This circuit serves as a reference for the components used and the time. The circuit is from 1967 RCA documentation. MOSFETs from that time are used.
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...