This circuit from the 1980s uses an operational amplifier that is uncommon today. The circuit can be designed with modern operators. The gain is 40 dB.
This circuit was obtained in a 1979 101 Electronics Projects. The circuit can be assembled easily,...
Suggested by a 90's Linear Databook, this circuit compensates for capacitor hysteresis. The main...
This circuit serves to isolate analog signals, for example, audio signals in a secure link...