IR Beam Break Circuit

[schapman43]

Basicly what I need is a circuit that will stop a micro switch from operating when the IR light can be seen by the IR reciever. It needs to run at around 5.8v. So far what I've found on the net hasnt been very helpful.

I wouldnt mind buying a pre-made circuit if I could find one.

 

[Russlk]

If the microswitch is normally open and you want it not to close, an open circuit relay that is operated by the IR receiver, connected in series with the switch is what you need. If the microswitch is normally closed and you want it not to open, then a closed circuit relay in parallel with the switch is what you need.

 

[mattg2k4]

Take the IR phototransistor, put it in series with a high value resistor, and connect a comparator input between these two components. Put a pot with the wiper on the other input and the other ends across the power supply, which you can use the calibrate the light level at which the comparator changes its output. Then you can connect a transistor to open/close a relay from the output of the comparator.