In this 2001 circuit we have the way to trigger an SCR with a phototransistor. The circuit appears elsewhere in this section, obtained from publications from different eras.
We found this circuit in a 1972 RCA technical documentation. The comparator can be any type and C1...
We found this circuit in a 90s Radio Electronics. The circuit uses a transconductance operational...
This circuit was found in a 1968 General Electric documentation. It has an input impedance of 2 M ohms...