Test circuit with bridge (CB22530E)

This bridge-biased transistor test circuit measures gain in the range 0 to 300. Circuit is from Radio Electronics June 1952.

Headphone Amplifier with the 741 (CB10248E)
This circuit was found in an English magazine from 1978, but it is still current, just change the...
Overtemperature Alarm (CB11839E)
This circuit causes a buzzer to emit an intermittent tone when the temperature sensed by the...
Null adjustment shield (CB4902E)
This microcontrolled null adjustment for operational amplifiers was obtained in a Linear...