This circuit triggers a relay when a light beam that hits the phototransistor is cut off. The circuit is from Electronics Now and the supply voltage depends on the relay voltage.
The presented circuit has a voltage gain of 10 times. We find it in the SGS manual of integrated...
We found this circuit in a 1966’s General Electric documentation. The circuit uses diodes in...
We found this circuit in a 1969 General Electric documentation. The circuit uses transistors of the...