There's a Department of Energy report at http://apps1.eere.energy.gov/buildings/publications/pdfs/ssl/lifetime_white_leds_aug16_r1.pdf on white LED lifetime.
Their conclusion is that if the LED is properly heat sunk, (heat sinked?) the lifetime should be around 35,000 - 50,000 hours. I suspect that there's a "you get what you pay for" in this regard, in that cheap LED lamps are not going to approach these figures but properly designed and manufactured ones will. I've disassembled a couple of cheap CFLs and I strongly suspect they won't last very long. The ones I disassembled failed for several reasons, including a drop onto the floor, but running them with base up is deadly - apparently the CFLs are designed with the assumption that they will be run base down for proper cooling. Some CFLs are expressly rated for base up operation and should be used when that's the operating mode. Jack K8ZOA Alan Bloom wrote: > On Fri, 2009-04-03 at 13:59 -0700, wayne burdick wrote: > >> I just replaced four gas-guzzling incandescent lamps in my dining room >> chandelier with four LED lamps that screw into the same bases. Went >> from 240 watts to 6 watts, total. >> >> The usual complaint about LED lamps is the cost. But prices are coming >> down fast: these were only about $4 each at Costco. Each contains 21 >> white LEDs, and they basically last forever, which means I won't >> constantly be replacing lamps in this fixture. >> >> If the world converts to LED lighting, we won't need to build any more >> power plants, and we can all use KW amps guilt-free :) >> >> Wayne >> N6KR >> > > Do they really last forever? I have had bad luck with LED night lights > gradually getting dimmer over a period of a few months. Do the > incandescent replacements have any specs on that? > > Al N1AL > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
