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SILICON SILIC CHIP www.siliconchip.com.au Publisher & Editor-in-Chief Leo Simpson, B.Bus., FAICD Production Manager Greg Swain, B.Sc. (Hons.) Technical Editor John Clarke, B.E.(Elec.) Technical Staff Ross Tester Jim Rowe, B.A., B.Sc Mauro Grassi, B.Sc. (Hons), Ph.D Photography Ross Tester Reader Services Ann Morris Advertising Enquiries Glyn Smith Phone (02) 9939 3295 Mobile 0431 792 293 glyn<at>siliconchip.com.au Regular Contributors Brendan Akhurst Rodney Champness, VK3UG Mike Sheriff, B.Sc, VK2YFK Stan Swan SILICON CHIP is published 12 times a year by Silicon Chip Publications Pty Ltd. ACN 003 205 490. ABN 49 003 205 490. All material is copyright ©. No part of this publication may be reproduced without the written consent of the publisher. Printing: Hannanprint, Noble Park, Victoria. Distribution: Network Distribution Company. Subscription rates: $89.50 per year in Australia. For overseas rates, see the order form in this issue. Editorial office: Unit 1, 234 Harbord Rd, Brookvale, NSW 2100. Postal address: PO Box 139, Collaroy Beach, NSW 2097. Phone (02) 9939 3295. Fax (02) 9939 2648. E-mail: silicon<at>siliconchip.com.au ISSN 1030-2662 * Recommended and maximum price only. 2  Silicon Chip Publisher’s Letter Let’s have no more of this carbon pollution nonsense As we approach the end of the first decade of this century, there are two great concerns: the global economic situation and global warming. Presently, with a view to improving their economic situation, most nations are not doing much about global warming, even if they have signed up to the Kyoto Accord. Ultimately, the economic situation in most nations will improve in a year or so and then it will be interesting to see if there is much action on global warming. Maybe in a year or so, the seemingly universal panic about global warming will abate somewhat. Maybe the “science on global warming” will not seem so “settled”. Sure, there will always be a proportion of hard-core fanatics who think we are headed for disaster and will always call for ever more drastic action to reduce “carbon pollution”, the prime suspect for global warming. Well, I sincerely hope that these sentiments will eventually come to be regarded as fanatic belief rather than sensible concern based on real science. For a start, let’s consider this highly emotive term “carbon pollution” which is constantly being bandied about. It only takes a moment’s thought to realise that there is no “carbon pollution” problem. It did exist 50 years ago, when we had steam trains and diesels with smoky exhausts and coal-burning power stations which had less than complete combustion. It used to be called soot. But it is not a problem now, in most countries. Now I know that some people use “carbon” as shorthand for carbon dioxide but it is sloppy thinking and generates worry in the unthinking masses that we are spewing all this carbon into the air. We’re not. We are burning tremendous amounts of fossil fuels and that is putting huge amounts of carbon dioxide into the air. Carbon dioxide is a greenhouse gas and that is a big worry, isn’t it? Well, maybe. But all these doom merchants who worry about carbon dioxide never say anything at all about the other greenhouse gas which is produced when fossil fuels are burnt. What is that? It’s called water vapour – the same stuff as in clouds. Is water vapour a problem? Definitely not. Just in case you don’t believe me, consider the combustion of petrol which is mainly octane, C8H18. When this is burnt, the chemical reaction is: 2C8H18 + 25O2 16CO2 + 18H2O octane + oxygen carbon dioxide + water If you calculate the molecular weights of the two combustion products, carbon dioxide and water, you will find that there is more water produced than carbon dioxide. But greenies never mention it. Why? Because they have either forgotten their high-school chemistry or they are completely ignorant of it. The point is that both water vapour and carbon dioxide are normal components of the air that we breathe. They are not pollution. They are both necessary for life to exist on the planet. If there was no carbon dioxide, plants would not grow (more high-school chemistry – it’s called photosynthesis). Without plants, no animals, including us, can live. It’s a simple as that. If there is more carbon dioxide in the air, plants grow more profusely. In fact, it is common practice to increase the carbon dioxide in greenhouses and aquariums to make the plants grow more vigorously. Alright, let’s say for the moment that carbon dioxide is BAD and must continued on page 45 siliconchip.com.au Eventually, after speaking to her husband, she gave me the go-ahead for option two. Replacing the electros in the power supply was fairly routine and I also spent some time looking for dry joints, especially to surface-mounted components. Unfortunately, I didn’t have a circuit diagram, so I was unable to identify the current-sensing circuit components and concentrate on that area. This circuit typically involves using a low-value resistor in the main B+ circuit and shuts the set down if the current goes too high. Gods not smiling A week later, after more extensive tests, I reinstalled the set in the client’s home and crossed my fingers. Unfortunately, the gods were not smiling on me because she subsequently phoned four days later to tell me, very coolly, that she had stopped the cheque. She wasn’t exactly rude but there was plenty of “hoity-toity” snotty-nosed attitude. There’s nothing like doing business with someone who thinks so highly of you! Anyway, she told me that the set lasted four hours before doing precisely the same thing as before. Just my luck, I thought – I have the set for two weeks and cannot fault it; she has it for four hours and it fails. That’s Murphy at his pernicious best. I reminded her that I had emphasised that repairing the power supply would be something of a gamble but it didn’t cut much ice. And even if it had, the fact was that the set was still faulty and I was obliged to give it another go. When I called to pick it up, her husband was there and he was much more relaxed and logical about things. After some discussion, he decided to go for option three (ie, replace the power supply) and hang the expense. And so that’s how this annoying intermittent fault was finally fixed. It’s the sort of repair that’s all part of the “dumbing-down” trend in the Publisher’s Letter . . . continued from page 2 be reduced. There are two ways to do this. The first is to reduce or stop burning fossil fuels, particularly in power stations. The second is so-called geosequestration whereby the carbon dioxide produced in the power station is separated from the other exhaust gases going up the stack (ie, nitrogen and water vapour) and then pumped underground. It turns out that this process is extraordinarily difficult. One way to do it might be to cool the smokestack gases sufficiently (to -78.5°C) so that the carbon dioxide solidifies (to dry ice). Or you could cool the gases sufficiently to separate the water and then compress it sufficiently to liquefy the carbon dioxide and allow the gaseous nitrogen to separate out. Or another scheme that has been suggested is for the power stations to burn the coal with oxygen rather than air – so that we don’t have the problem of removing the nitrogen. Whatever scheme is used, geosequestration will use enormous amounts of energy; perhaps 40% or more than is currently needed to generate electricity. Isn’t this insane? We want to get rid of carbon dioxide but we have to mine heaps more coal and burn it to do so. On the other hand, Australians mustn’t use nuclear power (which generates very little greenhouse gas) because that has all sorts of radioactive nasties. Never mind that a large proportion of the electricity generated by western countries already comes from nuclear power stations. I should note that the term “geosequestration” now seems to have been replaced by “carbon capture and storage (CCS) technologies” which seems to imply that there are lots of ways of doing it. The Federal Government proposes to spend lots of money promoting CCS – this is just more woolly thinking. And to think that Australia might take a lead with CCS and then sell it other countries that burn lots of coal just beggars the imagination. Just how gullible do we think they are? It is time that we called a halt on all this fear-mongering about global warming and greenhouse gases. The fact is that no matter how many socalled experts forecast that the polar icecaps will melt completely (they might) and sea levels will rise, we just don’t know if this will happen or how rapidly it might happen. Nor do we really know if global warming is wholly or partially caused by human activity. By all means let us stop wasting fossil fuels, particularly oil. We need to conserve oil for the future. And by all means let us accelerate moves to use more solar power, nuclear power, geothermal power or whatever. But let us not be panicked into enormously expensive moves to reduce carbon dioxide when we don’t really know if it’s a problem or not. Next time you see some politician or climate expert pontificating about global warming, ask yourself, “Do they even understand basic chemistry?” And remember, “carbon pollution” is not the problem! Leo Simpson Wanted: Electronics Technician An experienced electronics technician is required to repair & overhaul switchmode power supplies in our modern Hornsby workshop. Email your application to: ELECTRONICS SPECIALISTS TO INDUSTRY AND DEFENCE siliconchip.com.au SWITCHMODE POWER SUPPLIES PTY LTD (ABN 54 003 958 030) 1/37 Leighton Place, Hornsby, NSW 2077. Phone (02) 9476 0300 email: martin.griffith<at>switchmode.com.au webpage: www.switchmode.com.au June 2009  45