroller kit and get started... Fax a copy of From $295* RCM3400 Foam surrounds,voice coils,cones and more Original parts for Dynaudio,Tannoy and others Expert speaker repairs – 20 years experience Australian agents for products Trade welcome – email for your user ID Phone (03) 9647 7000 TAIG MACHINERY Micro Mini Lathes and Mills From $489.00 this ad and receive a • Prices exclude GST and delivery charges. www.dominion.net.au 4007 USB KITS: GPIB Interface, Thermostat Tester, LCD Module Interface, Stepper Motor Controller, PIO Interface, DTMF Transceiver, Thermometer, DDS HF Generator, Compass, 4 Channel Voltmeter, I/O Relay Card, USB via LabVIEW. Also available: Digital Oscilloscope, Temperature Loggers, VHF Receivers and USB ActiveX (and USBDOS.exe file) to control our kits from your own application. www.ar.com. au/~softmark SUPERBRIGHT LEDS, LED testers, nixie tubes and nixie clock kits. New 6-digit nixie clock/panel meter kit coming soon! Lots of other neat stuff, and always more items being added. www. ledsales.com.au WEATHER STATIONS: windspeed & direction, inside temperature, outside temperature & windchill. Records highs & lows with time and date as they occur. Optional rainfall and PC interface. Used by government departments, farmers, pilots and weather enthusiasts. Other models with barometric pressure, humidity, dew point, solar radiation, UV, leaf wetness, etc. Just phone, fax or write for our FREE catalog and price list. Eco Watch phone: (03) 9761 7040; fax: (03) • • • • • 6 Channels 10kHz frequency separation Size: 55 x 23 x 20mm Weight: 25gm Modular Construction Price: $A129.50 with crystal Electronics on your order! Tel: + 61 2 9906 6988 Fax: + 61 2 9906 7145 Mark22-SM Slimline Mini FM R/C Receiver speakerbits.com.au 5% discount Feature rich, compiler, editor & debugger with royalty free TCP/IP stack siliconchip.com.au New New New Stepper motors: 200 oz in $89.00, 330 oz in $110.00 Digital verniers: 150mm $55.00, 200mm $65.00 59 Gilmore Crescent (02) 6281 5660 Garran ACT 2605 0412269707 PO Box 580, Riverwood, NSW 2210. Ph/Fax (02) 9533 3517 email: youngbob<at>silvertone.com.au Website: www.silvertone.com.au Satellite TV Reception ELNEC IC PROGRAMMERS International satellite TV reception in your home is now affordable. Send for your free info pack containing equipment catalog, satellite lists, etc or call for appointment to view. We can display all satellites from 76.5° to 180°. Universal and specialised models High quality Realistic prices Large range of adaptors Free regular software updates Windows 95/98/Me/NT/2k/XP AV-COMM P/L, 24/9 Powells Rd, Brookvale, NSW 2100. Tel: 02 9939 4377 or 9939 4378. Fax: 9939 4376; www.avcomm.com.au PO Box 275, Wentworthville. 2145. Ph: 02 9896 7150 9761 7050; Unit 5, 17 Southfork Drive, Kilsyth, Vic. 3137. ABN 63 006 399 480. PCBs MADE, ONE OR MANY. Any format, hobbyists welcome. Sesame Electronics Phone (02) 9593 1025. sesame<at>sesame.com.au www.sesame.com.au S-Video . . . Video . . . Audio . . . VGA distribution amps, splitters, standards converters, tbc’s, switchers, cables, etc, & price list: www.questronix.com.au ImageCraft C Compilers: 32-bit Windows IDE and compiler. For AVR, 68HC­08, 68HC11, 68HC12, 68HC16. from $330.00 Atmel Flash CPU Programmer: Han- GRANTRONICS PTY LTD www.grantronics.com.au & MADE TO ORDER PCBs For more details: www.acetronics.com.au Phone (02) 9600 6832 email: acetronics<at>acetronics.com.au dles the 89Cx051, 89C5x, 89Sxx in both DIP and PLCC44 and some AVR’s, most 8-pin EEPROMS. Includes socket for serial ISP cable. $220, $11 p&p. SOIC adaptors: 20 pin $132.00, 14 pin $126.50, 8 pin $121.00. Full details on web site. Credit cards accepted. GRANTRONICS PTY LTD, PO Box 275, Wentworthville 2145. (02) 9896 7150 or http://www.grantronics.com.au continued on page 103 April 2005  101 THE AMATEUR SCIENTIST Two incredible CDs with over 1000 classic projects from the pages of Scientific American, covering every field of science... Arguably THE most IMPORTANT collection of scientific projects ever put together! This is version 2, 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. “A must for every science student, science teacher, science lab . . . or simply for those with an enquiring mind . . .” ONLY 49 $ 00 PLUS $7 Pack and Post within Australia (Overseas orders: please refer to Page 91 of this issue) 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 review in SILICON CHIP, October 2004. . . or read on line at www.siliconchip.com.au HERE’S HOW TO ORDER YOUR COPY: BY MAIL:# BY INTERNET:^ BY PHONE:* (02) 9979 5644 9-4 Mon-Fri BY FAX:# (02) 9979 6503 24 Hours 7 Days <at> BY EMAIL:# silchip<at>siliconchip.com.au 24 Hours 7 Days 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. siliconchip.com.au 24 Hours 7 Days ^ You will be prompted for required information There’s also a handy order form on page 91 of this issue (SILICON CHIP Bookshop pages). Exclusive in SILICON Australia to: CHIP www.siliconchip.com.au 102  Silicon Chip 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 39 stores in Australia and New Zealand. Our aggressive expansion programme has resulted in the need for dedicated individuals to join our team to assist us in achieving our goals. We pride ourselves on the technical knowledge of our staff. Do you think that the following statements describe you? Please put a tick in the boxes that do: Knowledge of electronics, particularly at component level. Assemble projects or kits yourself for car, computer, audio, etc. Have empathy with others who have the same interest as you. May have worked in some retail already (not obligatory). Have energy, enthusiasm and a personality that enjoys helping people. Appreciates an opportunity for future advancement. Have an eye for detail. Why not do something you love and get paid for it? Please write or email us with your details, along with your C.V. and any qualifications you may have. We pay a competitive salary, sales commissions and have great benefits like a liberal staff purchase policy. Advertising Index 4D Systems...........................35,101 Acetronics.................................. 1-1 Amateur Scientist CD (House)...102 Send to: Retail Operations Manager - Jaycar Electronics Pty Ltd P.O. Box 6424 Silverwater NSW 1811 Email: jobs<at>jaycar.com.au Altronics........................ loose insert Jaycar Electronics is an equal opportunity employer and actively promotes staff from within the organisation. Dick Smith Electronics........... 16-23 Av-Comm...................................101 Dominion Electronics............65,101 Eco Watch..................................101 Elexol...........................................47 Grantronics.................................101 Harbuch Electronics.....................57 Hy-Q International........................59 Instant PCBs..............................103 Jaycar ..................49-56,59,103,IFC PCB DESIGN Service/Project Development: Project design from your concept; PCB design – single & multilayer; Circuits professionally drawn; Instruction/Operation Manuals prepared; PIC software design/modification/programming; Prototypes constructed. Email: media.audio<at>optusnet.com.au Phone: 0414 356 409. KIT ASSEMBLY NEVILLE WALKER KIT ASSEMBLY & REPAIR: • Australia wide service • Small production runs • Specialist “one-off” applications Phone Neville Walker (07) 3857 2752 Email: flashdog<at>optusnet.com.au JED Microprocessors................5,59 Microgram Computers....................3 MicroZed Computers....................47 Newtek Instruments.......................7 Circuit Ideas Wanted Do you have a good circuit idea? If so, sketch it out, write a brief description of its operation & send it to us. Provided your idea is workable & original, we’ll publish it in Circuit Notebook & you’ll make some money. We pay up to $60 for a good circuit so send your idea to: Silicon Chip Publications, PO Box 139, Collaroy, NSW 2097. Nurve Networks...........................65 Ozitronics.....................................65 NewTek Instruments.....................81 Nurve Networks...........................95 Prime Electronics.........................87 Quest Electronics..................59,103 RCS Radio.................................100 RF Probes....................................83 Silicon Chip Binders................67,77 Silicon Chip Bookshop........... 92-93 SC Car Projects Book..................91 NOW AVAILABLE FROM Perf. Electronics For Cars....104,IBC Silicon Chip Subscriptions...........90 Silvertone Electronics................101 www.siliconchip.com.au Siomar Batteries..........................87 Speakerbits................................101 Taig Machinery...........................101 Telelink.........................................59 Project Reprints – Limited Back Issues –Limited One-Shots If you’re looking for a project from ELECTRONICS AUSTRALIA, you’ll find it at SILICON CHIP! We can now offer reprints of all projects which have appeared in Electronics Australia, EAT, Electronics Today, ETI or Radio, TV & Hobbies. First search the EA website indexes for the project you want and then call, fax or email us with the details and your credit card details. Reprint cost is $8.80 per article (ie, 2-part projects cost $17.60). SILICON CHIP subscribers receive a 10% discount. We also have limited numbers of EA back issues and special publications. Call for details! visit www.siliconchip.com.au or www.electronicsaustralia.com.au siliconchip.com.au VAF Australia ...........................OBC ____________________________ PC Boards Printed circuit boards for SILICON CHIP projects are made by: RCS Radio Pty Ltd. Phone (02) 9738 0330. Fax (02) 9738 0334. April 2005  103 From the publishers of The Lat SILICON s t n e t n o C UND TECH BACKGRO Intelligent turbo timer I SBN 095852294 - 4 TURBO BOOST & nitrous fuel controllers 9 780958 522946 $19.80 (inc GST) NZ $22.00 (inc GST) How engine management works We’ll let the contents speak for themselves: Not a reprint – new projects and articles not published before Learn how engine management works Build projects to control nitrous, fuel injection and turbo boost systems Switch devices on and off on the basis of signal frequency, temperature and voltage Build test instruments to check fuel injector duty cycle, fuel mixture and brake and coolant temperatures P L U S L O T S MORE 104  Silicon Chip t Managemen ng Engine stems work di an st er R 1: Und engine sy 6 CHAPTEhandle on how the various Getting a ement ine Manag anced Eng r ECU functions dv A : 2 R TE he 14 CHAP yond spark and fuel – ot Going be c Systems lled systems in a car er Electroni th O : 3 nically-contro R tro TE 20 CHAP rundown on the other elec A quick Systems pensive as Electronic ex odifying Carstems is not as difficult or M : 4 R TE electronic sy 26 CHAP Understa Systems ur car’s Modifying yo ink you might th n Modificatio Electronic right wires IY D : 5 R TE e 30 CHAP multimeter and finding th Using a ct Kits c circuits ronic Proje lding Elect successfully build electroni ui B : 6 R TE to basic skills 36 CHAP You only need a few , voltage er A Multimet – here’s how to measure eter TER 7: Using 40 CHAP make do without a multim can’t You resistance current and INSTRUMENTS Meter modes art Mixtureal time, see the operating TER 8: Sm 42 CHAP ur car’s fuel mixtures in re -load “lean-out” occurs if a high Track yo d be warned of the ECU an Cycle Meter devices o jector Duty cycles or use it to switch In : 9 R TE P ty 50 CHA monitor fuel injector du Digitally ads nt engine lo ometer off at differe igital Therm perature D to an incredible 1200°C m Te h ig H : re su TER 10 out, can mea mperature 58 CHAP or LED read D et te It uses an LC off at a pres vices on or can switch de SWITCHES AND TIMERS g rnal triggerin Auto Timer : Versatile er with lots of uses and exte 1 1 R TE P A le tim 66 CH se adjustab A multipurpo h – lots r the bonnet ltage Switc : Simple Vog the sensors already unde switching 2 1 R TE P A e in id 72 CH on and off us to nitrous ox es rol Switch devic and fan cont water-spray of uses from y up to ture Switch rk all the wa 3: Temperajustable design that can wo 1 R TE P A H ad 77 C ral-purpose A cheap gene C 5° 24 4 RS ICS FOR CA E ELECTRON PERFORMANC siliconchip.com.au S M test From CHIP off witch equency Syou switch devices on and TER 14: Fr 82 CHAP eap adjustable design lets This ch speed according to Timer ta Throttle on and off, based on how es TER 15: Del 86 CHAP tricky way of turning devic A really iving ally you’re dr enthusiastic ne anding Engi s – p.6 ONTROLLERS MODIFIERS & C Controller LCD Hand – p.105 r rrecto Speedo Co – p.129 r se Adjuste to reduce t : Digital Pul noids in your car – use it extra fuel in 6 1 R TE P A le an l d so ro lse nt 92 CH pu co e or th control of g assistance t Managemen Take eerin ge power st boost, chan r d Controlle Adjuster, Dig 7: LCD Hanprogram the Digital Pulse rcuits 1 R TE P A H r ci r to lle lle ro ro nt nt 105 C Co co t nic Boos is plug-in Use th t Electro Independen Adjuster and daptor d Injector A u need this 8: Peak-Hold fuel injectors? – if so, yolse Adjuster 1 R TE P A H Pu -hol l ak ta gi pe Di 108 C ve , er ha your car Cycle Met Does e Duty tor to use th roller simple adap c Boost Cont ni tro ec El t en nd pe de In or el Adjustered to adjust air/fuel rat 9: Digital Fu 1 be us R -loop TE P A th H r to at can ange closed 112 C ltage intercep or swaps and even ch vo t an illi br A inject or er et m allow air-flow acteristics running char t oject will ge o Corrector tio? – this pr R 20: Speedission or altered the diff ra TE P A H C 129 t the transm tely again Swapped ou speedo reading accura r nic st Controlle your electro ctronic Booost maps at the flick of le E t en nd depe rbo bo tween two tu PTER 21: In 134 CHAine being able to change be just that do u yo Imag ts is project le a switch – th troller even just to s Fuel Con el supply or R 22: Nitrouinjector for the nitrous fu TE P A H C 149 ntrol an extra Use it to co fan speeds vary pump or Timer rd you’ve gent Turbo atch how ha R 23: Intelliengine idle-down time to m TE P A H C 154 er set the This turbo tim been driving Engine Advanced t – p.14 Managemen ture Smart Mix Meter – p.42 Capacitor : Resistor & ENDUM 160 ADD Codes om Jaycar The Kits available fr and. See Ze Where To Buyoject described in this Abousoktralariae an d New al ery pr l over details. Kits for ev d dealers al for further s stores an ck covers ba e id Electronic ts ou front and the inside p.50 cle Meter – or Duty Cy Fuel Inject om.au siliconchip.c r t Controlle Turbo Boos – p.134 Turbo Intelligent 4 Timer – p.15 om.au siliconchip.c Order direct from SILICON CHIP Publications Price: Aust. $A22.50 (inc. GST & p&p); Overseas $A26.00 (inc. p&p via airmail). Silicon Chip Publications Pty Ltd, PO Box 139 Collaroy, NSW, Australia 2097. Phone (02) 9939 3295; Fax (02) 9939 2649. Email silchip<at>siliconchip.com.au siliconchip.com.au April 2005  105