Using an LDR as a sensor, this circuit is from the Radio Electronics magazine of December 1984. The operational amplifier is the 741 and the source must be symmetrical.
We found this circuit in a 1977 Radio Shack documentation. The circuit should be powered, for...
Found in American documentation from the 90s, this circuit uses a GASFET of the time. The circuit is...
This circuit generates pulses when the light beam incident on the phototransistor is interrupted. The...