

The LED's Dark Secret: "droop" - prakash
http://spectrum.ieee.org/semiconductors/optoelectronics/the-leds-dark-secret/0

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javanix
I've been trying to make a point of reading more IEEE Spectrum articles
lately.

They're well-written _and_ seem to be scientifically accurate - a rarity on
the web these days.

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ggchappell
An interesting article, but it makes me wonder: Do we have to worry about
droop at all? If we can't make an LED produce lots of light at high power,
then how about using lots of LEDs, each one at low power?

If someone points out that we don't know how to do this within certain price &
size constraints, then I reply, fine, that's a problem to solve. So is droop.
Solving either one of these problems get us the lighting we want. Is there any
reason to single out droop as _the_ problem that _must_ be solved?

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ars
You don't even need multiple LEDs, but rather multiple emitting areas in one
package.

Maybe the result would be too big to be practical. Or too expensive.

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Huppie
I think it's the latter. I have been looking at proper led-lighting for my
house a few months ago but when you want a lightbulb comparable to a 40W
incandescence lightbulb it's filled with 80 LEDs (though it consumes only 4W).
The cheapest I could find cost about €20,- while a simple incandescence
lightbulb costs about €0,50.

I could also get 'High-Power' led-bulbs, filled with only 3 - 10 LEDs and
producing the same amount of lumen but they all had a higher power consumption
than the 80-led bulbs and strangely where more expensive (this probably has to
do with heat removal requiring big heat sinks).

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dlevine
My super-bright LED flashlight runs on 1 AA and puts out as much light as my
halogen bike light from a few years ago (which has a huge rechargeable battery
pack).

This sounds like an engineering problem that will be solved (or at least
mitigated). I remember how a few years ago we were told that silicon processes
were nearing their limits, and then engineers figured ways to get around some
of the perceived hard walls.

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nazgulnarsil
said hard limits don't apply to consumer level devices since they are
concerned with economies and not absolute limits. it will be a long time
before consumer level devices actually approach the hard limits that are still
being talked about in the silicon world. by that time some new tech will take
over.

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hristov
I think they were incorrect in attributing the discovery of the LED. I thought
it was discovered by a Russian engineer in the soviet union shortly before
ww2. They attribute it much later and to a US company.

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vinutheraj
_A light-emitting diode (LED) (pronounced /ˌɛliːˈdiː/[1], or just /lɛd/), is
an electronic light source. The LED was first invented in Russia in the 1920s,
and introduced in America as a practical electronic component in 1962. Oleg
Vladimirovich Losev was a radio technician who noticed that diodes used in
radio receivers emitted light when current was passed through them. In 1927,
he published details in a Russian journal of the first ever LED.[citation
needed]_

According to wikipedia - <http://en.wikipedia.org/wiki/Light-emitting_diode>

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joubert
On a recent trip to South Africa, I saw a large range of LED lights being sold
for home use (in Builders Warehouse, similar to Home Depot).

Where in NY is a good spot to shop for LED lights?

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dryicerx
Usually home improvement stores now carry them, I bought several and very
pleased.

Although if you want super bright, go for the 10mm 100000mcd+ ones off ebay,
50 of them easily replaces a 70W light. I bought 1000 of them, cheap in bulk,
and their a lot of fun. If you're making your own LED series don't forget to
add resistor to limit the current.

~~~
lutorm
I'd be suspicious of super cheap LEDs on ebay -- they may be cheap but they're
unbranded and you don't know how long they'll last. And I'd definitely stay
away from the ones that consist of 50 normal LEDs all pasted together. Normal
LEDs aren't made to deal with the high current and heat you get from packing
them together, so their lifetime is anyone's guess.

I've been putting in LED spots for my office (instead of 25W halogen MR16
lights). I've tried some off of ebay that (claim to) have Luxeon or Nichia
LEDs. I've also gotten some from <http://www.ledwaves.com/>. All are pretty
nice, but I haven't decided what color temp I like so currently there's a
mishmash of cool and warm ones...

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eande
The key LED manufacturer are working hard with all kind of R&D programs to
improve the situation. I saw on a presentation lately that e.g. the new Osram
high bright LED has an improved process addressing the issue. I agree that
this is an engineering process improvement problem and will be mostly resolved
over time.

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jsares
For once I actually like the headline. Guess I'm a sucker for a decent pun.

