MrTallyman said:
I have run them at high current and have watched them fail, but that is
simply by adding voltage to a flashlight. I made no attempts to sink any
heat generated. That would certainly make them last longer and is
usually just about all the makers do when they "make" a high wattage
version. They make a good thermal circuit in their mechanical design and
the actual LED die is not a whole lot bigger. They will just handle more
continuous current without failing. I am sure they have a lower MTBF
regardless.
Those should last forever.
Yes, and I don't see the benefit of running them near max
in most cases. For a typical application, like a power on
indicator, I've always found them plenty bright at well
under max. In fact, sometimes I'll reduce the current
even more to dim them a bit.
If you're doing something like a visual locater beacon for downed
aircraft/payload/climber rescue/etc there's consideration of
battery life/LED life/weight etc. Overdrive too much and life
decreases; drive them too low and luminosity decreases or
weight increases to get higher output. Some people have had to
do that, and overdriving to some degree may be the best solution,
so you can't always under drive them. As you said, LED MTBF would
decrease, but as long as the LEDs last for that one time use
(i.e. outlast the battery), it doesn't matter.
That flashlight worked better than any LED flashlight I have ever seen.
It only worked for a short time though. Good thing it was a 12 LED cheap
$3 Harbor Freight job. I have a few of them. Really good, cheap
platforms for testing out things like overdriving, etc.
Yup. And some of their cheap flashlights are of surprisingly good
quality. They've got a 9 LED thing in a really nice metal housing
for ~$1.50 on sale. It looks like the one I bought from them a while
back, which is a pretty darn good quality housing. The LED pcb isn't
the best construction, but a soldering iron can fix a cold joint if
needed.
Did you ever try the bicycle LED headlight thing they sell?
Used to make music color lights out of them. Nowadays I use software.
The best in existence is G-Force from Sound Spectrum. It is a plug-in
for Windows Media Player. I like how it lets me place my images in the
background in false color, while it runs fractals and such up front.
It doesn't get any better.
http://www.soundspectrum.com/g-force/index.html?src=home
Nice link.
Ed
