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siliconchip.com.au June 2006  1 SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.jaycar.com.au Contents Vol.19, No.6; June 2006 SILICON CHIP www.siliconchip.com.au FEATURES    6 GM Allison’s Hybrid Drive Bus Innovative new diesel-hybrid electric system can dramatically improve fuel economy and reduce emissions by up to 90% – by Julian Edgar 13 New 6-Chip Ultra-Bright LED It’s brighter than a 20W halogen lamp and has applications ranging from workplace lighting to pocket video projectors, reading lights and car interiors 14 Television: The Elusive Goal; Pt.1 It’s now 50 years since the start of television in Australia. Here’s how it came about – by Kevin Poulter 78 Electric-Powered Model Aircraft; Pt.2 Converting the Cub to a brushless motor for a greatly improved result – by Bob Young PROJECTS TO BUILD 50 Years Of TV Broadcasting In Australia – Page 14. Pocket A/V Pattern Generator – Page 28. 28 Pocket A/V Test Pattern Generator Easy-to-build design generates nine different video test patterns and has left and right audio outputs as well – by Mick Gergos 38 Two-Way SPDIF/Toslink Digital Audio Converter Want to convert a Toslink digital audio optical signal into a coaxial SPDIF signal or vice versa? This low-cost unit converts digital audio bitstreams either way – by Jim Rowe 84 Build A 2.4GHz Wireless A/V Link It’s easy to build and is just the shot for sending A/V (audio/video) signals to a remote system – by Ross Tester 92 Starship “Enterprise” Door Sounder Simple circuit recreates the distinctive “ssshhhhhhh-thump” sound of the sliding doors opening or closing on the “Starship Enterprise” – by Jim Rowe SPECIAL COLUMNS 44 Circuit Notebook (1) PICAXE Drives Nokia LCD; (2) Improved PICAXE RGB LED Display; (3) Low-Coolant Alarm For EA-ED Falcons Two-Way SPDIF/Toslink Digital Audio Converter – Page 38. 48 Serviceman’s Log DOA – that’s “Dead On Arrival” – by the TV Serviceman 64 Salvage It! A high-current car battery charger for almost nothing – by Julian Edgar 98 Vintage Radio The Kriesler 41-29 “Trans-Mantel” – by Rodney Champness DEPARTMENTS   2   4 61 103 Publisher’s Letter Mailbag Product Showcase Order Form siliconchip.com.au 106 109 110 112 Ask Silicon Chip Notes & Errata Market Centre Ad Index 2.4GHz Wireless Audio/ Video Link – Page 84. June 2006  1 SILICON CHIP www.siliconchip.com.au Publisher & Editor-in-Chief Leo Simpson, B.Bus., FAICD Production Manager Greg Swain, B.Sc.(Hons.) Technical Editor Peter Smith Technical Staff John Clarke, B.E.(Elec.) Ross Tester Jim Rowe, B.A., B.Sc, VK2ZLO Reader Services Ann Jenkinson Advertising Enquiries Glyn Smith Phone (02) 9979 5644 Mobile 0431 792 293 glyn<at>siliconchip.com.au Regular Contributors Brendan Akhurst Rodney Champness, VK3UG Julian Edgar, Dip.T.(Sec.), B.Ed, Grad.Dip.Jnl Mike Sheriff, B.Sc, VK2YFK Stan Swan SILICON CHIP is published 12 times a year by Silicon Chip Publications Pty Ltd. ACN 003 205 490. ABN 49 003 205 490 All material copyright ©. No part of this publication may be reproduced without the written consent of the publisher. Printing: Hannanprint, Noble Park, Victoria. Distribution: Network Distribution Company. Subscription rates: $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 ISSN 1030-2662 * Recommended and maximum price only. 2  Silicon Chip Publisher’s Letter Mobile phone users have increased risk of brain damage As time goes on, there is more and more evidence that mobile phones do cause brain damage. In fact, the evidence of risk seems quite clear with people who are heavy users of mobile phones. For example, a recent Swedish study indicated a four-fold increase in the incidence of a benign brain tumour in people who had used a mobile phone for more than 10 years. And in Britain, another recent report has linked heavy use to non-malignant ear and brain tumours and concluded that most scientists had underestimated the risks. Meanwhile, scientists at Melbourne’s Swinburne University of Technology have found that radiation from mobile phone usage does affect brain function and may impair your ability to make snap decisions, such as when driving a car. Apparently, these effects are small but they are good enough for me and confirm a long-held suspicion of mine that mobile phones present a big risk to anyone who uses them a lot. In fact, it seems to me that many mobile phone users already exhibit evidence of brain damage; either that or they were morons to begin with. Yes I know that it is a prejudiced view but if you are forced to listen to the utterly banal mobile phone conversations that occur in banks, supermarkets and everywhere else, it places a serious question mark over the intelligence of the users. An even more serious question over mobile phone use concerns the high incidence of road accidents among young drivers. Apparently it is quite common for young drivers (and even not-so-young) to do text messaging while they are on the move! How utterly idiotic! It is bad enough that mobile phones are so widely used while driving, even if more people are now using them hands-free but to be attempting to read a small LCD screen and then thumb in text replies just beggars the imagination. Is this not evidence that these mobile phone users are utter nincompoops? Of course, you cannot legislate against idiotic behaviour but I find it truly amazing that many people are apparently so unthinking that they place themselves and other road users in serious jeopardy by drinking, taking drugs and now, by text messaging while driving. Maybe the brain damage caused by mobile phones is even more widespread than we thought! Seriously, mobile phones do present a risk of brain tumours and no-one should discount it because the tumours may be “benign”. That is a misnomer if ever there was one because an undetected benign brain tumour can kill just effectively as a malignant tumour. Consider also that whenever there is a report about possible brain damage from mobile phones, there is often a number of dissenting views which state that the tests have “yet to be replicated” or that there was some problem with the methodology or some other criticism. The same techniques were used to howl down reports about cigarettes and lung cancer. So how much evidence do you need? There is even evidence that mobile phone transmissions affect your brain function while you sleep! The message has to be: keep your mobile phone use to a sensible level. They are a wonderful convenience and vital in an emergency but when not needed, they should be switched off. Leo Simpson siliconchip.com.au Powerful enough to detect interest. The Navy’s fleet of ANZAC Frigates are equipped with the latest very long-range surveillance radar. Wade Barker Navy Electronic Technician When a piece of equipment fails it certainly is challenging, because there’s a requirement to get it up and running in the The power output of the ANZAC’s search radar equates to over 300 microwave ovens. shortest amount of time possible. Start on $25,400p.a. and earn over $46,500 p.a. after training. For your free Trade Careers CD ROM simply call 13 19 01, or visit www.defencejobs.gov.au APPRENTICESHIP SPECIFICATIONS NATIONAL QUALIFICATIONS GREAT PAY UNMATCHED BENEFITS PROMOTION OPPORTUNITIES NAVY TRADES Electronics Technician GPY&R MDFN0743/SC Marine Technician (Mechanical or Electrical) Aviation Technician - Aircraft Aviation Technician - Avionics If you’re good with all things electronic, the Navy opens up an exciting world of apprenticeship training unlike anything you’ll find anywhere else. As an Electronics Technician, you’ll be trained on sophisticated equipment including radar and sonar, communications and combat computers, as well as missiles and weapons systems. For more information on other Navy and Electronics trade careers, and to order your free CD ROM, call 13 19 01 or visit www.defencejobs.gov.au You’ll be paid a great wage while you train with a guaranteed job when you finish. Starting on $25,400p.a., you’ll earn over $46,500p.a. after training. You’ll also receive a $9,300p.a. seagoing allowance. You’ll enjoy all sorts of benefits like free medical and dental, subsidised meals and accommodation. siliconchip.com.au June 2006  3 Call 13 19 01 or visit www.defencejobs.gov.au MAILBAG Commercial killer triggered by station logo Regarding Max Maughan’s query about some sort of device that can detect the station logo and hit pause on the VCR, etc (page 5, April 2006), it did sound like a great idea. So good in fact that Elektor published a circuit for it in 2004. See this website: http://www.elektor-electronics.co.uk/Default.aspx?tabid=27&year=2004&month=1&art=51778&PN=On Matt Crump, via email. Comment: thanks to those other readers who sent in the same reference. Concern about passive DI box I have a concern regarding the passive DI box published in SILICON CHIP, May 2006. In the text on page 64 you state: “The resistor for the ring output also prevents the possibility of the signal from a stereo source being shorted to ground . . .” This is clearly not the case with the way that the circuit is drawn. The two ring connections are directly connected together and the resistors and transformer primary are in parallel with this link. There is no isolation between the ring connections of the input and through sockets; therefore a mono connector plugged into the through socket will still short the ring to ground. Additional isolation resistors would need to be provided between the two sockets to prevent shorting of stereo signals. This will reduce the signal level available from the through jack which may or may not be desirable depending on the application. Rodney Baker, Walkley Heights, SA. Comment: the resistors are included to provide mixing of the signal from stereo to mono. If a mono plug is inserted into the second socket then it will short the ring of a stereo plug that is in the other socket. This would also be the case in any DI box that has mono sockets. Typically, when a stereo plug is used, you would not be using the 4  Silicon Chip second socket or if you needed to you would use a stereo connection. If such a stereo socket was plugged into a standard DI box, the ring signal would be shorted to ground. This would not be the case in our DI box. In virtually all situations, the second socket is used when the signal goes both to the public address system via the DI box’s XLR output and to an amplifier via the 6.35mm jack connection. These signals would be mono and so cause no problem. Experiences with a Battery Zapper I have been following with interest your development of the Battery Zapper and would like to share my experiences with a commercial unit. I live on a farm that has 18 vehicles that need a battery for operation. Many of these vehicles are only used intermittently and battery maintenance has been a problem. After premature failures and a costly replacement program, all of the vehicles were modified to take standardsized batteries so that only several batteries are needed between all of the vehicles. The modifications even extended to the ride-on mower. When not in use, the batteries are shelved and connected to a float charger. However, premature failure was still a problem and a Megapulse brand unit was successfully used to extend the battery life by rotating the unit between the batteries while on the shelf. A visit to a scrapyard revealed a large quantity of batteries that appeared to be in good condition. Several batteries were purchased to determine if the Battery Zapper could rejuvenate them to a usable condition. From my experiences, the answer is yes and I have since been able to provide good batteries for all of the vehicles at a negligible cost. An interesting fact I have learnt is that high-quality batteries respond the best. Cheap batteries generally are a waste of time. As there is no price difference at the scrapyard, I make a point of carefully selecting prospective batteries by brand and by using a heavy-duty “battery load tester” to check for open cells. Back in the shed, following a week on the Battery Zapper, I have a very usable battery. I had read with interest of the original SILICON CHIP Battery Zapper (July 2005), however as I was satisfied with my methodology, I had no pressing desire to build one. However, after reading about the improved design of Battery Zapper (May 2006) and the ability to monitor what is happening, I have decided that I need to build at least one unit. Every farm should have one! Chris Ryan, via email. Easter egg helps remote repair They say that necessity is the mother of invention. A co-worker presented me with a problem: his remote which controls his entire hifi/TV system was working apart from the volume button. His dilemma was that a replacement was going to take almost two months to ship and his hifi had no external volume control, so he couldn’t use it until he got a new remote control. I tried cleaning the remote’s board and keys but the multimeter still showed very high resistance on the offending key’s rubber pad. The working keys had resistance of about 15kW-30kW, whereas this one had 1MW. I knew which keys were working by viewing the infrared LED via my mobile phone’s inbuilt camera. Being just after Easter, I had an Easter egg lying on my desk, so I peeled the foil off and glued it to the offending key and hey presto, a working remote! It’s not exactly hi-tech but sufficient to last two months. Trevor Nuridin, via email. siliconchip.com.au Hearing loss is a real disability Top Marks for bringing to our attention, and for your concern, about hearing loss in the Publisher’s Letter for the May 2006 issue. But to my mind you didn’t go quite far enough. To tell someone that “they may go deaf” has very little impact. Instead, they need to be told that: (1) You will soon be guessing what people say, even after they have said it several times. (2) Your children, grandchildren and others will think you are a bit simple because you don’t properly hear what they say. (3) You will have trouble with telephone conversations. (4) Conversations in a crowd will be almost impossible and you will say “yes” and “no” in what you hope are the right places, while Servicing a belt-drive turntable I recently repaired a Philips GA212 belt-drive turntable and I thought the process might be of interest. I originally bought it in about 1975 and had not used it for 10 years. I decided to digitise some of my LPs and built a small preamp for the magnetic pickup. However, when I switched on the turntable, it did not rotate. I removed the platter and found that the capstan whirred but the platter did not turn. The drive belt seemed to have had melted into black goo on the base plate of the turntable. Checking the internet, I found this was a typical problem. However the net also indicated that it is a very good turntable, so I thought it was worth trying to resurrect. I tried many solvents but in the end only paint thinners would shift the goo. Unfortunately the resultant (now much thinner) black goo then ran down into the suspension system which took a lot of cleaning to remove. It also took off some paint but that was no problem. Be warned! Take great care when applying thinners that none runs into the siliconchip.com.au you try to look intelligent. (5) Your family will be quite intolerant when you have the radio or television so loud. (6) When you go to the annual meeting of your favourite club or to a business meeting, you will not be able to understand what is being discussed and won’t be able to take part, for fear of making a fool of yourself. (7) You will have the inconvenience and discomfort of having to wear a hearing aid or maybe two, to survive in everyday life. (8) You will have to buy the said hearing aid(s), which could cost you more than your computer. (9) If you ever take an interest in “real” music or the theatre, you will not be able to enjoy it to the full. This is the reality of what hearing loss is all about! Clive Singleton, Wainuiomata, NZ. works or touches plastic. Use a cotton bud or cotton wool and squeeze out the excess thinners before applying so it does not run or drip. The goo was also wrapped around the capstan and this was very difficult to remove. It also stained the capstan’s brass so it is not a nice composition. I accidentally scratched the capstan while scrapping off the goo so I had to polish it while it was spinning, with fine wet-and-dry emery paper. I then had to buy a drive belt. I put a piece of wire around the belt path to measure the length and it was 555mm. WES Electronics had a 550 x 0.5 x 5mm belt for about $10. While this worked OK, it has proved to be a little loose and sometimes falls off the platter drive wheel. I shall buy a smaller belt which I hope will be tighter. The final results were quite good. I reassembled the whole drive system and it works well. Placing a fingernail gently against the side of the platter to simulate the small load of a pickup to the servo system is not a problem. The strobe markings on the platter showed hardly any change in speed. John Rich, via email. Atmel’s AVR, from JED in Australia JED has designed a range of single board computers and modules as a way of using the AVR without SMT board design The AVR570 module (above) is a way of using an ATmega128 CPU on a user base board without having to lay out the intricate, surface-mounted surrounds of the CPU, and then having to manufacture your board on an SMT robot line. Instead you simply layout a square for four 0.1” spaced socket strips and plug in our pre-tested module. The module has the crystal, resetter, AVR-ISP programming header (and an optional JTAG ICE pad), as well as programming signal switching. For a little extra, we load a DS1305 RTC, crystal and Li battery underneath, which uses SPI and port G. See JED’s www site for a datasheet. AVR573 Single Board Computer This board uses the AVR570 module and adds 20 An./Dig. inputs, 12 FET outputs, LCD/ Kbd, 2xRS232, 1xRS485, 1-Wire, power reg. etc. See www.jedmicro.com.au/avr.htm $330 PC-PROM Programmer This programmer plugs into a PC printer port and reads, writes and edits any 28 or 32-pin PROM. Comes with plug-pack, cable and software. Also available is a multi-PROM UV eraser with timer, and a 32/32 PLCC converter. JED Microprocessors Pty Ltd 173 Boronia Rd, Boronia, Victoria, 3155 Ph. 03 9762 3588, Fax 03 9762 5499 www.jedmicro.com.au June 2006  5 We drive hybrid drive . . . GM Alliso Hybrid D This diesel-hybrid electric system can improve bus fuel economy by up to 40% and reduce exhaust emissions by as much as 90%. With over 400 GM Allison hybrid buses already in service, the system is proving successful in the marketplace. We drove a GMAllison bus recently brought to Australia for evaluation by state governments. By JULIAN EDGAR W hen talk turns to improving fuel vehicle economy, two technologies are likely to enter the discussion: hybrid petrol/electric drivelines like that used in the Toyota Prius and high pressure common rail diesels fitted to vehicles from makers like Audi, Peugeot, and Mercedes. European manufacturers have long championed diesels, while Japanese company Toyota has an apparently unassailable lead in hybrids. Despite German automotive electronics powerhouse Bosch being a prime mover in the development of car electrics and despite Toyota building and selling diesel passenger cars, the obvious step of combining frugal diesel power with low emissions hybrid technology hasn’t yet occurred. Or has it? Coming in from left field is a completely new player – 6  Silicon Chip GM Allison. GM currently sells some ‘soft’ hybrids but it is their heavy vehicle transmission arm Allison that is the dark horse in hybrid technology development. Not only has Allison developed a high efficiency, patented, two-mode hybrid transmission but it is a selfcontained unit that can be bolted to a variety of different engines – including conventional diesels. Rather than being controlled by the engine management system, the Allison EP system controls the engine via a standard communications interface, allowing it to work with a range of engines. The Allison EP system is currently available in two configurations, both primarily suited to heavy vehicles that work in a stop/start environment such as urban buses and garbage trucks. However, GM and partners DaimlerChrysler and BMW will soon incorporate the technology siliconchip.com.au on’s Drive Bus in hybrid passenger cars, potentially providing some real competition for Toyota and Honda. So what do the heavy vehicle systems consist of and why has the technology implications for fuel-efficient passenger cars? System overview Two hybrid Allison drives are available. The EV40 has a rated input power from the engine of 209kW and 1235Nm of torque and a total short-term output power of 261kW. The EV50 can accept 246kW and 1420Nm and has a shortterm output of 298kW. Each system uses a transmission that combines three planetary gear-trains and two electric motor/generators. The drive system has a mass of 428kg and is 810mm long, 442mm wide and 312mmm high. In appearance it is very similar to Allison’s B400R transmission. The AC inducsiliconchip.com.au tion motor/generators mounted within the drive unit are each rated at 75kW. Synthetic transmission fluid is used to lubricate and cool the system. The battery pack uses NiMH cells and is designed and manufactured by Panasonic, the same company that makes the Prius high-voltage battery. However, Allison suggests that in this application, the robustness of the cells had to be increased so that they would cope with the almost continuous use of a commercial vehicle. In the Allison system the nominal battery pack voltage is 600V but system voltage can vary from 430-900V. The battery pack comprises six fan-cooled modules. In addition, when the bus air-conditioning system is running, a refrigerant feed can be drawn from it to cool an evaporator specific to the battery pack. The battery pack has a mass of 408kg and in bus applications, is mounted within a roof pod. June 2006  7 Fig.1: in a series hybrid system, the combustion engine drives a generator which charges the battery and/or drives the electric motor. [Allison] Fig.2: a parallel hybrid system differs from a series system in that either the engine or the battery/electric system can drive the wheels. [Allison] Fig.3: a series/parallel system has elements of both series and parallel systems. This diagram shows the schematic layout of an Electrically Variable Transmission (EVT) series/parallel hybrid. [Allison] The large dual power inverter module is built by General Motors. It contains two inverters that use IGBTs (Insulated Gate Bipolar Transistors) to convert the input/output of the motor/generators from DC to 160kW continuous 3-phase AC. The inverter has a mass of 91kg and is normally mounted at the rear of the bus adjacent to the engine. It shares its oil cooling with the transmission. Two Electronic Control Units are used. They are the same control unit used in Allison’s 1000/2000/2400 Series transmissions but with software optimised for their hybrid role. They have self-diagnostics and can be reprogrammed in service. The controllers each have a mass of 2.3kg. The controllers communicate with the diesel engine management system via the standard SAE J1939 protocol used in most diesel engine management systems. The primary information sent to the engine management system comprises torque and speed commands. Fig.4: this diagram shows the relationship between input, output, electric motor/generator and road speeds of the Allison hybrid drive system. Note that from 16 – 105km/h, the diesel motor’s speed doesn’t change and that over the full speed range of the vehicle, each motor/generator (ie, units A and B) stops rotating twice. [Allison] Fig.5: the highest mechanical efficiency of the transmission occurs at road speeds where either motor/generator is stationary (indicated here by stars). As can be seen, these occur at typical urban and highway bus speeds. Also note how the mode change allows the electric motor/generators to be “re-used” up and down in speed. [Allison] 8  Silicon Chip The drive system The breakthrough in the GM Allison hybrid system is siliconchip.com.au Fig.6: this diagram shows how pure mechanical drive occurs at 40-56km/h and 97-11km/h, the two most common speed ranges for buses working in urban and open road environments. Note also the high proportion of electric power used to accelerate from a standstill, the situation in which an electric motor produces maximum torque. [Allison] Fig.7: the components of the hybrid drive system are distributed around the vehicle. The compound split parallel drive replaces the conventional transmission and is located in front of the rear-mounted engine. The battery pack is placed under a pod on the roof, the dual power inverter module is placed next to the engine while one electronic control module is located near the front and one at the rear. [Allison] the compound split parallel drive unit. Like the Prius transmission, the Allison drive unit combines both series and parallel hybrid approaches. So what are series and parallel hybrid systems, then? In a series hybrid system, the combustion engine drives a generator that charges the battery and/or drives the electric motor. There is therefore no direct mechanical connection between the internal combustion engine and the wheels. Fig.1 shows this approach. A parallel hybrid system differs in that either the engine or the battery/electric system can drive the wheels (see Fig.2). As the name suggests, a series/parallel system has elements of both systems. This approach is characterised by the requirement to combine engine and electric power in a varying manner, depending on driving conditions. Fig.3 shows the schematic layout of an Electrically Variable Transmission (EVT) series/parallel hybrid. Allison sees the major benefits of the EVT series/parallel The drive system has a mass of 428kg and is 810mm long, 442mm wide and 312mmm high. In appearance it is very similar to Allison’s B400R transmission. The AC induction motor/generators mounted within the drive unit are each rated at 75kW. Synthetic transmission fluid is used to lubricate and cool the system. [Allison] siliconchip.com.au June 2006  9 Fig.8: a schematic cross-section of the hybrid drive system. It uses two AC induction motor/ generators, three planetary gear trains and two friction clutches. [Allison] drive system as: • Series Mode • Continuously variable transmission. • Very strong acceleration off the line because of the availability of a large amount of electric torque. • Parallel Mode • Lower cost as electric motor/generators and inverters are smaller. • Higher transmission efficiency. In addition, an EVT allows straightforward implementation of regeneration braking, gives strong acceleration assist and can be programmed for transient response. But all of these are also characteristics of the Prius Power Split Device, so what are the advantages of GM Allison’s patented drive system? The internal mechanical complexities of the Allison transmission will not be covered here; suffice to say that a torque damper input device works with three planetary gear-trains arranged so that various elements can be driven, braked or held still by the two electric motor/generators. (If you want to see how the internals work, see US patent 5931757, available from the search page at www.uspto.gov/patft/index.html). However, it is the relationship between inputs, output, electric motor/generator and road speeds which is the key to understanding the driveline benefits. Referring to Fig.4, the light blue line shows engine rpm, the red line the speed of the first motor/generator (Unit A), the green line the speed of the second motor/generator (Unit B), and the dark blue line shows the output shaft drive speed of the electric drive. All speeds are plotted versus road speed. Two aspects are immediately clear: first, that from 16 – 105km/h, the diesel motor’s speed doesn’t change and second, there is the expected fixed relationship between output shaft speed and road speed. However, over the full speed range of the vehicle, each motor generator stops rotating twice. An analysis of how the drive unit works can be divided into two operational modes. Mode 1 extends from zero up to about 40km/h. At speeds greater than this, the transmis10  Silicon Chip sion works in Mode 2. In Mode 1 the motor/generator B operates as a motor. Motor/generator A acts as a generator until about 25km/h and thereafter operates as a motor for the remainder of Mode 1. The change from acting as a generator to acting as a motor is seamlessly achieved by the relationship of the number of teeth on the various planetary gear subsets, which cause the speeds of the two motor/generators to reverse at various road speeds. Mode 1 can also be called ‘electric launch’, which is perhaps a more descriptive term! Motor/generator A, acting as a generator, is used to feed electric power to motor/generator B which can also call upon battery power. The change to Mode 2, is caused by the action of hydraulic clutches within the drive unit which simultaneously release certain planetary elements and clamp others. In Mode 2, motor/generator A continues to operate as a generator, a state it achieved late in Mode 1. However, by a road speed of about 50km/h, it reverts to acting again as a motor. In Mode 2 motor/generator B initially operates as a motor but when road speed passes 55km/h, it becomes a generator until road speed reaches about 100km/h, whereupon its speed has decreased to zero. Reverse gear is achieved by reversing the direction of motor/generator B. The battery pack uses NiMH cells, designed and manufactured by Panasonic. It has a nominal voltage of 600V, a mass of 408kg and in bus applications is mounted inside a roof pod. [Allison] siliconchip.com.au Driving the Bus We were able to drive the demonstration bus equipped with the EV40 system. The bus, a New Flyer built in Canada, was 12.2 metres long and had a mass of 17.7 tonnes gross vehicle weight. It used a Cummins ISL diesel with a maximum power output of 209kW. The drive was undertaken on a closed ‘county road’ circuit at the driver training facility at Mt Cotton, near Brisbane. From a passenger seat the bus felt largely like a welldriven conventional bus. Take-off from a standstill was smooth and torquey and the normal noises of a diesel bus could be heard. However, from behind the large steering wheel, the sensation was quite different. ‘Drive’ is selected via a pushbutton pad and with the air brakes released, the bus can be driven off. The torque provided by the low-speed mode of the transmission and the electric motors was immense. From the driver’s seat it could be more clearly felt that there was little torque converter flare – as would be experienced with a conventional auto transmission – and that only a small throttle movement was needed to get the large vehicle smoothly moving. But it was the regenerative braking that was the most impressive. When the throttle was released at 60 km/h, the bus smoothly but strongly decelerated, coming to almost a standstill before the regen switched itself off. In urban conditions, the conventional brakes would almost never need to be used. If required, the bus can decelerate at an astonishing 0.48G on regen alone. Apart from adapting to the fact that the driver need only lift his/her foot to heavily decelerate, little driver adaptation is needed. There are no ancillary dashboard gauges and so the driver is unaware of the power flows occurring within the system and the state of the HV battery charge. In fact, the demonstration bus didn’t even have a fuel gauge, a request made by US municipal authorities to prevent drivers coming back to the depot early with a perceived low fuel status. With the greater involvement of driving rather than being a passenger, some noises from the drive train could be heard – especially on regen, the sound of the motor/generators changed in pitch as their speed was constantly altered to provide the strong but smooth braking. A pitch change could also be occasionally heard when the transmission switched modes, although this was certainly nothing like the audible gear-change of a conventional automatic transmission bus. In short, the demonstration bus was extremely impressive to drive – powerful and smooth in both acceleration and braking. Julian Edgar has driven a lot of high-performance vehicles in his time but here it was a hybrid-powered bus at a closed country road circuit. It was smooth and powerful in off-the-line acceleration and had very strong regenerative braking. siliconchip.com.au June 2006  11 In this view, one of the two induction motor/generators can be seen at left. The transmission also incorporates multiple planetary gear trains. [GM] The road speed at which either of the motor/generators is stationary is termed a ‘mechanical point’ – at these road speeds the maximum mechanical efficiency occurs. As can be seen, the highest mechanical efficiencies in the drive system occur at typical urban and highway bus speeds. Fig.5 shows these four mechanical points of highest drive efficiency and also how the mode change allows the electric motor/generators to be “re-used” up and down in speed. Note that this is quite a simplified analysis. Allison engineers state that the system has 57 different operating modes. Results Buses equipped with the Allison hybrid drive system are currently being used in 25 US cities and have covered nearly 23 million kilometres. Allison claims reductions in emissions of particulates, hydrocarbons and carbon monoxide of up to 90% and oxides of nitrogen by 50%. The reduction in emissions is particularly successful in acceleration from a standstill, especially with a cold engine. The company also claims fuel economy improvements of up to 60% but admits that the improvement of buses actually in service ranges from 20 – 40%. In addition to the reductions in fuel consumption and emissions, brake pad wear is vastly reduced. Performance comparisons 12  Silicon Chip of two buses with similar mass and diesel engine power show that 0-97km/h (60 mph) times drop from about 67 seconds to 31 seconds. The cost of the drive system, including transmission, battery pack, inverter and control system, is about US$160,000. Buses using the system are able to be software-configured for bias towards performance or fuel economy. An electriconly mode can also be enabled, giving the buses a range of about 2km. However, even in this mode, the diesel engine continues to run to provide air conditioning, etc. Conclusion The patented compound split parallel drive unit has the potential to boast a greater efficiency than other hybrid transmissions and is already proving itself in bus applications. GM is to launch an SUV in late 2007 using a downsized version of the two-mode system and DaimlerChrysler is expected to follow suit with a hybrid luxury car. However, the very nature of stop-start urban bus duties lends itself particularly well to hybrid electric/diesel drivelines – expect to see the technology spreading worldwide. It’s not for nothing that GM Allison chose to send a full-size bus and engineering staff on a world trip… SC siliconchip.com.au New 6-chip LED is brighter than a 20W halogen lamp A new Ostar LED module from Osram has four or six series-connected chips in a hexagonal shape that allows for high packing densities. Producing 420 lumens at an operating current of 700mA, the six-chip version with an in-built lens is brighter than a 20W low-voltage halogen lamp. LEDs are therefore now suitable for use in more and more general lighting applications. For example, they can provide enough light now for a desk lamp or a pocket video projector such as the new models from Samsung and Toshiba. A specially developed hemispherical lens is part of the standard equipment. This lens improves the efficiency with which light is emitted without affecting the beam characteristics. Basic versions without lenses are available for customerspecific optics. Six-chip versions of these high-output LEDs produce At an operating current of 700 mA, the hexagonal OSTAR Lighting LED module with six chips and a lens provides 420 lumens, opening up even more applications in general lighting. Photo: Osram Looking for real performance? 160 PAGES 23 CHAPTE RS 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 mixtures and brake & temperature Mail order prices: Aust. $A22.50 (incl. GST & P&P); Overseas $A26.00 via airmail. Order by phoning (02) 9979 5644 & quoting your credit card number and expiry date. 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 420 lumens with a lens and 300 lumen without a lens, at an operating current of 700mA and an output of 15W. The four-chip version produces 280 lumens with the lens and 200 lumens without the lens, at an operating current of 700mA and an output of 10W. The OSTAR LED has such a high output thanks to its thinfilm technology which ensures that all the light produced internally is emitted at the top. The white light colour is constant from every viewing angle and comes from colour conversion based on the chip coating method. The yellow converter is located directly on the blue chip. With its high luminous intensity, the new OSTAR Lighting LED is ideal for a wide variety of applications in general lighting, including individual workplace lighting, reading lights and car interiors. It is also ideal as a rapid flashing light for effect lighting or stroboscopes because this mode of operation does not shorten its life. SC From the publishers of 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 June 2006  13 Television: the elusive goal History books record that television transmissions in Australia began at 7.00pm on September 16, 1956, with those now near-immortal words of the late Bruce Gyngell on TCN Channel 9, Sydney: “Good evening, ladies and gentlemen – and welcome to television.” But TV in Australia actually has a much longer history, going back some thirty plus years to the early 1920s . . . Part 1 – by Kevin Poulter 14  Silicon Chip siliconchip.com.au Australian television transmission, also using equipment similar to Baird’s. His ‘Radiovision’ experiments were conducted with Donald McDonald, transmitting from 3DB and 3UZ in Melbourne. This company developed early television and facsimile picture transmission. So television was looking very promising for Australia. The British General Electric Co announced in 1929 they were making 100,000 TV sets ‘soon’, with 5000 destined for Australia. Transmitters were installed in Melbourne’s Menzies Hotel. Two more were planned for Melbourne and one for Sydney. An article announced 3DB expected to have broadcasting apparatus installed ‘in a few days’. A few months later, Ernst Fisk of AWA announced picture transmissions would commence from radio stations 3LO Melbourne and 2FC Sydney as soon as business arrangements were completed. Much of this must have been undercapitalised competitive fanfaronade, as only experiments continued. The first long-distance TV reception in Australia was transmitted in 1932 by Marconi Wireless UK to AWA in Sydney, a distance of 21,000 kilometres. In 1934, T. M. Elliott and Dr. Val McDowell commenced experimental 30-line Baird system transmissions in Brisbane, sponsored by the Royal Society. Then in 1935, Tom Elliott made Australia’s first transmissions to a cathode ray tube. By 1938 he produced a 180-line television picture. John Logie Baird On the other side of the world, in the mid 1920s, Scottish inventor John Logie Baird was developing the Nipkow discshutter into a working low-resolution TV system. His early transmissions were across the Clyde in Scotland and then he moved to London to refine his system and to convince the BBC that Britain was ready for television. Remarkably, the cathode ray tube was known before 1900 and in 1925 Vladimir Zworykin even patented an all-electronic colour television system but Baird believed his electromechanical low-resolution system was the future of television. The BBC started broadcasting television on the Baird 30-line system in 1929. The first simultaneous sound and vision telecast was broadcast in 1930. Baird battled proponents of electronic TV for years, until in 1937 the BBC proposed a solution – a competitive demonstration of Baird’s 240-line system against the Marconi 405-line cathode ray type. Baird lost. A ustralian television began in the 1920s, when Tom Elliott experimented with electromechanical television similar to Baird’s system. The unlikely location for his futuristic lab was a convict-built windmill at Spring Hill, Brisbane. Wally Nichols, a 24-year old Sydney photographer, read all he could about Baird’s system and built a 16-line TV in 1928 but was forced to cease experiments due to the cost and time involved. By 1929, Gilbert Miles made the first siliconchip.com.au Inventors in Sydney, Melbourne and Brisbane all worked on Baird-style mechanical TV around 1927. By 1930, TV broadcasting was even declared ‘imminent’. This system was built by T. M. Elliott and Dr. Val McDowell. A large home-made spotlight is positioned behind the inventor’s chin, followed by a precision motor, then the Nipkow disc and sensor. The sign ‘Television Keep Clear’, kept the curious at bay. Just as well, as no electrical safety standards were followed. Note the hanging light with tin-can shade, apparently to spotlight the on-off switch without any light spilling into the darkened room. A reclaimed gramophone box houses some apparatus. (State Library of Queensland photo No. 22152 – www.aaa1.biz/sc.html) June 2006  15 An early AWA table-top receiver. Manufacturers made identical or near identical chassis, creating many variants by changing cabinet styles. The table-top was the base model, then with legs for a few guineas extra. Options included the same chassis with a larger speaker below (console) or wide-boy with speakers down the front side. An early AWA chassis with turret tuner on side. The first Australian TV picture tubes had very rounded screen and edges, so advertisers proclaimed it was ‘to see the image from a wide angle’. Later when screens were flat, the same was claimed, plus ‘for minimum reflections’. He had no choice but to redirect his creative energies to the cathode ray system. This he did quite successfully, though never making a fortune. Baird visited Australia in April 1938 to give an address on television to an international radio convention, organised by the Institute of Radio Engineers. Baird spent most of his career promoting television. He is therefore recognised in English textbooks as ‘the father of television’. Australia watched and impatiently waited as England and USA established TV services. World War 2 interrupted TV advocates, yet some politicians believed the world’s chaos would all be over in a year or two, so governments planned for an Australia in peacetime. A Parliamentary Standing Committee was set up in 1942 to advise the Government on establishing television in Australia’s capital cities. Debates flourished, with some claiming that ‘Australia could not afford television, due to a small population and vast distances’. Some politicians could see that TV was eagerly awaited; it was a potential government financial bonus and could be a great persuader plus a voice for government doctrine and edicts. The first AWA television receiver, made in 1948. Manufacturing AWA Picture Tubes, 1959. 16  Silicon Chip Chifley: commercial TV? No way! Prime Minister Ben Chifley was absolutely against commercial television, announcing the Australian Broadcasting Commission would solely broadcast TV. AWA had a long history of leading radio technology and in 1946 a small nucleus of engineers within the AWA Research laboratory was given the task of studying and investigating the basic principles and methods of television. Aided only by published technical literature and the patents available, the laboratory team set to work. Before they could start building a television receiver, a picture generator was needed to test it and before that, a special video oscilloscope to test the picture generator. siliconchip.com.au In February 1948, as a result of two years work, the first all-Australian electronic television picture appeared on a CRT (cathode ray tube) screen in the AWA research laboratories. A lecture and demonstration was given at the Institution of Radio Engineers in November 1948. The picture demonstrated was a geometrical test pattern similar to the pattern later transmitted by television stations many hours each week during downtimes – most useful for consumers and technicians tuning and adjusting receivers. By 1949, Americans were buying 100,000 TV sets a week, yet Australians could only read how great television and the entertainment was! The first camera – and an actual TV picture With the test picture, AWA had progressed as far as possible without the aid of a television camera. As Australia had chosen the 625-line system, it was not until 625-line camera equipment arrived from Marconi Co. of England in April 1949 that AWA was able to demonstrate an actual television picture. VIPs were invited to private screenings in the Research Laboratories. AWA’s first television demonstration outside the laboratory was a technical lecture on television picture quality, presented at the Institute of Radio Engineers’ Annual General Meeting on 18th October, 1949. The lecture was given by Mr. J. E. (Ernie) Benson, engineer in charge of television development, followed by a variety program featuring a cast of AWA works employees. The most ambitious demonstration of theatrical stage show television was made to over 500 people at the meeting of the Institute of Engineers, in the AWA Works Cafeteria on December 8, 1949. This was preceded by two short semi-technical talks on television by AWA chief of research W. W. (Wilf) Honner and J. E. Benson. The program was a 20-minute non-stop variety show, employing professional artists under the direction of Humphrey Bishop of radio station 2CH. During 1949 a number of public demon- A 1959 Admiral advertisement. strations were also presented by others, such as the Shellsponsored demonstration of PYE equipment in Castlereagh Street, Sydney. Eleven police had to keep tens of thousands of people moving. First medical TV: 1949! In June 1956, before regular broadcasts, this AWV pilot production run was demonstrated to ‘Radio TV and Hobbies’. The operator is using a tube in his mouth to control the flame, part of the process called ‘kinescope blowing’. siliconchip.com.au Television developers saw applications in science, medicine, industry, commerce and education. In 1949, one of the first non-entertainment uses of television was demonstrated. Dr W. D. Refshauge of the Women’s Hospital in Melbourne was organising a medical congress. He asked AWA if they could set up a closed-circuit television system for viewing by a large number of delegates. The enthusiasm of the medical authorities for television teaching surgical techniques resulted in further demonstrations in Sydney at King George V and Sydney Hospitals. Dr F. A. Maguire was present in 1947 at the WaldorfAstoria in New York when operations at the New York City Hospital were transmitted on a special wavelength to the hotel for 1500 members of the College of Surgeons. ‘The demonstrations that we have seen today (in Australia) are 100% better in every way,” he said. “The picture June 2006  17 they grew increasingly frustrated at the lack of real action. ‘Radio and Hobbies’ magazine published part 18 of their TV course in November 1950, followed in December 1950 by the wonder of colour TV and more of their TV course, over six pages. Domestic magazines also displayed TV stars and televisions. The public wondered how long it would be before Australians could also enjoy ‘Tee Vee’. The title ‘inventor of television’ is shared by many but if any one person deserves the credit, it is the RussianAmerican inventor, Vladimir Zworykin who developed the cathode-ray tube system. He visited Australia in 1951 and demonstrated a television only 20 inches Betty Cuthbert winning in the 100 metres in the 1956 Melbourne Olympics. On square, predicting managers could soon each side of the finish 10 judges watch intently in a tiered stand, plus others on the ground – about 25 judges! All the media in this area are employing 16mm supervise production-lines without leavcameras. Some would hastily process the film for interstate or international TV ing their desk. use, as video-recorders were not yet a viable proposition. Note the ‘media pit’. In 1953, public pressure resulted in a Royal Commission, set up to inquire is clear, vivid and to the smallest detail accurate, smooth into and report on television. Its recommendations set the with no interruptions and practically no flicker compared pattern for the future of Australian television – ABC and to those which I saw two years ago.’ commercial channels. The ABC channels (one in Sydney and one in Melbourne) were to be financed by licence fees PM says “TV would erode morals and family – a rather hefty five pounds per annum on receiving sets. unit” – and sentences us to commercials! Stations would be operated, as in radio, by technical staff When Chifley’s government fell in 1949, Robert Menzies of the Post Office. reversed the ‘Government monopoly’ policy, encouraging Commercial station licenses were to be limited to two private enterprise to set up commercial stations too. Despite channels in Sydney and two in Melbourne. Initially these strong public pressure for TV, Mr Menzies was in no hurry, licenses were to operate for three years but were later fearing it would erode morals and the family unit. extended to five years. The Commonwealth Government, Sir Ernest Fisk of AWA and most other public and commerhaving accepted the recommendations of the Royal Comcial interests strongly advocated for Australian television, mission, passed an amendment to the Broadcasting Act, knowing it would also generate new sales, opportunities and giving the Postmaster-General authority to set up television employment. AWA also knew a TV service in Australia was transmitters. only a matter of time. In order to keep abreast of overseas At last, in 1954, the Government called for tenders to developments in television and electronic engineering, supply 100kW ERP (Effective Radiated Power) television AWA sent a constant stream of engineers overseas, often staying up to a year with associated companies, like Radio Corporation of America and English Electric/ Marconi. Staff dispatched to the USA in 1949 investigated the manufacture of cathode ray tubes (kinescopes), plus production techniques and special-purpose valves for television receivers. In 1950, the Government’s Television Advisory Committee sent a group abroad to study the latest developments like programming and technical progress. They made many recommendations but the establishment of a television service was again postponed due to the economic crisis of 1951. Evidence of the hasty last-minute involvement of television in the 1956 Olympics can be seen in this photo. The ‘floor’ laid on scaffolding to the right is not fixed at all, with the camera tripod wheel amazingly close to falling off. Media and their assistants are squashed in every possible space, with some Meanwhile, the Australian public was resigned to standing. The monitors were quickly sourced – mostly PYE’s first essentially unaware of any progress, so domestic receiver, the P101, with protective panels on top. Frustrated public and a royal commission 18  Silicon Chip siliconchip.com.au transmitters in Sydney and Melbourne. AWA was awarded the contract to supply their Marconi-built 10kW transmitters (100kW with linear amplifer) at four of the six initial stations: commercial stations ATN-7 Sydney, HSV-7 Melbourne plus ABC stations ABN-2 Sydney and ABV-2 Melbourne. AWA continued further TV demonstrations, including televising the visit of Queen Elizabeth II to Australia in 1954 and the opening of Federal Parliament in Canberra, televised to the Canberra Hospital. As there was no outside broadcast (OB) van in Australia at the time, an Arnott’s Biscuit van was hastily converted in two days. These broadcasts were only viewed by a tiny minority. License allocation In order to allocate licenses for commercial stations, the Broadcasting Control Board held public sittings in January and February 1955, interview- PYE’s involvement in the ‘56 Olympics evolved at a rate of knots. At first ing applicants and representatives from they were supplying Channel 9 with cameras, then it was found the military interested parties like the arts. Much of communications equipment was too bulky for the games, so they became the the creative input was lost in the overall games communications supplier. Later it was found few of the 1200 press and radio men in the media room could see the scoreboard, so PYE General economic argument. Licenses were granted to compa- Manager Jack Carey (left) supplied a Lynx industrial camera and Enio Rayola nies already in communications, like (right) made a motor-drive to slowly scan across the scoreboard. The image was newspaper proprietors who showed converted to RF and shown on at least 15 PYE P101 receivers. they had sufficient financial backing for the first years of operation. The Government Royal Commission agreed to distance from Melbourne to USA meant that film would a cautious phased program for commercial and national be televised days out of date. This was a major factor in stations. Americans indicating no interest in paying for screening In spite of the rich success of commercial networks in sponsorship. the USA (revenues of US$500,000,000 in 1956), it was not Shell’s Australian Managing Director was charged with proven that Australian TV advertising sponsorship would marketing television rights. Britain had a new commercial be enough to fund many expensive transmitting stations. channel, Associated Rediffusion and in October 1955, the Television was also seen as a great medium for commerce, company agreed to 25,000 pounds for exclusive rights (extraining, production, health and education. In 1956, the cept Australia) and agreed to negotiate US sales, for about ES&A bank in Melbourne installed cameras in three of their $500,000. city buildings, so a customer could go to a special room Rediffusion’s negotiations with Westinghouse immediand see a ledger in another building – primitive compared ately failed. Then Rediffusion changed sides, representing to the computer and internet systems available to all now. the US networks. It should be noted Rediffusion held an interest in TCN Sydney and HSV Melbourne, so rather than 1956 Melbourne Olympic Games – almost representing the Olympic Organising Committee (OOC), without TV Rediffusion was soon intent on derailing negotiations. When Melbourne won the rights to stage the world’s largMelbourne’s OOC stood firm and was bombarded with a est event – the 1956 Olympic Games – some suggested this campaign against the sale of exclusive rights as ‘exploitawould be the ideal time for the introduction of television. tion’, with a ‘calamitous’ effect on film and television. NBC The event would have television cameras from many natold the Australian government that the Games were news tions present and millions more Australians could see the and therefore in the public domain. They also threatened to Olympics. If only they knew the trouble this would cause... stop American television coverage useful to Australia, like Commercial haggling for Olympic rights ensured telecastvisits by prominent politicians. ing was in great doubt weeks or even days before the event. The roof fell in when Rediffusion announced that the Local broadcasting was so uncertain that stations published US rights offer had been withdrawn and they no longer programs with no mention of the Olympics. In an era where were interested in the exclusive rights. Emotions ran high hundreds of millions of dollars are now paid for screening as worldwide networks demanded free access to the Olymrights, it’s hard to imagine that the networks told the Chairpics and even stated that anything less was undemocratic man of the Olympics Committee that they would only film – against the free-flow of information. if given free access to the Games. This is just a short synopsis of the press rights battle that In 1954, Associated Press in New York advised the waged on for years, right up until the line, threatening all siliconchip.com.au June 2006  19 Tivoli theatre, hosted by Eric Pearce and Danny Webb. By the Olympics, Melbourne TV was somewhat ready at the last second to cover this major international event. Ampol sponsored Channel 9 and their service stations would be converted into special tele-theatres to allow mass viewing. At Wesley College Melbourne, a Philips 50,000 volt television projector displayed a 13ft x 10ft image of ABV-2 and HSV-7 Olympic test transmissions. Up to 500 people at a time watched for a fee of five shillings, to benefit charity. You want two OB vans? As negotiations went right up until the last moment, Channel 9 airfreighted an extra camera from England to provide adequate coverage. Channel 9 only had As PYE’s involvement in the 1956 Olympics grew, a Communications and Television room was necessary, but most times it simply housed a fridge, one outside broadcast van parked outside specially brewed Olympics beer and a few chairs. A second similar room did the MCG but wanted to cover the swimhouse PYE Australian-made base stations. ming as well. So a VW Kombi was hastily converted into an OB van, utilising a wooden console and gear meant for the studios. media coverage of the Olympics. A link to the complete The system was linked by a microwave dish over the 35km story is in the credits page. ‘as the crow flies’ between the MCG and the Mt. Dandenong As the event opened, only a small number of independtransmitter. As channel 9 was not officially on air, their ent US, Japanese and Eastern Bloc stations screened the Olympic transmissions were test broadcasts. Melbourne Games. The BBC believed that those digging in Proof of the last-minute haste in televising the games can their heels were contributing to long-term media freedom, be seen in the photograph of TV cameras at the event. The so they read Olympic stories in front of still photographs. scaffold platform boards beneath the camera dolly are not Australian stations published full programming, without fixed at all. One wheel is perilously close to the edge of the Olympics. Television moguls were tough negotiators. 1956 became the year television would at last commence in Australia. Radio manufacturers like Astor and HMI (EMI) hastily converted space and expertise in their factories over to television. AWA was ready, adopting a similar design to the RCA Victor deluxe chassis with 22 valves, considered the Rolls Royce of Television at the time. Perhaps it was but AWA had always set high standards for radio performance and reliability, plus the residents in the hilly terrain of the Sydney basin benefited from superior performance. On July 13, 1956, TCN-9 (Sydney) began experimental transmissions, with HSV-7 (Melbourne) commencing tests just three days later. “Good evening ladies and gentlemen – and welcome to television” At 7 pm on September 16, 1956, Bruce Gyngell, resplendent in a dinner suit with a carnation, announced the opening of television in Australia. TCN-9 Sydney was transmitting from St. David’s Hall, Surry Hills, hastily rented as a studio, as the official studios at Willoughby weren’t ready. The cameras wobbled as they tracked over the uneven floorboards but for the first few months, St. David’s was the home of television, beamed to an estimated 3000 to 5000 sets. On October 27, TCN-9 became the first to commence regular transmission for three hours a night, then HSV7 Melbourne, ABN-2 Sydney, ABV-2 Melbourne and ATN-7 Sydney were all on-air by December 2nd. HSV-7 Melbourne opened with a variety show telecast from the 20  Silicon Chip This 17-inch set was home-made by F. Straford in 1957 from a kit of parts that cost approximately 125 pounds – about half the retail price. It was based on an AWA circuit, with the tuner and IF strip pre-aligned, to avoid costly test gear. The set has a light shade and safety-glass panel on the front, angled down to avoid reflections. siliconchip.com.au A 1957/58 Healing Manhattan with the American designer on screen. the raised stand. Packing is pushed out of the way. Beside the camera, domestic console TVs rather than monitors sit in the outdoor situation, with temporary weatherproofing panels added. In brilliant 29°C sunshine, 103,000 people watched in wonder as the masses of athletes from all nations entered the MCG for the opening of the Melbourne Olympic Games. At 3pm on Thursday November 22, 1956, H.R.H. the Duke of Edinburgh delivered the opening speech, followed by a thunderous 21-gun salute. A young Australian athlete, Ron Clarke, carried the blazing Olympic Torch to light the Olympic flame. A choir of 1200 voices sang Handel’s Halleluiah Chorus, then John Landy delivered the Olympic oath. This moment in history nearly didn’t happen, as he arrived at the rostrum to find . . . nothing! No promised typed sheet. Fortunately, he had transcribed the oath a few days before and reached into his pocket to save the day. In addition to TV cameras, many 16mm cine cameras filmed the spectacle for television and movie theatres. AWA/Marconi and PYE were the leading suppliers of studio cameras and equipment. Three VHF comms “networks” Angus Dawes and Ian Hyde of PYE Melbourne were given the exciting assignment of setting up and providing VHF telecommunications for the Olympic Games. The Army was to supply radio communications but only had siliconchip.com.au bulky HF equipment. So three PYE VHF networks were set up, one exclusively for the Duke of Edinburgh, who was bringing his Lagonda vehicle on the deck of the Royal Yacht ‘Gothic’. The Duke could communicate while driving around Melbourne from a PYE UK, VHF mobile to a base station sited at Xavier College Kew, then over a PMG landline to the ‘Gothic’ at her moorings. The second and third networks were for MCG officials and the marathon route. With a 60-foot mast and all telecommunications installed at the MCG, the PYE crew retired to the ‘PYE Communications and Television Workshop’. In reality, this room most times only housed chairs, plus specially-brewed Olympic beer in a large refrigerator. A similar room, the ‘Communication and Television Control Centre’ did house locally-built base stations. Soon it was evident the press couldn’t see the scoreboard from their otherwise excellent viewing position in the upper deck of the members stand. So a PYE Lynx industrial television camera driven by a panning mechanism filmed the scoreboard, for viewing by the press on dozens of television monitors. The monitors were the first locally assembled PYE televisions, model P101. There were many requests to install more P101 monitors, including the Managing Director of PYE asking for one in the second floor lounge of Phairs Hotel, the Indian team’s request for one in their Olympic Village room and another on board a visiting American destroyer. The PYE service van was a Vanguard, with a collection of official pass stickers almost covering the passenger windscreen. This gave them access to the MCG member’s car park and Olympic Village, in fact almost anywhere. When picking up a TV antenna from Homecrafts city store, they double-parked in peak hour. On their return, a parking inspector was carefully directing traffic around the Vanguard and not a ticket in sight! GTV-9 filmed the Olympics, with cameramen wearing grey dustcoats. Because PYE supplied all the television equipment to GTV-9, Ian Hyde was able to visit their outside broadcast van for the closing ceremony. The director, Norm Spencer contrived a great closing scene with one camera panning up the track to the Olympic flame with the Olympic flag superimposed over, then a fade to black. On completion, a voice came over the engineering link ‘Spencer, how many times have I told you to go to black before you close!’ Spence looked at the group and said ‘I went to black didn’t I?’ They all nodded. Spence grabbed the microphone and said ‘I went to ******g black’. In the rush and confusion to dismantle the communications and television systems, many PYE P101 televisions went missing. One sailed to America on the destroyer. Listener-In TV newspaper declared ‘Letters have poured into all three stations expressing wonder and admiration at the clarity and scope of the coverage. Some had been sceptical about TV until they saw the Olympic Games coverage and were now buying sets.’ Television had clearly arrived SC NEXT MONTH: TV Boom and Bust. As sales rocket, many sets destruct. June 2006  21 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 There are not many video test pattern generators on the market and the ones that are cost big dollars. This kit is a fraction of the cost of commercially available units, it’s portable and it has audio outputs as well! by Mick Gergos H ow often have you found yourself touching the end of an audio cable and listening for the 50Hz buzz, or shorting the ends of a video cable so that you can meter the other end to confirm its destination? How often have you needed a video source then reached for the VCR in the corner only to find that you don’t have a power lead or a tape with anything on it? No matter which facet of the electronic industry you work in, once you’ve experienced the convenience of this portable audio/video test signal generator, you’ll wonder how you ever lived without it. It is an essential piece of test gear for any techo’s toolkit. Whether you’re in CCTV, broadcast, TV/VCR repair, AV installation or just a devoted hobbyist, you’ll find that this will become one of the most useful and best value-formoney products in your arsenal. Features The Pocket AV Signal Generator literally is pocket-sized at just 123 x 80 x 25mm, including signal output sockets. An RCA socket provides the composite video, with nine fields (screens) to choose from, cycled through with the touch of a pushbutton. In addition, two more RCA sockets provide stereo channels of approximately 1.5kHz audio, with the right channel Colour Bars 28  Silicon Chip White clearly identifiable to assist in cable troubleshooting. And to make it completely portable, it operates from either a 9V battery or a 9V DC plugpack. Operation Operating the Pocket AV Signal Generator could not be easier. Simply insert a 9V battery for up to 10 hrs of operation or connect a 9V plugpack for continuous operation. Connect the RCA cables, flick the power switch, push the button, select your required test pattern and away you go. The Pocket AV Generator has a professional look and feel thanks to the deluxe Hammond case from Altronics. At the business end you’ll find the video output, along with the L & R audio outputs on low profile RCA sockets. You will also find the 9VDC socket (centre positive) and a toggle power switch, recessed to avoid accidental bumps. Further down the case you’ll find the pattern select push button and LED power indicator. With energy conservation in mind, the power indication LED flashes with an 8% duty cycle, which also serves to attract more attention. Using the video output The default test signal at power up is 100% saturated Green Red Blue siliconchip.com.au Specifications Composite video output Video output source impedance Frame rate Vertical synchronisation Horizontal synchronisation Composite synchronisation Chroma sub-carrier frequency Colour system Sub-carrier to horizontal phase Patterns (shown below) 1 V p-p (Pulse & Bar terminated into 75W) 75W 25Hz 50Hz 15.625kHz As per Australian standards 4.43361875MHz PAL Non-synchronous 100% Colour bars Flat Fields; white, red, green, blue & black Crosshatch 20 x 15; vertical line width 0.2mS Dot 20 x 15; dot width 0.2mS Pluge with 2T Pulse & bar 550mV p-p (-12dBm with RCH ID) <600W <450mW (<50mA <at> 9V) Audio output Audio output source impedance Power consumption colour bars. Other than confirming correct operation of the device or cable under test, colour bars are of limited use to the average user. Their primary role is in the television broadcast industry where they are used as a reference, aiding the interchange of recorded material and checking the quality of ‘video bearers’. Colour bars provide a reference for black, white and sync level, burst to chroma phase & colour saturation. Pressing the button cycles through the various patterns – eight in all. Five flat fields are available: white, green, red, blue & black. Excluding black, these rasters are used primarily for purity adjustments on colour TV sets or video monitors. The black output can be used for a variety of applications where a composite sync source is required. Be aware, however, that the subcarrier is not locked to the horizontal sync (no 8-field sequence). This makes the device unsuitable as a master genlock source in any live switched colour video system such as a linear edit suite, where the subcarrier-to-horizontal phase is critical. Next are the crosshatch and dot patterns, used to check and adjust raster centering, geometry and convergence. The lines and dots are perfectly centred, resulting Black siliconchip.com.au Crosshatch in an array of 20 x 15 perfect squares corresponding to a 4 x 3 aspect ratio. The final test pattern combines a couple of lesser known but very useful signals: Pluge and the 2T Pulse & Bar. The latter (2T Pulse & Bar) is the more visible signal which may be used for transient analysis of video processing systems while the Dot Pluge/2T Pulse & Bar June 2006  29 Fig.1: the generator is based around two ICs – a PIC16F84A-20P which sets up all the timing and waveforms; and an AD724JR which converts these to composite (PAL) video. Pluge is there simply for brightness adjustment. What’s a Pluge? If you wind up the brightness you will vaguely see a bar that appears lighter than black level, followed by a bar that is slightly darker than the black level. The idea is that you gradually adjust the brightness so that the lighter bar can barely be seen but the blacker one cannot be seen. This enables you to accurately set the brightness of your display, subject to the ambient lighting conditions. This is very handy for AV installations such as board rooms or home theatre systems where the preset brightness position doesn’t suit. If you view the video output on an oscilloscope equipped with TV field triggering, it is interesting to note that when changing patterns, the synchronisation is not interrupted. Also note that you can trigger to either field 1 or field 2. It is the inclusion 30  Silicon Chip of the serration pulses in the vertical block that makes this possible. Many of the cheaper test signal generators and even some PC video cards omit this important feature defined by Australian standards. Using the audio outputs There are two audio outputs; left and right. Both outputs are fixed in phase, frequency (1.5625kHz) and level (550mVp-p), corresponding to -12dBu. There is however, one important and useful difference: the right channel breaks briefly every few seconds to identify it from the left. This is extremely useful when looking for left right swaps in cabling or patching. The audio signals produced from the RCA outputs are not perfect sinewaves but they are not far from it – you will be able to clearly identify level and clipping with certainty. As a field technician, I felt that phase, level, channel identification, low cost and circuit simplicity took precedence over the ability to take distortion measurements. Circuit description Fig.1 shows the complete circuit diagram which employs only two integrated circuits, a PIC16F84A-20/P microprocessor and an AD724 RGB to PAL/NTSC encoder. The circuit is powered from a standard 9V alkaline battery or a 9V DC plugpack. Using typical 500mAh alkaline batteries, you should get around 10 hours of continuous operation and of course significantly longer intermittent use. The PC-mount DC socket is switched (break before make) so you need not worry about paralleling the power sources. Diode D1 provides reverse polarity protection while the 7805 (REG1) regulates the incoming supply to 5V. siliconchip.com.au Fig.2: here’s a representation of the Pocket AV Generator’s sync waveform, showing how the odd and even fields are time shifted with respect to one another. Note also the serration pulses during the vertical blanking interval – the start of the odd field is identified by an extra pulse. with serration pulses for field identification. At this point, all of the signals remain in the digital domain; ie, they are either 0V or 5V. The intelligence is contained within the timing relationship of the signals. RGB signal conditioning Note that the various sections of the PC board are laid out in a star pattern from the regulator to isolate the digital from the analog circuitry. Inductor L1 and associated capacitors provide decoupling for the PIC processor while inductor L2 and its capacitors decouple the rails to the PAL encoder IC. RGB, sync & audio generation The pre-programmed PIC16F84A20/P microprocessor generates all the signals required to produce the test patterns and audio and it monitors the pushbutton for a pattern change request on pin 13. Pins 17 & 18 provide a 1.5625kHz square waveform to the audio filters while pins 7, 8 & 6 provide the raw R, G & B pulses respectively. The pluge pattern requires some additional signals from pins 1 & 2. Lastly and most important is the composite synchronisation signal from pin 10. This signal contains all the horizontal and vertical synchronisation, along siliconchip.com.au A resistor divider network attenuates the raw RGB (red, green, blue) signals from the PIC to an appropriate level, while three 10pF capacitors provide noise filtering before the signals are coupled via 100nF capacitors to the inputs of the AD724 RGB to PAL/ NTSC encoder. The 10pF capacitors form a single pole filter with a -3dB point around 2.8MHz. This may seem a little low but keep in mind that the maximum output frequency of the PIC is only 2.5MHz. The 10pF capacitors are tied to the positive supply line for IC2. This ensures that the RGB signals are filtered with respect to the device for which they are intended (ie, the AD724). The additional signals being bled into the RGB input lines via the 330kW resistors are for the Pluge pattern and are only active during the time that this pattern is selected by the pushbutton. Scanning begins at the top of the picture and moves from left to right across the screen. The brightness of the electron beam varies in intensity as it scans. Upon encountering a horizontal sync pulse, the beam is blanked and quickly retraces to the left side of the screen before scanning the next line. The beam scans 312.5 lines before encountering a vertical sync pulse, which once again blanks the beam and retraces, this time to the top of the screen ready for the beginning of the next field. To interlace the two fields, the second field must be shifted down slightly with respect to the first. This is done by offsetting the horizontal lines with respect to the vertical sync pulse as shown in Fig.2. Note the serration pulses during the vertical interval. These assist the TV’s horizontal oscillator to maintain lock during the vertical interval and also provide a means of identifying each field. The inner workings of the AD724 are typical of most PAL encoders. We’ll briefly touch on the basics of PAL encoding without fully analysing the PAL encoding Before discussing any PAL theory we should review the basics of television. A standard Australian television picture is made up of 625 horizontal lines that are refreshed 25 times per second. To avoid flicker of the picture, the 625 lines are divided into two interlaced fields consisting of 312.5 lines each, effectively doubling the refresh rate. The frequency of the vertical sync is therefore 50Hz (20ms) and the horizontal sync 15,625Hz (64ms). The A-V generator can be powered by an external 9V DC plugpack or by its own internal 9V battery, as seen here. June 2006  31 Fig.3 (left): raw RGB information from the PIC is fed into the AD724, where it’s weighted and added together. Horizontal and vertical sync pulses are added to the mixture to create the luminance (Y) signal. Fig.4 (below): the two colour difference signals (R-Y & B-Y) are modulated with a reference frequency and a burst reference signal added, after which they’re added together to form the ‘chrominance’ signal. Following a short delay, luminace is added to chrominance to create the final PAL composite signal. gizzards of the AD724. Initially, the RGB signals are attenuated according to their weightings then summed to make the luminance or Y signal. This Y signal is then subtracted from the R and B signals to produce the R-Y and B-Y signals respectively. Sync is then added to the luminance signal to create the monochrome video signal (often still referred to as the Y signal). The monochrome video component contains all the detail, brightness and contrast information within the picture. In addition, the luminance signal carries the horizontal and vertical synchronisation pulses. The R-Y and B-Y signals are often referred to as the colour difference components and contain only the colour information. Note that when there is no colour information in the picture, the R-Y and B-Y signals remain at 0V. The diagram of Fig.3 illustrates the process. Once the Y, R-Y and B-Y signals have been produced we quadrature modulate the R-Y and B-Y signals along with the ‘burst reference signal’ onto a 4.43361875MHz suppressed carrier to make what is called the ‘chrominance signal’. Finally the luminance signal is delayed to compensate for the delays caused by chrominance processing. Together, the luminance and chrominance signals are referred to as ‘S-video’ or separate video signals. Adding the luminance and chrominance signals produces the complete PAL composite video signal (see Fig.4). The term ‘composite’ refers to a collection of signals, in this case the red, green, blue, horizontal sync, vertical sync and serration pulses. One feature not shown in the dia32  Silicon Chip grams is the PAL (phase alternate line) switching. In summary, the phase of the carrier fed to the R-Y modulator is inverted every second line. At the receiver, any phase errors caused by the transmission path are cancelled out by vectorial subtraction with the previous line via a one-line delay. The process of PAL encoding may seem a little complicated however there were several prerequisites when it was initially proposed. Firstly, it had to be backward compatible with B&W television sets, which is why the RGB matrix produces the Y signal. Secondly, the frequency for the colour sub-carrier had to carefully chosen so it did not produce a significant visual effect in the picture. Thirdly, it had to be better than the American (NTSC) system, thus PAL switching was implemented, eliminating the need for tint control at the receiver. The AD724 can accept separate horizontal and vertical sync but in this case we tie the VSYNC input low and feed a composite sync source to pin 16, via the 1kW resistor from pin 10 of the PIC. Crystal X2 and trimmer VC1 form an adjustable, parallel resonant circuit that is the reference for the internal 4FSC clocks. The AD724 quadruples the reference frequency at pin 3 to 4FSC (4 times the subcarrier frequency). This assists the internal generation of the required phase shifts for the R-Y balanced modulator; ie, 90° and 270°. The 2Vp-p composite video output appears at pin 10 of IC2 and is fed via a 75W resistor which thereby sets the source impedance. Thus when used with a good quality 75W cable such as RG59 and a suitable termination, considerable distances can be achieved without serious degradation of the signal. A 220mF capacitor couples the signal to the video output connector. Capacitive coupling the video results in some distortion; however this is not considered a problem as the black level clamps (otherwise known as DC restoration) at the TV set or monitor take care of this. Audio signal conditioning The audio circuitry is a very siliconchip.com.au straightforward arrangement that was chosen for its simplicity and cost effectiveness. Two square waves generated by the microprocessor at 1/10th of the line rate (ie, 1.5625kHz) pass through the low pass filters, each consisting of three 1.5kW resistors and three 100nF capacitors. These 3-pole low pass filters attenuate the signal to an appropriate level while removing the upper harmonics to give the signal a more sinewave characteristic. Polyester capacitors with a 5% tolerance have been used to eliminate the need for level adjustments. The audio signals are buffered via emitter-follower output stages consisting of transistors Q1 & Q2 then coupled to the RCA connectors via 220mF capacitors. The 100nF capacitors connected between base and collector of Q1 & Q2 serve to increase the stability of the output stages and reduce the risk of oscillation. Breaking the right channel audio for identification purposes is achieved by increasing the frequency of the right channel square wave to 7.8125 kHz for the period of the break. This results in the signal being severely attenuated by the 3-pole low pass filters. This technique ensures that the average DC level is unchanged at the output, thus eliminating any thuds that would be heard if the output from the microprocessor switched off altogether. Construction All components for the Pocket AV Test Signal Generator mount directly on the PC board so there is no external wiring, with the exception of the 9V battery snap. Case preparation Before starting construction, use the PC board as a template to drill the hole for the “pattern select” pushbutton switch. Place the PC board copper side up into the top half of the case then mark the exact point for the button using a 1mm drill in a pin-vice. Gradually increase the size of the hole using bigger drills until you get to 8.5mm. You can also mark out the position of the power LED by marking the case with the position of the two legs of the LED. Next, centre your pin-vice between these two marks and gradually drill out to 3mm. Using the template as a guide, you should now drill out A pinvice is one of the handiest tools you can have in your workshop – here one is being used with a 1mm drill bit to accurately mark the two hole positions in the case lid. And here’s what you’re trying to achieve: the pushbutton switch (left) advances the pattern while the LED blinks to show the device is on. Fig.5: component overlays for both sides of the PC board. Start with the copper side and IC2, the AD724JR surface-mount chip, then turn the board over and mount the other components in the conventional way. The 9V battery snap can go on at the end, otherwise it could get in the way. Note that much of the testing is done before you insert and solder IC1. Compare these diagrams with the completed project photo overleaf. siliconchip.com.au June 2006  33 If you don’t have a suitable hand drill, simply use a power drill that is not plugged in. The chuck can still be easily turned, giving you greater control of the cut. Start with smaller holes, then gradually work your way up to the required size. PC board construction The AD724JR surface-mount IC (ringed here in red) mounts on the copper side of the PC board. You’ll need a fine iron and a steady hand – and for heaven’s sake, don’t put it in the wrong way around. The battery snap wires also solder to this side of the PC board after passing through the tension hole at the opposite end. the holes in the front panel. There are three 9 mm holes for the low-profile RCA connectors, a 7mm hole for the DC socket and a 2.5 x 6.5mm elongated hole for the recessed power switch. To reduce the risk of breakage, the holes should be drilled out by hand. You’ll find that the front panel will be ripped from your clutches if using a power drill or drill press. Check to make sure that the PC board fits in to the case. If it needs filing, it’s easier to do it now than later. It’s also a good chance to check your drilling. It is worthwhile temporarily fitting the RCA sockets to make sure that the plastic posts overhang the PC board. If not, file the PC board to that they just overhang. The sockets should be firm to insert into the PC board. This assists the solder joints of the RCA socket to cope with the stress of plug insertion and removal. Contrary to our normal practice, which is to leave semicondutors until last, we are going to start by soldering in the surface-mount IC2 (AD724JR) which is placed on the rear (copper side) of the PC board. You should be at least somewhat competent at surface mount soldering to do this; fortunately the pitch on this IC is not too fine. Use a fine tipped iron – if you are having trouble, try using a good quality flux to assist with the flow. Be careful not to overheat the device and be sure to get it the right way around! Pin 1 is clearly marked on the PC board for your convenience. Begin loading the through-hole components starting with the reverse Here’s what the composite output from the generator looks like when the colour bar pattern is selected. Compare this to the diagram in Fig.4. Note the spot-on signal amplitude of 1Vp-p. 34  Silicon Chip protection diode D1. Keep the cut leads from D1 and use them for TP_GND and the earth link for IC2. Solder in the resistors noting the orientation of the uprights. Try to copy the prototype in the photos. Use a the resistor colour code table and/or a digital multimeter if there is any doubt. Now solder in the non-polarised capacitors and inductors. That done, mount some of the miscellaneous components such as the IC socket, Q1, Q2, VC1, X1 and X2 making sure that X2 is a low profile device. Mount the tantalum capacitors noting the polarity and laying them over as per the photograph. Special care should be taken to ensure that the electrolytic capacitors are pressed firmly against the PC board (see photo). Failing this, the top of the case will not go on properly. REG1 needs to be bolted to the PC board as it provides a link between earths. Be sure to use a shake-proof washer with the nut. Mount the remaining hardware such as the power switch, DC socket and low-profile RCA sockets, making sure that the plastic posts on the RCA sockets overhang the front edge of the PC board as discussed earlier. Mounting the pushbutton switch seems straightforward; however make sure that the orientation is correct. If it is wrong, you will find that the pattern changes continuously. There are four pins on this switch but only two poles! The push button switch should be mounted flush against the PC board. By sheer fluke, The serration pulses are clearly visible in the output, with the even field shown here in the upper trace, odd field in the lower. siliconchip.com.au this puts the top of the switch exactly flush with the face of the Hammond case. The last PC board-mounted component is the power LED. Again, note the orientation as this component is polarised. The height should be set the same as that of the pushbutton switch. Finally, feed the cables of the 9V battery snap through the hole in the lower left corner of the PC board. This will remove any stresses on the solder joints of the 9V battery snap. Solder the ends to the pads provided on the copper side of the board, noting the polarity. Once again this is clearly marked on the PC board for your convenience. You should now have an attractive package that fits neatly into the case, ready for setup. The last component to fit is the pre-programmed microprocessor PIC16F84A20P but it is best to wait until after the setup and test procedures before inserting this component. Expect a few thousand ohms. If all is well, connect the battery (with IC1 still removed), switch on the power and immediately check the voltage at pin 3 of REG1. It should be very close to 5V; if not check the path from the 9V snap, through the DC socket and diode D1 to the input of IC3. If you’re happy that REG1 is Setup and test First things first: check and recheck the orientation of IC2 and all other polarised components, including the electrolytic capacitors (don’t forget the tantalums!). Make sure that REG1 is bolted down. Check resistor values and placement. When you are satisfied that all is well and there are no solder bridges, do a quick ohms check between pin 3 of REG1 and TP GND. The reading may take a while to settle due to the decoupling capacitors however there shouldn’t be any shorts to TP GND. regulating, check the voltage between ground (battery snap black wire) and both pin 14 of IC1’s socket and pin 14 of IC2. Both should be 5V. If you’re satisfied that none of the components are operating in their Chernobyl mode, disconnect power, insert the pre-programmed microprocessor ensuring correct orientation and re-power the device. Close-up of a horizontal sync pulse, highlighting the 10-cycle colour burst signal which follows it. The onscreen measurement shows that the burst occurs 5.6ms after the falling edge of the sync pulse, as required by the PAL standard. siliconchip.com.au You should immediately notice the illumination of the power LED, shortly followed by an intermittent flashing. This means the processor is functioning. If this does not happen, remove power and start checking component orientation again. Unfortunately, if you are experiencing difficulties, you’ll need a ’scope to track down the fault. Check that the This shot highlights the break that is inserted in the audio tone of the right channel. The 7.8125kHz signal is attenuated nicely by the RC filter, with about 20mVp-p evident here. Recovery to the normal frequency (nominally 1.5625kHz, here measured at 1.402kHz) is clean and ‘popless’. June 2006  35 RGB signals at the input to IC2 are about 700-750mV p-p. Check the SYNC signal is getting to pin 16 of IC2. Also check for oscillation of X2. Use the theory of operation described earlier as a guide to finding the source of your fault. If all appears well, connect the video output to the video input of a television. If you are not immediately rewarded with colour bars, try adjusting VC1 with a suitable non-metallic tweaker. If you find that the generator is cycling through patterns continuously, check the orientation of the pushbutton switch. Check the audio outputs and note that the tone is present on both channels but breaks on the right channel intermittently. If you want to accurately set VC1 you will need access to a spectrum analyser. For the rest of us, simply adjust VC1 so that you get colour lock every time you flick the power switch. Try it on various TVs as some sets will have a tighter capture window than others. Scope shots Finally, you should check the video levels on an oscilloscope or waveform monitor. The waveforms shown here were captured using a short length of RG59 terminated into a T-piece at the input of the oscilloscope, as seen below. Parts list – Pocket AV Generator 1 PC board, 63 x 77mm, coded AV Sig Gen 1 deluxe Hammond case with 9V battery snap 1 pushbutton switch, DPST, PC-mount (S1) 1 miniature toggle switch, SPDT, PC-mount (S2) 3 low-profile RCA sockets, PC-mount (CON1-3) 1 DC socket, PC-mount (CON4) 4 x M2.5 self-tapping screws 1 6mm M3 screw, nut and shakeproof washer Semiconductors 1 PIC 16F84A-20/P, pre-programmed (IC1) 1 AD724JR PAL encoder (IC2) [Alternate AD722] 1 78L05 regulator (REG1) 1 1N4004 diode (D1) 1 3mm LED (green) (LED1) 2 BC547 transistors (Q1, Q2) 1 20MHz 3-pin ceramic resonator (X1) 1 4.43361875MHz low-profile crystal (X2) Capacitors 3 220mF 25V electrolytic 3 47mF 10V tantalum 1 470nF polyester (code 474 or 470nF) 6 100nF polyester 63V 5% (code 104 or 100nF) 5 100nF monolithic (code 104 or 100nF) 1 10nF monolithic (code 103 or 10nF) 1 150pF ceramic (code 150 or 150p) 3 10pF ceramic (code 10 or 10p) 1 5-30pF variable capacitor (yellow) (VC1) Inductors 2 47mH inductors (L1, L2) Resistors (0.25W, 5%) 6 330kW 4 5.6kW 6 1.5kW If your level is not close to 1Vp-p or your TV is having trouble synchronising, it’s likely that you have some resistors in the wrong place. Measurement tips; White level should be 1V (±5%) with respect to sync tip. There are no adjustments for the video levels as they rely purely on the tight tolerances of the metal film resistors. • Use field triggering and time delay to capture one line of video. This will display the waveform more clearly as the non-synchronous SC-H phase and capacitively coupled video output make the signal appear noisy if viewed using line triggering. • Ensure that VC1 is set correctly as it can cause weird effects. SC 6 1kW 1 150W 1 75W Where from, how much A complete kit of parts (cat K-2725) will be available from Altronics Distributors retail stores in Perth, Sydney and Melbourne, from selected dealers and also via the Altronics online store at www. altronics.com.au, for $129.00 plus packing and postage. Firmware is not available separately, nor will it be altered to facilitate NTSC or on-screen text capabilities. Resistor Colour Codes o o o o o o No.   6   4   6 6   1   1 36  Silicon Chip Value 330kW 5.6kW 1.5kW 1kW 150W 75W 4-Band Code (1%) orange orange yellow brown green blue red brown brown green red brown brown black red brown brown green brown brown violet green black brown 5-Band Code (1%) orange orange black orange brown green blue black brown brown brown green black brown brown brown black black brown brown brown green black black brown violet green black gold brown siliconchip.com.au Custom-made Lithium Ion, NiCd and NiMH battery packs Smart Chargers www.batterybook.com (08) 9240 5000 High-capacity 280mAh rechargeable 9V 2400mAh NiMH AA cells siliconchip.com.au High-quality single cell chargers with independent channels. Charge any combination of NiCd & NiMH AA and AAA cells High-capacity 9Ah rechargeable D June 2006  37 By JIM ROWE Two-Way SPDIF/Toslink Digital Audio Converter Need to convert the Toslink digital audio optical signal from your DVD player into coaxial SPDIF form, to feed the only remaining digital input on your home-theatre amplifier? Or do you want to convert from a coaxial SPDIF signal to Toslink form? This low-cost unit converts digital audio bitstreams either way. M URPHY’S LAW SEEMS to apply to digital audio bitstream signals and inputs just as much as it does to any other aspect of electronics. For example, let’s say that you have only one digital audio input left on your home-theatre amplifier and it’s an optical one. Now guess which kind of digital audio output you’ll find on your new DVD recorder or DTB set-top box when you bring it home? That’s right, Murphy’s Law will ensure that it will be an coaxial output. It won’t be an optical one, because that would match the remaining input on the amplifier and make things easy for 38  Silicon Chip you. On the other hand, if your amplifier has only a coaxial digital input remaining, you can bet your last dollar that your new set-top box will have an optical digital output instead! Either way, these are both situations where the easiest solution is to use a converter – one that can convert coaxial digital audio signals into optical, or vice-versa. And that’s exactly what this little gadget does. It uses only a handful of parts, yet can easily convert coaxial digital bitstream signals into optical form and/or the other way around. It’s also easy to build and will set you back significantly less than a pair of commercial converters. Digital audio signals Basically, the digital audio signals found in domestic equipment are all in the form of SPDIF (Sony/Philips Digital Interface) bitstreams – either as 400mV electrical signals sent along 75ohm coaxial cables or as optical signals (pulses of 660nm red light) sent along fibre-optic cables. The optical signal form is often called “Toslink”. Although domestic digital bitstream audio is split almost equally between the coaxial and optical forms, they’re both virtually identical in terms of the SPDIF/BMC encoding and serialisation used (see panel). So it’s relatively easy to convert between the two, in either direction. In fact, once you get hold of suitable Toslink optical transmitter and receiver modules, the rest is no problem at all. How it works Fig.1 shows the circuit details for the converter. It’s based on a pair siliconchip.com.au of low-cost Toslink optical modules which are now being sold by Jaycar Electronics: the ZL-3002 receiver and the ZL-3000 transmitter. The receiver is used at the input of the optical-to-coaxial converter section at the top of Fig.1, while the transmitter is used at the output of the coaxial-to-optical converter section in the centre of the diagram. The bottom part of Fig.1 is the power supply section and this provides a +3.3V DC rail for the other two sections. In operation, the ZL-3002 optical receiver accepts the incoming Toslink optical bitstream and converts it into an electrical signal with roughly TTL logic levels at its pin 1 output. This is then fed through CMOS inverter stage IC1f and then through parallel-connected inverter stages IC1a, IC1b & IC1c which together act as a buffer. The resulting “squared-up” signals are then fed through a 150nF DC blocking capacitor to a voltage divider consisting of 390W, 220W & 160W resistors. This divider network delivers a 400mV peak-to-peak SPDIF signal to output connector CON2 and also ensures correct impedance matching, so the output signal is at the required 75W impedance level. And that’s all there is to the optical-to-coaxial converter. The second converter stage is just as straightforward. The incoming coaxial bitstream signal is fed to CON1 and then fed via a 100nF capacitor to a Schmitt trigger stage based on IC1e and its associated 100W and 10kW feedback resistors. This stage “squares up” the bitstream signal and converts it into a 3.3V p-p CMOS signal. The 300W resistor connected across CON1 is included for impedance matching. It acts in conjunction with the 100W resistor in the signal path to give a 75W input impedance. The output from IC1e appears at pin 10 and is fed to inverting buffer stage IC1d. This in turn drives the ZL-3000 Toslink transmitter module where it is converted into an optical bitstream signal. Power supply The power supply section has been designed so that the converter can be operated from almost any source of 9-12V DC capable of supplying about 55mA. This means you can operate it from either a small plugpack supply or from batteries. The incoming 9-12V DC is first siliconchip.com.au RFC1 47 µH +3.3V 150nF 1 14 100nF 2 CO-AXIAL SPDIF OUT IC1a 3 IC1f 1 13 3 12 DIGITAL OPTICAL RECEIVER (ZL-3002* ) 2 150nF 4 390Ω CON2 IC1b 5 220Ω 6 160Ω IC1c IC1: 74HC04 10k CO-AXIAL S/P-DIF IN +3.3V 150nF 2 100nF 100Ω CON1 11 IC1e 10 IC1d 9 8 3 7 300Ω 1 DIGITAL OPTICAL TRANSMITTER (ZL-3000* ) D2 1N4004 K 9-12V DC INPUT D1 1N4004 CON3 A * JAYCAR CAT. NUMBER A REG1 7805 K IN 39Ω OUT GND 470 µF 25V +3.3V K ZD1 3.3V 10 µF A 1N4004 A SC 2006 K IN ZD1 A K 7805 GND OUT TWO-WAY SPDIF/TOSLINK CONVERTER Fig.1: the circuit is based on a pair of Toslink optical modules (a receiver and a transmitter) plus hex inverter stage IC1 to buffer the output and input signals. Power can come from any 9-12V DC source – eg, a plugpack or batteries. passed through reverse-polarity protection diode D1 and filtered using a 470mF capacitor. The resulting DC rail is then applied to 3-terminal regulator REG1 (7805) to derive a well-regulated +5V rail. This is then further regulated down to +3.3V (as required by the Toslink modules) using a 39W resistor and zener diode ZD1. Diode D2 protects REG1 from damage if the 9-12V DC input is disconnected while the 10mF electrolytic capacitor across the regulator’s output is fully charged. Construction This unit is a cinch to build. As shown on Fig.2, all the parts (including the connectors) are mounted on a single PC board coded 01106061 (76 x 46mm). This fits neatly inside a UB5size jiffy box (83 x 54 x 31mm) – or more accurately, it mounts directly on the inside of the lid, with the outside of the lid being used as the base. Note that the board has a rounded cutout at each corner, so that it clears the integral pillars in the box. Fig.2 shows how to install the parts. Begin by fitting the resistors, making sure you fit the correct value in each position. Table 1 shows the colour codes but we recommend that you also check them using a digital multimeter, just to make sure. Follow these with the 47mH RF choke, then fit the monolithic and MKT capacitors. The 10mF tantalum June 2006  39 What Are SPDIF And Toslink? The acronym SPDIF (or S/PDIF) stands for Sony/Philips Digital Interface. Basically, it is a standardised serial interface for transferring digital audio data between consumer-level equipment such as DVD and CD players, DAT and DVD recorders, surround-sound decoders and home-theatre amplifiers. SPDIF is very similar to the AES3 serial digital interface used in professional recording and broadcasting environments. In operation, each digital audio sample (16-24 bits) is packaged along with status, control and error-checking information into a 32-bit binary word. This is then modulated or encoded into a serial bitstream using the Biphase Mark Code (BMC). BMC involves combining the data bits with a clock signal of twice the data bit rate, in such a way that a binary “1” results in two polarity reversals in one bit period, while a binary “0” results in a single polarity reversal. This double bit-rate signal is selfclocking at the receiving end and has no DC component. The BMC encoded serial bitstream is then transmitted as a 400mV peak-to-peak signal along a single 75-ohm coaxial cable. In most cases, the cable connectors used are standard RCA or “Cinch” connectors, as also used for analog audio and composite video. Although originally developed for conveying linear PCM (LPCM) digital audio signals as used in CD and DAT audio, and 470mF electrolytic capacitors can then go in, taking care to ensure they are correctly orientated (since they are polarised). Next, fit the two 1N4004 diodes (D1 & D2), followed by zener diode ZD1. Once again, these parts are polarised so be sure to fit them with their banded ends orientated as shown. Regulator REG1 is next on the list. This mounts horizontally with its three leads bent down by 90°, so that they pass through their respective holes in the PC board. To do this, first bend its leads down­ wards about 5mm from its body, then fit the device in position and secure its metal tab to the board using an M3 x 6mm machine screw and nut. SPDIF has also been adapted for conveying compressed digital audio, including Dolby Digital (AC-3), DTS and MPEG-2 audio. Toslink is essentially just the SPDIF signal format converted into the optical domain, for transfer along optical-fibre cables. The accompanying table (see above) shows the most common domestic audio bitstream formats and the SPDIF/Toslink bit rates for each one. Note that LPCM audio is rarely used for DVD-Video, because even a stereo audio track requires a BMC bit rate of 6.1Mb/s. Many current-model DVD players and recorders are provided with either coaxial SPDIF or Toslink digital audio inputs and outputs, or quite often a mixture of both. Similarly, many hometheatre amplifiers are provided with coaxial SPDIF and/or Toslink inputs. This is also the case with many up-market PC sound cards. The Toslink receiver and transmitter modules can now go in. These are very similar in appearance but it’s impossible to get them mixed up since the receiver module has five pins while the transmitter has just three connection pins plus two plastic locating spigots. The final component to fit to the board is IC1. An IC socket was fitted to the prototype but this is optional and you can solder the IC straight in instead. Make sure that the device is orientated as shown in Fig.2, with its notched end towards the left. If you are soldering the IC in directly, take care because it’s a CMOS device and easily damaged by static electricity. The rules are quite simple: use an earthed soldering iron, discharge yourself of static before handling the device, avoid touching the pins and solder pins 7 & 14 first (to enable the internal protection diodes). Final assembly The board assembly is now complete and the next step is to drill and cut the various holes in the box. Fig.3 shows the details. Note that the round 9mm hole for CON2 on the righthand end of the box has an 8mm-wide slot cut below it, to allow final case assembly with the board mounted on the lid. Note also that the 9mm hole for the power connector (CON3) must go in the rear of the box – see Fig.3 and the photo. Table 1: Resistor Colour Codes o o o o o o o o No.   1   1   1   1   1   1   1 40  Silicon Chip Value 10kW 390W 300W 220W 160W 100W 39W 4-Band Code (1%) brown black orange brown orange white brown brown orange black brown brown red red brown brown brown blue brown brown brown black brown brown orange white black brown 5-Band Code (1%) brown black black red brown orange white black black brown orange black black black brown red red black black brown brown blue black black brown brown black black black brown orange white black gold brown siliconchip.com.au Par t s Lis t COAX OUT TOSLINK TX 150nF OPTICAL OUT 3.3V 160Ω 74HC04 390Ω IC1 2 CON2 10k 220Ω 1 100Ω 6002 © 16060110 1 3 150nF 2 100nF TOSLINK RX OPTICAL IN 47 µH 3 + ZD1 150nF REG1 7805 39Ω 100nF D2 300Ω COAX IN CON1 10 µF 470 µF 4004 4004 CON3 D1 9-12V DC IN Fig.2: here’s how to assemble the parts onto the PC board. Make sure that the semiconductors and electrolytic capacitors are correctly orientated. 1 PC board, code 01106061, 76 x 46mm 1 UB5 Jiffy box, 83 x 54 x 31mm 1 Toslink optical receiver (Jaycar ZL-3002) 1 Toslink optical transmitter (Jaycar ZL-3000) 1 47mH RF choke (RFC1) 2 RCA sockets, PC-mount (CON1, CON2) 1 2.5mm concentric DC socket (CON3) 4 M3 x 10mm machine screw, csk head 4 M3 star lockwashers 1 M3 x 6mm machine screw, round head 5 M3 nuts, metal 4 M3 nuts, Nylon Semiconductors 1 74HC04 hex inverter (IC1) 1 7805 +5V regulator (REG1) 1 3.3V 1W zener diode (ZD1) 2 1N4004 diodes (D1,D2) An IC socket was fitted to the prototype but you can solder the IC in if you wish. Note how the 3-terminal regulator (REG1) is mounted. The two rectangular holes are for the Toslink optical transducers. These can be made by drilling a series of small holes around the inside of the marked cutouts, knocking out the centre pieces and filing to shape. The four holes in the lid are for mounting the PC board. After drilling, these should each be fitted with an M3 x 10mm countersink-head screw, a star lockwasher and an M3 Nylon nut – ie, the Nylon nuts form the mounting pillars for the PC board assembly. That done, the PC board can be fitted in position and secured using four M3 metal nuts. The final assembly step is to fit the lid assembly to the case. To do this, you Capacitors 1 470mF 25V RB electrolytic 1 10mF 16V tantalum 3 150nF MKT metallised polyester 1 100nF multilayer monolithic 1 100nF MKT metallised polyester Resistors (0.25W, 1%) 1 10kW 1 160W 1 390W 1 100W 1 300W 1 39W 1 220W The PC board is mounted on the lid of the case, with four M3 Nylon nuts used as standoffs. This assembly is then fitted to the base of the case (right) which must be pre-drilled to accept the various connectors and provide access to the DC socket. siliconchip.com.au June 2006  41 It’s a good idea to leave the plastic dust caps in place on unused Toslink connectors, to keep dust off the lenses. way around (just remove it, rotate it through 180° and replace it). Finally, turn the complete assembly over and fasten the lid down using the four self-tapping screws provided. Your Two-Way SPDIF/Toslink Converter is now ready for use. Quick checkout Fig.3: this full-size diagram can be used as a template to mark out and drill the various holes in the plastic case. first have to remove plastic protection caps from the Toslink connectors. That done, it’s just a matter of slipping the two input connectors through their holes in one end of the case and lowering the other (output) end of the lid assembly into position (ie, by sliding CON2 through its 8mm-wide slot). Now check that the power connector (CON3) is visible through its matching hole in the rear of the case. It not, you’ve got the lid the wrong Fig.4: check your PC board against this full-size etching pattern before installing the parts. 42  Silicon Chip There are no setting-up adjustments but if you’d like to give it a quick functional check first, this is easily done. Simply apply power to CON3 from your 9-12V DC plugpack (centre pin positive) and check that a small beam of red light emerges from the Toslink transmitter on the righthand end of the box. If it is, the odds are that your converter is working as it should. A “no red beam” condition means that you’ve probably connected one of the diodes the wrong way around, or wired up the DC power input plug with the wrong polarity. Otherwise, you can go ahead and use the finished converter to connect your new digital audio source to that otherwise incompatible SPDIF input on your home theatre amplifier, PC sound card or SC DVD recorder. Fig.5: if you’re not building from a kit, this full-size label can be attached using double-sided adhesive tape. siliconchip.com.au PC Oscilloscopes & Analyzers Get the full picture with BitScope Mixed Signal Oscilloscopes 100MHz Digital Oscilloscope  Dual Channel Digital Scope using industry standard BNC probes or analog inputs on the POD. 40MS/s Logic Analyzer  8 logic, External Trigger and special purpose inputs to capture digital signals down to 25nS. Mixed Signal Oscilloscope  True MSO to capture analog waveforms time-aligned with logic using sophisticated cross-triggering on any input. Turn your PC into a powerful Digital Storage Oscilloscope! Real-Time Spectrum Analyzer  See spectra and waveforms in real-time displayed simultaneously See inside your circuit with simultaneous analog, logic and spectrum displays to make tracking down those elusive real-time bugs much easier. Waveform Generator  Load up to 128K arbitrary waveform and replay via BNC B. Capture circuit response simultaneously on BNC A Standard 1M/20pF BNC Inputs 200uV-20V/div with x10 probe S/W select AC/DC coupling Switchable 50ohm termination Arbitrary Waveform Generator BitScope combines a high speed synchronized storage scope and logic analyzer with a programmable waveform generator and spectrum analyzer. With "Smart POD" connected active probes and multiple software options you've got the perfect low cost high performance test and debug solution! BitScope Smart POD probe connector 8 logic channels, cross-triggering Dual channel analog inputs Async serial I/O for external control Supports active probes USB 2.0 or Ethernet Connectivity Single cable to PC or switch Compressed data transmission Ethernet option uses UDP/IP Internet addressable device Expandable and Programmable Simple ASCII Protocol BitScope Scripting Language Add active probes and devices Supplies up to 500mA via POD BitScope DSO software for Windows and Linux BitScope's integrated design uses standard oscilloscope probes and a growing range of custom probes to provide functionality equal to instruments many times the price. BitScope plugs into third party software tools and has an open API for user programming and custom data acquisition. BitScope Designs siliconchip.com.au Ph: (02) 9436 2955 Fax: (02) 9436 3764 www.bitscope.com June 2006  43 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. PICAXE drives Nokia LCD This circuit and the accompanying BASIC program demonstrate how to interface an old Nokia mobile phone liquid crystal display to a PICAXE microcontroller. While the complete unit could be used as a stand-alone serial LCD module, the circuit and program could also be integrated into an existing PICAXE project – assuming that there are sufficient port pins and memory space available! A Nokia 5110 mobile phone was used as the source for the LCD module. These are identified by type number LPH7366-1 and have nine connections. Displays from the 3210 and 3310 models may also be suitable, although these haven’t been tested with the program. The LCD is an 84 x 48 pixel graphics type with an “SPI” type serial 44  Silicon Chip interface. Table 1 shows the pin assignments when looking at the back of the module and reading from left to right. Note that the 3210 & 3310 displays omit the “OSC” pin, which isn’t used for this application. The phones are easily dismantled (you’ll need a T6 Torx screwdriver) to get access to the internals. On the 5110, the display is clipped to one of the PC boards, making contact with it via an elastomeric strip. For practical reasons, the display must therefore remain attached to the circuit board. However, the board can be cut down so that it is only slightly larger than the display, as none of the existing parts (except for the LEDs) are of any further use. Connections to the tiny round pads on the rear of the PC board are made using a fine-tipped soldering iron with the aid of a magnifying glass. Use light-gauge multi-strand hookup wire for the job, removing all but one strand to avoid shorting to adjacent pads. Once soldered, hot-melt glue can be used to secure the wires to the rear of the LCD for strain relief. The circuit diagram reveals a very simple interface scheme. 1kW resistors are used on all the interface connections to protect the LCD module in case of a PICAXE programming error. As per the usual PICAXE download circuit, a 22kW resistor is used to limit current on the serial port input, allowing connection to either a PC serial port or a simple logic-level (TTL) port from another microcontroller. An LM317 programmable voltage regulator (REG1) is used to provide the 3.3V supply for powering both the LCD and the PICAXE. Alternatively, the regulator circuit could be omitted and three 1.2V rechargeable cells used instead. Note that a diode would need to be connected in series with the cells to reduce their total voltage to below the maximum of 3.3V. Finally, a 1mF capacitor connected to “VOUT” is included to filter the internally generated LCD supply voltage. No other connection should be made to this pin! Unfortunately, the BASIC program (NokiaLCD.bas) is too large to reproduce here but can be downloaded from our website. The program is based on information gleaned from www.microsyl.com/nokialcd/nokialcd.html and other Internet sources. As presented, it receives serial data at 2400 bits/s on input6. However, this is easily modified for other port pins and data rates. All received non-alphanumeric characters except for “space” and “full stop” are replaced with an asterisk (*). In addition, lower case characters are converted to uppercase, before a look-up table (stored in EEPROM) is used to decode and display the characters on the LCD. For example, “Hello! How are you?” siliconchip.com.au Table 1 Robert is this m Gatt on winner th’s Peak At of a las Instrum Test ent Pin No. 5110 Pin No. 3210/3310 Name 1 1 VDD 2 2 SCLK Serial clock line 3 3 SI Serial data line 4 4 D/C Data/Control mode select 5 5 CS Chip select (active low, connect to GND) 6 Description 2.7-3.3V OSC Oscillator (not used, connect to VDD) 7 6 GND GND 8 7 Vout LCD power supply (internally generated) 9 8 RESET Apply to initialize chip (active low) WHERE can you buy SILICON CHIP You can get your copy of SILICON CHIP every month from your newsagent: in most it’s on sale on the last Wednesday of the month prior to cover date. You can ask your newsagent to reserve your copy for you. If they do not have SILICON CHIP or it has run out, ask them to contact Network Distribution Company in your state. SILICON CHIP is also on sale in all stores . . . again, you can ask the store manager to reserve a copy for you. PIN 1 Or, to be sure that you never miss an issue and save money into the bargain, why not take out a subscription? The annual cost is just $83 within Australia or $89 (by airmail) to New Zealand. Subscribers also get further discounts on books, and other products we sell. Silicon Chip Binders Connections to the 5110’s display are made via a row of eight pads on the rear of the circuit board, as shown here. By contrast, the 3310’s display (not shown) is self contained and includes a tiny 8-pin connector with 1mm spacing. It only takes a few minutes to com­ pletely disassemble a Nokia 5510 – all you need is a Torx T6 screwdriver! Here’s the board that carries the display. It can be cut down in size with a little care. after this filtering and conversion process would be displayed as “HELLO* HOW ARE YOU*”. The LCD modules used in all of the above-mentioned models are based around the Philips PCD8544 controller IC. Datasheets for this siliconchip.com.au IC can be downloaded from www. semiconductors.philips.com. Those that don’t already have a phone suitable for cannibalisation will find old phones and new LCD modules are available on the ‘net. Note that the 5110 models in particular suffer from display problems, often curable by fitting a new display frame and display contact strip. These are still listed by Cellink as spare parts – see www.cellink.com. au. Contact Wagner Electronics on (02) 9798 9233 for availability. Robert Gatt, Port Fairy, Vic. 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 order. 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. June 2006  45 Circuit Notebook – Continued Improved PICAXE RGB LED Display As described in the “PICAXE RGB LED Display” item in Circuit Notebook (September 2005), a very simple multi-colour display can be created with little more than an 8-pin PICAXE and an RGB LED. The simplicity of the original design means that there is a lot of flickering and a full spectrum of colour is difficult to achieve. However, by adding a few components and rewriting the code (see Listing 1), the visual effects can be considerably improved. As shown in the circuit, three transistors (Q1-Q3) allow PWM control of the three LEDs from a single PICAXE output pin (out2). In addition, each LED can be individually enabled or disabled by setting outputs out0, out1 and out4 high or low. If desired, the values of the LED current-limiting resistors can be adjusted to achieve a good white balance. Suitable RGB LEDs are available from Jaycar Electronics (Cat. ZD-0270) and Altronics (Cat. Z-0999). Gordon Appleton, Auckland, NZ. ($35) Listing 1: PICAXE RGB LED Display 'RGB LED Display PICAXE-08M let dirs = %00010111 main: let pins = %00000101 gosub fade let pins = %00000110 gosub fade let pins = %00010100 gosub fade let pins = %00000111 gosub fade let pins = %00010110 gosub fade let pins = %00010101 'set all used pins to outputs 'power Q1 emitter to drive red LED 'power Q2 emitter to drive green LED 'power Q3 emitter to drive blue LED 'red & green combination 'green & blue combination 'red & blue combination gosub fade let pins = %00010111 gosub fade goto main 'red, green & blue combination 'repeat forever 'Create a fading in and out effect using pulse-width modulation. fade: for b1 = 255 to 0 step -1 pwm 2,b1,1 next b1 for b1 = 0 to 255 step 1 pwm 2,b1,1 next b1 return 'increasing brightness 'decreasing brightness Contribute And Choose Your Prize As you can see, we pay good money for each of the “Circuit Notebook” items published in SILICON CHIP. But there are four more reasons to send in your circuit idea. Each month, the best contribution published will entitle the author to choose the prize: an LCR40 LCR meter, a DCA55 Semiconductor Component Analyser, an ESR60 Equivalent Series Resistance Analyser or an SCR100 Thyristor & Triac Analyser, with the compliments of Peak Electronic Design Ltd – see 46  Silicon Chip www.peakelec.co.uk So now you have even more reasons to send that brilliant circuit in. Send it to SILICON CHIP and you could be a winner. You can either email your idea to silchip<at>siliconchip.com.au or post it to PO Box 139, Collaroy, NSW 2097. siliconchip.com.au Low-coolant alarm for EA-ED Falcons Back in the November 2004 issue, SILICON CHIP published details on adding a coolant float switch and warning indicator to Falcon models EF & EL. Apparently, these items are not factory fitted in the low-end models. A similar situation applies to the EA-ED range and again, it’s not difficult to retrofit the float switch from the high-end models. As described in the earlier issue, the switch plugs into the existing loom, making the signal wire accessible from behind the dash for connection to the warning circuit. The improved circuit given here provides an additional feature not present on the earlier design – an “anti-slosh” delay to prevent false alarms when braking, accelerating and cornering. An op amp (IC1) is used to detect the position of the float switch. Its inverting input is held at one-half of the supply rail voltage, while the non-inverting input monitors the voltage developed across the float switch. Assuming a nominal rail of 12V, this input sees about 8.5V when the float switch is open (low coolant level) and 2.9V when the switch is closed (normal level). This arrangement ensures reliable switching with varying rail voltages. In normal operation, the voltage on pin 3 will be higher than on pin 2. This means that the op amp’s output will be close to ground, switching on transistor Q2 and triggering the 555 timer (IC2). The 555 is wired as monostable, with a time period determined by the 100kW resistor and 47mF capacitor connected to pins 6 & 7. Despite being triggered, the 555’s timing period cannot end (ie, its output remains high) because Expertise From SILICON CHIP • • • • the timing capacitor is shunted to ground via Q2. However, when the float level drops, the op amp’s output swings high, switching off Q2 and allowing the 47mF capacitor to begin charging. After about five seconds the 555 times out, bringing pin 3 low and operating the warning LED and buzzer via D1. Should the float return to the normal range within the five-second period, then the capacitor is immediately discharged and the timing period reset – hence providing the anti-slosh function. Transistor Q3 together with the 1kW resistor and 100mF capacitor provide a short lamp/buzzer test at ignition switch-on. Finally, the two 16V zener diodes and their series resistors protect the circuit from the voltage transients typically found in an automotive environment. S. Buckland, Warwick, Qld. ($45) 160 PAGES 23 CHAPTE RS 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 mixtures and brake & temperature Mail order prices: Aust. $A22.50 (incl. GST & P&P); Overseas $A26.00 via airmail. Order by phoning (02) 9979 5644 & quoting your credit card number; or fax the details to (02) 9979 6503; or mail your order with cheque or credit card details to Silicon Chip Publications, PO Box 139, Collaroy, NSW 2097. siliconchip.com.au From the publishers of 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 June 2006  47 SERVICEMAN'S LOG DOA – that’s “Dead On Arrival” It’s not uncommon for sets to turn up in the workshop DOA (dead on arrival). But there are varying degrees of DOA, ranging all the way from completely dead to not quite dead! nects the aquadag to ground was also faulty. When this set spilt its guts, it must have been spectacular, with so much “blown up”. It is really hard to know the sequence of events but fortunately, that was the end of its troubles. A large 2002 Philips 32PW4523 TV set was brought into the workshop and pronounced DOA. This popular set uses an L01.1A chassis which isn’t quite so popular with technicians as it can sometimes be a bit hairy to fix. In this instance, I seemed to have got the full treatment. Fuse 1500 had blown and this told me that the switchmode power supply was also blown. I replaced it, along with chopper FET 7521, its driver Q7522, the diode in its base (D6523 and D6525) and R3530. To add to my woes, IC7520 (TEA1507), R3521 and R3523 were also faulty but it still wasn’t done with me. The set was still dead, with no red LED. There was also no drive pulse on pin 6 of IC7520, the power supply controller. The voltage on pin 1 (Vcc) of this Another Philips IC should have been greater than 11V (13.8-16.8V is marked on the circuit). In fact, it was less than 5V and this turned out to be due to C2526 (470nF) being leaky. A new one brought on a little life, with the red LED now flashing. I then replaced the infamous C2455 (47mF) in the line driver stage as a matter of course, as it dries out. Then I noticed a very obvious pregnant flyback transformer TR5445 (see photo). It must have got very hot to melt the plastic case in this fashion. I replaced this and the line output transistor, before attending to the east-west FET (7400) and R3411 and D6460. But there was more to come. R3344 and R3346 (22W) in parallel were burnt out on the EHT-info line on the CRT Panel B1 from the CRT aquadag, while VR3345 which con- The flyback transformer in the faulty Philips 32PW4523 had been getting quite hot, as is obvious by the bulge in the plastic housing on one side. 48  Silicon Chip The 2000 Philips 29PT9418 TV is quite a popular set, using the MG3.1A chassis. It’s a top-of-the-line TV with some additional options such as cordless/wireless Dolby 5.1 surround sound (it has about eight microprocessors), not to mention full digital features. Consequently, it is a very complex TV and repairing it is not for the faint-hearted. Until now, I had only seen a smattering of sets with fortunately fairly simple problems like dry joints on pin 2 of TR5204 and the vertical output IC (IC7600). Recently, however, two sets turned up with more complicated problems. The first set I had arrived from a colleague who had given up on it. Its symptom was that the set was dead with a flashing red LED. The sequence for switch-on is: solid red = standby, amber = start-up sequence, solid green = on and flashing red = protect mode. This was one of a series of models that Philips, with great fanfare, introduced with a Dealer Service Tool (DST), which is a remote control (RC7150) that can interrogate the set and communicate with the microprocessor and EEPROM, even when the set is in protect mode. It also has the ability to automatically tune the set to a predetermined arrangement. Unfortunately, neither this, nor the ComPair (Computer Aided Repair) I2C system designed for these models is available in Australia. The reason, I gather, is that they are too expensive and now possibly not available. Besides that, the management here believe that if you are a trained technician, you just don’t need them. siliconchip.com.au I disagree. Anything that makes our lives easier and the jobs quicker must be economically viable. Indeed, in the early days of colour TV, most German TVs had plug-in diagnostic systems which worked very well. Because these useful tools are not available, the SAM (Service Alignment Mode) and SDM (Service Default Mode) are only available by delving deeply in and finding (often unmarked) service pins near the microprocessor. When these modes are activated, some of the protection circuits are made less critical, occasionally even allowing the set to actually come on. As I also had a working TV in stock, I was able to quickly establish that there was a problem with the power supply – or more specifically, “Top Supply Panel B”. I immediately checked for the dry joint on pin 2 of transformer 5244 but it was OK, so I then ran this SOPS (Self Oscillating Power Supply) module on the bench alone, with a 100W globe across D6224 to monitor Vbat (+141V). This showed that the power supply was pulsating on this rail. I then found that all the other siliconchip.com.au voltage rails (16V, 11V, 8.6V, 5.2V and ±VS) were also pulsating and there were no obvious shorts. Next, I tried swapping components with the good supply, starting with the electrolytic capacitors. I then made sure that the DC-protection was disabled by shorting the line to ground, after which I tried removing or substituting the crowbar circuits (SCR D7232 and various zener diodes) on all the rails. I also checked out the feedback control circuit involving D7212 (TL431CLP) and the optocoupler, before swapping the control IC, C2204 (680pF) and also L5240, L5211 & L5212 and their series capacitors. Going nowhere I was really going nowhere until I noticed that “Va”, which should be at 18V and is the “take over” supply to the control IC, was very low and pulsating. C2203 and D6210 were both OK which made me suspect the chopper transformer (5202). This was swapped over and it turned out to be the culprit, the power supply now bursting into life. So what was wrong with the faulty transformer? I fully expected to find shorted turns where the wires come out to the PC board lugs but these were all in order. However, when I looked on the top side of the transformer, there were two wires that were part of the “Va” voltage winding and where they crossed over a plastic ridge, there was a very faint imperfection in the wire. On very close examination, the single core leads were both cut but were still making Items Covered This Month • • • • • Philips 32PW4523 TV set, L01.1A chassis Philips 29PT9418 TV set, MG3.1A chassis Panasonic TC25V50A TV set; MX2A chassis Sony KV-S34SN1 Kirara Basso TV set (G1 chassis) Sony KV-E29SN11 TV set (BG1L chassis) – postscript June 2006  49 Serviceman’s Log – continued an alternative strategy, he will have to purchase an exchange module. Same symptoms a “touch connection”. I can’t be sure whether these had been cut on purpose or by accident but resoldering them fixed the problem. Reinstalling the supply in the set was straightforward but there were still other problems to solve. The set would try and come on, going through the red, yellow and green phases of the standby LED but ending with it flashing (the red LED is supplied by switching the +5V Standby rail from the micro and the green LED by switching the +8.6V rail). I then found that initiating the SAM or SDM modes by shorting pins 1 & 2 or 2 & 3 of connector O356 on the Small Signal Panel (SSP K board – K7 circuit) allowed the set to come on. The error buffer then showed a 068 error, denoting a fault on the 8.6V rail. Clearing the buffer and the doing a self-diagnostic test cleared this error and no other errors were indicated. Switching the set off to standby with the remote and then switching the set on again produced the same results as above, with the 068 error reappearing. Occasionally when switching the set on from cold, it would fire up without putting it into the Service Mode. The east-west pincushion correction wasn’t working and this was fixed by replacing FET Q7480 (STP16NE06). 50  Silicon Chip I also found that there was nothing coming out of the external surround sound speaker connections and so I replaced IC7760 (TDA2616Q). However, neither of these faults affected the 068 error and the failure to start up normally. Feeling somewhat frustrated by now, I then swapped all the remaining boards with those in the good set until the fault was transposed with the SSP (small signal panel). I then measured all the voltages on the SSP – 3.3V standby, 3.3s, 3.3VA, 3.3VB, 5DA, 5DB, 5DC, 5.2, 7.7, 8VA, 8VB, 8VR and 8.6V. As far as I can make out, the OTCuP (Onscreen display and Teletext Controller Microprocessor – IC7003, SAA5800/1) detects the 8.6V on pin 105 via resistors R3006 and R3009. At the junction of these two resistors is a double zener diode arrangement. Anyway, I checked all these components and could find nothing wrong – even when heating and freezing them. In the end, I could only assume that the SSP (small signal panel) was faulty. However, I’m not prepared to try replacing the 120-pin surface-mounted processor, although I did change the EEPROM IC7008. Anyway, I passed the diagnosis on to my colleague and unless he can find The second set had the same symptoms – dead with the red LED flashing. Putting it into the Service Modes made the LED go full green and the sound come on but there was no picture and the CRT heaters were off. As before, I started to swap boards and found this time that it was A1, the deflection module. And when I got a picture, I could see that I had an error 073 line deflection protection fault. The line deflection board is large, with a lot that could go wrong. I noticed that in the green LED mode, you could hear the rush of the +32kV EHT charging the picture tube, so I was fooled into thinking there was EHT. However, the +13D rail was very low (8V) and then dropped right off. I was further convinced there was EHT when I got a shock removing the final anode cap. It wasn’t until I put an EHT meter on it that I realised that the EHT came on initially and then very slowly decayed off. Next, I removed plug O320 to the B board (O328), thus disabling the audio output ICs and the DC-protection circuit. I could not find any shorts on this board and tried swapping IC7484 (LM358N). The east-west circuitry also appeared to be OK. The circuit I had showed a convoluted diagram (A2) for the CRT filaments called FBCSO (Fixed Beam Current Switch Off), involving a regulated FET (Q7340) for power saving and a crowbar protection circuit. In reality, none of this was fitted to the board I was working on. I was beginning to suspect the TDA8177 vertical output IC (IC7600), even though I could find no shorts on the 13V supply rail to it. Finally, I decided to unplug IC7484 which also operates the x-ray protection circuit. This then allowed the line deflection stage to try to operate uninhibited. It immediately went into a pulsating mode, with all the line-derived voltages rising and decaying. The flyback transformer was groaning and the line output transistor (Q7421, BUX2520DX) was getting hot. However, before I could connect a CRO to Q7421’s collector, it decided to expire by going short circuit. You can purchase repair kits for this set for each of the major boards but in siliconchip.com.au this case a new BUX2520DX output transistor and a new flyback transformer fixed the problem. Make sure you get the correct part number for the flyback transformer, as some sets have the focus and screen controls built in and some have them on a separate part. A couple of things make life difficult with this series of sets. Access to the solder sides of the motherboards is difficult and the non-Murphy-proof plugs are also a problem. The latter are not only unmarked but are very easy to plug into the wrong sockets. Some are not even colour-coded! On one occasion, I managed to plug the vertical deflection coils (0325) into the Frame Rotation 0390 socket. Consequently, this blew R3447 and Q7442. LT W ® Waterproof Connectors The DOA Panasonic The 1995 Panasonic TC25V50A TV set that came in was also DOA. The set was an MX2A and is a well-known model which gives very little trouble. I guess the most common fault is the failure of R833, a 22W resistor in the emitter of Q802 in the power supply. Interestingly, if Q802 is short circuit, 90V will be applied to D820 (a 36V zener diode in the collector circuit of Q802), eventually destroying it and resistor R1111. Also, if an earth jumper is routed near IC1106 (Poweron-reset 5V IC to pin 7 of the microprocessor IC1102), Q802 will be turned on every time a reset pulse is sent. This causes stress in D820 and eventually a consequent chain reaction. This particular set gave the impression of switching on fully when the power switch was depressed. You could hear the rush of static to the CRT and the sound coming on. However, no picture ever appeared as the line output stage was immediately being switched back off by the lack of line drive pulses from pin 19 of IC607 (AN5607NK). The horizontal oscillator is switched off via pin 20 (xray protect), which monitors the 26V at TP-E4 and the current flow through R411 on its way to pin 6 of IC451 (LA7833S; TA8403K in other models). It also monitors the vertical output and you can override this protection by shorting pin 20 to ground. The vertical ICs in some Panasonic sets can be dryjointed due to their small solder pads, which if not fixed will cause the IC to fail. And when it does, a voltage appears on pin 20, causing the set to close down. Replacing the vertical output IC and the electrolytic capacitors around it (as they dry out due to their proximity to the heatsinks) fixed the fault. Introducing LTW waterproof connectors... Altronic Distributors have recently been appointed distributor for LTW products in Australia. LTW are an ISO certified specialist waterproof connector manufacturer. They have been producing connectors since 1993 for many industries. Please check our website for items currently stocked. LTW produce many other models and pin configurations. These are available through Altronic Distributors in OEM quantities, check LTWs website: www.ltw-tech.com for further details. ■ IP66, 67 & 68 ratings for harsh environments ■ Multipin circular DIN, D-Sub, RJ45 (line and chassis) models ■ Protective dust covers are available to suit most connectors Applications: Agricultural • Industrial • Marine • Mining DISTRIBUTORS PTY. LTD. ■ Sydney ■ Melbourne ■ Perth Phone: 1300 780 999 Web: www.altronics.com.au Dry joints God bless dry joints! Without them, I would have been on the streets years ago, as they are still the most common cause of faults in TV sets regardless of manufacture. Recently, I had a Sony KV-S34SN1 Kirara Basso (G1 chassis) come in. This is a very expensive and complicated 80cm TV set which weighs in at 81kg. The owner’s complaint was that it wouldn’t turn on. Actually it would to some extent but unfortunately it was only the flashing red LED that was coming on, the set immediately going into the “protect mode”. Fortunately, most of the faults in this model are well known and mostly involve dry joints – in particular to the siliconchip.com.au June 2006  51 Serviceman’s Log – continued IC regulators spread out on almost every board. Eventually, I got the power supply board F out and found hairline fractures around D610, a common cathode double diode which feeds the +15V rail. I also reworked the solder on the board and all the other known problems, such as around IC208 and IC209 on the A1 board, IC2603 on the A board and IC503 (STV9379) on the D board, as well as all the VC board soldering. Finally, I did the C570 (220mF) modification on the D board. That fixed the set and I suspect this particular monolith will now do another 100,000km without requiring another service. Postscript Finally, I have a postscript to last month’s story on the Sony KVE29SN11 (BG1L). Afterwards, I had another go at the problem of the burning components in the 5V backup and standby circuit. 0 00 $10 I Z E P R OL! PO Basically, R615 (0.47W) and D608 supply 70V to the collector of Q601 (2SA1315) via R606 (18W). Q601’s emitter then supplies 10V to 5V IC regulator IC002 via the 22W resistor in the JW158 link position. These components were badly overheating and failing. So what was the common part in all this? The answer is transistor Q602 (2SC3209), which drives Q601. Well, actually it doesn’t normally drive it as it is switched off and Q601 is biased to give 10V out. However, when Q602 is switched on, Q601 gives a much higher output voltage at its emitter. And if Q602 was faulty, perhaps it would cause the full 70V to go through to the 5V IC regulator. The only thing was that Q602 measured perfectly in circuit and even out of circuit was only slightly leaky. But when measured on a PEAK Atlas Component Analyser (DCA55), this NPN transistor was found to be behaving like a common cathode double diode! Replacing it stopped the pyrotechSC nics immediately. 2006 SILICON CHIP Excellence in Education Technology Awards NOW OPEN SILICON CHIP magazine aims to promote the education, development and application of electronic technology in all fields throughout Australia. As part of that aim, we are announcing the SILICON CHIP Excellence in Education Technology awards, with a prize pool of $10,000. Separate awards will be made to students of secondary schools throughout Australia and to students of universities and TAFE colleges throughout Australia. AWARD FOR EXCELLENCE The secondary school awards will have three categories: (a) Best final year assignment of an individual student involving electronics technology (b) An award to the school sponsoring the winning individual student (c) Best school project involving electronics technology The university and TAFE college awards will have three categories: (a) Best project from a student as part completion of a degree, diploma or certificate in electronics or a related field (ie, mechatronics) (b) Best research project from a post-graduate student working in an area of applied electronics (c) An award to the university faculty or school sponsoring the best research project. Entries and judging The awards will be judged by the editorial staff of SILICON CHIP, convened as a judges panel. The decisions of the judges will be final. Entries for the 2006 awards are now open, with final submissions to be made by September 30th, 2006. All submissions will be confidential, until the winners are announced, in the December 2006 issue of SILICON CHIP. Each award will take the form of a cash prize and a commemorative plaque. All enquiries about these awards should be directed to the editor via email to: awards<at>siliconchip.com.au 52  Silicon Chip siliconchip.com.au Hydrogen Fuel Cell Powered Model Car This kit includes a 30mW proton exchange membrane fuel cell that will convert hydrogen and oxygen to electricity and when connected appropriately, will generate clean fuel to run the model car. • Comprehensive instruction booklet provided. • Car chassis measures 235(L) x100(W) mm. • Requires: 2 x AA alkaline batteries and distilled water. • Educational kit for ages 12+. Cat. KT-2525 $ 95 149. Proton Exchange Membrane (PEM) Fuel Cell To operate the cell, a low pressure source of oxygen (or air) and hydrogen is required. The cell will convert these gases up to 60% efficiency and run indefinitely (subject to heat removal) given unlimited supplies of "fuel". Cell measures 64(H) x 54(W) x 27(D)mm and requires distilled, not purified water. • Instructions supplied • Voltage 0.65V • Current 300mA • Power Output 30mW Cat. ZM-9080 $ 00 99. Roadies Cable Tester This rugged unit will enable quick, convenient and reliable testing of most popular audio cables such as balanced XLR, phono, Speakon, DIN and more! • Requires one 9V battery (not included) • Measures 102(W) x 45(H) x142(D)mm Cat. AA-0404 $ 95 KIT OF THE MONTH Starship Enterprise Door Sound Emulator Ref: Silicon Chip June 2006 This kit emulates the unique noise made when the cabin doors on the Starship Enterprise open and close. The unit can be triggered by switch contacts (normally open), which means you can use it in conjunction with a Cat. KC-5423 $ 95 reed switch assembly, IR beam or PIR detector. • Requires 9-12VDC • Kit includes PCB with For All You overlay, case and all electronic components Trekkie Fans! Tool Kit with Carry Case 23 Piece Presented in a stylish silver case, the tools are kept securely in place by a foam base and elasticised fittings. Tools included are: driver bit handle, 2 x Phillips, Pozi, and slotted screwdriver bits, an adaptor for hex to square drive, 10, 9, 8 and 7mm nut drivers, a telescopic pickup tool, 1m tape measure, and a set of long nose pliers with wire cutter. • Case measures 160 (L) x 115 (W) x 35 (H) mm. 39. Cat. TD-2063 $ 95 19. Low Cost Stereo Amplifier Ideal for small offices, workshops, or as a church PA amp. This simple, low cost 18W per channel transistor amp is protected from accidental speaker wiring shorts and if abused, will simply shut down and reset after it has cooled off. It has a front panel microphone input, bass and treble controls as well as a master volume control. See website or catalogue for details. Cat. AA-0472 $ 95 39. 29 Pcevailable also a Toolkit2066 $29.95 TD- SPDIF/Toslink 2-Way Converter Kit Ref: Silicon Chip June 2006. This kit converts coaxial digital audio signals into optical or vice-versa. Use this bit stream converter in situations where one piece of equipment has an optical audio signal and the other a coaxial digital signal requirement. Kit includes Toslink optical modules, PCB with overlay, case with screen printed lid and all electronic components. • Requires 9-12VDC power Cat. KC-5425 $ 95 24. Two Way Paging Car Alarm with Rechargeable Remotes 39. Stereo Amplifier with Remote Control A no-nonsense stereo amplifier that will form the heart of an impressive stereo system. Rated at a generous 100WRMS per channel this two channel amplifier features a microphone input and quality screw down speaker Cat. AA-0470 terminals. See our website or $ 00 catalogue for full specifications. 199. This alarm utilises FSK technology which will relay the status of your vehicle to the key fob up to 3km (direct line of sight) away. In addition to the system's massive transmission range, the alarm also features remote control arm and disarm, car park locator, auto rearming, anti-burglary, anti-hijacking and silent arming. Each remote control has an integrated rechargeable battery, alarm clock, with visual, audible and vibrating alert functions. • Purchase LA-9030 $29.95 for microwave movement sensors • Purchase LA-9019 $99 for spare remotes WHAT YOU GET • Electronic black box controller • 2 x code hopping two way paging remote controls with rechargeable lithium-ion batteries • Vehicle remote control battery charger • Shock sensor with adjustable sensitivity • Ignition cut out relay • Wiring looms • Battery backup siren • Car transmitter Cat. LA-9018 $ 00 299. FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 INTERNET> www.jaycar.com.au 1 Battery Charger with USB Power Automotive Laptop Power Supply This Ni-Cd/Ni-MH 4 xAA/AAA fast battery charger has 3 convenient methods of power input: mains power for charging at home, an in-car charger for when you're on the move and a USB power plug for the classroom or office. It also has a voltage detection device to prevent overcharge and a discharging mode. Provides 15,16, 18, 19, 20VDC <at> 6A or 22, 24VDC <at> 5A. regulated and supplied with 6 changeable plugs - one for Dell laptops. Cat. MB-3539 $ 95 39. High Current Power Connectors You'll find these connectors in many 4WD applications, boating, automotive and other industries. Supplied individually with a pair of contacts and rated to 600V. Was $119 SAVE $59.05 Cat. PT-4420/22/24 The range includes: Current 30 Amp 50 Amp 120 Amp 175 Amp Poles 2 2 2 2 Cat PT-4405 PT-4420 PT-4422 PT-4424 Price $4.50 $12.95 $28.95 $37.95 59. 10 Million Candle Power Spotlight 59. $10 Weatherproof Dynamo AM/FM Radio with LED Torch This weather resistant radio/torch is powered by a manual hand crank. Wind for 90 seconds for 20 minutes of use. The unit also features a high intensity LED Cat. AR-1773 $ 95 torch. Delivers 600 watts of continuous power. Ideal for laptop computers, recharging power tools or batteries, 68cm televisions etc. Also features fan assisted cooling. • 600W continuous • 1500W surge Was $249.95 Mains Timer with LCD A switching contact rated at 30 amps! Featuring 8 on/off programs across 16 combinations of days or blocks of days for unrivalled flexibility. This unit also has a one touch 'summertime' button to convert to daylight saving time when it arrives. oor s, for ind Great , hydroponic Cat. MS-6110 g nd in a n g e n rd ti $ 95 ga ligh securityuch more m Huge current! Ideal for testing and running high drain low voltage equipment such as car audio, marine accessories, and automotive gear. A must for serious lab work. See website for details. Was $99.95 179. 12V 7.2Ah Sealed Lead Acid Battery Cat. MP-3078 $ 95 89. LED Lantern with Solar Charger A super bright white LED lamp with an integrated outlet for charging both the internal battery and external devices such as MP3 or CD players and mobile phones. The lamp can be charged via mains power, car charger or solar panel, all of which are supplied. The top of the lantern has a compass so you'll know where you are Cat. ST-3128 $ 00 at all times. $20 Cat. GG-2130 $ 00 179. 99. 12V Camping Shower All you need is a bucket of warm water to wash away the cares of the day. The assembly plugs into your vehicle's cigarette lighter and includes a flow control valve, pump, showerhead and carry bag. Was $19.95 Digital Handheld Anemometer 2 19. With an 18 - 36x zoom and eyepiece that is adjustable for any viewing position between 0 & 90° the uses are endless. Great for bird (the feathered kind) watching, whale watching, star gazing, or target practice etc. SAVE Was $199.95 14. 69. SAVE Now even lower in price! With $16.55 leak proof construction, long service life and high discharge capability our range of SLA batteries represent excellent value for money. r our f o store fo Was Cat. SB-2486 See in- ensive range rs eh ge $36.50 $ 95 compr ies and char batter Swing View Spotting Scope Cat. YS-2800 $ 95 A handy tool for the sailor, windsurfer or the everyday enthusiast. Measures the speed of wind in mph, km/h, m/s or knots, dispalyed on an LCD display with a Beauford SAVE wind scale bar graph. $10 39(L) x17(W) x 98(H)mm Was $79.95 Cat. QM-1640 $ 95 SAVE $70 Cat. MI-5108 $ 95 SAVE $10 13.8V 20A Switchmode Bench Power Supply SAVE $5 39. SAVE $5 600 Watt 12VDC to 230VAC Inverter Life in the great outdoors... Featuring an ultrabright quartz halogen globe and a switch for dim lighting to conserve power this torch is perfect for outdoor recreational activities. The internal 12V 7Ah battery can be charged through your car's cigarette lighter or by the supplied plug pack. • Supplied with mains and in-car charger and carry strap • Replacement globe use Cat. SL-3223 $12.95 Was $69.95 Cat. ST-3306 SAVE $ 95 They charge your batteries without fuss, switching to trickle charge when they reach capacity. •Will not charge a totally flat battery i.e. zero volts. Two types available: 6V Cat. MB-3525 Both Types 12V Cat. MB-3526 $ 95ea Was $24.95 19. Cat. MP-3466 $ 95 29. Cat. PT-4405 Lead Acid Battery Chargers 12V Air Pump Great to use on air beds, beach balls, lifejackets, rafts etc. Operates from any 12 volt outlet and is supplied with 3 sized nozzles to fit almost any item. Cat. GH-1110 $ 95 9. Satellite Finder Make dish aiming a snap! This is an absolute must for portable systems like those in RVs or anyone installing their own satellite dish. Cat. LS-3300 $ 95 29. 40 Channel UHF Pocket CB Radio Short range communication without mobile phones! Keep in touch within 1km in the city, or 5km in an open area. Operating on standard 40 channel CB frequencies, they can be used with CB repeaters throughout Australia. Accessories available, see website for details. Cat. DC-1010 $ 95 34. Buy 2 for $59.90 and get two DC-1016 car chargers FREE! Save $39.90 FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 INTERNET> www.jaycar.com.au Active 2 Way Speakers 3 Channel Headphone Amplifier These stylish piano finish speakers are suitable for TM use with PCs, MP3 players, iPods and any other digital audio device. They feature shielded drivers to minimise electrical interference to other digital equipment such as TVs and a DC output jack to TM enable charging of your IPod or MP3 player while you are listening. •2 x 3WRMS output power •80 x 86 x 100mm Listen to the same music source on three separate sets of headphones. The unit has a master volume control and is fitted with a 2.5m input cable that is terminated with RCA connectors. • 3.5 stereo to 2 x RCA adaptor included. Was $39.95 SAVE $10 This product is ideal for children watching a movie in the back seat. Cat. XC-5182 $ 95 39. Portable Wireless PA Amplifier and Microphone Cat. AA-0400 $ 95 29. 2.4GHz Wireless Amplifier and Speaker System Share your favourite music with others all around your house or entertainment area without messy wiring. Our new 2.4GHz wireless amplifier and speaker system offers unrivaled flexibility and crystal clear audio signals up to 50 metres away. Wireless Indoor Console Speakers Listen to music, the radio, or just about any sound source anywhere around the house without running messy wires. • 2 x 30WRMS Power Output • Dimensions: Transmitter 70(W) x110(H) x 36(D)mm Amplifier 590(W) x119(H) x125(D)mm. Cat. AR-1896 $ 95 Wireless Audio Transmitter & Receiver This wireless amplifier system consists of a stereo transmitter and amplified receiver that can be placed anywhere around your house. Connect your speakers and listen to music wherever you like. Cat. AR-1894 $ 00 199. 249. Automotive Audio Super Car Tweeters SAVE $10 High quality tweeters, made by a specialist manufacturer. These have an extremely flat response and are versatile in their mounting arrangement. • Two bases, one flat and one angled 40° • System power: 40WRMS (with 3.3µF x'over cap) Cat. CS-2210 Was $45 $ 00 35. Car Amplifiers Affordable, high quality Subwoofer speaker boxes! Made from 17mm MDF these boxes are pre-carpeted with black quality material and are internally lined with sound dampening material. The enclosures are supplied with recessed terminal posts and a pre-wired. Cat. CS-2533 750mm length of speaker cable. $ 95 • Available in two sizes. Cat. CS-2535 10" 20 Litre Cat. CS-2533 $ 95 12" 28 Litre Cat. CS-2535 49. 69. Kevlar Cone Coaxial Speakers Fantastic quality! This range of coaxial speakers offer high performance and great looks. They have a large super tweeter and their Kevlar cones take them into a realm of their own. 4" Kevlar 2 Way Cat. AA-0425 $ 00 • 40WRMS power • 86.5dB sensitivity Was $99.95 2 x 150WRMS 5" Kevlar 2 Way 399. This is easily one of the best value 2-channel amplifiers on the market today, offering a massive 500WRMS when bridged into a 4 ohm load • 2 x 150WRMS <at> 4 ohms • 2 X 255WRMS <at> 2 ohms • 1 x 500WMRS <at> 4 ohms Cat. AA-0424 $ 95 249. • 50WRMS power • 89.5dB sensitivity Was $109.95 6.5" Kevlar 2 Way • 75WRMS power • 91.3dB sensitivity Was $119.95 6" x 9" 2 Way 89.95 $ Cat. CS-2322 99.95 $ Cat. CS-2324 109.95 $ Cat. • 80WRMS power CS-2328 • 93.5dB sensitivity $ 129.95 Was $139.95 FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 Cat. CS-2320 INTERNET> www.jaycar.com.au SAVE $10 Cat. AM-4075 $ 00 99. 2.4GHz Wireless Audio Video Sender Send stereo audio and video pictures around your home, shop or office. Watch your favourite TV programs or listen to hi-fi quality stereo sound in any part of your home, all without the need to run cables. Features a phase-locked loop (PLL) electronic circuit that constantly Cat. AR-1842 adjusts, locking onto any input signal $ 95 and avoiding any reception drift. 69. Additional receivers sold separately AR-1843 $44.95 Also available with IR remote control extender AR-1844 $84.95 Speaker Enclosures 4 x 100WRMS A full range digital amplifier to run full range speakers. Drawing a mere 50A at bridge mode producing a whopping 550WRMS of total power! • 4 x 100WRMS <at> 4 ohms • 4 x 150WRMS <at> 2 ohms • 2 x 300 WRMS <at> 4 ohms Perfect for small public address applications and spruikers. The system consists of a compact yet powerful amplifier with a built-in crystal locked radio receiver with a wireless microphone. See our website or catalogue for full specifications. Carbon Fibre Subwoofers Featuring high quality Carbon Fibre cones and dual voice coils, these subwoofers offer great performance and durability. See our website for full details SAVE $10 10" Carbon Fibre Subwoofer • 250WRMS power handling • 87db sensitivity Was $179.95 Cat. CS-2278 $ 95 169. SAVE $10 12" Carbon Fibre Subwoofer • 300WRMS power handling • 88.2dB sensitivity Was $219.00 Cat. CS-2279 $ 00 209. 1 & 2 Farad Capacitors with Coloured LED Display Avoid clipping problems from power under supply with these high farad capacitors. They act as a surge current reservoir for your amplifier and other electrical equipment. Featuring recessed terminals to avoid accidental shorts the units come complete with a multi-coloured LED display, other illuminated graphics and a row of blue LEDs. 1 Farad 2 Farad Cat. RU-6752 $ 95 Cat. RU-6751 $ 00 99. 149. 3 This feature packed unit has two alarms with a choice of 4 wake up sources, up to 20 presetable radio stations, a USB port to allow use with an iPod™ or MP3 player and a in-built SD/MMC card reader so you can play and copy from one device to another. Cat. GE-4064 • 240VAC Power $ 00 Plug in your music device or attach it to you PC and listen to clear sound through the four speakers. Choose from 4 different programs to change the colour effects on the panel. Supplied with power supply, attachments and measures 305(W) x45(H) x Cat. GH-1026 80(D) mm. $ 95 Dynamo AM/FM and Shortwave Radio with Alarm 99. A heavy duty radio which will withstand a lot of punishment. Housed in a sturdy rubber and plastic casing it features an alarm, FM/MW/LW and shortwave radio bands. It can be either self-powered by its hand crank (dynamo) or 2 x AA batteries (not included). Colour Changing LED Panel This unit features 3 display settings, 3 speeds and an in-built timer. Purchase multiple units to create an exciting display . • 16 translucent 40mm squares • Mains adaptor included • Measures 70mm (D) x Cat. GH-1814 200(H) x215mm(W) $ 95 49. 'Retro' Wooden Stereo AM/FM Radio A great gift idea for radio buffs or lovers of all things "retro". This stylish woodencased radio has a distinct "retro" look with modern high quality stereo sound at a very affordable price. • 240VAC mains power only Personal Ozone Sanitiser MP3 Clock/Radio/ Music Centre with Dual Alarm USB Mood Speaker Panel with Colour Changing LEDs Cat. AR-1779 $ 95 39. 129. Cat. AR-1749 $ 95 49. Wireless Weather Station with Computer Interface This affordable computer connect weather station monitors indoor and outdoor temperature along with humidity, rainfall, barometric pressure, wind speed & direction, wind chill, and dew point. Cat. XC-0291 $ 00 399. This emits ozone that rapidly kills bacteria and neutralises odours. Absolutely safe and pollution free, this ozone sanitiser uses no chemicals or cover-up sprays. • Requires 6 x AA batteries (not included) Cat. GH-1192 $ 95 39. Intelligent Automatic Rubbish Bin Hands full? No worries! SAVE Just wave your hand, foot, or $10ea 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. 23L capacity. • Requires 4 x D size 42L Stainless Steel Mains Operated batteries bin also available. Cat. GG-2315 Was $39.95 GG-2317 $99.95 $ 95 29. Pet Dishes with Auto Sensor We stock an extensive range of Weather Stations in-store or online. The lid automatically opens as your pet gets within 30cm of the sensor then closes when your pet has had their fill and walks away. • Removeable stainless steel dish • Small measures 80(H) x 150(dia)mm • Large measures 95(H) x 200(dia)mm • Powered by 4 x AA batteries (not included) Small Large Cat. GG-2319 $ 95 Cat. GG-2318 $ 95 29. 34. Automotive Gadgets Automotive Current Tester Simply plugs into any standard blade fuse holder and provides an easy-to-read LCD display of the circuit's performance. The unit will measure up to 48V max, current up to 20A. With a 400mm cable. • Supplied with 12V A23 battery Cat. QP-2251 • Measures: 86 x 37 x 28.5mm $ 95 RC 500,000 Candle Power Pan/Tilt Spotlight 29. The unit's vacuum rubber base allows it to be secured to any flat surface and its IR remote control permits 360° horizontal rotation and 240° vertical elevation. The halogen spotlight also incorporates a red strobe light for emergency or service vehicles. Fitted with a 1.2m power cord, terminated to a standard 12VDC fused cigarette lighter plug. Cat. ST-3294 $ 95 • Approx 250mm high Eliminate glare and heat. The fine mesh fabric and its adjustable base and height allows the shade to fit almost all automotive rear windows. The 5m lead (with bare ends) makes DIY installation Cat. GH-1027 $ 95 easy and the remote control allows for convenient functionality. 69. Automotive Tester This voltage tester detects from 3 to 28 volts and will light up and buzz when positive voltage is detected. Made from rugged chrome metal construction it is safe to use with ECMs, air bags, sensors, transducers etc. Does not require a ground wire or clip, so it is easy to check in hard to reach places. Was $24.95 79. Cat. QP-2212 $ 95 SAVE $5ea Digital Tyre Pressure Gauge SAVE $5ea 19. Strobe Lights with Controller Runs off 12V DC power and has a speed control for changing the flashing frequency. They can also be set to flash simultaneously or alternately. The connection cables are a generous 3 metres in length making installation easy. Cat. ST-3176 $ 95 • Sold as a pair • Light colour: Bright White 39. 4 SHADOW 3-Point Engine Immobilising Car Alarm Remote Controlled Automotive Sunshade Quick and easy tyre pressure measurement! Simply press this unit onto the tyre valve and it will display the tyre pressure. It also features an integrated torch, and keychain attachment. Was $19.95 Cat. GG-2310 $ 95 14. Australia & New Zealand Standards Approved. Most insurers require, as a minimum, an Australian Standards approved (AS/NZS 4601:1999) alarm. The Shadow meets and exceeds these insurers’ requirements by having the required standard two internal immobilising circuits as well as a third external immobilising circuit. • Purchase SY-4070 relay and SY-4069 relay base to give the third immobilisation circuit. WHAT YOU GET: Recognised by leading Car • Black box electronic module. Insurers! • 2 x 433MHz Codehopping remote control FOBs. • High Security all-black wiring harness, including central locking output wiring. SAVE • Flashing dashboard LED. $30.50 • Installation and user manuals. Originally $129.50 Cat. LA-8970 $ 00 Immobiliser Upgrade WHAT YOU GET: • Multi-Tone 20 watt Battery Back-Up Siren with security key shut-off • Shock Sensor (adjustable sensitivity settings) • Bonnet Pin Switch (protects engine bay from tamper) • Supplementary Installation booklet 99. Cat. LA-8975 $ 95 49. FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 INTERNET> www.jaycar.com.au 600VA Uninterruptible Power Supply Protect your valuable computer system and critical data from black-outs, brown-outs, and power surges. Battery backup time is 10 minutes which lets you power down without loss of data! The UPS is supplied with a 7AH SLA battery, USB interface cable, Cat. MP-5200 $ 00 and software. 3.5" HDD Enclosure with Back-Up Quick, easy installation. This tough aluminium enclosure provides 480Mbps USB 2.0 high speed data transfer with hot swappable, plug and play. • Suits most 3.5" IDE hard drives • One button backup software for PCs Cat. XC-4660 included $ 95 • Enclosure compatible with PC and Mac 69. 139. 4 Port Video Splitter An ideal solution for providing distributed video from a single computer. The video splitter takes your computer's monitor output signals and sends them to four separate analogue monitors that can be Cat. YN-8099 up to 65 metres away. 95 • Supports VGA, SVGA, XGA, Multi Sync $ 99. ADSL Central Splitter/Filter This central ADSL filter/splitter provides an RJ11 socket for connection to the telephone line and a filtered RJ11 socket for connection of a fax or alarm dialer etc. Another RJ11 socket is provided for connection to the ADSL modem/router. • Meets AS/ACIF S002:2001 specifications Cat. YT-6097 • ADSL.2 compatible $ 95 34. Hot swappable, easy installation and no software required! Suits high capacity IDE/ATA/ultra ATA drives up to 400GB. Features a 2 port USB 2.0 hub, card reader, and a 40mm fan for Cat. XC-4662 additional heat dissipation. $ 95 • Compatible with PC and Mac 99. Boost Your Wireless Signal! Boost you signal strength and your data rate. This 12dB 3.5GHz antenna can be mounted inside the house or in a protected outside location for optimum reception. Supplied with a 1 metre N type to MCX lead and mounting bracket. Was $129.95 SAVE 119. $10 No More Cold Coffee A stylish addition to your computer workstation. Featuring 21 Hot keys including three ACPI keys for easy Cat. XC-5157 access to the internet, email and $ 95 multimedia applications. 14. With its ergonomic design to perfectly fit into your hand, an optical lens for precision aiming, and a rubber-like finish to prevent it slipping in your hand, this mouse stands out as a very Cat. XM-5132 modern piece of equipment. $ 95 39. USB Computer Mouse with Laser Pick-up 19. SAVE $5 Extremely versatile memory device! Full speed USB 2.0 data transfer and a compact 28(W) x 80(H) x 20(D)mm package. Limited Quantity. Cat. XC-4768 Was $34.95 $ .95 USB Aromatherapy Diffuser 29 SAVE $5 14. USB Pink Keyboard with Mouse 39. 19 Key USB Numeric Keypad Great for laptops! One key feature that doesn't come with a laptop is the numeric keypad. This unit is compact, 'plug and play', and only measures 67(W) x110(L) x20(H)mm. Cat. XC-5155 95 • Keypad lead length 700mm. $ Was $29.95 24. SAVE $5 Features 21 hot keys including three ACPI keys for easy access to the internet, email and other multimedia applications and includes a matching pink mouse. • Bonus heart shaped mouse pad included Cat. XC-5151 $ 95 29. FOR INFORMATION AND ORDERING INTERNET> www.jaycar.com.au Includes 3 cooling fans and locking switch! This ATA133 compatible hard disk drawer allows you to remove the drive from your computer for security purposes or to move large amounts of data between computers. Includes self Cat. XC-4674 $ 95 closing door to seal the drive bay when the drive is removed. 69. Network Storage External Hard Disk Case No computer needed! Featuring a network interface built into the rear of the case, anyone on a network can access the disk’s contents via FTP or SMB (Windows networking)! If you know what you’re doing, you can even connect to the Cat. XC-4679 device over the internet. $ 95 2.4GHz Wireless Headphones with USB Transmitter This USB powered warmer comes with a stainless steel mug with lid. It will keep your favourite beverage warm throughout the working day. • 75mm diameter heating coaster Was $24.95 Cat. GH-1365 $ 95 Enjoy the health benefits of aromatherapy as you work with this unique lavender scented personal diffuser. Ltd qty. Cat. GH-1044 Was $19.95 $ 95 800dpi resolution, that's double the resolution of an optical mouse! This reduces the strain on hands and wrists by minimising the movements required to Cat. XM-5133 $ 95 move the cursor. TELEPHONE> 1800 022 888 SAVE $5 64MB USB 2.0 Flash Disk with Built-In Card Reader USB Wireless Rechargeable Optical Mouse Removable IDE Hard Disk Drawer with Power Switch 199. modem not included USB Gadgets Black and Silver USB Multimedia Keyboard Use an ordinary IDE or SATA disk drive on a USB 2.0 interface. The adaptor can be powered from the existing computer power supply or from the supplied mains adaptor. Plug and play support for Windows ME, 2000, and XP. • Interface cables included Cat. XC-4833 $ 95 79. 3.5" Multifunctional HDD Enclosure Cat. AR-3274 $ 95 USB to IDE and SATA Hard Drive Adaptor These wireless headphones work brilliantly. They use state-of-the-art digital audio technology to receive 2.4GHz signals from the USB transmitter (provided) which easily plugs into a desktop Cat. AA-2035 $ 00 computer or notebook. 119. USB Missile Launcher Connected to your USB port the software will allow you to navigate the missiles trajectory, pan 180°, tilt up to 45° and provide realistic sound effects. The missiles are made from soft foam so its safe to use at home or in the office. • Software compatible with Windows 2000 and Windows XP • Not suitable for children. Cat. GE-4072 $ 95 59. USB Colour Changing LED Lava Lamp Brighten up that special area in your house or office by using this colour changing LED ice rocket. It is easily connected to any USB port and instantly begins to change colours slowly and deliberately enhancing the dullest of rooms. Cat. GH-1520 $ 95 • 170mm tall 14. 5 CCD Colour Camera Disguised as a Smoke Detector Featuring a SonyTM CCD sensor this camera is ideal for covert, indoor surveillance applications. Cat. QC-3555 $ 00 169. Professional Camera Housing with IR and Heater This weather resistant enclosure is ideal for protecting our professional range of CCD security cameras from wind and rain in sheltered outdoor situations. The ABS plastic housing features a glass lens for clear vision, LED illumination for night vision and a ventilation fan and heater to remove moisture and eliminate condensation. See our website for our full range Cat. QC-3386 $ 95 of professional cameras. Housed in a strong die-cast aluminium base with a L-shaped bracket and a reinforced polycarbonate dome, this vari-focal camera is designed to withstand the harshest of environments. SonyTM sensor and manual Sony TM S ensor focus 3.5 - 8mm Inside CS type lens. Cat. QC-3297 $ 00 299. IR Door or Perimeter Entrance Alert The perfect electronic entrance guarding device. Utilises infrared and microprocessing technologies to create a reliable and invisible infrared beam up to 20 metres. Cat. LA-5184 Requires 2 x 9V alkaline batteries 95 (SB-2423) or a 9VDC adaptor (MP-3003). $ 49. Infrared Security Spotlight The long range beam has a range of 30 metres and will switch on automatically as darkness falls. 99. Bracket to suit: QC-3387 $19.95 Professional Camera Housing without IR & Heater: QC-3385 $59.95 Professional IR Cameras Vari-Focal Colour Dome Camera with L Bracket Cat. QC-3652 $ 95 79. These units are triggered 'ON' automatically by a CDS sensor during low light conditions and 'OFF' when there is sufficient light. They incorporate a high resolution 1/3" Sony sensor with 16x digital zoom, built-in internal synchronisation and are suitable for permanent long range surveillance applications. Cat. QC-3286 • 12VDC operation $ 00 • Measures 110(D) x195(L)mm 399. Professional Camera with IR range up to 35m Cat. QC-3288 $ 00 Professional Camera with IR range up to 50m 599. 2.4GHz 4 Channel Wireless Receiver with Remote Control Audio and video! Receiving up to four 2.4GHz cameras, you can switch between cameras manually, or set it to automatic. Composite video output allows display or recording on any device. Cat. QC-3593 Mains plug pack & cables are also supplied. $ .95 Was $129.95 Buy two QC-3595 Save $30 cameras and one QC-3593 receiver for $239 save $230.85 99 2.4GHz Wireless Colour CCD Rechargeable Camera with Audio Higher p spotlig ower availab ht also le QC-3 655 $249.9 5 The ultimate in portability! This camera features an internal Lithium-Ion rechargeable battery that Cat. QC-3595 can operate the camera for up $ .95 to 5hrs per charge. 169 Remote Monitoring GSM Alarm Automation Transmitter Receiver Zoom Colour Camera It can be utilised as the heart of your home automation or security system. With 2 onboard relays (expandable to 8) it easily connects to eight different pieces of equipment such as the air conditioner, central heating system and electric gates. Keep up to four different sensors under surveillance and in the event of a security breach, or AC power failure, the unit will send an SMS alarm message or an email to a PC. See our website or page 294 of our catalogue for full specifications and application areas. Expand the G-smart to switch Cat. LA-5370 6 extra relays to control $ 00 additional applications LA-5372 $99.00 699. USB Pan/Tilt Colour Camera You can log onto a preset IP address, and take control of the pan/tilt functions. Software is included and is compatible with Windows 98, SE, ME, 2000, and XP. • 640 x 480 pixels resolution. • CMOS sensor • 110(L) x97(W) x86(H)mm Was $229.00 Cat. QC-3395 SAVE $ 00 $10 6 219. Sony TM Senso r Inside This professional surveillance camera has 22x optical and 16x digital zoom and can be adjusted via our QC-3213 controller and our scanner motor QC-3218 (shown below). The camera supports auto iris, focus, backlight compensation and gain control, auto white balance, and features flickerless picture, integrated on screen display for set-up Cat. QC-3502 00 menu adjustments and has a built-in microphone. $ 599. Pan and Tilt Motor Mount with Zoom Control Features zoom and focus controls to suit our zoom camera QC-3502 (shown above) and will pan through 355° and tilt through 100° via its high speed, high torque 24VAC motor. See our catalogue or Cat. QC-3218 website for full specifications. $ 00 Excellent for 2.4GHz security surveillance transmissions. This 24dB directional parabolic antenna is also suitable for all 2.4GHz wireless networks and is designed for outdoor permanent locations. • Mounting hardware Cat. AR-3276 included $ 95 • Picture may vary from stocked product 159. IP Camera with 6 IR LEDs 299. Pan/Tilt/Zoom Controller Combine this unit with one our receivers like the one shown below to provide individual pan, tilt and zoom control of cameras at up to 100 remote locations. The unit has a 2 wire interface, PELCO D control protocol and has focus and iris Buy the QC-3213 controls Cat. QC-3213 controller and our QC-3212 included. $ 95 pan/tilt/zoom receiver together for $349.90 SAVE $50! 2.4GHz Parabolic Antenna 249. Pan / Tilt / Zoom Control Receiver Very versatile! Will nterface with a controller like the one shown above to control Pan / Tilt / Zoom cameras, as well as focus and iris controls when required. Can be used up to 2km away from the controller, and also has a relay output for controlling Cat. QC-3212 $ .95 lighting or locks etc. This compact IP can be used in a network and will provide world-wide video coverage through Internet Explorer. The camera incorporates a built-in web-server and includes motion detection software which provides automatic intruder sensing. The camera has six infrared LEDs to provide night vision capabilities. • Supplied with mounting bracket, software, and mains power adaptor 149 Cat. QC-3396 $ 00 249. Wirele ss IP also av camera a QC-33 ilable 98 $34 9 FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 INTERNET> www.jaycar.com.au Electronics Demystified Book 10mW Green Laser Module Extremely Bright! This laser module consists of a 10mW laser SAVE diode, lens, and driver PCB. $10 Simply connect a 3VDC supply, Was $149.95 and you have a great high power Cat. ST-3117 laser. Datasheet included. $ 95 •Measures 65(L) x 11(dia) mm The book starts at simple DC circuits, goes through AC circuits, impedance, reactance, power supply concepts, semiconductor basics, amplifiers, oscillators, RF, telecommunications and finishes on antennae. At the end of each chapter is a straightforward quiz. • Softcover 480+ pages • Dimensions: 230 x 185mm 139. Cat. BM-7106 $ 95 34. Lead Free Soldering Station This is an industrial quality product. If your work requires compliance with 'Reduction of Hazardous Substance' (RHoS) directives, you must use lead free solder. This quality Japanese made station will go from cold to 350°C in six seconds! See our website for full specifications. Was $599.00 SAVE Cat. TS-1490 $50 $ 00 549. Cluster Type T1 3/4 LED Lamp • Power supply: 10V <at> 20mA • Output light: 1950mcd <at> 20mA • Cluster-type red/green T1 3/4 LEDs • Lens: Waterclear • Common Annode • 14 LED Cluster (8 green/6 red) • 660nm for red/570nm for green Cat. ZD-0350 • Mounting hole diameter: M3 $ 95 • Size: 26mm(dia) x 39mm(L) 12. Testers SAVE $5 Volt Sensor 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. Was $24.95 Cat. QP-2274 $ 95 Sound Level Meter 19. Features include data hold, selectable time weighting in 2-stages, high and low range selection (35 to 100dB and 65 to 130dB), A&C weighting and an in-built calibration circuit. A tripod 3/8" thread is also provided, along with a removable foam windshield. The meter is powered by a single 9V battery (included) and includes a soft foam insert zip-up carry case, complete with shoulder strap. Limited quantity. Was $149.95 SAVE Cat. QM-1588 $60 $ 95 89. Non-Contact Digital Thermometer SAVE $40 This infrared thermometer quickly takes the surface temperature of any object and features a built-in laser pointer for targeting from a distance. • 50 to +500degrees C Was $119.95 Cat. QM-7222 $ 95 79. LCD Modules Wide viewing angle of standard 16 character, 2 line LCD display. • Module Dimension: 85(W) x 30(H) x13.2(T)mm • Viewing Display Area: 65(W) x16(H) mm • Character Size: 2.78(W) x4.89 (H) mm Cat. QP-5517 Two models available: $ 95 Without backlight QP-5517 Cat. QP-5518 $ 95 With backlight QP-5518 29. 23. A large character size LCD that can be viewed from a further distance, handy for when the Cat. QP-5520 panel needs to be mounted $ 95 behind perspex. • Module Dimension: 122(W) x44(H) x13.2 (T) mm • Viewing Display Area: 99(W) x24(H) mm • Character Size: 4.9(W) x9.7 (H) mm 39. This DMM can be taken places where the others can't go. IP67 rated, it can survive harsh environments and will resist the ingress of fines everywhere from the dusty outback to any filthy warehouse in the big smoke. See website or Cat. QM-1541 $ 95 catalogue for full specifications. 99. Smart Home Cable Tester VDV Multimedia Cable Tester. Tests all common low voltage cabling systems found in today's automated homes such as Voice, Data, and Video Networks. Comes with remote terminator. Was $199.00 SAVE $20 Digital Megohmmeter Price breakthrough! Megohmmeters generate high voltage, low current signals for testing the breakdown strength of electrical insulation. Includes a rubber holster, test leads with alligator clips, 200M and 2000M Ohm ranges and simple, one button, "push to test" operation. See our website or catalogue for Cat. QM-1492 $ 95 full specifications. 99. FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 INTERNET> www.jaycar.com.au 699. Laser Level with Tape Measure The range of the laser line projects up to 6m indoor and covers an angle arc of 45 and 90 degrees. The unit incorporates a horizontally spread laser to create illuminated guide lines along walls, horizontal and vertical levels. It also has a handy 2.5m tape measure and ruler. Was $39.95 SAVE $5 Cat. ST-3113 $ .95 34 Metalic appearance, SPST with momentary action. Available with a red, green or blue LED. Vertical SP-0612 Red SP-0613 Green SP-0614 Blue Horizontal SP-0615 Red SP-0616 Green SP-0617 Blue Vertical ea $ 49 Horizontal ea $ 49 3. 3. Temperature DMM IP67 Rated DMM 179. SAVE $300 The ideal CRO for the busy workshop. Features 40Mhz bandwidth and a big clear screen. Supplied with 2 sets of probes. See website for full specifications. Limited qty available. Was $999 Cat. QC-1901 $ 00 PCB Mount Vertical & Horizontal Tactile Switches with LED Dot Matrix LCD Alphanumeric Module Cat. QP-2290 $ 00 40MHz Dual Trace CRO A low cost DMM which includes temperature measurement and a "HV" warning on the display when high voltage ranges are selected. A data hold button is positioned in the centre of the selection wheel for easy access. Includes test probes and temperature lead. Cat. QM-1521 $ 95 19. Electrical Tester with Polarity Checker and LED This unit's LED display will indicate to the nearest voltage up to 690V with polarity indication. It will also check for low impedance, continuity, do a single pole phase test and show rotary field indication. A LED light is included for use in poor light conditions and the probes are IP64 rated. • Requires 2 x AAA batteries (included) • Voltage test works Cat. QP-2286 $ 95 without batteries 49. Network Cable Tester and Digital Multimeter This innovative device is ideal for network installers or technicians and will allow the user to easily check cable integrity or measure AC & DC voltage, etc. without needing to carry two separate devices. See our website or catalogue Cat. XC-5078 $ 95 for full specifications. 79. 7 Battery Zapper Kit Mk II Ref: Silicon Chip May 06 Like its predecessor this kit attacks a common cause of failure in wet lead acid cell batteries: sulphation. The circuit produces short bursts of high level energy to reverse the damaging sulphation effect. The improved unit features a battery health checker with LED indicator, new circuit protection against badly sulphated batteries, test points for a DMM and connection for a battery charger. Kit includes machined case with screenprinted lid, PCB with overlay and Cat. KC-5427 all electronic components. $ 95 • Suitable for 6, 12 and 24V batteries 99. Battery Zapper Add-On Kit Ref: Silicon Chip May 06 If you are one of our many satisfied customers of the original battery zapper kit, buy this add-on and upgrade your zapper to the full functionality of the Battery Zapper Mk II (KC-5427). New components and processed case supplied however, to complete the upgrade some original Cat. KC-5428 $ 95 components need to be recycled. YOUR LOCAL JAYCAR STORE Freecall Orders: Ph 1800 022 888 NEW SOUTH WALES Albury Ph (02) 6021 6788 Alexandria Ph (02) 9699 4699 Bankstown Ph (02) 9709 2822 Blacktown Ph (02) 9678 9669 Bondi Junction Ph (02) 9369 3899 Brookvale Ph (02) 9905 4130 Campbelltown Ph (02) 4620 7155 Erina Ph (02) 4365 3433 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 Sunshine Ph (03) 9310 8066 QUEENSLAND Aspley Ph (07) 3863 0099 Mermaid Beach Ph (07) 5526 6722 Townsville Ph (07) 4772 5022 Underwood Ph (07) 3841 4888 Woolloongabba Ph (07) 3393 0777 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 Christchurch Ph (03) 379 1662 Glenfield Ph (09) 444 4628 Hamilton Ph (07) 846 0177 Manukau Ph (09) 263 6241 Newmarket Ph (09) 377 6421 Wellington Ph (04) 801 9005 Freecall Orders Ph 0800 452 9227 8 59. Voltage Monitor Kit Ref: Silicon Chip May 06 This versatile kit will allow you to monitor the battery voltage, the airflow meter or oxygen sensor in your car. The kit features a 10 LED bargraph that lights the LEDs in response to the measured voltage, preset 9-16V, 0.-5V or 0-1V ranges complete with a fast response time, high input impedance and auto dimming for night time driving. Cat. KC-5424 Kit includes PCB with overlay, LED 95 bargraph and all electronic components. $ •12VDC •Recommended box: UB5 HB-6015 $2.50 19. The 'Flexitimer' Ref: Electronics Australia March 1991 We have revised the original design and now provide two modes of operation. The original on-shot count down mode is retained and we have added an interval mode with a 50% duty cycle. The kit can switch a number of different output devices and may be powered by a battery or mains plug pack. •Kit includes PCB & all components! Cat. KA-1732 •Requires 12- 15V DC (use $ 95 Cat. MP-3006 plug pack) Velleman PIC Programmer Checker Module Versatile! Supporting 8 pin, 14 pin, 18 pin, and 24 pin PIC microcontrollers, this board is quite versatile. The kit includes test buttons and LED indicators for on-board experimenting and testing, as well as programming software. Includes a PIC16F627. Cat. XC-4402 $ 00 119. Interface your computer to the real world There are five digital and two variable gain analogue inputs. Eight digital and two analogue outputs are available. Supplied with all components, silk screened PCB, assembly manual, and software. Cat. KV-3600 $ 95 69. 18. AVR Adapter Board Stereo Headphone Distribution Amplifier Ref: Silicon Chip March 06. A low cost method of stand-alone programming. The board contains 5 programming sockets, 1 for each group of micros with common ISP pin outs. Kit Includes: on board regulated power supply, clock source and microcontroller IC sockets. Designed in Cat. KC-5421 conjunction with KC-5340 shown below. Power: $ 95 12VDC 150mA (use MP-3002). Ref: Silicon Chip November 05 Enables you to drive up to two stereo headphones from any line level (1volt peak to peak) input. The circuit features a facility to drive headphones with impedances from about 8-600 ohms. The Jaycar kit comes with all specified board components and quality fibreglass tinned PCB. Cat. KC-5417 $ 95 34. AVR ISP Serial Programmer Kit 29. Ref: Silicon Chip October 2002 Program, erase and rewrite the program and data memory in your AVR microprocessor without removing it from the application circuit. This kit connects to the computer serial port, uses royalty-free software available on the Internet and allows you to program a multitude of micros in the AVR 8-bit RISC family (see Cat. KC-5340 website for full listing). Kit supplied with $ 00 PCB, Jiffy box with silkscreened lid and all electronic components. Headphone Amplifier Power Supply Kit Ref: Silicon Chip October 05. To ensure the best possible performance to the Headphone Amplifier Kit, this will provide regulated +/- 15V and +5 outputs. •Toroidal transformer required Cat. KC-5418 $ 95 use MT-2086 45. 17. High Performance Electronic Projects for Cars High Performance Electronic Projects for Cars Book Australia's leading electronics magazine Silicon Chip, has developed a range of projects for performance cars. There are 16 projects in total, ranging from devices for remapping fuel curves, to nitrous controllers, and more! The book includes all instructions, components lists, colour pictures, and circuit Cat. BS-5080 layouts. There are also chapters on engine management, advanced systems and DIY $ 80 modifications. Over 150 pages! All the projects are available in kit form. 19. Nitrous Fuel Mixture / Motor Speed Controller Frequency Switch This is a great module which can be adapted to suit a It makes a great motor controller, to control an electronic range of different applications.You could configure it water pump, additional fuel pump, cooling fans to trigger water spray cooling on deceleration, and more. It is suitable for use with most fuel We stock an shift light activation, adjustable aerodynamics injectors, or pumps and motors up to 10 amps. extensive range of based on speed, intake Kit supplied with PCB and all electronic automotive kits manifold switching and components. much more. Kit supplied •Please note that the use of Nitrous with PCB, and all Oxide systems is for race use electronic components. only. Use of these systems on Cat. KC-5382 the street is Cat. KC-5378 $ 95 illegal. $ 95 24. PRICES VALID TO 30/06/06 35. FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 INTERNET> www.jaycar.com.au PRODUCT SHOWCASE DSE makes soldering (even lead-free soldering) a pleasure! Dick Smith Electronics have submitted a range of new soldering products, including some still-relatively-hard-toget lead-free solder in handy dispensers. With the new EU directive now in force, local manufacturers wishing to sell into Europe (and many other countries) have to comply with the lead-free solder edict. The new 13g DSE lead-free solder tubes (lower left) contain either 99.3% tin and 0.7% copper (Cat N1633 <at> $1.98) and 95.5% tin, 4% silver and 0.5% copper (Cat N1635 <at> $2.96 ea). Also in the top pic is the 8W Battery-Powered Soldering Iron (Cat T2502 <at> 29.97). Unlike most battery irons on the market, this operates on AA alkalines, giving a continuous run time of about 40 minutes. Alongside is the T1256 Heavy Duty Soldering Iron Stand (yes it is heavy!), complete with tangled spiral brass tip cleaner (retail price $14.90) and at bottom right is the T2574 Heavy Duty Solder Sucker (retail price $14.99). The lower pic shows the new T2250 240V Temperature Controlled Solder Sation. This has easy adjustment of tip temperature from 150-450°C with a LED digital readout. The iron itself is a fast-response, lightweight 55W type with a highly flexible silicone rubber cable. This soldering station is ideal for all users from the hobbyist through to general service and production lines. One handy feature of this iron is a lock to prevent other people adjusting temperatures: perfect for production work! It also includes a similar heavy duty soldering iron stand, similar to the one shown above (without the brass tip cleaner). Recommended retail price is $99.99. $1 coin hopper/sorter/dispenser from Oatley: one man’s junk is another man’s treasure! When we first heard about these we thought “what junk!”. Apart from the fact that they nearly were (junked, that is!) when Branko from Oatley Electronics bought a whole pallet of the things, when we saw them we quickly changed our minds! If you happen to need to sort/count/ dispense a lot of $1.00 coins, you will be laughing. These are brand new, in perfect condition. Otherwise, if you happen to need a really nice DC motor and metal-gear gearbox (shown separately in front; rated at 24V, has plenty of grunt at 12V and will start turning at about 2V!) along with a plethora of other bits and pieces . . . at just $12 each or three for $27 they are a real bargain. There’s more info on Oatley’s website. Hey, garage door opener anyone? siliconchip.com.au Contact: Dick Smith Electronics PO Box 500, Regents Part NSW 2143 Tel: 1300 366 644 Fax: (02) 9642 9155 Website: www.dse.com.au AUDIO MODULES broadcast quality Contact: Oatley Electronics PO Box 89, Oatley NSW 2223 Tel: (02) 9584 3563 Fax: (02) 9584 3561 Website: www.oatleye.com Manufactured in Australia Harbuch Electronics Pty Ltd 9/40 Leighton Pl. HORNSBY 2077 Ph (02) 9476-5854 Fx (02) 9476-3231 June 2006  61 Telelink gets into ZigBee Telelink Communications, one of Australia’s most respected distributors of professional and OEM wireless data modules, have announced a distribution deal with UK-based Telegesis to distribute their new ZigBee modules in Australia. ZigBee now joins Telelink’s extensive range of VHF and UHF wireless data solutions. Telelink’s Jack Chomley said that ZigBee was definitely shaping up as “the wireless of the future” with applications “in just about everything,” he said. “They’re even talking about putting ZigBee into light switches to drastically reduce building wiring! The beauty of ZigBee is that it runs on the smell of power and offers high performance over short ranges.” Telelink already stocks the Telegesis ETRX1 ZigBee modules with the new ETRX2 designs expected as this isue went to press. They offer a high level of technical backup and even design service to OEMs, contractors and industry and are contactable 24 hours a day, seven days a week. Radio, Television & Hobbies: the archive on DVD “You’ll remember young Albert Ramsbottom, got eat by lion at zoo. . .” so goes the monolog written by the late Neville Williams (with apologies to Stanley Holloway, of course). Well, that’s one of the lesser technical gems, almost lost to the annals of history, which you’ll find on the DVD containing the Complete Archives of Radio, Television and Hobbies Magazine (predecessor to the now-defunct Electronics Australia). And you thought R, TV &H was all technical articles! This remarkable collection of PDFs covers every issue of R & H, as it was known from the beginning (April 1939 – price sixpence!) right through to the final edition of R, TV & H in March 1965, before the change of name to EA. Contact: Telelink Communications PO Box 5457, Nth Rockhampton, Qld 4702 Tel: (07) 4934 0413 Fax: (07) 4934 0311 Website: www.telelink.com.au For the first time ever, complete and in one handy DVD, every article and every issue is covered. If you’re an old timer (or even young timer!) into vintage radio, it doesn’t get much more vintage than this. If you’re a student of history, this archive gives an extraordinary insight into the amazing breakthroughs made in radio and electronics technology following the war years. And speaking of the war years, R & H had some of the best propaganda imaginable! And even if you’re just an electronics dabbler, there’s something here to interest you. SILICON CHIP (which now owns Wireless World, Radio TV and Hobbies, Electronics Australia and Electronics Today titles and copyright) is continually requested to provide back issues (now non-existent!) or photostat reprints of R & H or R, TV & H articles. Now you can have them all – and discover all those articles you’d probably forgotten even existed. Then there are all those names of the past: John Moyle, Neville Williams, Keith Jeffcoat, Maurie Findlay, Ian Pogson, Phil Watson . . . – yours to read once again, over and over. (Apologies to the dozens of writers not mentioned!) This incredible DVD is available exclusively from SILICON CHIP Publications for the ridiculous price of just $69.00 including pack and post. (When you consider just one project reprint costs $8.80, you can see just what amazing value this DVD really is). Don’t miss out on adding this one to your collection. You can order it by mail, by phone, by fax, by email or via the SILICON CHIP website. There is a handy order form on page 103 of this issue. SILICON CHIP WebLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK OurWEBLINK website SC is updated with overSC WEBLINK specialiseSCinWEBLINK providingSCa WEBLINK range of SC WEBLINK SC SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK We SC WEBLINK WEBLINKdaily, SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK WEBLINK SCsolutions WEBLINKfor SCOEM’s WEBLINK SC WEBLINK SCavailable WEBLINKthrough SC WEBLINK products our SC WEBLINK LowSC Power Radio to SC WEBLINK5,500 SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK secure online ordering facility. incorporate in their wireless technology SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK Features include semiconductor dataSC WEBLINK based products. innovative range SC WEBLINK SC SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SCThe WEBLINK SC WEBLINK WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK WEBLINK SC WEBLINK WEBLINK SC WEBLINK WEBLINK SC WEBLINK sheets, media releases, SC software includes products SC from MK Consultants, theSC WEBLINK SC SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK downloads, muchSC more. world-renowned specialist manufacturer. SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC and WEBLINK WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK Tel: 022 Tel:(07) 4934 0413 Fax: (07) 0311 Tel: 1800 1800 022 888 888 SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC4934 WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK ilicon hip SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK Want your product or service featured both here and on the SILICON CHIP website for the one low price? Contact Glyn Smith on 0431 792 293 for all the details! 62  S C TeleLink Communications JAYCAR JAYCAR ELECTRONICS ELECTRONICS WebLINK: telelink.com.au WebLINK: WebLINK: www.jaycar.com.au www.jaycar.com.au siliconchip.com.au SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC CompactDAQ from National Instruments National Instruments’ new USB-based modular data acquisition system – NI CompactDAQ is ideal for sensor and electrical measurements on the benchtop, in the field and on the production line. The NI CompactDAQ system offers an eight-slot chassis that accepts I/O modules capable of measuring up to 256 channels of electrical, physical, mechanical and acoustic signals in signal streams for synchronous analog a single system. By combining the and digital I/O for data-intensive plug-and-play simplicity of USB applications including sound and with the performance and flexibility vibration, mixed-signal automated of modular instrumentation, NI Comtest and high-speed data logging. In pactDAQ provides fast and accurate addition, the small size (25 x 9 x 9cm) measurements in a small, simple and and flexible power options (AC or 11 affordable system. - 30VDC) make NI CompactDAQ ideal The new system delivers connecfor a wide range of test settings, such tivity and signal conditioning for as in-vehicle, benchtop and automated measurements including voltage, temtest applications. perature, strain, sound and vibration, Prices start at $US999. as well as digital I/O and switching. Contact: All modules are hot-swappable and National Instruments Australia autodetectable for simplified setup, PO Box 382,North Ryde, NSW. 1670 and offer up to 2300V RMS of isolaTel: 1800 300 800 Fax: (02) 9888 6611 tion to ensure PC and user safety. The Website: www.ni.com/oceania system delivers four dedicated USB Contenders for 78xx replacement? Linear Technology Corporation’s new LT3012B and LT3013B micropower low dropout regulators (LDOs) have input voltage capability up to 80V and feature low dropout voltage of only 400mV, while delivering up to 250mA of output current. The wide VIN capability of 4V to 80V makes these devices ideal for automotive, 48V telecom backup supplies and industrial control applications. Additionally, their very low quiescent current as low as 40mA (op- erating) make them an excellent choice for battery-powered “keep alive” systems that require extended run times. The LT3013B’s Powergood flag features programmable delay to indicate output regulation. Contact: Soanar Inc (LTC Distributors) Unit D1, 3-9 Birney Av Lidcombe NSW 2141 Tel: 1300 889 883 Fax: (02) 9741 0155 Website: www.soanar.com.au And the winner is... The April monthly winner of one of these superb DSE 20MHz dual-channel ’scopes is Mr Peter Morton of Greenock, SA Want to be a winner? Simply subscribe to SILICON CHIP (or renew your subscription) and your name could be drawn! See P91 of this issue for full details! Bargain Morphing software Ever wondered how those manipulated or exaggerated sections of photos are created? It’s called “Morphing” and this feature is sometimes built into expensive photo manipulation software packages. But you can do it cheaply: a new edition of Morpheus Photo Warper (V3.0) is now available for just $US29.95. Now you can exaggerate physical features of friends, family, celebrities, politicians, pets – anyone or anything; create hilarious warps and picture distortions you can email to friends in seconds! Log onto www. morpheussoftware.net for a free trial download. C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SCWe WEBLINK WEBLINK SC WEBLINK SC WEBLINK supplySC Radiometrix VHF & UHF OEM radio SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SCmodules WEBLINKfor SCwireless WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK data comms, control and SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK For everything in radio control for aircraft, JED designsSC and manufactures a C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK WEBLINK SC WEBLINK SC WEBLINK monitoring. We also stock low costSCeasy to model boats and planes, etc. WeSC also carry SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK WEBLINK SC WEBLINK SC WEBLINK rangeSC of WEBLINK single board computers (based SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK use Bluetooth modules and the new rfBASIC an extensive range of model flight control on Wilke Tiger and Atmel AVR), as well as SC WEBLINK C WEBLINK SCprogrammable WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK radio modules as wellSCasWEBLINK other SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK modulesSC including altitude and speed, SC WEBLINK LCD SC displays andSC analog and digital I/O SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK WEBLINKGPS, SC WEBLINK SC WEBLINK WEBLINK WEBLINK SC WEBLINK RF accesssories. C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SCand WEBLINK SC WEBLINK SCmakes WEBLINK interfaces, autopilotSC WEBLINK and groundstation for PCs controllers. JED also a SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK Radiometrix - Engineers preferred choice for controllers. More info on our website! PC PROM programmer and RS232/RS485 C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK VHF & SC UHF Low Power Radio Modules C WEBLINK SC WEBLINK WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK converters. C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK Tel:(07) 4639 1100 Fax: 1275 (02) 9533(07)4639 3517 C WEBLINK SC WEBLINK WEBLINK WEBLINK SC WEBLINK WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK WEBLINK WEBLINK WEBLINK Tel: (03)SC9762 3588SCFax: (03)SC 9762 5499 SC WEBLINK Tel: (03)SC 6331 6789 SC Fax: (03) 6331 1243 SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SCTel/Fax: C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK une C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK C WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK RF Modules Australia Silvertone Silvertone Electronics Electronics Jed Microprocessors Pty Ltd WebLINK: www.rfmodules.com.au WebLINK: www.silvertone.com.au WebLINK: silvertone.com.au WebLINK: jedmicro.com.au siliconchip.com.au J 2006  63 SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC SC Salvage It! BY JULIAN EDGAR A high-current car battery charger for almost nothing Want a high-current 12V battery charger but don’t want to pay big dollars? It’s easy – just scrounge a salt-water pool chlorinator and modify it. H IGH-CURRENT battery chargers are expensive. Those that can deliver a genuine 15A or 20A, rather than just say 3A, can cost hundreds of dollars, which most of us find hard to justify. Well, forget about high costs and instead find a salt-water pool chlorinator someone is throwing away. It can be easily adapted to make a high-current battery charger, as we shall see in this article. Salt-water chlorinators Salt-water chlorinators are used with some swimming pools, whereby salt – rather than chlorine – is added to the pool to provide disinfection. In operation, a high-current, low-voltage DC power supply is connected to an electrolytic cell through which the salty pool water is pumped. This process then breaks the salt down into sodium hypochlorite. Inside a typical salt-water chlorinator control box you’ll find a big mains power transformer, a bridge rectifier (or alternatively, two stud diodes) and a pressure switch. In addition, there will often be a front-panel ammeter (occasionally marked in odd units relating to chlorine), a fuse, an on/off switch, a pilot lamp and sometimes a high/low (summer/winter) switch. Some of the fancier units may also have an electronic timer. They may also be able to monitor chlorine levels and include automatic polarity reversal circuitry to periodically clean the electrolytic cell. All these latter bits can be discarded for this project. The current and voltage specifications vary from unit to unit. For example, the three units I recently picked up ($30 total!) have ratings of 25A at 8.6V, 12A at 4.6V, and 25A at 7V. Ignoring for the moment the added bits and pieces like timers, the design of the power supply also varies. Fig.1 shows a mains transformer using a centre-tapped secondary, with two diodes used for the rectification. Fig.2 shows another approach – in this case, a mains power transformer connected to a bridge rectifier. Increasing the voltage These salt water chlorinators look like old junk but here is nearly all that you need to build a high-current car battery charger. Chlorinators often appear the worse for wear because of their exposure to salt but inside, the important components usually still work fine. 64  Silicon Chip So how do you increase the voltage output of these devices? After all, 4.6V, 7V and 8.6V outputs are all too low to charge a 12V battery – for that you need at least 15V and preferably 16-18V. The approach you take depends on the internal design of the chlorinator. If the chlorinator uses Fig.2’s approach, you’ll need two such units. siliconchip.com.au You then wire the secondaries of their transformers in series (and in phase, so that their combined AC output voltage is added) and use a bridge rectifier on the output. By taking this approach, with the voltage outputs of the two transformers effectively added together, the maximum current output is dictated by the transformer with the lowest rating. For example, lets say you have two chlorinators – one with 25A output at 8.6V and another with 12A output at 7V. In this case, they can be combined to produce an output voltage of about 16V at a maximum current of 12A. Alternatively, if your chlorinator uses the approach shown in Fig.1, it’s even easier. In this case, twice the nominal output voltage can be gained (at half the current) by discarding the existing diodes and connecting the transformer’s secondary output to the AC inputs of a bridge rectifier and heatsink instead (note: the centre tap wire is no longer used). This approach is easier because you don’t need to fit a second transformer inside the one box – instead, all you have to do is make some internal wiring changes and add the bridge rectifier and heatsink. In addition to a source of high current DC, you’ll also need a resistor. This resistor is used to limit the maximum current that can flow when you connect the charger to a flat battery, to prevent damage to both. Although the value of this resistor can be calculated, it’s much easier in practice to try different resistors and make a few measurements. We’ll show you how to do that shortly and describe how to make a suitable high-power, low-resistance, adjustable resistor. Finally, the charger should automatically disconnect when the battery is fully charged. This is achieved by using a modified “Simple Voltage Switch” kit, as originally described in SILICON CHIP’s “High Performance Electronics for Cars” book. The obligatory warning! OK, the theory is pretty straightforward so now let’s do it! But first, a word of warning. Unlike some of the other projects covered in this column, this definitely isn’t a 5-minute job. By the time you repaint the metal box, make a current limiting resistor, build the “Simple Voltage Switch” and put it all together, siliconchip.com.au Fig.1: salt-water chlorinators commonly use a transformer with a centretapped secondary and two diodes for rectification. If the diodes are replaced with a bridge rectifier and the centre tap no longer used (see Fig.2), the output voltage is doubled while the current rating is halved (although still very high). This makes for a very effective high-current battery charger. Fig.2: another common approach is to use a bridge rectifier with a noncentre tapped transformer. To increase the output voltage, a second transformer needs to be added, with the secondaries connected in series and in phase. The voltage outputs of the transformers are then added together, with the current output capability dictated by the transformer with the lowest rating. it’s probably a full day’s work. And it’s not a project for the inexperienced. On the other hand, it’s a lot of fun, you’re guaranteed to learn something and you won’t need to reach very deeply into your pocket. Best of all, you’ll end up with a high-current battery charger that should prove really useful from time to time. Picking the donor Salt water chlorinators commonly appear anywhere junk is being discarded – especially in areas where there are lots of swimming pools! Garage sales, the shops associated with municipal tips, household goods auctions and secondhand stores are all good places to look. Of course, like many of these things, if you specifically go looking for them, you’ll never see any, so it’s best to keep a look out over some time. The chlorinators ideally suited for battery charger conversion have a transformer with a centre-tapped secondary. You’ll have to open it up Main Features • • • • • • • High current charging Automatic switch-off when battery charged Ammeter to indicate charging rate Fan cooling – essential! Over-temperature shut-down Charge-finished indicator Very low cost to check this out – look for three wires coming from the secondary (low-voltage) side of the transformer and their associated large diodes. In addition, it should have an ammeter, a high current rating and a voltage output that can be doubled to 16-20V to make it suitable for battery charging (ie, an initial DC output of 8-10V). A high/low setting will also give your completed charger greater versatility. June 2006  65 heatsink from one, the power switch from another, and so on. Making the modifications ➋ ➌ ➊ ➍ ➎ ❼ ❽ ❾ ➏ This is what a typical chlorinator with a centre-tapped transformer secondary looks like inside: (1) transformer; (2) pressure switch; (3) one of the two diodes (the other is closer to the camera but hidden); (4) ammeter; (5) DC output connector; (6) DC output pilot lamp; (7) AC fuse; (8) winter/summer switch; (9) power switch. This type of design is easily modified to produce double the original output voltage at half the current, making it suitable for car battery charging. Obviously, you also want the transformer to be working but this can be difficult to assess when looking at a discarded unit – the fuse, internal pressure switch and pilot light may all be broken, so it can be difficult to tell! However, if it’s cheap enough, buy it anyway – in most cases, the transformer is fine. In fact, if you can buy two or three low-cost chlorinators, do so – you may be able to take the bridge rectifier and Check The Mains Wiring Before making any modifications, it’s important to carefully check the original mains wiring, to make sure it is safe. First, the Earth lead from the mains cord should make good contact to the case. Use your multimeter to check for continuity between the Earth pin of the mains plug and the case – you should get a reading of zero ohms. Next, check that the mains cord is in good condition (no nicks or cuts) and that it is securely clamped. The Active and Neutral wiring should have insulation that is in good condition and the leads must be correctly terminated. Check also that the mains plug is wired correctly. It may have been replaced at some stage and someone might have made a wiring mistake! Finally, it’s a good idea to insulate any exposed mains connections that might be present (eg, at fuseholders and switches), to avoid the possibility of receiving a severe (possibly fatal) shock. Do not attempt any work unless you know what you are doing. 66  Silicon Chip Now let’s modify the salvaged chlorinator. The first job is to electrically bypass the pressure switch (in the original application, this switch is used to detect water flow). That done, check the fuse (replace it if necessary) and reinstall the cover. Next, connect the unit to mains power and use your multimeter to check the DC output voltage. If this is present, place a load across this output (eg, a 50W car headlight bulb) and check that the ammeter (if fitted) reads correctly. If there is no DC output, switch off immediately and pull out the mains plug. Remove the cover, then measure the resistance of both the primary and secondary windings of the transformer. In each case, the measured resistance should be very low – a few ohms or less. If it is infinite, the coil winding is open circuit and the transformer is faulty. OK, let’s assume that you have a unit with a working transformer. We’ll also assume that the transformer has a centre-tapped secondary and that the unit uses two rectifier diodes (ie, it uses the configuration shown in Fig.1). The modification procedure is as follows: (1) Check that the mains plug has been pulled out of the wall socket, then remove the diodes and the associated heatsink. (2) Cut and insulate the centre-tap lead (ie, the wire on the secondary side of the transformer that went straight to the negative output terminal). (3) Connect the transformer’s two secondary leads to the AC (~) terminals on a bridge rectifier. Assuming you have salvaged the bridge rectifier from another chlorinator, make sure that it has a current rating at least as high as the rating of the modified unit. This bridge rectifier should be mounted on a heatsink. (4) Connect cables to the plus (+) and minus (-) terminals of the bridge rectifier and temporarily run them out of the case. These form the DC output leads (use red for positive and black for negative). (5) Reinstall the cover, connect the chlorinator to mains power and switch on. You should now be able to measure twice the original DC output voltage, siliconchip.com.au while the maximum available output current will be halved. (6) Switch off and install a fuseholder in the positive line. A fuseholder can be salvaged from other equipment or you can use an in-line fuseholder that takes an automotive-type blade fuse. Match the fuse rating to the new current rating of the power supply (remember, if you double the voltage, you halve the available current). In the author’s unit, a square hole had to be cut in the rear panel in order to install the bridge rectifier and its associated large heatsink. This heatsink had been held in place in another chlorinator by means of pop rivets and so rivets were also used to secure it in its new location. However, before doing this, the metal box was stripped of all components and painted inside and out with rust-proof paint. Incidentally, if you want a really impressive visual result, get the cabinet sand-blasted and powder-coated – it will look like new. Making a resistor The next step is to organise the large current-limiting resistor. After trying a number of approaches, including commercially-available resistors and light bulbs, the following method was adopted: (1) Buy a small reel of 0.9mm galvanised steel wire from a hardware store ($5). (2) Stretch out 3m of wire, then double it back on itself and twist the two lengths together using a bench vice and pliers. (3) Wind the twisted wire tightly around a pair of insulating posts spaced about 100mm apart and mounted on an aluminium bracket. The prototype used a couple on porcelain insulators that were scrounged from the local tip (see photo) but you could also use the formers from jug elements. The beauty of this scheme is that most of the resistance wire is exposed to cooling air. Alternatively, you could also wind the wire tightly around a long narrow mirror or a glass jar (the wire is stiff enough to keep its shape and position). Take care to ensure that the windings do not touch each other. That’s it – your high-power resistor is complete! Hint: one way of tightly winding a coil on a glass jar is to first wind it on a former with a slightly smaller dia­ siliconchip.com.au Salt-water chlorinators with non-centre tapped transformers use a bridge rectifier (arrowed) rather than two diodes. The bridge rectifier can either be removed and used to double the ouput voltage from an existing centre-tap design (see text) or, alternatively, a second transformer can be added to increase the available voltage. Either way, it makes sense to collect a few salt-water chlorinators when you’re buying. Galvanised steel fencing wire is used to wind the resistor that limits the charging rate. Here it has been wound between two ceramic insulators but it can also be wound on a narrow glass mirror salvaged from a scanner or photocopier. Directly above the resistor is the adjustable temperature switch (another salvaged part) that turns off the charger should the cooling fan fail. meter. The completed coil can then be slipped over the jar and the lid used to mount the terminals. The beauty of making your own is that its value can be easily adjusted. If less resistance is needed, just shorten the wire. Conversely, if more resistance is needed, use a longer wire! The steel wire has a far higher resistance than copper (so a much shorter length can be used) and is rugged. Note that in this application, the resistance June 2006  67 When the resistance value is correct, the completed resistor can be installed inside the box. When picking the mounting location of the resistor, remember that it will get very hot – don’t place it too close to other components and make sure it has plenty of ventilation. In fact, we strongly suggest that you install a cooling fan inside the box. Suitable 12V fans can be easily salvaged from old PCs, printers and photocopiers, to name just a few sources. Locate the fan so that it draws air out of the box – most chlorinators already have plenty of inlet vents built into them. Fig.4 (covered in detail later) shows how to wire the fan into circuit. The chlorinator modified by the author has two “power” levels, controlled by a front-panel switch that selects between two primary windings on the power transformer. This gives a charging current of either 18A or 9A when matched with a 1.5-metre length of resistance wire. At this stage, you effectively have a working charger. However, it’s much too risky to rely on manual control, as this could lead to serious over-charging and irreversible battery damage. It’s much safer and more convenient to have an automatic switch that turns the charger off when the battery reaches its fully charged state. An over-temperature cut-out adds another worthwhile safety element. Fig.3: the Simple Voltage Switch needs a number of modifications to perform in its new role. These include components that are deleted or changed, two tracks that are cut and some added underboard wiring. wire will get very hot, so be sure to use ceramic formers or a glass jar, rather than a wooden dowel that would char and perhaps catch fire. Using the resistor So what do we do with the resistor? First, you’ll need to have modified the chlorinator as described above (ie, output voltage doubled and an in-line DC fuse). The unit should also have a working ammeter – if not, you can use your multimeter if its current rating goes high enough. You’ll also need a “flat” lead-acid car battery – ie, one at about 11V (leaving car headlights on is a good way to flatten a battery). Next, make sure the cover is back on 68  Silicon Chip the chlorinator box, then connect your home-made resistor in series between the charger and the battery. Switch on and closely watch the ammeter. If the current flow is less than the new maximum that can be drawn, switch off and shorten the resistance windings (they will be hot, so give them time to cool). Conversely, if the current flow is too high, increase the length of the resistance winding or use only one strand rather than two. Note: the 1.5-metre resistor length (ie, a 3m-length of wire doubled over) is based on a measured DC output voltage of about 16V. If the no-load output voltage is higher than this, start off with a 3m length of doubled wire for the resistor. Voltage switch Apart from incidentals like cable ties and nuts and bolts, the automatic voltage switch is the only part of the system that you should need to buy new. In this case, we’re using the Simple Voltage Switch (Jaycar Cat. KC-5377) and as the name suggests, it switches a relay on the basis of monitored voltage. This particular project was originally designed for use in cars (where it can monitor engine management sensor outputs, switching fans and warning lights, etc) but in this application, we use it to switch off the battery charging current when the battery voltage rises above a preset level. The circuit is easy to build and features an adjustable trip-point, adjustable hysteresis (the difference between the switch-off and switch-on voltages) and an onboard 5A double-pole, double-throw (DPDT) relay. siliconchip.com.au However, the circuit does require a few simple modifications for use here. The first problem is that it was designed for use with car voltages. This means that it could easily be damaged if the battery charger has a no-load output of 18-20V and was switched on without the battery connected. Second, the hysteresis also requires some changes and a reset pushbutton needs to be added. And finally, because we want the regulator to drive a second high-current relay and a “Charge Finished” pilot light, some alterations need to be made to the power supply. Fortunately, the modifications are straightforward (see Fig.3): • Change the 8V 7808 regulator to a 12V 7812 type and fit it with a heat­ sink. • Delete zener diode ZD1. • Replace the 10W resistor with a wire link. • Replace the 10kW resistor next to D3 with a 1kW resistor. • Change the 100mF 16V electrolytic capacitor (the one below ZD1) to 470mF 63V (this will be a tight fit and the capacitor will need to be mounted a little off the PC board). • Delete the 100nF capacitor and wire two flying leads to its solder pads (these go to the Reset button). • Cut the PC board track that goes to pin 8 of IC1 and connect pin 8 directly to the output of the regulator. • Cut the track that supplies power to the relay above the 100mF capacitor and to the left of LED1 – see Fig.3. • Connect a flying lead between the regulator output and the positive terminal of the 100mF capacitor. Incidentally, the PC tracks are easily cut by using a sharp drill-bit rotated by hand. The Simple Voltage Switch needs to be built in the “Low-to-High” switching configuration – ie, we want the switch to activate as the battery voltage rises to the preset level. To achieve this, the 1N4148 diode needs to be mounted with its band nearest the top of the PC board and the wire link (LK1) placed in the righthand position (the original project article – included with the kit – covers these points in more detail). The on-board relay used with the Simple Voltage Switch doesn’t have sufficient current capability for the battery charger, so we need to add a high-current automotive relay. Again, siliconchip.com.au The charger uses the Simple Voltage Switch kit to disconnect the charger when the battery voltage reaches a preset level. Some modifications need to be made to the kit to allow it to perform satisfactorily in its new role. Blobs of silicone have been used to help secure the regulator heatsink and a new large capacitor. it’s available for nothing – every wrecked car less than 20 years old has half a dozen! As shown in Fig.4, a 1N4004 diode is wired in parallel with the relay’s coil, with its cathode (banded) end to positive, to protect the voltage regulator from spikes as the relay switches off. In addition to triggering this relay, we also use the on-board relay to turn on a “Charge Finished” 12V pilot lamp. Referring to Fig.4, the common (COM) terminal of the on-board relay is connected to earth, while the NC (normally closed) relay contact goes directly to one side of the external relay’s coil. The other side of this relay coil is connected the +12V regulator output via a thermostatic protection switch (which is detailed in a moment). That way, the high-current relay is normally activated and so the battery charges via the current-limiting resistor (made earlier) until a preset voltage is reached. At that point, the relay on the Simple Voltage Switch clicks over and disconnects the charger’s output from the battery by breaking the ground connection for the external relay – ie, the external relay turns off and its NO contacts open. At the same time, the on-board relay connects one side of the “Charge Finished” lamp to ground. The other side of this lamp is supplied with +12V 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 have a use for the highquality 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! June 2006  69 Fig.4: the output of the transformer is rectified using a bridge rectifier. It then passes through a heavyduty relay, a custom-made current-limiting resistor, a fuse and an ammeter, before reaching the charging output. The battery is subsequently automatically disconnected when fully charged by a modified Simple Voltage Switch (which monitors the battery voltage), while a thermostatic switch protects the charger from overheating if the in-case temperature exceeds a preset point. and so the lamp lights to indicate that charging is complete. Note that there’s no “Charger On” indicator light. This was deemed unnecessary for two reasons: (1) the fan runs (and is audible) when ever the charger is switched on; and (2) the ammeter shows if any charging is occurring. Fig.4 also includes the temperature protection switch. Since we have a heavy-duty relay controlling the charger current, this switch can be incorporated in the relay coil’s supply. A bi-metallic thermostat from an oilfilled space heater is an ideal candidate here, although a variety of adjustable temperature switches (or thermostats) can be used (see the “Salvage It!” 70  Silicon Chip siliconchip.com.au ➌ ➎ ➏ ➋ ❼ ➍ ➊ ❽ ❿ ❾ An inside view of the charger: (1) heatsink for bridge rectifier; (2) high-current relay; (3) voltage switch; (4) transformer; (5) high/low charge switch; (6) on/off switch; (7) mains fuse; (8) DC fuse; (9) one of the two insulator supports for the resistor wire; (10) adjustable temperature switch. Note the uninsulated terminals on the mains fuseholder, the on/off switch and the high/low charge switch – these should all be insulated to avoid possible contact. for July 2005). These switches are normally closed (ie, they open when the set-point temperature is reached), so if one is wired in series with the feed to the high-current relay’s coil, it will switch off the charger if the temperature inside the case exceeds its set-point. Finally, the buzzer and diode across the output provide a warning if the battery is incorrectly connected. Normally, the diode is reversed biased and so the buzzer if off. However, if the battery is connected the wrong way around, the diode will be forward biased and so the buzzer will sound. No damage to the circuit will result siliconchip.com.au if the battery is incorrectly connected, provided that the charger itself is switched off. If the charger is on, then the DC fuse will probably blow. Setting the Voltage Switch At what voltage should the charger switch off? The near-new car battery that I used as the “guinea pig” in the development of this charger has written on it: “Maximum charging voltage: 14.8”. However, this is a very high cut-off point – normally, the voltage is set between 13.8V and 14.4V. To set the cut-off level, temporarily mount the voltage switch outside the box so it’s easily accessible, without exposing you to any danger of electrocution from high voltages inside the unit. Now charge the battery and monitor its voltage with a multimeter. Then, when the battery voltage reaches the desired level, very slowly rotate the multi-turn trimpot (VR1) on the Simple Voltage Switch until the main relay clicks off (the “Charge Finished” light should illuminate). The hysteresis pot (VR2) should be set fairly high (eg, 80% clockwise) otherwise as soon as the charger disconnects from the battery, the battery voltage will fall sufficiently to immediately reconnect it. When the “Charge Finished” lamp June 2006  71 OK, so it’s not exactly the best-looking charger you’ve ever seen but it cost very little to make. The heatsink and bridge rectifier used were taken from another chlorinator unit, while the fan and its grille were also salvaged. The sticker came from the shop at the local dump (there was a whole bag of ’em!). turns on, press the Reset button to reconnect the charger to the battery. The charger should immediately disconnect again and the “Charge Finished” lamp again illuminate (this is because the battery voltage will still be above the lower hysteresis level). Now turn on the high-beam headlights of the car for a few minutes. This time, after Reset is again pressed, the charger should spring into action, staying on until the cut-off voltage is again reached. This is also a good way of double-checking the cut-off voltage setting. Note: the LED on the Voltage Switch acts as a relay-tripped indicator. It will be off while the battery is charging but Follow These Precautions! (1) Hydrogen gas (which is explosive) is generated by lead-acid batteries during charging. Always charge batteries in a well-ventilated area. (2) Make sure the charger is switched off before connecting it to the battery, to prevent arcing at the terminals (a spark could cause the battery to explode!). Similarly, switch the charger off before disconnecting the battery. (3) The electrolyte inside lead-acid batteries is corrosive. Wear safety goggles when making connections to the terminals, removing vent caps or otherwise dealing with the battery (note: the vent caps can normally be left in place for charging). (4) Make sure that the battery is correctly filled with fluid before charging. (5) Make sure that all battery connections are clean and tight before connecting the charger for in-car charging. (6) Disconnecting a battery from a car will require you to re-enter the PIN security code for the radio. Other memory settings may be lost as well, including the memory for an adaptive transmission. (7) Do not operate this unit unattended. If the voltage cutout fails to operate due to a fault, the electrolyte in the battery could boil dry and seriously damage the battery – and perhaps cause other damage as well. 72  Silicon Chip The completed unit can charge at a continuous 18A and is nothing like those cheap units you can pick up for $30. will light when the Voltage Switch trips and the external relay turns off and disconnects the battery. You could of course mount this LED on the front panel but we chose to use the separate (and much brighter) 12V pilot lamp instead. Setting the thermostat The easiest way of setting the temperature switch is to temporarily disable the fan and then charge a battery for a few minutes on a hot day (if it’s a cold day, direct a hairdryer through the box vents). If the charger has a switchable “high” charge rate, set it to this mode. After a few minutes, the currentlimiting resistor should be hot and the inside of the case should be quite warm – so switch off mains power, pull the plug and open up the cover. Now turn the temperature switch until it audibly clicks off and then turn it back the other way a little. Set like this, siliconchip.com.au Over-Rating The Charger The charger that I built had an original rating in salt-water chlorinator form of 25A at 8.6V. After re-wiring the centre-tapped secondary into bridge rectifier configuration (the bridge rectifier complete with a large heatsink was taken from another unit rated at 25A at 7V), the charger would have had a nominal rating of, say, 10A after allowing for the 100Hz pulse current waveform in its battery charger role. However, I used a resistor that allowed a peak current flow with a flat battery of 18A – substantially higher than the transformer’s nominal rating. But isn’t this dangerous – won’t the transformer get very hot? The answer to that is “no”. After a few hours of continuous use in 30°C ambient conditions, my trusty infrared thermometer showed a rectifier temperature of 60°C, a transformer temperature of 55°C, and a resistor temperature of 85°C. The reason for these relatively low temperatures (the resistor is supposed to be hot – it’s dissipating about 100W!) is the very strong fan-forced cooling that I had added. As mentioned in the main text, fans are free when salvaged from innumerable consumer goods and can easily be driven by the battery charger. In addition to keeping the resistor cool, the fan also circulates a huge amount of air past the transformer, effectively boosting its power rating. If you’re pushing the boundaries of power ratings, monitor things very carefully, but with careful thermal and electrical design, it’s possible to get some very hefty power outputs – all at a very low cost. However, don’t expect the transformer to last as long as it would if rated much lower – if you are using the charger continuously (for example, to maintain the charge of a bank of lead-acid batteries), always respect the original power rating. the fan would have to stop working for several minutes before the temperature switch activated. If the temperature switch triggers too early in use, set it a little higher. Odds and ends You’ll need heavy duty cable and a pair of large alligator clips to connect the charger to the battery. In my case, the battery clips were one of the very few items I bought new. The heavy cable came from one of the chlorinators I’d salvaged. As mentioned previously, a DC fuse needs to be installed and every chlorinator already has an AC mains fuse. Make sure the values of the fuses match their new applications. Using the charger Before connecting the battery, make sure that the charger is switched off or that an isolating switch (if fitted) is off (see panel). It’s then just a matter siliconchip.com.au of connecting the charger leads to the battery (making sure the polarity is correct) and then switching the charger (or isolating switch) on. If you do get the polarity wrong, the warning buzzer will sound. In that case, disconnect the leads and reconnect the battery correctly. Assuming all is correct, the ammeter should immediately indicate that charging is occurring. If the “Charge Finished” lamp immediately comes on and the charge rate drops to zero, press the Reset button. If the charger again immediately reverts to its “Charge Finished” mode, the battery voltage may already be high – ie, it doesn’t need to be charged! Alternatively, if the “Charge Finished” lamp comes on and the charger has a “High/Low” charge-rate switch, try setting the switch to the lower rate. In fact, it’s best to charge the battery on the high level until the “Charge Finished” lamp comes on, then press the Reset button and continue charging on the lower of the two settings until the “Charge Finished” lamp again illuminates (charging is then finished). If the ammeter shows no charge occurring but the “Charge Finished” lamp is off, switch off mains power, pull the plug and check that the tem- perature switch hasn’t tripped. After that, check the fuses. Conclusion There’s a battery charger I’ve had for years. It has “Four Amps RMS” written on the front panel and I’ve never had any reason to check its charging current with an ammeter. But after spending hours testing the charger described here – and being amazed at how quickly it can bring up battery voltage – I decided to test “ol’ faithful”. I connected it to a battery which had a reasonably healthy voltage of 12.6V and measured the charging current. Would you believe it – just 0.25A! By contrast, the salvaged charger can pump in no less than 18A at the same battery voltage! No wonder the voltage was coming up faster than I expected – the dirtcheap salvage charger under the same conditions delivers about 70 times the current of the commercial unit! So as you can see, there are chargers and there are chargers. And the one SC shown here? It’s a charger! Acknowledgement: thanks to John Clarke and Robert Edgar who contributed to the design of this unit. June 2006  73 SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.altronics.com.au/ SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.altronics.com.au/ SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.altronics.com.au/ SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.altronics.com.au/ A much better result with a b ELECTRIC FLI Our first article in the February 2006 issue showed the potential of the electric Piper Cub model aircraft. This month we continue our investigation by converting the Cub to a brushless motor to obtain a greatly improved result. By BOB YOUNG I n the last article we recounted the trials and tribulations associated with using the original Speed 400 brush motor supplied with the Cub kit. In passing, I mentioned the possibility of fitting a brushless motor to the Cub at a later date. This is the story of how a duckling was transformed into a swan. (For the politically correct, there is of course nothing wrong with being a duckling. Ducklings are nice too.) For those who missed the previous article, the brush Speed 400 motor supplied with the kit caused serious radio interference, especially with FM receivers, resulting in greatly reduced range. This problem was eventually overcome by replacing the FM radio with an AM radio (see box “AM & FM?”). Therefore there was much interest in examining the outcome regarding radio range when the brushless motor was fitted. In addition there were several minor flaws in the aerodynamics of the Cub as originally supplied in the kit. These included too little down-thrust and adverse yaw during aileron turns. Even with these drawbacks, the Cub flew very nicely in its original form and provided several hours of very happy test flying. (To think I get paid for doing this...) However it was obvious that the Cub could stand some improvement. Aerodynamic improvement Altering the down-thrust angle on the motor originally supplied would have been very difficult. Luckily the decision to fit the brushless motor solved that problem as well. The brushless motor chosen was a small LSE outrunner. The outrunner style motors have the windings (stator) at the 78  Silicon Chip centre, fixed to the motor mounting flange. The bell housing holding the magnets (rotor) surrounds the windings and the propeller is fastened to it. Thus the rotor and propeller spin together. Long-term audiophiles will recognise these brushless motors as being very similar in construction to the highquality Papst motors used in reel-to-reel tape recorders. Outrunners deliver more torque than the brushless inrunners but do not rev as fast. It is interesting to note that the outrunner with no gearbox drove the same size prop at approximately the same RPM as the brush motor fitted with a 3:1 gearbox. Mounting the outrunner required the removal of the original front former and the construction of a small box to move the motor/prop forward into the correct position for the re-fitting of the engine cowling (see photo opposite). The outrunner mounting flange was attached to a plywood plate that was mounted on this small box. Thus it was a simple matter to shape the box to tilt the plate at the correct angle for the down-thrust and right thrust required. As it turned out, I had set a fraction too much down-thrust and the angle had to be adjusted after the first test flight. With the correct down-thrust and right thrust angles, the aircraft will fly straight on full power and continue on flying straight when power is suddenly reduced. If the aircraft turns right, there is not enough right thrust and if it dives, there is not enough down-thrust. Conversely, the model needs less right thrust if it turns left and less downthrust if it climbs after reducing power. This is a most important part of setting up an aircraft correctly. A well set up aircraft is much easier to fly and places a lot less strain on a tyro R/C pilot. Learning to fly siliconchip.com.au brushless motor IGHT Part 2 an R/C model is difficult enough without the additional complication of a badly trimmed aircraft. The adverse yaw was cured in a relatively simple manner. A small amount of rudder movement was mixed into the aileron channel via the mixing function in the transmitter. Thus when the ailerons are moved, a smaller but proportional amount of movement was programmed into the rudder. At full aileron deflection approximately 10° of rudder is applied. This is sufficient to overcome the adverse yaw and now the model does well-balanced turns with no sign of adverse yaw. A switch was inserted into the mixer to switch the coupled aileron/rudder (CAR) mixing on or off. It is a good idea to switch the CAR off during take-offs and landings, as the CAR will induce a heading change each time the ailerons are moved to level the wings during the landing approach. This makes accurate landing approaches more difficult and that is not a good thing when learning. The pilot that can land the aircraft well and from even the most difficult of situations or emergencies will be rewarded with models that live a long time. This is why I practise landings and take-offs at every opportunity. Forget the loops and rolls. They are easy. The landing is the manoeuvre that separates the boy pilots from the men. Electronic improvements The difference in the electronic performance of the model with the brushless motor was staggering. I expected an improvement but not as much as was obtained. First of all, the radio interference completely disappeared and we could return to the original FM receivers without the range problems previously encountered. siliconchip.com.au June 2006  79 Secondly, the performance of the model was greatly improved. Where take-offs were marginal even on tar with the original Speed 400, take-offs are now so brisk that short, tufted grass is no longer a problem for the take-off area. The model will also climb more briskly and on a fully-charged battery, loop from level flight. This is a staggering improvement from a motor that is smaller, lighter and runs much cooler than the Speed 400. In addition, the speed controller supplied with the brushless motor has some very natty features although these had to be found the hard way as the original instruction sheet was a piece of paper approximately 75 x 25mm covered in Chinese or Korean writing! The first of these features is a programmable voltage cut-off to allow for the use of two or 3-cell LiPO batteries. As discussed in the first article, LiPO batteries are very fussy to work with. They need to be handled with great care in both charging and discharging. The point about discharging LiPOs is that from about 2.7V per cell downward, irreversible chemical changes begin to occur in the cells and by the time the cell voltage falls to 2.4V or lower, the cell is permanently damaged. It is very difficult to obtain agreement on a definite voltage at which the cell is destroyed, with figures quoted from 2.7V down to 2.4V. However what is almost universally agreed upon is that speed controllers should contain a voltage cut-off circuit that will cut off power to the motor at a minimum of 3V per cell. The LSE electronic speed controller (ESC) used in the Cub is fitted with a lead ending in a 2-pin header plug. If a micro-shunt is fitted to this plug, the cut-off voltage is set for two LiPO cells. If the shunt is removed, the ESC is configured for 3-cell operation. The nominal voltage of a LiPO cell is 3.7V per cell, giving a total of 7.4V and 11.1V for two and 3-cell packs. Be very careful with this because if you run a 3-cell pack on a 2-cell cut-off, terrible things are going to happen to that 3-cell pack. While we are on this point, it is mandatory that LiPO batteries be unplugged from the model at the end of each flying session. There is no ON/ OFF switch in this type of ESC, thus there will be a small current drain on the battery, eventually leading to cell voltages falling below 3V and thereby damaging or destroying the batteries if the battery is left plugged into the model for an extended time. For the same reason, do not leave LiPO cells lying around for extended periods without recharging, as selfdischarge will eventually destroy the battery, Voltage cut-off circuits will not protect against the last two scenarios, so make sure each battery pack is recharged at least once every three months to be on the safe side. The second feature of the ESC is a self-arming/calibration routine. The ESC will not operate until the throttle is moved to low throttle and the transmitter turned on. At this point the ESC is armed and will now operate the motor via the throttle channel. Another interesting point here is that the ESC will set the low throttle point when the transmitter is switched on. It is also possible to program in a dynamic brake during the switchon routine. The dynamic brake will prevent the prop from wind-milling in gliding flight. Electric models can be a dangerous to work around as the motor can start suddenly when least expected and low throttle arming is a great safety feature. Having a model leap off a bench, or worse still, inflict a nasty cut from a prop is no fun. So be very careful at all times when working with electric-powered models, especially with high-powered models! Unplug the motor battery whenever possible, keep the transmitter off as much as possible and if it must be on, put it somewhere where the throttle lever cannot be accidentally bumped to high. The motor will not start accidentally with the transmitter switched off. The scope grabs tell the story . . . This first ’scope grab shows the output of the FM detector on the bottom (magenta) trace, the supply rail is on the middle (cyan) trace while the active lead on the motor is shown on the top (yellow) trace. All ’scope grabs use the same order for the traces. This grab was obtained with the Speed 400 motor stopped. 80  Silicon Chip The motor signal with the Speed 400 motor running. Note the spikes on the supply rail. However, have a look at the receiver detector trace. It has been obliterated and this was with a moderately strong signal from the transmitter. Three brands of FM receivers were tried and all gave much the same result. siliconchip.com.au One of the things that I cannot get used to with electric models is the lack of a definite throttle-stop as I prefer to land with the motor set at an idle of approximately 1000 RPM. In IC motors the throttle barrel is pulled hard against a mechanical stop so that the idle RPM is constant at all times. In an electric model the idle point will vary a little with battery voltage, making landing approaches less predictable. If the throttle trim is pulled too far back, then the motor stops completely then restarts if the throttle is advanced. All this takes some getting used too after years of flying IC engines. I also miss the noise and have been toying with the idea of sticking a bit of cardboard into the prop like we used to do when we were kids on pushbikes. Either that or perhaps I will fit an onboard tape recorder with speakers and recorded motor sounds. The sight of a Piper Cub roaring off the runway with absolutely no sound is a little unnerving for those who cut their R/C teeth on IC motors. Still I do appreciate being able to go to a local cleared area and not disturb the neighbours. Another nice feature with the ESC is a motor cut-off that is instantaneous upon striking an object. The modern brushless ESC uses back-EMF sensing for its timing. These motors are wired as 3-phase motors in either star or delta configuration and therefore need to be timed to sustain rotation. The timing No, this isn’t the front of the motor or just a part of the motor. It is THE motor – it’s an LSE Outrunner and it gave a staggering improvement over the original electric motor supplied with the Piper Cub kit. Minor modifications were required to fit it, though . . . signal is derived from the motor windings and no longer requires extra wires for the timing signal. If for any reason the shaft stops rotating for even the briefest period, the motor drive current is cut off immediately. This is also a great safety feature. This type of sensing is extremely clever and calls for a simple explanation. By summing the two driven windings, a reference voltage can be derived. The undriven winding, which will have a voltage induced into it because it is being moved through a magnetic field, is compared to the reference. When a zero crossing is detected it is time to rotate the magnetic field to the next position. The above works once the motor is spinning. This shows the same order of traces but with a Silvertone AM receiver fitted and the Speed 400 stopped. Note the inverted detector signal and higher detector output. The next grab (at right) shows the Speed 400 running with the AM receiver and the same signal strength from the transmitter. siliconchip.com.au However before it starts spinning there is no zero crossing to detect so the designer must resort to interesting techniques such as ringing the windings to try to work out the position of the motor so a clean start may be performed. It is much easier to do this if the controller knows the motor characteristics. If they are not known, the controller must learn them. Some It was impossible to sync the ’scope due to noise but the detector signal is clearly visible and at full strength. However the audio filter must have been working its little capacitors to the bone, filtering out the rubbish being passed on from the detector. In spite of the noise the receiver still had full control of the ESC at 80% of its normal range. June 2006  81 controllers are so smart that they can recognise brush or brushless motors and configure themselves accordingly. Incidentally, brushless motors may be reversed by swapping any two of the three motor wires. If the ESC is disarmed after striking an object, the transmitter must be switched off and left off for 10 seconds or so and then turned back on, making sure that the throttle is correctly set at the desired low throttle setting. The most common cause of this type of disarming is clipping the prop in a bouncy landing. Finally, the last feature is the low voltage cut-off that will determine for you when flying stops on that battery pack. Once the pack hits 3V a cell, all temptation to continue flying is removed. That pack is now out of bounds until recharged. Do not be tempted to let the pack rest and pick up a surface charge and so continue flying. Go home and recharge the pack. With two 1800mAh LiPO packs and an 8 x 6 slow-fly prop on the Cub, I find I am gone from home for at least an hour and a half, sometimes more. This includes a five-minute walk each way to the field and the rest is taken up with non-stop take-offs and landings with the occasional loop and roll thrown in for good measure. I did say I bought the Cub because it was a pretty aircraft when taking off and landing! How is this possible? At best, the maths show 30 minutes flying time. This is one of the most complex questions in aerodynamics so the following answer is much simplified. Take a look at Table 1. This shows static (0km/h) current consumption against RPM for the 8 x 6 slow-fly prop. The table shows a non-linear rise in current for each 1000 RPM, with the last 200 RPM requiring as much current as the change from 3000 to 4000 RPM. Why is this so? The ESC appears to deliver a linear current with throttle stick position, so what is happening? The answer is found in the formula for aerodynamic drag: FD = 0.5 CD p A V2 The culprit is the V2 bit of the equation. As the prop speed increases the power required follows a square law and this is what makes selecting the correct prop for any motor/model combination so difficult and so important. The same applies to the model as well. To double the flying speed requires four times the power. Do you want or need a Piper Cub with a scale speed of 400km/h? Why not opt for a Cub with a scale speed of 140km/h and a battery life several orders of magnitude greater? Each branch of electric modelling is different and the prop requirements must be balanced for the task in hand against the design of the model. A slow-flying, high drag aircraft requires a larger diameter, fine pitch prop whereas a slick, fast-flying model requires a smaller diameter, coarse pitch prop. The choice of prop is one of the most difficult parts of aircraft Now have a look at these ’scope grabs. On the left, the brushless motor is stopped while on the grab at right it is running. The gain on the supply trace has been increased tenfold to get a look at the noise on the supply rail. This 82  Silicon Chip Table 1: static current consumption vs RPM for the 8 x 6 slow-fly propellor. design. Most modellers using 2-stroke IC engines tend to over prop their motors (too large a diameter mainly) and I suspect that electric flyers tend to do the same. For example, an increase of one inch in prop diameter can increase current consumption by 25%. However, electric flyers have a method of recognising prop efficiency in that flight times will indicate an efficient or inefficient prop/motor combination. Measuring flight time in the absence of in-flight telemetry is an important method of determining motor/prop efficiency. Propellers have many important characteristics including blade shape, blade section, pitch and diameter. The latter two are the most easily explained. Diameter is the length of the prop from tip to tip and will determine the mass flow through the prop. The pitch is how far the prop will pull the model in a single revolu- is processor switching noise and is barely visible. The FM receiver detector output is clean and stable with only processor noise visible and the audio filter easily filters this out. siliconchip.com.au tion. Broadly speaking, the prop is the aircraft transmission and a fine pitch gives great pulling power at low speed whereas a coarse pitch prop will give less pulling power. However there is a complication in that the faster a model flies the smaller the effective pitch angle becomes due to the angle that the air meets the prop being reduced as a result of forward motion. So once the aircraft gets moving the coarser prop becomes finer in effective pitch; take-off being the big problem for fixed-pitch propellers. Full-size aircraft usually use variable pitch props or constant speed props. Thus during take-off the pitch is set to fine (low gear) and at high speed the pitch is gradually increased to keep the engine RPM constant. Now this has important ramifications for electric flight models in that current consumption drops as the model gets up to flying speed. For example a 9 x 7 Masters e-prop that draws 11A at 5400 RPM at 0km/h will draw only 7.5A and the revs will increase to 6700 RPM at 60km/h. At 40km/h, the motor draws 8.5A and at 20km/h 9.5A. Thus referring back to Table 1, at anything less than 3,000 RPM in flight the motor in the Cub would be drawing fractions of an amp. And this is precisely how the model is flown when doing circuits and bumps. Full power is only applied during take-off and climb to altitude (about 100 ft). From then on the model is throttled back and cruises on approximately one-third throttle or less for the rest of the circuit. In conclusion then, where I began flying the outrunner with the recommended 9 and 10-inch props (props are still measured in inches) on the Cub, I finally settled on an 8 x 6 inch slow-fly prop, thereby reducing the static current from 11A to 7A and thus extending the flight time accordingly. The aircraft also flies at a more realistic speed – another nice touch. REAL VALUE AT $12.95 PLUS P & P Radio performance improvement A major, staggering, improvement was obtained upon fitting the brushless motor. It was impossible to obtain a reliable range with an FM receiver with the Speed 400 installed and we had to resort to installing a Silvertone AM receiver to obtain the desired range. The series of scope screen grabs tell the story. Field-testing told the same story. In hours of test flying there has not been a single glitch from the FM receiver, even with the model at extended range. So there you have part two of the electric flight story. I could say with warts and all again but there were no warts. Was the effort and expense of the change of motors worthwhile? Too right! SC AM and FM? For the technically-minded, scratching their heads and trying to make sense out of the statement that the AM receiver out-performed the FM receiver in a high noise environment, fear not! The laws of physics have not been rewritten. What the model trade refers to as FM is, in fact, Narrow Band Frequency Shift Keying (NBFSK) and R/C-type AM is ON-OFF Keying (OOK). NBFSK as applied to R/C equipment employs a ±1.5kHz frequency shift as against the 70kHz frequency shift in a true FM broadcast system. The signal-to-noise ratio of an NBFSK system when compared to an FM system is very poor. OOK on the other hand is not AM as the data transmitted is carried in the position of the OFF spikes (Pulse Position Modulation, PPM) and not the amplitude of the carrier. This means that the carrier is either full ON (100%) or OFF (0%) for very brief periods – about 350ms. The AGC time constant holds the AGC on during the 350ms OFF spikes. Thus the receiver AGC clamps the receiver in the least sensitive state until the last 20% of the receiver range, at which point the AGC is almost useless and the receiver is wide open to noise, as it is now at full sensitivity. This gives the OOK system a much improved signal-to-noise ratio compared to the true AM system. In practice, the signal-to-noise ratios of the two systems (OOK and NBFSK) are about equal. However, in many cases the AGC provides superior protection against electric motor and spark ignition noise than the limiters in the NBFSK receivers. This does not always hold true but experience has shown that swapping an OOK receiver for an NBFSK receiver will often give better results. siliconchip.com.au Silicon Chip Binders These binders will protect your copies of S ILICON CHIP. They feature heavy-board covers & are made from a dis­ tinctive 2-tone green vinyl. They hold 12 issues & will look great on your bookshelf. H 80mm internal width H SILICON CHIP logo printed in gold-coloured lettering on spine & cover H Buy five and get them postage free! Price: $A12.95 plus $A7 p&p per order. Available only in Aust. Silicon Chip Publications PO Box 139 Collaroy Beach 2097 Or fax (02) 9979 6503; or ring (02) 9979 5644 & quote your credit card number. Use this handy form Enclosed is my cheque/money order for $________ or please debit my  Bankcard   Visa    Mastercard Card No: _________________________________ Card Expiry Date ____/____ Signature ________________________ Name ____________________________ Address__________________________ __________________ P/code_______ June 2006  83 We’ve published a few audio/video transmitters/ receivers over the years but none were as compact as this 2.4GHz model. Whether you want it for legitimate security/monitoring applications or simply for fun, it’s easy to build and a lot cheaper than buying by Ross Tester a ready-made system! 2.4GHz Wirele T his transmitter and receiver pair is delightfully simple to build because most of the hard yakka is already done for you. The transmitter and receiver are both pre-assembled modules – all you have to do is solder them to a couple of PC boards, add some power supply components, a video source . . . and that’s it! The transmitter board is not much bigger than a postage stamp (actual size is 30mm square x 13mm high [not including antenna]), so if you wanted to, you could conceal this little board virtually anywhere (eg, for surveillance/security or even hazardous area monitoring applications) and have the receiver feeding a monitor some distance away. The 2.4GHz band Once upon a time, 27MHz was regarded as the “garbage band” – just 84  Silicon Chip about anything and everything was chucked in there, including model control, garage door controllers, industrial, scientific and medical equipment (that, in fact, was/is what the band was called) – and even the first CB radios and low-cost marine radio transceivers (which of course exist to this day). In recent times, 2.4GHz has earned much the same reputation. You name it and it’s in that frequency band – everything from microwave ovens to WiFi and Bluetooth, cordless phones and doorbells to almost limitless types of “wireless” links. And of course, all sorts of A/V equipment. Which brings us to the reason for this interlude: there are three channels to choose from in the system presented here to hopefully allow you to avoid frequencies which are already in use (we’ll go into setting channels later). You may need to experiment to find which one is right for you. On the prototype, Channel 1 was initially used – which knocked my WiFi system off the air. The converse was also true – my WiFi system interfered severely with the reception, even with the transmitter and receiver at very close range. It was akin to the interference, both vision and audio, which you get on your TV when a Vee-dub drives by (no, I’m not a VW hater!). Fortunately, changing channels on the A-V link cured the problem (I didn’t want to go to the trouble of changing channels on the WiFi – let sleeping dogs lie, and all that!). The transmitter There are three main parts to the transmitter: input, which we’ll look at in just a moment; the transmitter module itself, which is pre-assembled, and lastly, the power supply components for the transmitter. siliconchip.com.au Here the AV Link receiver is feeding directly into one of Jaycar’s QM-3752 18cm LCD monitors about 12m from the transmitter shown at left. It runs from the same 12V power supply which powers the receiver. ess A-V Link The last two parts are assembled on the one PC board and to save space, are mounted layer-fashion one on top of the other. Those components which will fit are mounted hard down on the PC board, with the transmitter module mounted above them via some header sockets (with a little surgery!). The larger components, specifically three electrolytic capacitors, mount along the edge of the board. A 31mm length of stiff wire acts as an antenna. This is soldered directly to the RF output pin of the transmitter module. For extra range, an external 2.4GHz gain antenna could be connected to this point and earth via a short length of 50W coax cable but this would possibly mean the transmitter would no longer be legal. The camera The transmitter module will accept both composite video and stereo audio siliconchip.com.au signals. These would normally be from a video camera and microphones or as in the case of the prototype, a combination unit with both. This 1/3-inch, CMOS camera operates in very low light conditions (down to just 3 lux) and is also from Oatley While not supplied with the kits, this tiny colour camera from Oatley Electronics is an ideal partner. It has an inbuilt microphone but those aren’t real IR LEDs! Electronics. It measures just 25 x 35 x 14mm with a swivel mount and appears to have six infrared LEDs mounted around the lens. We have been assured by Oatley that these are not actually IR LEDs – they’re dummies! The camera was hard-wired onto the PC board, with the lead glued to the back of the board via hot melt or epoxy to prevent it flexing and damaging the solder joints. Input could also come from a zerolight camera (such as an infrared type) but could also come from any other device capable of producing composite video (PAL) signals, such as a video recorder, DVD player, etc – so the transmitter could form the basis of a video distribution system around your home, office, etc. The transmitter module is designed to operate from a 3.3V supply. This could be derived from a 6V “lantern” battery (for long life) but the prototype June 2006  85 The complete surveillance transmitter, complete with tiny camera. While this shows a 9V battery snap, current drain, especially with the camera, is a bit beyond a 9V battery, except for short-term use. was wired for a 9V battery (mainly for its small size). Note that we are not expecting a very long life from this configuration – the manufacturer’s specification for the transmitter module alone (ie, no battery or regulator) suggests 55mA, so even an alkaline battery would not last more than perhaps a day. When you take into account the regulator and video camera, consumption goes up to around 90mA – definitely not equating with long- term battery life! It might be OK for a short-term surveillance operation but not much good for long-term use. A much better proposition would be to power it from an AC adaptor or, if you must have it in a non-powered site, perhaps a rechargeable battery topped up each day by solar cells (see Stan Swan’s article in April SILICON Fig.1: the circuit diagram for both the transmitter and receiver. Both are based on pre-built modules so all you have to do is add power supply components and input/output connections. 86  Silicon Chip siliconchip.com.au Here’s the matching receiver – this time complete with a “bowtie” antenna in a reasonably weatherproof case. This antenna gives longer range, albeit at the expense of operation in other directions. CHIP for some really neat, low-cost recycling ideas). The receiver At 17 x 50 x 62mm, this board is larger than the transmitter. Once again, it incorporates a prebuilt 2.4GHz module, a power supply (the receiver module requires 5V) and three “RCA” output sockets – one for video, two for stereo audio. Unlike the transmitter, the receiver module is soldered directly to the PC board (ie, there’s nothing underneath it). The only other components on the board are seven capacitors and a 5V regulator. The power supply for the receiver could be just about any DC plugpack with a 9V to 12V output. Receiver current drain is less than 100mA so you won’t find many plugpacks which can’t handle this. The receiving antenna can be the same as the transmitting antenna – a 31mm length of stiff wire, or for more range it can be a gain antenna without transgressing any laws (Oatley’s K-198 bowtie antenna kit is ideal). Gain antennas simply concentrate signal to or from one direction at the expense of most other directions. Therefore they appear to offer higher performance than a “stick”. Construction We’ll start with the receiver because it’s the simpler of the two. Start by mounting the seven capacitors (six electrolytic and one monosiliconchip.com.au lithic) in their respective positions on the PC board. Solder in the monolithic first – it is not polarised. Identification of the electrolytics shouldn’t be difficult: the 220mF capacitor is the largest, the two 100mF are in between and the two 10mF are the smallest. In all cases, watch polarities: the ‘+’ side of the electros all go the same way on the PC board. Now solder in the 7805 regulator – its metal tab goes towards the middle of the PC board – followed by the three RCA sockets. They will only go in one way but make sure you don’t bend the pins underneath them! OK, the slightly more difficult part follows: you need to identify and bend out the RF input pin so you can connect an antenna to it. Turn the module over (pins up) and note the set of eight pins close to one corner. The second pin down from the corner is the RF input pin. With a fine pair of (needle nose) pliers, bend this pin down so it points out from the edge of the board. Note that you can only do this once because if you try to straighten it or do it again, the pin will almost certainly break off. You have been warned! With that pin bent out, push all of the other pins through their holes in the PC board (the module will only go one way) and solder the module in place. Apart from power supply and antenna wires, the receiver module is now finished. Solder in the power supply wires (red and black hookup wire) to their appropriate places on the PC board. You now need to make a decision as to the type of antenna you are going to use: wire or external. If it’s a wire, cut a 31mm length of tinned copper wire and solder its very end to the bent-out pin (pin 2) of the module, taking care not to short to adjacent pins or to the module case. In fact, it would be a good idea to slide a length of insulation over the antenna to make sure it doesn’t get bent and short later on. If you’re going to use an external antenna, the inner wire of the coax solders to pin 2 (as above) with the shield soldering to the point directly underneath (on the bottom side of the PC board). Again, make sure that you don’t short anything out – and also make sure that you keep the length of the inner conductor to an absolute minimum. To prevent the coax flexing, we used a tiny cable tie to secure it to the corner of the PC board at the opposite end of the edge to which it had been soldered. Solder the opposite end of the coax to your external antenna (if it’s the Oatley antenna, see the instructions which come with it). Transmitter module There’s not much difference between the construction of the receiver and transmitter, except that the transmitter module solders onto two rows of header pins after first soldering June 2006  87 Fig.2: the receiver module is soldered onto the PC board in the normal way, with the exception of the ‘RF in’ pin. It is bent up to allow the antenna to be soldered directly to it – but be careful. The pins do not like too much bending! Also note the 100mF capacitor at the power input: it is the 25V type to allow for variations in plugpack voltages. some components underneath. Start with these components: the two 68W resistors, the 100nF monolithic capacitor and the 7805 regulator. In the latter case, you’ll need to bend down the ends of the regulator’s pins – say 5mm from the bottom – by 90° to allow them to pass through the PC board holes and allow the regulator to lie flat on the PC board. Now solder the red and black 9V battery snap wires in place. Last to go in are the two rows of header pins. You will note that the transmitter module doesn’t have pins of its own; rather, it has half-holes along each edge into which the header pins sit (and are soldered). There is copper on the top side of the board so it’s not too difficult to do. But it’s far easier to solder the header pins onto the board first, then solder the transmitter module to those, rather than try to solder the module to the pins then insert the assembly. The header pin under the antenna (2nd from left) is not used – in fact, it must be removed because there is no hole in the PC board for it. So on the left of the PC board, from the bottom, you will have one header pin, then a gap, then six header pins. On the opposite side all eight pins are used. Push the module down onto the Fig.3: if you’re using an external antenna, here’s where to connect it. Keep the bared wires as short as possible. header pins (the right way around!) and very carefully, solder each pin to the PC board with a fine soldering iron. Assuming you will be using a simple wire antenna (as distinct from a gain antenna) on the transmitter, cut and solder a 31mm length of stiff tinned copper wire to the antenna (RF out) pad. Ideally, the antenna should be 31mm from the module’s PC board to the tip, so it might pay you to solder say, a 35mm length on, then carefully measure and snip it back to 31mm long. You don’t want any wire below the module’s PC board because this would create an unbalanced dipole. If you want to use a gain antenna (see the warning above), its 50W coax cable will solder to the antenna pin and to the square pad underneath the PC board as follows for the signal connections. Detail of the RF output modifications on the receiver board – the pin is not soldered to the PC board but bent out so that the 31mm wire antenna can be soldered directly to it. At left is the underside of the module showning this bent-out pin. 88  Silicon Chip siliconchip.com.au Parts List – 2.4GHz A-V Link Transmitter: 1 2.4GHz transmitter PC board, labelled K229T, 30 x 30mm 1 AWM632 2.4GHz transmitter module 1 7805 5V regulator Capacitors 3 100mF 16V electrolytic 1 100nF monolithic (code 104 or 100n) Fig.4: at left is the component overlay for the transmitter board, with the transmitter module shown dotted. The regulator, two 68W resistors and 100nF capacitor mount underneath the module which itself is then soldered onto the two rows of header pins . The antenna is soldered directly to the “ANT” position (it is end-on in the photo at right so is almost perfectly camouflaged!) All of the signal connections (audio and video) can be made direct to the appropriate header pins on the edge of the PC board, or they can be made to the pads under the PC board if you wish to anchor (glue) the cable to the PC board for security. Our diagrams show these connections – they are made with the inner wires of the shielded cables. You need to remove 1cm of outer insulation and bare back the shield wires/braids so that the inner conductor insulation is exposed. Remove 3mm of insulation from the inner conductor to allow you to solder it to the pin. The shields (earths) of each of the wires solder to the square pads immediately alongside the signal connection points. If connecting an external antenna, the shielded cable must be the right type: 50W UHF (low-loss) coax and the length kept to a minimum. All coax cables are lossy at 2.4GHz and most are intolerable – the higher the frequency, the more lossy coax cables become. Many perfectly good cables at HF (high frequencies – up to 30MHz) are totally useless at UHF (300MHz–3GHz) and above. Only a few cables will be made for use at UHF (coax cable supplied with the Oatley K198 kit is the right stuff). In any event, the length of inner conductor exposed from the shield must be kept to an absolute minimum (a few millimetres is OK, a few centimetres definitely not!). Just be careful that the shield doesn’t short onto the inner conductor or the pin it is soldered to or, indeed, adjacent pins. Selecting the frequency As we mentioned earlier, there are three channels available for selection and the transmitter and receiver modules must both be selected to the same channel. If you turn the transmitter board over, you’ll see in the copper pattern three square pads with a shorting bar running alongside them – they’re under the module, diagonally opposite electrolytic capacitor C3. At left is the transmitter module, clearly showing the half pads along two edges to which the header pins solder. At right, the finished transmitter PC board – not far off life size. siliconchip.com.au Resistors (0.25W, 1%) 2 68W (code blue-grey-black-brown or blue-grey-brown-gold-brown) Miscellaneous 2 8-pin header pin sets 1 9V battery connector 1 50mm length tinned copper wire for antenna (see text for alternative) [All above components are in the Oatley Electronics 2.4GHz transmitter kit, Cat K229TX]. Receiver: 1 2.4GHz receiver PC board, labelled K229R, 50 x 62mm 1 AWM630 2.4GHz receiver module 3 PC-mount RCA connectors 1 7805 5V regulator Capacitors 1 220mF 16V electrolytic 1 100mF 25V electrolytic 2 100mF 16V electrolytic 1 10mF 16V electrolytic 1 100nF monolithic (code 104 or 100n) Miscellaneous 1 length red hookup wire to suit (+ power) 1 length black hookup wire to suit (– power) 1 50mm length tinned copper wire for antenna (see text for alternative) [All above components are in the Oatley Electronics 2.4GHz receiver kit, Cat K229RX]. Options (as photographed): 1 mini colour video camera, with inbuilt microphone (Oatley CAM9) 1 2.4GHz bowtie gain antenna, with case and coax cable (Oatley kit K198) June 2006  89 One (only) of these pads must be connected to the shorting bar – you’ll probably find it easiest to solder a very short length of resistor pigtail offcut across the gap (it’s often hard to get solder to flow over even a small gap when you want it to). (This is the converse of one of the more famous of Murphy’s corollaries: if you don’t want solder bridging out two pads or tracks on a PC board, it will do so very easily . . .) Similarly, on the receiver board, there are four pads and a shorting bar diagonally opposite capacitor C2. Hang on a sec – four pads? Yes, there are four – but the last one is not (and can not) be used. As we said before, the shorted pad must match on both transmitter and receiver. Is it finished? And that’s just about it. Now it’s time for a test. You’ll need a TV set with an AV/TV switch (most do these days, even the cheapies!) and a 3-way RCA-RCA lead for connecting video and stereo audio channels (you can connect a single channel of audio if you wish). Plug the receiver in and connect it to power – as we mentioned before, a 9-12V DC plugpack would be ideal. Just make sure you get the polarity right – check with your multimeter because many plugpacks are not the expected “centre positive”! Assuming you’re using a small video camera (with microphone) directly wired to the transmitter module as described before, connect a 9V battery to the transmitter and you should find a picture appears on the screen and sound comes from the TV speaker/s. If not, you obviously have something wrong: the obvious errors are power supply connections, different channels selected on transmitter and receiver, shorted video, audio or antenna connections, etc. If you are using a directional antenna on the receiver (and/or the transmitter) make sure it is/they are aligned with each other – a perpendicular line from the receiver’s antenna PC board should point directly at the transmitter (and vice versa if you have it) for longest range. Having said that, however, we found that it wasn’t that critical – on our test setup (about 20m), a quite usable picture was obtained with the antenna completely off-axis but it was certainly 90  Silicon Chip best aligned as above. This system will not work as an audio-only link: the audio doesn’t work without video – ie, you must have video running to hear anything. However, you can have video without audio. of these sources can be used to check that the system is working. Note that you cannot use webcams or similar if they are fitted with USB connectors. These do not have the required output. Range You can use one transmitter and several receivers to distribute an AV signal around your home – again, as long as all receivers are on the same channel as the transmitter. And once again, aim the receiver antennas at the transmitter. If you have cable or satellite TV, for example, you can use this system instead of paying a monthly rental for a second set-top box/receiver. The main drawback, of course, is that you can only watch one channel at a time. And there are some set-top boxes which do not have video/audio out sockets. While our test setup was limited to about 20m, Oatley Electronics have assured us that their tests over a much longer distance – 100m – were entirely satisfactory and in fact suggested that the range would be significantly longer than this. Oatley’s setup included the bowtie antenna on the receiver only; the transmitter had the wire antenna as described here. A bowtie antenna at the transmitter end as well might well mean dramatically longer range, though this has not been tested. Other video sources You might like to wire the transmitter with its own video and audio sockets (eg, RCA), to allow different signal sources. Just make sure that the cables are secured to the PC board so they don’t place any strain on the board’s copper pads – they don’t like being stressed. As a matter of fact, the mini video camera photographed with this kit originally came with RCA plugs – they were cut off when the camera was hardwired to the PC board. As we mentioned earlier, just about any composite video (PAL) source can be used, such as a VCR, DVD player, handycam or minicam, etc. Even digital camcorders usually have a video out socket (and it is usually yellow). Check with your manual to find which socket it is. If the budget can’t quite stretch (yet!) to a dedicated mini camera, any A video distribution system Where do you get it? This project was designed by Oatley Electronics, who hold the copyright on the PC board patterns. The transmitter, receiver, gain antenna and video camera are all sold separately so you can make design your system to suit your needs. The transmitter kit (Cat K229TX) sells for $17; the receiver kit (Cat K229RX) sells for $32; while the “bowtie” gain antenna (K198) sells for $7.00, complete with a suitable case. The tiny video camera you see photographed with this kit is a standard Oatley stock line, Cat Cam9, selling for $39.00. It comes with the swivel bracket but does not have infrared LEDs which are seen in the photo. Contact Oatley Electronics on (02) 9584 3563; by mail at PO Box 89, Oatley NSW 2223; or via their website, SC www.oatleyelectronics.com This Oatley Electronics K-198 2.4GHz bowtie antenna kit comes with the weatherproof case shown earlier and will extend the range of the 2.4GHz A-V link quite significantly. Best of all, it’s really cheap! (For more information on this design, see SILICON CHIP, January 2004 issue). siliconchip.com.au PRIZED VALUE AT $399! SUBSCRIBE TO THIS... ...AND YOU COULD WIN THIS! A 20MHz dual trace oscilloscope from Dick Smith Electronics Every reader who takes out a new subscription this month (printed edition only), or renews an existing print edition subscription, goes into a draw to win a brand spanking new dual-trace 20MHz oscilloscope, as reviewed in the March 2006 edition of SILICON CHIP (p62), each valued at $399.00! You could be the envy of all your friends if you had this fine instrument on your workbench. It comes complete with two 10:1 divider probes, enabling you to do all sorts of measurements. You love the magazine. Why not subscribe and save? Subscribing is actually CHEAPER than buying over the counter. And for a limited time only, we are maintaining the present subscription prices. Subscribe now and beat the price rise later this year. At the same time, have a great chance at winning this superb ’scope! General info: 1) The winner will be drawn from the new and renewing subscribers for the month of June. Entries for the draw will close on Friday, June 30. No correspondence will be entered into. 2) The winner will be randomly drawn by computer at the SILICON CHIP office, Unit 8, 101 Darley Street, Mona Vale NSW 2103, on the next business day after the close of entries. 3) This offer is valid only for subscriptions to the printed edition of SILICON CHIP and is open only to residents of Australia and New Zealand. 4) Winners will be announced in the next available SILICON CHIP magazine and on the SILICON CHIP website, www.siliconchip.com.au. NSW permit no TPL 06/01824. 5) The promoter is SILICON CHIP Publications Pty Ltd, ABN 49 003 205 490, PO Box 139, Collaroy NSW 2097. 6) Your new subscription will normally start with the next month to be printed (if you wish, you can nominate an alternative starting date). YES PLEASE! I wish to subscribe for Start my subscription from the o next issue or o ............................. issue and enter me in the draw for the oscilloscope! o 2 years ($160) o 2 years with 2 binders ($186.00) o 1 year ($83.00) o 1 year with binder ($96.50) *these prices valid for Australian subscribers only. NZ subscribers will be included in the draw but subscription rates are slightly higher. Please refer to the order form in this issue. Enclosed is my cheque/money order for $­______or please debit my: o Bankcard o Visa Card o Master Card We make it easy to subscribe! Card No. Signature ___________________________ Card expiry date_____ /_______ Mail this form (or a copy) to: Silicon Chip Publications, PO Box 139, Collaroy, NSW, Australia 2097. Name ______________________________ Phone No (___) _____________ Or fax PLEASE PRINT your details to (02) 9979 6503 (inc credit card!). Street _________________________________________________________ Or email the same details to silicon<at>siliconchip.com.au Suburb/town _______________________________ Postcode _____________ une 2006  91 Or log onto siliconchip.com.au Jand click on “print edition” siliconchip.com.au email: __________________________________________________________ Or call (02) 9979 5644 & quote your credit card details By JIM ROWE Starship Enterprise Door Sounder Here’s a project especially for trekkies. At the closure of remote switch contacts, it recreates that distinctive “ssshhhhhhh-thump” sound of the sliding doors opening or closing on the “Starship Enterprise”. Use it for generating sound effects for your own sci-fi movies or for hooking up to a bedroom or wardrobe door so you can pretend you’re aboard the “Enterprise” in deep space, going where no man has gone before! G ENE RODDENBERRY’S original TV series of “Star Trek” broke quite a bit of new sci-fi ground in its day, with imaginative thoughtprovoking stories and a collection of interesting characters: Captain James T. Kirk, science officer Spock, engineer Scotty (“you canna’ change 92  Silicon Chip the laws of physics, Jim”) and so on. Small wonder it spawned a number of spin-off movies and a follow-on series, along with a huge following of ‘trekkie’ fans who seem just as dedicated today as they were 30 years ago – no doubt helped by the release of all the original episodes on DVD. Of course, along with those original episodes, many keen trekkies also like to acquire “Star Trek” memorabilia: replicas of the costumes worn by the “Enterprise” crew, copies of Mr Spock’s pointy ears, fake phaser guns and so on. They also like being able to generate some of the distinctive siliconchip.com.au Fig.1: the circuit uses an HK828 sound recorder chip (IC1) to store two different “Starship Enterprise” door sounds. This drives audio amplifier stage IC2 to replay one of these sounds when switch S1 or S2 is momentarily closed. sound effects which helped make the first series so memorable. So if you have a friend or relative who’s one of these dedicated trekkies, you might want to build this project for them – or for yourself! It recreates the “ssshhhHHHh-thump” sound that always accompanied the sliding power doors opening or closing on the “Starship Enterprise” and can be triggered by either pressing a pushbutton or closing the contacts of an external switch (eg, a reed switch activated by a bedroom door or sliding wardrobe door). It’s also quite easy to build and can be operated from a 9V battery or 12V plugpack. Coming up with the sound When I was first asked (by Jaycar) to develop this project, I initially spent some time watching old “Star Trek” episodes and listening to the sound of “Starship Enterprise” doors opening and closing (hard work, but somebody siliconchip.com.au had to do it!). I also examined the shape of the waveform envelope and did a few spot checks of the frequency components present at various points in the waveform. Armed with this information, I then set to work and came up with quite a fancy circuit which generated a burst of white noise, shaped its envelope to produce a “ssshhhHHHh” sound and then mixed in some low-frequency components to produce the required thump as the door closed at the end. Well, to cut a long story short, it did work and the sound it made was a reasonable reminder of an Enterprise door operating. Since this sound was less than one second long, it could easily be recorded in a solid-state voice recorder chip, like the HK828 device used in the Voice Recorder module described in the May 2005 issue of SILICON CHIP. That way, constructors would not have to build the original circuit which was rather complicated. Instead, the synthesised sound produced by that circuit would be pre-programmed into HK828 devices and supplied with the kits (Jaycar has copyright – see panel). In fact, the HK828 is capable of recording about 30 seconds of sound at its highest sampling rate, so it can easily store as many as four different sound “files” like the “Starship Enterprise” door sound. So that’s the basis of this project. It’s essentially a stripped-down version of the May 2005 Voice Recorder, able to play back two slightly versions of the “Starship Enterprise” door sound from pre-programmed HK828 chips. How it works Fig.1 shows the circuit diagram of the unit. It’s very similar to the Voice Recorder, the main difference being that here we’re using the HK828 chip for playback only. That’s because it June 2006  93 Fig.2: this block diagram shows what’s inside the HK828 sound recorder chip. The circuit blocks associated with recording are not used in this particular application, since we are using the playback function only (the chip is supplied pre-recorded). will be supplied pre-programmed with the sound effect “recordings”. Because the HK828 chip still forms the functional heart of the project, we’ll give you a quick rundown on what’s inside it. You can see the chip’s basic architecture from the block diagram of Fig.2. We won’t worry about the internal circuit sections used for recording, because they’re not being used in this case (if you want to understand how they work, refer to the May 2005 article). In fact, the only section on the lefthand side of Fig.2 we’re making use of here is the “Internal Oscillator”. This section actually generates the HK828’s sampling clock for playback, as well as recording. Its frequency is determined by an external resistor (from pin 7 to ground), which in this case has a value of 22kW to give a sampling rate of about 8.7kHz – about as fast as the HK828 can operate, to achieve its best audio bandwidth. Now although the recorded audio is stored as samples inside the HK828, this is done using an analog sampleand-hold system rather than the more common digital sampling. This is because it stores the samples in an array of 262,144 (256K) Flash EEPROM analog storage cells, each of which can store any of 256 different voltage 94  Silicon Chip levels. This gives the equivalent of 8-bit digital recording. As shown in Fig.2, the recording and playback of samples in the storage array is controlled by analog write and read circuits, along with the message control and message addressing circuits. When a recorded sound is being played back, the signals are fed through a low-pass filter to remove sampling noise and then fed to the internal output amplifier. The rest of the circuitry inside the HK828 chip is used for overall device control and mode switching, etc. As mentioned above, the HK828 can be configured to store and play back either a single sound “recording” (like a tape recorder) or a fixed number of shorter recordings. In this case, it’s configured to play back either of two shorter recordings. Main circuit Now let’s go back to the main circuit – see Fig.1. As shown, the replayed audio signal is taken from pin 14 of the HK828 (IC1) and fed via a 10kW series resistor and 10mF capacitor to trimpot VR1 which is used to adjust the output volume. The audio signal is then fed via a 2.2mF capacitor to the non-inverting input of IC2, a TDA1905 audio power amplifier. This is config- ured to have a voltage gain of 100, as set by the 10kW and 100W resistors in the negative feedback divider. IC2 can deliver about 800mW of audio power to an 8W speaker with a 9V DC supply and about 1.4W of power with a 12V DC supply – enough to produce a convincing sound level from the 57mm mini-speaker. Of course, it will produce an even more convincing sound from a larger speaker. As stated, the HK828 chip can be configured to split its internal memory into either two or four chunks. This is done by connecting either one or the other of its MSEL pins (pins 24 & 25) to ground. In this case, the device is configured for two recorded sounds by connecting pin 24 to ground, via a small copper track on the underside of the PC board. To trigger the HK828 into replaying one of its sound recordings, a negativegoing pulse with a duration of about 500ms is applied to one of its trigger inputs – ie, M1-bar to M4-bar. In this circuit, only M1-bar (pin 1) and M2bar (pin 2) are used, to replay the two recorded sounds. The actual triggering pulses are provided by closing the contacts of either remote switch S1 or remote switch S2. In each case, this applies a negative-going pulse to the corresiliconchip.com.au Fig.3 (left: follow this parts layout diagram and the photo above when installing the parts on the PC board. The LED can either be mounted on the PC board (and used for testing purposes only) or it can be mounted on the front panel and connected to the PC board via flying leads. Make sure that all polarised parts are correctly installed and that IC1’s pins all go into the socket and are not bent underneath the device or splayed out. sponding chip input via an associated 2.2mF capacitor. The capacitor then subsequently discharges again via its associated 220kW resistor when the switch contacts open again. This prevents the chip from being repeatedly triggered if the switch contacts remain closed. In fact, they must be opened and the capacitor allowed to discharge, before being closed again in order to retrigger the circuit. The main idea of this is to allow you to use remote reed switches or micro­ switches, so that the unit can be wired to operate automatically when you open or close a bedroom door, etc. When the HK828 is playing back a sound, it switches its Strobe-bar pin (pin 22) low once every 200ms or so. This drives LED1 via a 680W current-limiting resistor, so that the LED “blinks” during playback. Power supply The HK828 has a maximum supsiliconchip.com.au ply voltage of 6V. As a result, a 7806 3-terminal regulator (REG1) is used to derive a +6V rail from the 9-12V DC supply used to power audio amplifier IC2. Diode D1 prevents damage due to accidental reversed polarity. The 9-12V DC source used to power the project can be either a plugpack or battery. This must be capable of supplying about 25mA continuously when the circuit is at idle and up to 150mA or so when it is producing sound. Construction Apart from the loudspeaker (and possibly LED1), all the components are mounted on a PC board coded 01206061 and measuring 111 x 57mm. This board has rounded corner cutouts at one end, so that it fits snugly inside a standard UB3-size jiffy box at that end. The speaker is mounted on the box lid, while the 9-12V DC power source is fed in through a 2.5mm concentric DC connector mounted on the PC board. Also on the board is a small terminal block. This accepts the leads from remote trigger switches S1 & S2, the leads entering via small holes in the side of the box. Fig.3 shows the parts layout on the PC board. Begin by fitting two PC board terminal pins at one end of the board for the connections to the speaker. Once these are in, you can also fit connector CON1 and the small terminal block. Next, fit trimpot VR1, making sure you orientate it correctly, then fit the resistors. Follow these with the capacitors, beginning with the small monolithic ceramics and then working your way through the MKT, tantalum and aluminium electrolytic types. Remember that while the monolithic and MKT types are not polarised, the tantalum and aluminium electrolytics are indeed polarised and must June 2006  95 (as in Fig.3). If you choose the latter option, you will have to drill an extra hole in the front panel and secure the LED using epoxy adhesive. Note that the flying leads for LED1 are soldered directly to the board rather than to PC board pins. The final component to fit to the board is regulator REG1, which is mounted horizontally. To do this, first bend its leads downwards by 90° about 6mm from the regulator package. That done, fasten it in place using an M3 x 6mm machine screw and nut before soldering its leads to their respective board pads. The PC board assembly is now complete and you can fit the wires used to connect the speaker. These speaker wires can be made from a 110mm length of light-duty figure-8 flex. Par t s Lis t 1 plastic utility box, UB3 size (130 x 67 x 44mm) 1 PC board, code 01206061, 57 x 111mm 1 57mm mini speaker, 8-ohm impedance 1 3-way screw terminal block, PC-mount 1 28-pin IC socket, 0.6-inch PCmount 1 2.5mm concentric DC connector, PC-mount (CON1) 2 PC board terminal pins 4 M3 x 10mm machine screws, countersink head 1 M3 x 6mm machine screw, round head 9 M3 nuts 1 20kW horizontal trimpot (VR1) Semiconductors 1 HK828 sound recorder chip, pre-recorded (IC1) 1 TDA1905 audio amplifier (IC2) 1 7806 +6V regulator (REG1) 1 5mm green LED (LED1) 1 1N4004 power diode (D1) be fitted the correct way around. The wiring diagram indicates the positive lead of each polarised capacitor with a small ‘+’. One point to watch with the 100nF capacitors is that two of these are multilayer monolithic ceramics, while the remaining four are the larger rectangular MKT type. The monolithic capacitors go in the indicated positions at either end of IC1, while the MKT types go in the remaining positions. Once the capacitors are all in position, fit diode D1. This is again polarised, so make sure you orientate it as shown. That done, install IC2, which Capacitors 1 2200mF 16V RB electrolytic 1 1000mF 16V RB electrolytic 1 220mF 10V RB electrolytic 1 100mF 16V RB electrolytic 1 47mF 16V RB electrolytic 2 10mF 10V RB electrolytic 1 4.7mF 25V tantalum 4 2.2mF 25V tantalum 1 220nF MKT metallised polyester 4 100nF MKT metallised polyester 2 100nF multilayer monolithic Resistors (0.25W 1%) 3 220kW 2 100W 6 22kW 1 47W 2 10kW 1 1W 1 680W Final assembly The PC assembly is now ready to be mounted into the box. Before doing so though, give it a careful inspection to make sure that you haven’t made any bad solder joints or left solder bridges shorting between tracks or IC pads. It’s also worth double-checking that you’ve fitted all polarised parts with their correct orientation. Once you’re satisfied that everything is OK, the board can be mounted inside the box. This is secured using four M3 x 10mm countersink-head machine screws, which are passed up from the underside and secured using star lockwashers and M3 nuts which also act as spacers. The board is then lowered onto these “spacers” and secured using four more M3 nuts. The speaker is mounted on the rear of the box lid, behind an array of holes which are provided to let the sound out. It is held in place using “Araldite” or similar epoxy cement, which is applied to the front of the speaker’s outer rim before introducing it to the Where To Buy A Kit This project was sponsor­ ed by Jaycar Electronics, who own the design copyright. A complete kit of parts is available from Jaycar for $39.95 – Cat. KC-5423. should be soldered directly into the board. This is important for its stability and also improves heat dissipation. By contrast, IC1 plugs into a 28-pin socket. Be sure to install this socket with its “notched” end towards the 47W resistor, to guide you in plugging in the HK828 chip. When the socket pins are all soldered to the board pads underneath, you can plug IC1 into the socket. Be sure to do this without damaging any of its pins. LED1 can either be mounted on the PC board (as in the prototype), or it can be mounted on the front panel and connected to the PC board by flying leads Table 1: Resistor Colour Codes o o o o o o o o No.   3   6   2   1   2   1   1 96  Silicon Chip Value 220kW 22kW 10kW 680W 100W 47W 1W 4-Band Code (1%) red red yellow brown red red orange brown brown black orange brown blue grey brown brown brown black brown brown yellow violet black brown brown black gold gold 5-Band Code (1%) red red black orange brown red red black red brown brown black black red brown blue grey black black brown brown black black black brown yellow violet black gold brown brown black black silver brown siliconchip.com.au rear of the lid. Once it’s in place, you can apply a bead of the cement around the rim for good measure. Place the assembly aside for a few hours to allow the cement to cure. When the epoxy cement has cured, solder the free ends of the speaker connection wires to the speaker lugs. That done, pass the bared ends of the connecting leads for the remote trigger switches (S1 and S2) through the holes in the lower side of the box and connect them to the terminal block using the screws. Note that the “earth” wires from both switches connect to the centre hole of the terminal block. It’s a good idea to twist them together before pushing them in and tightening the screw. The project is now ready for checkout and adjustment. Checkout & adjustment Before applying power, adjust trimpot VR1 to roughly the middle of its range. That done, connect a 9-12V DC power supply to CON1 and touch the ends of the connection wires for S1 together briefly. You should immediately hear the recorded door sound, lasting almost a second. When it ends, try touching the ends of the wires for S2 together, to produce the second sound recorded on the HK828. LED1 should blink while either sound is being played. You should be able to adjust the Fig.2: the circuit board fits neatly inside a standard UB3-size plastic case and is secured using M3 x 10mm machine screws and nuts – see text. The loudspeaker is secured to the lid using epoxy adhesive. volume of the sounds up or down to the level you want using trimpot VR1. This is the only adjustment to be made, so once you’ve found the right volume setting, the unit can be completed by screwing on the box lid using the four self-tapping screws provided. That’s it! Your Door Sounder is now finished and ready for use. Beam me SC up, Scotty! Looking for real performance? NOT A REPRINT – Completely NEW projects – the result of two years research & development • Learn how engine management systems work • Build projects to control nitrous, fuel injection and turbo Fro m the pu bli sh ers 160 PAGES 23 CHAPTE RS of boost systems • Switch devices on and off on the basis of signal frequency, temperature and voltage Intelligen t turbo timer • Build test instruments to check fuel injector duty cycle, fuel mixture and brake and coolant temperatures • Speedo Corrector, Turbo Timer & Digital Thermometer Projects Mail order prices: Aust. $A22.50 (incl. GST & P&P); Overseas: $A26.00 via airmail. I SBN 095 852 294 9 7809 5 8 5229 4 $19.80 (inc GST) -4 s fuel cont rollers 6 NZ $22.00 (inc TURBO B OOST & nitrou GST) How eng in managemene t works 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 June 2006  97 Vintage Radio By RODNEY CHAMPNESS, VK3UG The Kriesler 41-29 “Trans-Mantel” Developed during the early 1960s, the Australian-made Kriesler 41-29 “TransMantel” was a 7-transistor receiver based on PNP germanium transistors. It was an excellent little set that could be used both as a mantel receiver and as a portable. T HE TRANSISTOR RECEIVER era effectively started in Australia with the importation of a number of radios from Japan in the mid-1950s. These early sets were not brilliant performers as I soon found out when I bought a small Sony pocket receiver. It proved to be extremely “hissy”, even when tuned to a strong local station. In fact, the signal had to be quite strong for the set to even receive it. Despite these shortcomings, I became hooked on this new technology – a technology I didn’t understand at the time but wanted to learn about. I kept the little pocket set for a quite few years but its limitations meant that it had very little use and I mostly listened to my old faithful valve radios. Australian manufacturers started making transistor receivers in the late 1950s. Initially, they assembled the sets in the same way as their valve sets, with point-to-point wiring, and in some radios, the transistors were even mounted in special sockets – just like valves. This method of manufacture was expensive, particularly when Australian manufacturers had to compete with the Japanese manufacturing techniques of PC board construction and cheap employee wages. However, Australian manufacturers quickly realised that transistors should be treated as just another component. Mounting most of the receiver on a PC board would also be cheaper, with fewer wiring mistakes. These techniques coupled with tariff barriers helped Australian manufacturers stay competitive until the barriers were reduced in the early 1970s. The transitional Kriesler This is the fully-restored set, shown here with its carrying handle raised. Its styling resembled the earlier valve mantel receivers. 98  Silicon Chip Kriesler Australia was one of many firms making both valve and transistor sets in the 1960s. Like most manufacturers at that time, they built their transistor receivers in a style that suited valve technology. Just why they did this isn’t clear. It’s hard to be sure whether the manufacturers were ultra-conservative when it came to designing their radios (cabinets in particular) or whether they felt that customers would not accept the styling changes that were possible with transistors (including portability). In reality, it was probably a combination of both scenarios. The 41-29 is one of these transitional receivers, being called a “TransMantel”. It is in a case similar to the Kriesler 11-90 valve mantel receiver, although the dial mechanism is quite different. It could be used either as a siliconchip.com.au Fig.1: the Kriesler Model 41-29 employed a conventional superhet circuit based on seven PNP germanium transistors. conventional portable (although the cabinet may not be all that rugged) or as a cordless mantel receiver. Unlike some other sets, the battery life was quite good, as a 286 battery was used to provide power. The 286 was in reality two 276 type batteries in the one case. In fact, a life of up to 1000 hours has been quoted for this battery in some of the Kriesler receivers. Main features The Kriesler 41-29 is housed in an attractive plastic case and its size suited both portable or mantel-piece operation. It has a large slide-rule dial and is tuned by a relatively large knob at the righthand end of the scale. Apart from that, there are just two other controls: a combined on-off/ tone control and a volume control at bottom right. It all adds up to a rather neat and functional layout. The rear of the set is held in place by two screws, which serve dual functions. When viewed from the back, the lefthand screw is also the antenna connection, while the righthand screw serves as the earth connection. It is necessary to remove these two screws and the back to replace the battery. In fact, the instructions for this are on a small piece of paper attached to the underside of the receiver. Another set of instructions, this time inside the back, describe how the rest of the receiver can be dismantled. This same piece of paper also has a layout diagram of the major parts on the PC board, plus a rather small copy of the circuit. This circuit is hard to siliconchip.com.au This rear view shows the fully restored set, just before the back was refitted. read because of its small size but it’s much better than having no information at all about the circuitry. Dismantling and cleaning The two control knobs fitted to the unit that was given to me to restore were certainly not the originals. They were both black and much bigger than the originals that came with the set, so they certainly looked out of place. Fortunately, I had some old Kriesler knobs stashed away and I found two which looked similar to the original knobs. The two black control knobs and the tuning knob were then removed, followed by the four screws that secured the chassis to the front of the cabinet. That done, the front of the cabinet came away in three separate pieces (that’s how it was made). The chassis was dusty but a few minutes work with an old paintbrush fixed that. The dial pulleys were then oiled, as were other moving parts. In this set, the volume and tone control shafts are split down the centre and require a knob with a metal insert (this insert anchors to the sides of the knob). The Kriesler knobs that I’d dug up (originally scrounged from a Kriesler TV set) were suitable but to accommodate the metal inserts, I had to increase the width of the slots (the June 2006  99 This rear view shows how the PC board could have been hinged for easier service access. Despite its age, no PC board parts required replacement. The alignment required adjustment though, to get the set to tune correctly. remove as it could have been due to the location of the “earth”, which is also the mounting plate for a screw holding the back of the set against the metal chassis. First, the single-strand wire from the oscillator section of the tuning gang to the PC board has to be desoldered, after which the four screws holding the board in place are removed. The “earth” plate is then sprung outwards so that the board can be removed. In practice, the board can then be turned over (so that the parts face upwards) and a piece of cardboard or cloth placed underneath it to prevent shorts to the frame during testing. This procedure could have been simplified by mounting the board in a slightly different position, so that it could be directly removed without the “earth” being in the way. In fact, with a little more thought, the board could have been hinged on the edge near the centre of the receiver, which would have made it a dream to service. The old AWA P1 portable TV set had a hinged board and it made the set very easy to service. In fact, AWA did such a good job of making the P1 accessible that the picture tube could be replaced in 15 minutes. Circuit details original knobs obviously had a much narrower insert). This was done by carefully filing them with a needlenosed file. That done, the inner retaining screw for the tuning knob was cleaned and repainted with gold spray paint, as was one stud underneath the cabinet front. In addition, the dial pointer was resprayed with white paint, as it too was looking a bit grubby. The speaker had some fluff trapped at the front of the cone, which meant it had to be removed. This involves first removing the PC board (more on this later), after which it’s a matter of undoing the nuts and bolts that hold the speaker in place. In the end, it was necessary to only 100  Silicon Chip partially remove the speaker, after which the fluff was easily brushed out. The speaker was then correctly refitted into position. Next, the cabinet and tuning knob were washed using soapy water, a nailbrush and a toothbrush. However, I did take care to ensure that the paper stickers didn’t get wet. Any shallow scuff marks in the case were then removed using automotive cut and polish but there were also some marks that were too deep to get out – at least not without cutting well into the plastic case. However, the remaining scratches are not particularly obvious. Removing the PC board The PC board wasn’t as easy to The circuit configuration is similar to many other transistor receivers of the era – see Fig.1. It’s a standard 7-transistor superhet circuit, with the front-end using an OC170 transistor as an autodyne converter. Kriesler economised on the windings on the loopstick antenna by connecting the low-impedance section of L2 to both the base of TR1 (via R1, C1 & R3) and to the antenna via a broadlytuned coil (L1). Coils used in the L1 position are usually tuned below the broadcast band when used with a 7-10m long antenna. This coil boosts the performance at the low-frequency end of the dial, as the performance here is usually inferior to that at the high-frequency end. The output from TR1 is fed via 455kHz IF (intermediate frequency) transformers IFT1A and IFT1B to the base of the first IF amplifier (TR2, OC169). It then goes to IF amplifier stage TR3 (OC169) and from there to detector stage D2 (OA79) which also provides the AGC voltage. Resistors R17 and R18 forward bias D2 almost to the point of conduction, thereby siliconchip.com.au Despite its apparent simplicity, the Kriesler Model 41-29 Trans-Mantel is not all that easy to disassemble for service. greatly increasing its sensitivity and reducing distortion. As the signal strength increases, D2 applies an increasingly positive voltage to R10 and hence to the base of PNP transistor TR2. This AGC voltage in turn causes TR2 to draw less current as it cuts off. As a result, the voltage at the junction of IFT2 and R12 becomes more negative (note: the circuit is positive earth). Now let’s consider the action of diode D1 (OA90), which is effectively wired between the collector circuit of TR1 and the collector circuit of TR2. siliconchip.com.au Normally, D1 does not conduct as TR1’s collector is at -7.1V and TR2’s is -5.1V (ie, D1 is reverse biased). However, as TR2 shuts down due to AGC action, its collector voltage progressively becomes more negative. When this voltage goes below about -7.3V, D1 becomes forward biased and conducts, thus causing the signal from TR1 to largely bypass TR2 and go straight to TR3 (via IFT2). As a result, the gain of the set is reduced on strong signals. At the same time, the selectivity is also reduced, as IFT1 is bypassed and only IFT2 and IFT3 are effectively in circuit. This loss of selectivity probably doesn’t matter a great deal and actually has the benefit of improving the audio quality on strong signals. Following the detector, the audio is fed to volume control R21 and then to the first audio amplifier (TR4, OC71). This is then followed by audio stage TR5 (OC75) which in turn drives two class B audio transistors TR6 and TR7 (OC74s) via transformer T1. TR6 and TR7 operate in push-pull configuration and drive the loudspeaker via transformer T2. Negative feedback is applied from the loudspeaker voice coil to the emitter of TR5. The output stage quiescent current is regulated by R37, a negative temperature coefficient (NTC) thermistor. Germanium transistors are particularly prone to thermal runaway as their temperature increases. In fact, it can be so bad in circuits like this that the transistors can self-destruct. To overcome this, the NTC thermistor decreases its resistance with increased temperature, thereby reducing the forward bias on the bases of transistors TR6 and TR7. This compensates for the tendency of the TR6 and TR7 to conduct more heavily with increasing temperature. In this circuit, the thermistor senses the ambient temperature inside the case but some later transistor equipment had the thermistor physically connected to the output transistor June 2006  101 the rest point for the pointer changed which wasn’t good. I then found that the plastic gear shaft on the dial reduction drive had expanded, so that when tuned to the end of the dial, you could keep turning it even though the tuning gang was now stationary. This was easily fixed by drilling through the plastic gear and the brass tuning capacitor shaft and then locking the two together with a wire pin. Summary The geared drive for the tuning capacitor is inside the compartment to the left. This made difficult to drill a hole to lock the gear to the tuning capacitor shaft. heatsinks to improve the response time and provide more effective control. Restoration Initially, this set was completely dead but this was quickly traced to a faulty on/off switch. Not having a replacement on hand, I decided to simply bypass the switch until a suitable control became available. The set then showed signs of working. Next, I sat my Leader LSG11 signal generator on the other side of the workshop, so that it could provide a weak test signal for the set. This was tuned to 455kHz and I could immediately hear a beat tone from the radio, so it was quite a sensitive set. The cores of the IF amplifier transformers had all been sealed but their alignment appeared to be pretty much spot on. However, I found that the set would only tune down to 600kHz instead of the more normal 525kHz. This was easily fixed. All I had to do was adjust the oscillator coil so that it tuned down to 525kHz with the gang shut, then adjust the oscillator trimmer so that it tuned to 1620kHz with the gang fully open. There seemed to be little interaction between these two adjustments so I then aligned the antenna circuit by adjusting the position of the loopstick coil for best performance at about 600kHz and the antenna trimmer for best performance at around 1500kHz. The set was now working rather well and that was with no external antenna. In fact, it worked so well that the addition of an external antenna almost caused overload. At this stage, I ran into a problem. The dial scale has a “start point” marked on it but I couldn’t get it right. I tuned to either end of the dial and Kriesler made many interesting receivers over the years and the 41-29 Trans-Mantel was an excellent little set with long battery life. The dial drive system is a little more complicated than needed and the PC board could have been mounted in such a way that it could have been hinged for easy service. However, these are comparatively minor quibbles. Finally, note that the circuit indicates that the on-off switch is part of the volume control. In practice, it’s part of the tone control instead, so someone didn’t check the circuit too well. Errata In Vintage Radio for June 2004, I stated that the suppressor grid on a valve caught the electrons that bounced off the plate. This isn’t strictly correct as the electrons that hit the plate dislodge other electrons, which are collected by the suppressor. This is called “secondary emission”. It has also been pointed out that the screen grid reduces the capacitance between the grid and the plate. This should have added to my statement that the screen grid screens the grid SC from the plate. 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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 Unwanted whistle from speed-controlled motor I have just built a 10A speed controller kit with four Mosfets for use on a golf buggy. It is mounted in an aluminium enclosure but I have a very annoying audible high-frequency sound coming from the motor. Is this just a side effect of the switching frequency or is it a curable condition? (J. G., via email). • As you have surmised, the noise is due to the switching of the motor on and off to regulate the speed. You can reduce the noise by increasing the PWM frequency by a small amount. At present, the frequency is 2kHz. You could try changing the .068mF (68nF) capacitor to a 33nF to double the frequency and reduce noise. However, increasing the frequency too much will actually reduce the motor speed due to the motor’s inductance. Wienstone bridge circuit Sometime in the last 18 months I saw an article in an electronics magazine using a Wienstone bridge circuit. It used a dual op amp (8-pin, not TL0x2 but pin-compatible) amongst its parts. As I rarely look at other publications, I figure it probably was in SILICON CHIP. Can you assist me by telling me what issue it was in if I am guessing correctly? (J. L., via email). • You are possibly confusing a Wien bridge oscillator with a Wheatstone bridge circuit. A Wien bridge oscillator was published in the Circuit Notebook pages of the January 1994 issue. This used a TL072 op amp and a single pot to vary the output frequency. This was not a project article and did not have a PC board. If you want a complete design for a high-quality audio generator with digital readout, have a look in our February and March 1999 issues. Remote control for speakers After reading your article on the Remote Hifi Volume Control (SILICON CHIP, April 2006), I thought this might be the answer to a problem I have been toying around with for a long time now. I have two sets of stereo systems (not identical) which I want to use simultaneously to play my music. One is a receiver/amplifier with provision for two sets of speakers – Speakers A (left Microwave Ovens Powered By DC/AC Inverters I am seeking some advice on using microwave ovens running from a DC-to-AC power inverter supply. My experience is that an 800W microwave oven fails to operate on an inverter which supplies 1500W continuous of modified sinewave power. I can think of two possible reasons – either a pure sinewave power signal is required for the microwave generator (like a fluoro light or other EMR generator) and/or the timing electronics requires a true sinewave signal to control the microwave 106  Silicon Chip generator. Could you please comment on other reasons beyond my knowledge base which might explain why a microwave oven fails to operate from a modified sinewave which supplies double the required wattage? (R. M., via email). • An 800W microwave oven will draw at least 1600W from the mains and there will be an initial turn-on surge as well. So not only do you need a big inverter but you need a big battery as well, otherwise the inverter will not manage to start the microwave. & right) and Speakers B (left & right). The output is controlled by a single (main) volume control. What I want to do is put in another volume control so I can control the levels of the two sets of speakers independently. The other system I have is a 5.1 channel surround sound unit but which I use mainly for stereo sound. It has an output for a subwoofer but is also controlled by a single volume control. In the same principle, I want to add another volume control to operate my subwoofer independently of the front speakers. Right now, no matter if the subwoofer’s own volume control is on full, if I turn down the main volume, the bass is also diminished. I want the subwoofer to remain at the same level even when the front speakers are fully off. Next, I want to connect my CD player to both systems through an audio splitter so both will play my music simultaneously. In this instance, I need the opposite: a single master volume control for the whole combined system. Would this be possible without extensive modification of internal circuitry of the amplifiers, using your remote volume control project as external add-ons only? (B. D., Quakers Hill, NSW). • The receiver/amplifier probably has the speaker pairs connected in parallel in the “both” position. This means that there is no way of controlling the volume of the pairs individually unless you do it with a resistive stereo volume control such as units sold by Altronics (Cat. A2305, A2306, A2312, A2313 or A2386). It’s difficult to comment on the 5.1 channel unit, as there are so many varieties on the market. Assuming it incorporates a separate subwoofer amplifier, then you may be able to find the signal input to that amplifier and control it with a potentiometer. You’d need a copy of the service manual or have a certain level of competency before attempting any modifications. siliconchip.com.au Add-On Control Circuit Won’t Fully Charge A Car Battery I purchased a Jaycar kit based on an EA article (July 1997) for the Arlec battery charger add-on unit. In the article, it states the design objective as being to be able to leave a lead-acid battery on charge indefinitely, a dramatic improvement over the basic charger which would overcharge the battery in that situation. The design seems to be effectively acting as a fixed voltage charger, the text suggesting a voltage setting of 14V or thereabouts. However, conventional lead-acid charging theory would have a charge voltage of perhaps 14.3V or 14.5V but then a float charge of 13.4V to 13.6V once the charge current has dropped to a low level – indicating the battery is charged. Would not this charger circuit be a sort of half-way house, in that it will take a long time to fully charge the battery when using 14V, yet that You could certainly use the remote volume control project as a “master” control by inserting it in the CD player’s signal line. Electronic wind vane wanted Thanks for the low-cost anemometer in the March 2006 issue. I was wondering how to modify it to also provide wind direction. As I have a small yacht, I have been thinking about such a project for long time, as I have not worked out any way to tell which direction the wind is from for night sailing. (K. W., via email). • We published an electronic wind vane with a 16-LED display in the March 2000 issue. You would have to build it as well as the anemometer. Noise cancelling in cars I am wondering if there has been a circuit published that utilises reverse phase noise cancellation. I am looking into reducing the noise in my car by placing microphones outside, to pick up road noise, traffic and engine revs, to then play them back in my car stereo siliconchip.com.au voltage is too high to leave permanently connected, eventually causing damage? Of course, a voltage setting of 13.6V could be chosen, so the charger could certainly be left connected indefinitely, but then the battery would be in danger of never achieving full charge. It occurred to me that I may have misunderstood the design, since the charge voltage is actually disconnected at, say, 14V. But as soon as the voltage falls it reconnects, so surely the average charging current is still the same as having a voltage regulated 14V permanently connected – which will overcharge the battery? Of course there’s also the argument that this is no different than any car’s charging system but in fairness, a car charging system is not connected indefinitely (for days or weeks at a time) and also draws on the battery. out of phase, to cancel each other out. I would still like to be able to play music through the same speakers so it would have to have a source input, mic input, and filtered output. Do you know of a circuit, or product that would allow me to do this? (J. T., via email). • We published an FM radio intercom for motorbikes in the October and November 1989 issues. This circuit used a noise-cancelling microphone and you may be able to use the same principle in your application. Queries on PortaPal float battery charger The March 2003 issue features a 12V SLA float battery charger built around an LM317 adjustable voltage regulator. The designer gives a brief description of the operation of the 317 and mentions that the reference voltage, nominally 1.25V, developed across the output and adjust terminals, will regulate the current through the 120W resistor to 10mA. This would be the case if the 120W resistor was solely connected between the output and adjust terminals. However, the inclusion of the 1kW resistor, (D11 anode to ADJ pin) alters this. I thought about potential modifications to cause the voltage point to switch once full charge was reached but current sensing from the half-wave rectified charging source proved too difficult. Have I misunderstood this design or is it not a design that can truly be left connected indefinitely. If it is, then it’s in fact worse than a car’s charging system in that respect? (C. L., via email). • You have not misunderstood the design. It does indeed charge to 14V, then disconnects, waits for the voltage to drop below 14V and then reconnects again. Depending on the current output of the charger, it could eventually cause damage to the battery. If you want a 3-step charger, you may want to consider our Charger for Deep-Cycle Batteries, published in the November & December 2004 issues of SILICON CHIP. The 317’s data sheets go some way to explaining this. They include application notes, which feature the 317 configured as an adjustable current limiter. In this configuration, the 120W resistor is referred to as R1 and the 1kW resistor is replaced with a variable resistor. The load would then take the place of trimpot VR7 and the other 1kW resistor on the charger schematic. By adjusting the variable resistor, one can adjust the load current from a maximum value of 1.25/R1 amps down to almost 0mA. This can readily be demonstrated on the bench. A 121W resistor was used instead of 120W, along with a 1kW variable resistor. A 25W resistor was used as the load; ie, in series with R1. With the variable resistor set at 0W, a measurement of 10.44mA was obtained through the 25W load. As the variable resistor was increased, the 10.44mA measurement started to decrease. A reading of 3.22mA was obtained for a variable resistor setting of 276W. The designer seems to suggest that because the adjustment pin draws negligible current then practically all of the 1.25V will be dropped across the 120W resistor, yielding a current June 2006  107 VGA To Component Video Connection I recently purchased and built the RGB to Component Video Converter kit published in the October 2004 issue. The kit was very professional and easy to assemble. My intention is to use the converter to allow me to send a video signal from my PC video card to my Sony TV. However, when I tested the card, it appears that there is no sync signal present. Is there an easy way of adding the vertical and horizontal sync signal present on the VGA output to the component outputs of the converter, either internally or externally? (D. T., Bathurst, NSW). of 10mA. I don’t believe that’s the case when the 1kW resistor is connected back to the adjust pin. Instead, I calculate the current to be 1.25/(1000 + 120) or 1.11mA. Is this correct? (J. O., via email). • In a typical regulator arrangement where we require more than 1.25V, the LM317 is used with a resistor between the adjust terminal and the output terminal and between the adjust terminal and ground. In our case we use a 1kW resistor and a 500W trimpot (VR7) in series from the adjust terminal to ground. The resistor between the output and adjust terminal sets the resistor current and hence the output voltage. This occurs as follows. The voltage between • It’s not entirely clear what you are aiming to achieve. If you want to feed the VGA outputs from your PC video card out to your Sony TV, this won’t work because VGA signals use quite different vertical and horizontal scanning frequencies. Even if you could feed those to the TV, it wouldn’t be able to lock to them and present a stable picture. However, if your video card does provide a “TV standard” set of RGB video outputs (ie, with a vertical frequency of 50Hz and a horizontal frequency of 15,625Hz) in addition to the usual VGA “monitor” outputs, then using this second set the output and adjust terminals is set at a nominal 1.25V and the regulator maintains this with varying load currents. The adjust terminal is simply a voltage monitoring terminal and does not affect the voltages substantially since it draws a maximum of 100mA. The 120W resistor between the output and adjust terminals sets the current at 1.25/120 amps or 10.42mA. We can usually ignore the 100mA current in the adjust terminal. The current therefore flows through the 1kW resistor and trimpot VR7 from the adjust terminal to ground. The regulator’s output voltage with respect to ground is thus the 1.25V between the adjust terminal and ground plus the voltage developed across the 1kW Frequency Switch For LPG Conversion I bought a Frequency Switch kit, as featured in “Performance Electronics for Cars”, and I need to know if it will do the job I need it for or is there something else to try. I am putting a gas system on my 4x4 and what I need is something to switch it on at 1000 RPM and then switch it off if I go above, say, 3000 RPM but stay on while I am in that range of 1000-3000 RPM. Now the kit article says that it will switch on a rising or falling frequency. So if I switch it on with rising RPM and then, after going past the trip point, back off, will it 108  Silicon Chip turn off straight away or will it wait until it goes under the trip point? Is there a better kit for the job or can this kit be modified to do the job? (G. T., via email). • The only way we can see how you can do this is to build two frequency switches, with one set to switch on at above 1000 RPM and the other set to switch off above 3000 RPM . The contacts from one relay would be connected in series with the second relay; ie, connect the two NO contacts together and use the common contacts to do the switching. of outputs to feed your TV is more feasible. In this case, you should be able to extract the sync signals from the green (G) video output from the card, using an LM1881 chip in a sync separator circuit like that used in our “Component Video to RGB Converter”, as described in the May 2004 issue. You could use either the composite sync output from the LM1881 (pin 1) to provide the sync signals for the TV, or the signal from pin 1 as the H-sync signal and the signal from pin 3 as the V-sync if the Sony needs two separated sync signals for component video inputs. resistor and trimpot VR7. If VR7 is set at 0W then the voltage between the adjust terminal and ground will be 10.42mA x 1kW or 10.42V. Adding the 1.25V will give us the total of 11.67V. If the adjust terminal is not tied directly to the voltage divider formed by the 120W resistor and series 1kW resistor and trimpot VR7 but via a 1kW resistor, then there will be a small voltage drop across this resistor that will affect the output voltage. The drop across the resistor will be a maximum of 100mA x 1kW or 100mV. This voltage is negligible for our application since we can adjust this out with VR7 when setting the output voltage. The resistor was included in the adjust sensing leg so that transistor Q2 could be used to control the output voltage to limit the charging current to 1A, as explained in the circuit description. The resistor does not, as we have described above, affect the output voltage significantly. Connecting a 2.4GHz AV sender I purchased a 2.4GHz audio/visual sender unit some time ago and only recently connected it to TV sets in two sections of my home. This was prompted by purchase of a new TV set and the staging of the recent Commonwealth Games. Connecting the sender unit to my new TV set was relatively simple – just siliconchip.com.au insert three plugs into the AV (audio/ visual) sockets and connect to power. However, when I began to install the receiver unit to the (much older) remote CRT TV set, I discovered to my consternation that the set was not equipped with AV sockets. I was somewhat surprised because I was sure that many years earlier I had tried a less sophisticated and inexpensive “rabbit” unit, which connected simply to the same TV set. As it happened, this “rabbit” unit was unsatisfactory in terms of range and the project was abandoned. I now believe that the “rabbit” output to the remote TV set must have been simply “RF out”, replacing the antenna connection. No AV sockets were involved! So I have the dilemma of a 2.4GHz receiver with three plugs unable to be plugged into my older TV set. I have had a preliminary scan of the circuitry, to evaluate the remote possibility of replicating AV sockets but it all looks too hard. Is there any simple solution to my problem, possibly some sort of interface box accepting the AV plugs from the receiver and converting to a single RF output for connection to my old TV set antenna socket? Of course one possible solution might be to replace the old TV set with a new one equipped with AV sockets. However, the old set is very far from decrepit and it would be a waste to have to abandon it for the sake of a few sockets. Can you help please? (B. G, via email). • DSE and Jaycar have an AV modulator which will solve your problem. Alternatively, if you have a VCR you can use that to connect the AV signals to your TV. Notes & Errata Passive DI Box, May 2006: the end of the third paragraph in the third column on page 64 states: “The resistor for the ring output also prevents the possibility of the signal from a stereo source being shorted to ground. This could otherwise happen if a mono jack plug is inserted into the ‘thru’ socket”. This is incorrect. It should read High power train controller I built several model train controllers featured in the April 1997 issue, designed by Rick Walters. The controllers have proven to be very reliable and operate perfectly, giving very smooth and realistic control over the model trains. However, I find that they lack a little in terms of output power, particularly with some of the high draw models that I have. I was wondering if it is possible to modify the controllers to give an output of around 18-20V and if so, what components would I have to change in order to achieve such an output? (L. G., Penrith, NSW). • It is possible to increase the output voltage of the unit to 18-20V. All you need do is increase the transformer to 15V-0-15V and increase its current rating if your want more current output. However, you will also need much bigger heatsinks on the output transistors, as they will get very hot. You really would be better off going to one of our switchmode designs as follows: “A stereo source will not be shorted because of the use of a stereo socket and the isolation of the left and right channels via 4.7kW resistors required for stereo mixing. This would not be the case if a mono socket were used instead. Note that the stereo source will be shorted at the ring terminal if a mono jack plug is inserted into the ‘thru’ socket”. which are far more efficient. Have a look at the Railpower design described in the October, November & December 1999 issues of SILICON CHIP. Looking for kit radio circuit I have an “RSC” radio that is not working. I spoke to a fellow in Queensland and he told me that it is a radio kit brought out by “Radio Hobby” magazine. The radio was called “Little General”. I am looking for a circuit diagram for it. It is a 4-valve configuration: 6V6GT, 6G8G, 6J8GA and the rectifier I think is a 665. (P. L., via email). • The set most closely matching your valve line-up was described in “Radio & Hobbies” in March 1956, in an article entitled “A Mantel Set From Old Parts”. The basic line-up was 6J8, 6C8, 6V6 and 6X5 as the rectifier, although alternative valves were nominated. It doesn’t match the “Little General” sets described in 1956 or 1961. We can supply a photostat copy of the article for $8.80 including SC postage. 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 June 2006  109 MARKET CENTRE Cash in your surplus gear. Advertise it here in Silicon Chip. CLASSIFIED ADVERTISING RATES Advertising rates for these pages: Classified ads: $27.00 (incl. GST) for up to 20 words plus 80 cents for each additional word. Display ads: $49.50 (incl. GST) per column centimetre (max. 10cm). Closing date: five weeks prior to month of sale. To book your classified ad, email the text to silicon<at>siliconchip.com.au and include your credit card details, or fax (02) 9979 6503, or post to Silicon Chip Classifieds, PO Box 139, Collaroy, NSW, Australia 2097. _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ Enclosed is my cheque/money order for $­__________ or please debit my o Bankcard   o Visa Card   o Master Card Card No. Signature­­­­­­­­­­­­__________________________ Card expiry date______/______ Name _____________________________________________________ Street _____________________________________________________ Suburb/town ___________________________ Postcode______________ Phone:_____________ Fax:_____________ Email:__________________ 110  Silicon Chip FOR SALE LEDs – SUPERBRIGHTS from just 25 cents each. 12 volt LED lightbars and kits, great for solar/camping. New IN14 nixie clock kit available now! Lots of other interesting stuff, if I don’t have it, just ask! www.ledsales.com.au ezChassis PRE-PUNCHED CABINETS for DIY amplifiers. Three heights, variants for valve and transistor amplifiers. Supplied with labels, screws and feet. Also heatsinks, handles and sockets. www.designbuildlisten.com More control solutions for you! NEW iUSBDaq Data Acquisition Module: features 8 12-bit analog inputs, 16 digital I/O, 2 PWM outputs, 1 high speed counter. High sampling rates. Free software, Labview driver and dll component. N1500LC Load Cell Panel Meter: New Low Cost, Great Accuracy, Fully programmable Indicator with 4-20mA and 2 relay outputs. USB to RS422/RS485 converter: with 1500V Isolation, RTS or Auto Data Flow control. Heaps of other features. Electronic Thermostats: with digital temperature displays, 2 control relays, can be used in heating and cooling. NTC thermistor or J TC or Pt100 sensors. Temperature and Humidity Sensors: Great accuracy, 4-20mA output. Wall and Duct mounting available. Signal Conditioners non isolated and isolated: convert thermocouples, RTDs to 4-20mA or 0-10V Fully programmable. Stepper Motors: we have a selection of Stepper motors for hobby and high torque CNC applications. DC Motors for both hobby and high torque applications. DC, Stepper and Servo Motor controller kits. Counter and Timers: 7-digit and 10year battery operated. Multi Function Timer and Cyclic Timer/ Pulse Generator Serial and Parallel Port relay controller cards. siliconchip.com.au SPK360 3/5/06 1:10 PM Page 1 DVB Channel Processors 20 years experience! HI-FISPEAKER REPAIRS TO551 Specialising in UK, US and Danish brands. Speakerbits are your vintage, rare and collectable speaker repair experts. Foam surrounds, voice coils, complete recone kits and more. Original OEM parts for Scan-Speak, Dynaudio, Tannoy, JBL, ElectroVoice and others! SPK360 YOUR EXPERT SPEAKER REPAIR SPECIALISTS tel: 03 9647 7000 www.speakerbits.com TAIG MACHINERY Micro Mini Lathes and Mills From $489.00 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  Laceys.tv ™ 42 Brunel Rd Seaford VIC 3198 Tel (03) 9776 9222 web:www.laceys.tv also Sydney, CoffsHarbour, Ulverstone Satellite TV Reception International satellite TV reception in your home is now affordable. Send for your free info pack containing equipment catalog, satellite lists, etc or call for appointment to view. We can display all satellites from 76.5° to 180°. AV-COMM P/L, 24/9 Powells Rd, Brookvale, NSW 2100. Tel: 02 9939 4377 or 9939 4378. Fax: 9939 4376; www.avcomm.com.au ELNEC IC PROGRAMMERS       Pump and Trip Alarm controller card. Duty-Standby operation. PIC MicroProgrammers: serial and USB port operated. 2, 4 & 8 Relay Cards: suitable for TTL and Open Collector Outputs. Switch Mode, Battery Chargers and DC-DC converters. Full details and credit card ordering available at www.oceancontrols.com. au Helping to put you in control. SECONDHAND ISSUES OF “NEW SCIENTIST” MAGAZINE FOR SALE. Email dobs<at>ozemail.com.au for further details. ImageCraft C Compilers: 32-bit Wind­ows IDE and compiler. For AVR, 68HC­ 08, 68HC11, 68HC12, 68HC16. from $330.00 Atmel Flash CPU Programmer: Hansiliconchip.com.au Universal and specialised models High quality Realistic prices Large range of adaptors Free regular software updates Windows 95/98/Me/NT/2k/XP GRANTRONICS PTY LTD PO Box 275, Wentworthville. 2145. Ph: 02 9896 7150 Best high end DIY audio kits on the planet! www.aksaonline.com 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 from SC, EA, ETI, HE, AEM & others. Ph (02) 9738 0330. sales<at>rcsradio. com.au, www.rcsradio.com.au www.grantronics.com.au RCS RADIO/DESIGN is at 41 Arlewis St, Chester Hill 2162, NSW Australia and has all the published PC boards QUALITY LED TORCHES, 1-watt R-bin: Fenix L0P, L1P, L2P using AAA, 1 or 2 AA cells. 3-watt: Nuwai QIII, TM-301X-3 using 1 or 2 CR123 cells. AIT Nightstar using no batteries at all! www.torchworld.com.au/sc/ S-Video . . . Video . . . Audio . . . VGA distribution amps, splitters, standards converters, tbc’s, switchers, cables, etc, & price list: www.questronix.com.au June 2006  111 Do You Eat, Breathe and Sleep TECHNOLOGY? Opportunities for full-time and part-time positions all over Australia & New Zealand Jaycar Electronics is a rapidly growing, Australian owned, international retailer with more than 39 stores in Australia and New Zealand. Our aggressive expansion programme has resulted in the need for dedicated individuals to join our team to assist us in achieving our goals. We pride ourselves on the technical knowledge of our staff. Do you think that the following statements describe you? Please put a tick in the boxes that do: Knowledge of electronics, particularly at component level. Assemble projects or kits yourself for car, computer, audio, etc. Have empathy with others who have the same interest as you. May have worked in some retail already (not obligatory). Have energy, enthusiasm and a personality that enjoys helping people. Appreciates an opportunity for future advancement. Have an eye for detail. USB KITS: Gas Sensors (CO, LPG, Alcohol), 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 Oscillo­ scope, Temperature Loggers, VHF Receivers and USB ActiveX (and USBDOS.exe file) to control our kits from your own application. www.ar.com. au/~softmark PCBs MADE, ONE OR MANY. Any format, hobbyists welcome. Sesame Electronics Phone (02) 9593 1025. sesame<at>sesame.com.au www.sesame.com.au POWER LEDs, Super Flux LEDs, 12VDC LED modules & blank PCBs. Quantity discounts. www.luxtronics. com.au WEATHER STATIONS: windspeed & direction, inside temperature, outside temperature and windchill. Records highs and 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, 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. Altronics............................. 51,74-77 Amateur Scientist CDs............... IBC Send to: Retail Operations Manager - Jaycar Electronics Pty Ltd P.O. Box 6424 Silverwater NSW 1811 Email: jobs<at>jaycar.com.au Aspen Amplifiers........................ 111 Jaycar Electronics is an equal opportunity employer and actively promotes staff from within the organisation. Av-Comm................................... 111 Australian Defence Force............... 3 BitScope Designs......................... 43 Dick Smith Electronics............ 22-27 humidity, dew point, solar radiation, UV, leaf wetness, etc. Just phone, fax or write for our FREE catalog and price list. Eco Watch: phone (03) 9761 7040; fax (03) 9761 7050; Unit 5, 17 Southfork Drive, Kilsyth, Victoria 3137. ABN 63 006 399 480. www.davisinstruments.com.au Eco Watch.................................. 112 WANTED Instant PCBs.............................. 112 WANTED FOR WALKABOUT SCOOTER MODEL W100: copy of service manual and circuit diagram of its electronics. John (02) 6766 3331. Jaycar .................. IFC,53-60,63,112 KIT ASSEMBLY MicroZed Computers.................. 101 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 SERVICES *PRINTED CIRCUIT DESIGN*: a professional-quality PCB design, circuit diagram and parts list from your sketch circuit for $120. Single or double sided, up to 50 components, any size. 0414 356 409; or media.a<at>bigpond.net.au ED SPICER CONSULTING: PCB design; PCB loading; prototype to any quantity; components sourced; RF, microwave and analog design; kits repaired. edspicer<at>ozemail.com.au or phone 0418 765 994. Do you have a good circuit idea? If so, sketch it out, write a brief description of its operation & send it to us. Provided your idea is workable & original, we’ll publish it in Circuit Notebook & you’ll make some money. We pay up to $60 for a good circuit or you could win some test gear. send your idea to: Silicon Chip Publications, PO Box 139, Collaroy, NSW 2097. 112  Silicon Chip Advertising Index Elexol........................................... 51 Furzy Electronics........................ 111 Grantronics................................. 111 Harbuch Electronics..................... 61 JED Microprocessors................ 5,63 Laceys TV.................................. 111 Ocean Controls.......................... 110 Quest Electronics.................. 63,111 Radio Parts.............................. OBC RCS Radio................................. 111 RF Modules.................................. 63 Silicon Chip Binders..................... 45 Silicon Chip Bookshop........ 104-105 SC Perform. Elect. For Cars.... 47,97 Silicon Chip Subscriptions.... 91,103 Silicon Chip Technology Awards... 52 Silvertone Electronics................ 111 Siomar Batteries.......................... 37 Speakerbits................................ 111 Taig Machinery........................... 111 Telelink.................................... 37,63 PC Boards Printed circuit boards for SILICON CHIP projects are made by: RCS Radio Pty Ltd. Phone (02) 9738 0330. Fax (02) 9738 0334. siliconchip.com.au