This circuit was obtained from Signetics documentation from the 80's. The components used are from that time. The circuit can serve as a basis for repair, maintenance or projects with modern components.
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...