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.
The circuit shown is from an old European publication. In it we have the way to activate a relay...
We found this circuit in a European publication from the 1990s. Transistors are still common types...
This circuit was found in an American documentation and can be added to common amplifiers of any...