Found ina 1970 American documentation this fast-reading circuit uses a photodiode. Transistors support modern equivalents. The circuit can be used as a shield.
The high sensitivity of this type of SCR recommended in our assemblies allows it to be triggered by low...
Found in a 90s documentation, this circuit triggers the SCR when there is an overvoltage in order...
This circuit was found in a 1989 documentation and was intended to be part of a presence...