[Elecraft] totally OT, except to the extent that it's QRP: LED lamps

[Jack Smith]

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
>
>
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