This circuit was found in an old manual of integrated circuits. The operational is of the time, uncommon nowadays. The power supply must be symmetrical.
This circuit was found in a 90s Hands-On Electronics. When a signal appears at the headphone...
This circuit is powered by 1.5 V and has a long lifespan as it consumes only 320 uA. The circuit is...
We found this circuit in an old American documentation. Transistors can be modern equivalents. ...