michael brown wrote:
> What really bugs me about the whole thing is that you can buy an LED that
> puts out blinding light using milliwatts of power virtually forever, yet we
> still think nothing of putting 100 watts into a bulb that has a relatively
> short life span.  Is it possible that there is not a more efficient way?
> Traffic lights are all becoming LED based, why cant I just buy a light
> source built onto a pcboard that just screws into the socket.  With the
> variety of LED colors available now, simulating a basically white light with
> LED's shouldn't be that hard.  I realize the "quality of whiteness" might
> not be ideal, but in your basement, shed, garage, or attic, who cares?

The Feb 2001 issue of Scientific American has an article that answers your
question. Unfortunately its not accessible from their web site. The short answer
is that its a cost/consumer acceptance problem. Its not yet cheap enough to
compete with conventional lighting in the home market, but its making headway in
commercial and utility applications, namely traffic lights. The article also
says that only 10% of the traffic lights in the US are LED based.

"The best commercial white LEDs now cost about 50 cents per lumen, compared with
a fraction of a penny per lumen for a typical incandescent bulb."

"...it may be a while before consumers accept LEDs, which cost more up front but
are cheaper over the span of a decade. As energy prices rise and the
consequences of global warming become more urgent, LEDs should become more
attractive."

It looks like its just a matter of time and consumer demand.

Why don't you design an led adapter for light sockets? Maybe use RGB LED's and a
PIC so you can change the color at will. I'd pay for that. Come to think of it,
if you don't do it, I will. :) How many LEDs does it take to equal a 60W light
bulb?

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