We obtained this circuit in a technical documentation from the 90's. The circuit has its sensitivity adjustment in the potentiometer. The supply voltage can be reduced with a 1k resistor change.
Suggested by Harris in documentation from the 80s, this circuit uses components from that time. It...
This high-voltage regulator uses only two components. The resistor is a wound wire type with 1 W...
This circuit uses an impact sensor transistor called Pitran rare today. The circuit is from 1969...