In a message dated 8/30/2004 11:01:28 PM Pacific Standard Time,
ben_englund@... writes:
I've heard that green LEDs can act as photodetectors. They are cheap
if you could get them to work. Then just put a bunch in a circle a
detectors and one on a disc on the shaft as an emitter. Anybody have
any luck using LEDs as detectors?
Ben Englund
----------------------------------------
Yes,
I have used "plain jane" red leds as photodetectors. A voltages is produced
across the leads in response to direct sunlight. It appears to be fairly
sensitive.
A different voltage (lower) was read with the LED exposed to light, but in
the shade opposed to direct sun light.
Ken
[Non-text portions of this message have been removed]
ben_englund@... writes:
I've heard that green LEDs can act as photodetectors. They are cheap
if you could get them to work. Then just put a bunch in a circle a
detectors and one on a disc on the shaft as an emitter. Anybody have
any luck using LEDs as detectors?
Ben Englund
----------------------------------------
Yes,
I have used "plain jane" red leds as photodetectors. A voltages is produced
across the leads in response to direct sunlight. It appears to be fairly
sensitive.
A different voltage (lower) was read with the LED exposed to light, but in
the shade opposed to direct sun light.
Ken
[Non-text portions of this message have been removed]