Found in a 1967 EEE, this circuit generates a constant amplitude signal, stabilized by a zener diode. The circuit can operate with voltages from 18 to 22 V.
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...