Adjustable light detection switch


Posted on Apr 11, 2012

R2 sets the circuit`s threshold. When the light intensity at PCI`s surface is decreased, the resistance of PCI a cadmium-sulfide photo-resistor is increased. This decreases the voltage at the inverting input of the 741. When the reference voltage at the 741`s noninverting input is properly adjusted via R2, the comparator will switch from low to high when PCI is darkened


Adjustable light detection switch
Click here to download the full size of the above Circuit.

This turns on Q1 which, in turn, pulls in relay Kl.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Shutter-speed tester
markII
ic 555 motorcycle alarm circuit
auto power off schematics
Speaker protector
Voltage-Controlled Oscillator
45 Years Anniversary of Walter Bruchs PAL Color Television
One zero trigger thyristor power adjustment circuit
Suitable comparator circuit headset detection



Top