Found in a 1966’s General Electric documentation, this circuit uses a triple diode from the time. The output current is 5 mA. It serves as a voltage reference.
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...