Help me EE people! Looking for an LED light

[paulney]

I recently saw at a certain event a very cool art installation which had LED lights that changed colors gradually. Not just a usual RGB-flash LED which jumps between three colors with a distinct flash, but LEDs that smoothly shifted colors (I think I saw all rainbow colors there, but could be my imagination).

What are they and where can I get them?

I browsed eBay, but most LEDs I see there are either single color or RGB flash LEDs.

Thanks.

 

[paulney]

Here's an example:
http://www.youtube.com/watch?v=G_Th8FnQfFA

 

[OS]

i don't know for specifically what you had in mind, but they have LEDs where you have three dies in one package (RGB) and then you could use an IC to drive the three dies to vary the color.

 

[paulney]

So basically the real secret is in the controller? And any RGB LED would be able to create a light of a certain color if the controller feeds the right dies with the right voltage?

What's the difference between a fast and slow flashing LED light then? The response time of a die?

 

[OS]

i don't know for sure, i did briefly work for an LED manufacturer couple years ago and at the time there wasn't a single die product that straight up did all the colors.

But like i said, we did have the three dies (RGB) in one package, if you ran all three dies you got white, just red and blue you got purple, etc.

 

[Aluvus]

The traditional approach would be to use 3 LEDs and drive them with a microcontroller's PWM output.

There are simpler ways to do it; here is an example (with YouTube video!); it owes something to Bit-Tech's version.

 

[paulney]

Ok, I found it!

It's called a rainbow LED, and it comes with its own microprocessor which cycles the LED in a predetermined fashion.
All you need is to supply the voltage. An example part is RL5-RGB-ACC Color Changing LED.

Once I get this project done, I'll look into manually controlled tri-color LEDs. I want to start with something simple.

 

[OS]

glad you got it figured out and glad to know i am not totally full of sh*t