Random oscillator circuit for high-power LEDs?

[TigerhawkT3]

I'm looking for a circuit (the simpler and cheaper, the better) that can drive three or more LEDs at 200-350mA each, randomly flashing/strobing them at 5-20Hz. Input power should be low-voltage DC. A range for Vin, instead of an exact 5.0V or whatever, would be a big plus. It'd be nice if the circuit could handle more than one LED being on simultaneously, but it's not vital.

I don't have any PIC programming stuff, and I'd rather use fewer components.

If I've left out anything important, please let me know.

 

[TigerhawkT3]

:bump:

Any suggestions?

 

[hopkins]

Do you need random flashes of the LED's that would pass a true
Random Number Test like what security encryption codes require?

Or just something that looks random to the human eye?

 

[TigerhawkT3]

Just something that looks random.

 

[hopkins]

this circuit will flash at your needed current (thru a Cree or similiar) but still need
some kind of randomizing circuit addon. Thats the real trick ehh?

 

[hopkins]

Here's a led flicker circuit (looks like a flame) Maybe you can merge then for your project needs.
http://members.shaw.ca/novotill/FireLightFlicker/index.htm

 

[TigerhawkT3]

I love how the AC-powered circuit in the "flickering candle" page is clearly labeled "DO NOT BUILD THIS CIRCUIT."

 

[TigerhawkT3]

"Combining" circuits is way out of my league. Any other circuit suggestions?

 

[climberkid]

you caught my eye here buddy. i have been looking to build one myself.

 

[hopkins]

Tigerhawk
This circuit should do it. 2 IC chips and some caps and resistors plus a power transistor and a Cree or Rebel LED. Needs more the a tiny 9volt battery. Maybe 6 Dcells or an Ac adapter for 9volts DC. The parts can be salvaged from the mountains of electronic junk to be found everywhere. A high power soldering gun will ease
the removal from the junk circuit boards if cutting them off does not leave enough leg to use.
In case you have not done this - to get the data sheet on a electronic
component just google the code number printed on it and look for the .pdf file.
Its all free on the web. You'll get the hang of it.

http://i34.tinypic.com/34nkuxl.jpg

 

[TigerhawkT3]

I think I'm mostly understanding that schematic. RS will probably have the resistors and capacitors, but I can't find a good place to buy a few of those 4000-series ICs. Recommendations?

 

[GoldStar611]

www.jameco.com is the place I use for all my electronic orders. Unless I can get bigger quantites off ebay.
4584
4013

 

[TigerhawkT3]

www.jameco.com is the place I use for all my electronic orders. Unless I can get bigger quantites off ebay.
4584
4013

Awesome! Thanks very much! :thanks:

 

[marschw]

I use Jameco for small orders or things that I need immediately, since they're 1 stop down highway 101 from me (and they do will call), but their selection is nothing compared to DigiKey, Mouser, and Newark. Jameco's catalog is about the size of a National Geographic... DigiKey's is bigger than the yellow pages. Jameco's also given me SMT chips when I ordered DIPs, but it was no big deal since they fixed it right at the counter.