See Below:
--- John Allain <allain(a)panix.com> wrote:
It's a week after the solstice. It's dark.
Light
candles.
Pack-Rat tip:
I got some of those Christmas exterior 'rope
lights'. They have
360 small bulbs in a 30' armored plastic tube.
Seems a cheap
alternative for lighting your storage space.
Question...:
I recently bought 2 each of all the white LED's that
Jameco
sells. While *white*s are OT, they are nonetheless
impressive.
The light density, efficiency, color, and longevity
they have is
pretty amazing, to me anyway. Jameco rated them at
4 foot
candles at 20ma, which seemed a little 'opto'mistic.
I tried them out, and they reach near peak light at
more like
180ma, getting just noticeaby warm. At 250ma they
are
'uncomfortably' warm, hence question:
Did they really mean 20ma? at that proportion
they're
putting out <10% peak, but 180ma is WAY above
spec,
Jameco's spec anyway. So I guess Jameco's wrong?
Could I be loosing lifespan at this current?
Maybe the
not-too-warm test is good enough?
John A.
remember, I'm a software guy.
I think the way these are made, they are blue LED's
with a phosphor coating (on the die). I got one jacked
up to the point where it got _very_ warm and started
to turn blue. After cooling, it seemed to work
normally, and I don't want to do any extensive
experimentation at $3 a pop. I have read that these
don't have the life expectancy of a "pure" LED because
the phosphor will wear out (?)
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