Light Emitting Diodes

[Leonis]

Can anyone explain how they work exactly?

How do they differ from an incandescent bulb; why don't they get that hot; etc?

Cheers!

[johnny]

hope this helps

[Leonis]

Why yes actually. That's exactly what I needed, thank you. What a cool site...

[johnny]

I'll take that beer now, thank you very much. [img]graemlins/showoff.gif[/img]

[Indemaijinj]

A limitation the article fails to mention that severely hampers diodes as an all-purpouse light source is that they produce light of only one wawelength.

Thus they are relatively worthless as a source of illumination because you cannot make them produce white light. Even making an array of LEDS in all the colours of the rainbow is not feasible since LEDS who produce blue and purple lights are expensive as precious gemstones.

[Thoran]

Blues are more expensive, but not nearly as bad as they were a few years ago. With volume comes the beneficial price decrease.

[Indemaijinj]

Yeah, blue diodes are now often used to increase a Hi-Fi rig's bling-bling factor.

Still, if we put wawelength on the X axis and price on the Y axis we'll get a beautiful exponential curve.

[ 08-21-2003, 01:28 PM: Message edited by: Indemaijinj ]

[Leonis]

I was talking about LEDs with a colleague (a lighting designer) last night. We use little white (??) and blue LED torches in parts of backstage in theatres as they throw less than our maglites.

He was saying how stage lights are available with rows of LED clusters (so a cluster of LEDs instead of a single bubble) - and the applications of such devices. They are ridiculously expensive next to a par can or even a moving light.

And he had no idea how they work - hence johnny's info will hit him via an audio guy! (me)

Like Tasmanian beer johnny? [img]graemlins/cheers.gif[/img]

[ 08-21-2003, 11:51 PM: Message edited by: Leonis ]

Originally posted by Indemaijinj: A limitation the article fails to mention that severely hampers diodes as an all-purpouse light source is that they produce light of only one wawelength. Thus they are relatively worthless as a source of illumination because you cannot make them produce white light. Even making an array of LEDS in all the colours of the rainbow is not feasible since LEDS who produce blue and purple lights are expensive as precious gemstones.

This information is a bit outdated [img]smile.gif[/img] You can now buy white (or near white) LED flashlights for less than $20 I am getting one to add to my hiking gear. They usually have several LED's arrayed in a circle around the reflector and are pretty bright.

My girlfriend also bought us a couple of nightlights that use white LED's.

Now we are even seeing Blue Laser CD and DVD burners which will increase the data density..these are based on Blue LED technology I believe.

[Leonis]

Yeah I thought so. My head LX has a white LED torch. Blue is very common for under $30 here... The technology is on the radip decrease price wise due to rapid usage. I'm yet to see a true purple yet though...