On Thu, 6 Apr 2006 22:36:42 -0400, "Michael Kennedy"
wrote:

Hi, I have a IR led and don't know much else about it.. Does anyone know
what value of resistor would be good to power on on a 3v battery? I found
this nice calculator but don't know any if the ratings abut the LED..
http://ourworld.compuserve.com/homep...Bowden/led.htm

Swag the forward voltage drop for an IR LED at 1.2 V and aim for
something close to 20 mA. So a good standard resistor value would
be 100 ohms.

If you need some way to tell if you're turning it on, Radio Shack
carries (at least some, still, maybe) an IR LED and phototransistor
pair, Catalog #: 276-142.

--
Rich Webb Norfolk, VA