LED specs

[Vikstar]

Hi, I've had my TrackIR 3 Pro for about 4 years now, and it recently died. Tried it on two different computers... the little blue LED inside lights up very faintly but windows xp doesn't reckognise any hardware being connected. So, instead of throwing it away, I'd like to salvage some parts from it, specifically the Infra-red LEDs. Could you send the specs on the 4 LEDs that TrackIR 3 Pro uses so that I can use them in home hobby electronics?

[VincentG]

The LEDs emit at 880nm and are standard off the shelf IR LEDs; we run them all the time when the unit is turned on. There are 4 of them and they each have a total radiant output of about 23mw/sr, which is 23miliwats per ster radian. Total output power is NOT 4 X 23 mw/sr as the LEDS do not overlap exactly; they create a coverage pattern with slight overlap at the edges. Also, the LEDs to not emit a uniform brightness, they have an angle to half intensity, so the center of the overlapping LEDs is the SAME brightness as the center of each LEDs output, hope that makes sense.

[Vikstar]

Wow thanks, that is very comprehensive performance data, but I was mainly looking for stuff like forward voltage and current. Initially I would guess 2V with 20mA, but 23mw/sr sounds pretty powerful, so it'll probably be different.

[VincentG]

5V, 16mA