Multi-color led's

[Evad Nomenclature]

hey guys.

first off, i'm cutting this from a PM i sent, so forgive the wording in places =)
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i did a build of my own the other day and i wanted to use one of the multicolor LED's that you sent me to snazz it up a bit.
it was really weird, when i got it all boxed up, the LED would be full red and stay that way. when i pulled the cord out partway of the input jack it would change colors, but the light would be way dimmer than when it was full red.
ok... so to make sure i didn't screw up something in the box, I breadboarded all the LED's that i got, to see if i could figure out what the deal was. I got one LED to have full color  change 1 time, but when i plugged the LED back in, it wouldn't change *lol* even though it went in the same exact input/output on the breadboard.  It stayed full red again... WTF!?!

So anyway, have you used any of these?  I'm not sure if there is something else i have to do to make it change, or if they are just buggy or something... it seems completely random when they want to change and when they want to stay solid red.

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yeah thats it...
so... any ideas?

[Andi]

I've only tried one once, but I seem to recall that they're really picky about the supply voltage.

[Kearns892]

I didn't read anywhere that you placed a resistor in front of the LED. It's possible you supplied to much power and burned part of it out. It's really the only thing I can think of.

[grolschie]

Check out this thread. I had similar problems with a multi-colour LED in a Ibanez TS7. Complicating things, the LED was incorporated into the transistor switching circuit, so simply swapping out the stock LED wasn't enough. After ALOT of help from Oskar, we got it working though.

It would seem that these LEDs need enough power to switch colours. I my experience, when mine didn't have enough power, it got stuck on the first colour. I initially thought that I had fried mine. Allowing more current, enabled it to switch through more colours. Finally it switched through all 7 colours.

From what I read, with the basic colours (red, yellow, green, blue, white), some colour LEDs draw more power than others. And depending on your LED, some other in-between shades of colour might use multiple LEDs to generate the colour, thus drawing even more power. I hope that this helps.

[Evad Nomenclature]

yeah man.

I was messing around with them again, and I found that the only way I ever got it to switch colors (I should have hooked it to a pot to get the threshold resistance instead of just switching out resistors)
was by using a 100 ohm resistor in series with the LED.  The next one up I tried was like a 500ish ohm and that would just be solid red and stick on it.

So all in all, I would say they are pretty cool, but only with DC jacks.  those mofos would probably juice a 9volt battery pretty quick with such little resistance before it.

thanks guys
dave