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.
In this circuit of an American documentation of the 90s, when the light is cut, we have the...
The circuit shown was found in a 1995 documentation. This circuit is powered by a voltage of 6 to...
This simple regulated power supply was found in a 1977 documentation. The zener diode determines the...