We found this circuit in a 1960 Radioarama magazine. The instrument tests common general-purpose transistors indicating their gain on a moving coil instrument. The loop serves to adjust the circuit.
This circuit was found in the Electronics Experimenter Handbook from 1991. The sensor is a diode...
This circuit can be used on audio, video, or data links to receive modulated infrared signals. The gain is...
With this circuit it is possible to obtain a voltage modulated in amplitude with a maximum current of...