Detecting presence of IR -
See this web page: http://www.circuitstoday.com/photo-relay-circuit
I cannot get it to work. I want to activate the NO contacts on a relay when ever IR light in the 800-950nm wavelength range strikes the IR Photodiode. The Photodiode does appear to work as it produces 0.6 volts at the leads whenever I shine a IR LED at it. But the above circuit activates the NO contacts all the time when the 9V source is applied, IR or no IR pointed at it.
I also tried it with 2 transistors (Darlington hookup) and that did nothing new.
Any help appreciated.
Mike Taylor
Katy TX
See this web page: http://www.circuitstoday.com/photo-relay-circuit
I cannot get it to work. I want to activate the NO contacts on a relay when ever IR light in the 800-950nm wavelength range strikes the IR Photodiode. The Photodiode does appear to work as it produces 0.6 volts at the leads whenever I shine a IR LED at it. But the above circuit activates the NO contacts all the time when the 9V source is applied, IR or no IR pointed at it.
I also tried it with 2 transistors (Darlington hookup) and that did nothing new.
Any help appreciated.
Mike Taylor
Katy TX