This circuit delivers at its output a voltage that proportional to the amplitude of the input signal in a range of 36 dB. We found it in an American documentation from 1966.
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...