This circuit was found in a 1980s American documentation. The circuit is based on integrated CMOS 4001 that are common today. The load is a relay according to the power supply from 6 to 12 V.
In the figure we have the way to implement a 5 to 45 V zener diode with 50 mA of maximum current...
We found this circuit in a Radio Shack documentation from 1977. The circuit serves for a link of...
This circuit was found in the 1977 National Semiconductor FET Databook. The FET can be the BF245...