LED and Blue LED...

[BigToque]

What makes an LED different from a light bulb?

Also, why are Blue LED's expensive? Are they all expensive (red/green)?

Why are there so few colors of LED's? I've only seen green and red. What other colors are there?

 

[Mixxen]

There's orange, white, yellow, purple, and probably more. LED's are Light Emitting Diodes.

They're different from light bulbs because LED's are diodes, and current can only flow in one direction. Also, LED's are solid state devices that produce light with current draw. It doesn't use electricity to heat up gases like florecent blubs to produce light.

I dunno why blue one's are more expensive...maybe cause they are brighter?

Oops...

 

[obenton]

Radio Shack sells packets that contain an assortment of colors.

 

[pm]

The type of semiconducting material used to make the LED (Light Emitting Diode) determines what color of light it will produce. It turns out that you can make red using fairly common materials (I don't recall which ones, however). But the blue LED has long been sought after due to the small wavelength allowing far greater storage capacities than red (which has a longer wavelength). Blue was only (relatively) recently discovered/invented and not too long ago they could barely get one to last more than a few hours. Now they are commonly produced. The materials required are still fairly exotic (compared with silicon, anyway) and so they are more expensive. Plus, the company who discovered it has a patent on the method (IIRC) and so there are royalties involved.

I read an interesting article on the history leading up to the discovery of the blue LED - all the different methods tried, etc. It was fascinating although, unfortunately, I can't recall where I read it (Scientific American?).

It has to be said, though, that the blue color given off by these LED's is particularly cool looking. It's like a deep blue neon color.

 

[Mixxen]

Interesting...and yes the blue LEDs do give off a neon blue color! Buy one at radio shack, and your computer will be cool.

 

[kuk]

pm: I read the same article also. I'm 98% sure that it was on Scientific America. I think I understanded near 1/10th of the article (well, come on, I'm 16 with a scientific american and absolutely nothing to do )The guy who developed these thingies is Japanese (what the hell can't they do?) and now is involved with some work at an university in California.

Hmm, maybe I should develop a white led ....

 

[pm]

They beat you to it - there's a white LED available. A bunch of us Intel engineers were trying to figure out how they make them at lunch yesterday, but regardless of the fact that we couldn't figure it out (the materials used to make the various colors are totally different), apparently they are available. They are hotter and cost more than the blue LED's and Radio Shack carries them as well.

 

[kuk]

Darn it ... well ... Guess I should move on to my world domination plan. Siiiiiiiiiighhh

 

[jbaj007]

Red, green, orange and yellow are cheap (~.09-.15) White and/or blue about $3.00. You can bet it isn't just materials, but also some patent pricing as well.

 

[Zucchini]

use this as a jump point to more led links

LED LED LED

kinda want the white ones they use for led flashlights.... put a couple inside ur case and have light leak out everywhere I bought a blue led from radioshack today.. i think i got ripped off. It turned out to be red #@%

 

[Venomous]

I have had a White LED for my Hard Drive and Blue for my Power and TEAL for my NIC for almost a year. The blues cost me about $5.00 a pop , the whites were $6.00 and the teals were about 3. These things are so bright, that if you turn off all the lights in the room, the thing just GLOWS a DEEP neon on BLUE.. The white is the least bright of the bunch. The blue and teal put out so much light, you can compare it to almost the output of a regular $4.00 flashlight at home depot. Its hard to decribe, but i have a couple pics of them i took with my digital camera if any of you want to see.

 

[Zucchini]

Heh bring em on, i still have to finsih my %#@ case

 

[OS]

Zucchini

unfortunately, it does seem you got ripped off. Go back and raise hell. The LED should SCREAM blue, there is no mistaking it for red

 

[Zucchini]

Aright, i also think i blew it it was red, so being a dumba$$ i reversed it and pop

 

[OS]

It shouldn't die if you apply a reverse voltage on it. Unless of course you were running an obscene amount of voltage.

 

[Zucchini]

I think leds are unidirectional or something, you can destroy them by reversing the current. It ran nice and bright... RED off the motherboard, i got pissed off and tried 5volts from the molex.. thats when it popped from being reversed i think. the led is rated for 5v

 

[Rigoletto]

Only fluorescent type light uses a gas to produce the light by passing electricity through... electrons freed from their orbitals or something.
Normal bulbs use an inert atmosphere and a current through a thin tungsten wire. The gas is there to protect the tungsten from corroding, not make light.
LEDs are economical but puny. Don't use just little LEDs on your bike in the dark if you want to stay alive!

 

[OS]

That's why, you ran lots of current through it backwards.

 

[Zucchini]

Hmm grumble.. guess i can't return it It was their last one anyhow.

 

[Ben]

White and Teal huh?

Sounds like I'm going to Radio Shack tomorrow. If their anything as good looking as the blue's, I'm buying a bunch. I'll figure out what to use them for later.