This circuit is from Motorola's Linear Databook from 1990. The integrated circuit and transistors are uncommon, but the circuit can be assembled with equivalents.
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...