This circuit uses CMOS integrated circuits and can operate with CMOS logic from 3 to 15 V or TTL with 5 V power. The power is obtained from the circuit under analysis.
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...