host light for IR emitter

[penguinland]

I'm looking to make an IR light for night vision use. I found this 20mm emitter on DX http://www.dealextreme.com/details.dx/sku.4669 but as I have never modded a light I would like a suggestion for a host light. I think this will work but please let me know if I'm on the wrong path. http://www.dealextreme.com/details.dx/sku.4240 . I have one of these lights already and if I take it apart I see a star board with 2 with soldered to it. Are all star boards the same size ?

 

[r-s]

I would like some info on that IR LED too. Someone on the DX site posted "Drive at 1.7v with 300ma." Is there a driver board that can supply that output -- or the 3.4V @ 300ma, to drive two of these LEDs in series? (or some other voltage for some other multiple of the LED?)

Or should they just be direct-driven? (If that's the case, hmm... gotta dig out my Ohm's Law I guess -- I will be driving these from power "stolen" from a security camera's power line, 15VDC, so in any event I'll probably need do do some fancy footwork -- either figure out a resistor, or, find a driver board that will handle that input voltage (or put more than one driver board in series across the 15V input).

I wish that DX had put a "use this driver with this LED" link on the product page!

 

[r-s]

I wonder if a driver board that was suitable for a single 1W LED (white, with 3.x volt requirement) would handle two of these in series?

Offhand I can't think of any reason why it shouldn't work. Series-connected LEDs work OK, unlike parallel-connected devices (unless each parallel LED has its own current-limiting resistor), because when run in parallel, one of them will draw most of the current, until it burns out, at which point the remaining LED will get all of the current until it burns out too.

I am planning on hooking up a bunch of these to light up an area that is shaded from my merc. vapor yard light -- which is coincidently a location where we have ongoing vandalism problems. Time for someone to go to jail, methinks. Police say if I can get the plate number on videotape, they'll haul him in.