星期二 [ 2010-1-26 9:50:01 | watches2009 ]   EARTH TALK Dear EarthTalk: What's the story with LED light bulbs that are reputed to be even more energy-efficient than compact fluorescents? - Toby Eskridge, Little Rock, Ark. Perhaps the ultimate "alternative to the alternative," the LED (light-emitting diode) light bulb may well dethrone the compact fluorescent (CFL) as king of the green lighting choices. But it has a way to go yet in terms of both affordability and brightness. LEDs Pandora Necklace Charm have been used widely for decades in other applications - forming the numbers on digital clocks, lighting up watches and cell phones and, when used in clusters, illuminating traffic lights and forming the images on large outdoor television screens. Until recently, LED lighting has been impractical to use for most other everyday applications because it is built around costly semiconductor technology. But the price of semiconductor materials has dropped in recent years, opening the door for some exciting changes in energy-efficient, green friendly lighting options. According to HowStuffWorks .com, LED bulbs are lit solely by the movement of electrons. Unlike incandescents, they have no filament that will burn out. And unlike CFLs, they contain no mercury or other toxic substances. Proponents say LEDs can last 60 times longer than incandescents and 10 times longer than CFLs. And unlike incandescents, which generate a lot of waste heat, LEDs don't get especially hot and use a much higher percentage of electricity for directly generating light. But as with early CFLs, LED bulbs are not known for their brightness. According to a January 2008 article in Science Daily, "Because of their structure and material, much of the light in standard LEDs Other articles: http://www.msbw518.com/Blog/View/?267 浏览(213) | 回复(0) |