Found in an EEE from 1970, this circuit supplies a voltage of 12 V DC x 10 mA current from the power grid. The NOR or NAND port used is TTL.
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...