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June 14, 2007
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Enlighten yourself Here’s to the first gadget that really captured the hearts and minds of geeks everywhere: the light bulb. Before the incandescent bulb, doing stuff at night required fire, either on top of a candle or using a wick and liquid fuel of some kind. Naturally, these solutions were dangerous and often inconvenient. The light bulb uses a heated filament to convert about 2 percent of the electricity it consumes into visible light. If that sounds low to you, you’re right. There are better ways to convert electricity into light rather than waste it on heat. Compact fluorescent (CFL): If you’re at all environmentally inclined or just follow the latest wacky laws out of California, you’re probably heard the gospel of CFL. They use less energy than incandescents and last longer, so why wouldn’t you use them? California is considering a ban on the sale of incandescents, joining similar plans in Australia and Canada that go into effect in a few years. There are, of course, downsides to this miracle technology. The advertised life is usually 10,000 hours, which is longer than cheap incandescents, yes, but there are long-life incandescent bulbs available that last just as long. CFLs are also more expensive than incandescents, but that difference is more than made up by paying for 75 percent less electricity. As with many technologies that save energy when they’re used, CFLs take more energy to manufacture. They consist of not only a spiraled, gas-filled tube, but also an electronic ballast for controlling the bulb, encased in a plastic shell. There’s also a touch of mercury, a toxic element that’s normally a bogeyman of the environmental movement. Since a CFL requires about a quarter of the amount of energy to provide the same light as an incandescent, though, less coal is burned at power plants and less mercury is released into the atmosphere that way. Considering that coal plants are getting cleaner and a fair percentage of our electricity comes from nuclear and other sources, I personally consider the mercury debate a draw. Dispose of your spent CFLs at toxic waste collection days and the concern goes away. Light-emitting diode (LED): Used for decades in electronics as displays, indicators and diagnostic lights, LEDs typically don’t provide all that much illumination. They’ve begun to replace traditional bulbs in traffic signals and brake lights on cars, things that are meant to be seen, not to make their surroundings visible. Diodes are small semiconductors that release photons, also known as light particles. Until recently, semiconductors have been too expensive to put into light bulbs, but like many electronics, costs have plunged over time, so now the diodes can be made bigger, and multiple LEDs can be combined to make brighter bulbs. LEDs are about as energy-efficient as CFLs, but don’t come with the environmental problems. They last even longer, up to 100,000 hours. They also come in many different colors. Even though LEDs have come down in price, they’re significantly more expensive than incandescents or CFLs, and it’s hard to find an LED bulb that fits into standard household sockets. The price continues to fall, though, and they’re expected to become a primary light source in a decade or two. |
5/31/2007 USB is cool
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