This circuit is from the LM107 manual. This operational is from the 80s, but the configuration is valid for any operational. The formulas give the gain of the circuit.
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...