This protection circuit for symmetrical 28 V power sources was found in a 1968 EEE documentation. The circuit can be adapted to use modern equivalent components.
This circuit was obtained in the manual of the used integrated circuit. Equivalents may be used...
The UVTRON tube is an ultraviolet radiation sensor. In this circuit from Radio Electronics from...
This circuit was suggested by Popular Elecronics from the 90's. The circuit has high input...