Page 1 of 1

Very Low-frequency Oscillator to Power Tr-Color LED's

Posted: Sun May 04, 2008 4:35 pm
by Yerry
I'm building some "nighttime" special effects for my Super Mouse Trap module. I took an old vacuum tube, removed the pins and drilled the holes out to fit a 5mm LED. I stuck a few monochrome LED's in it, and by varying the voltage got some interesting effects from the colors reflecting off the chromed interior parts. Went with two-colored LED's and Red/Green/Yellow mixing worked even better. Now I'm using tri-color.

I want to automate the color changing. Right now it's powered by three LM317 circuits with three 5K pots. Ideas I've had for doing this:

1) Three mechanisms from CD drive platters moving pot positions. Slightly different motor voltages would generate randomness & varying colors.

2) Three 8-bit, constantly changing registers and three DAC's powering three high-power op-amps as buffers

3) Three very slow sawtooth generators with a high-powered buffer. I like this one the best. I'm looking at 1/10 Hz or slower, with a max output of 5V (thyanks to dropping resistors, this part is negotiable; I just want to be able to drive any kind of LED, including ultraviolet)

Posted: Sun May 04, 2008 4:51 pm
by MrAl
Hi there,

Cant help but think this is the perfect app for a microcontroller.
You could experiment with different programming for different
I did one long time ago with red and green bicolor led and a
home brewed super microcontroller. It looked like a candle
flickering, but the programming could be boot loaded to get
other effects too.