This shield circuit is from an American documentation from 1969. The components can be modified according to the relay and power, and the coupler can be of a modern type.
This circuit is based on one of the first germanium transistors. The power comes from a solar cell...
Found in a Radio Electronics we have in the figure a circuit to disconnect an SCR with direct...
With this power supply it is possible to use automotive devices with currents up to about 8A on the...