We found this circuit in a 1966 documentation. The circuit is intended for a door opening system by the headlight of a car. The sensor is a photo-FET, an uncommon component today.
This circuit was published in a recent magazine as a past project. It is a crystal radio from...
When powering this circuit by activating S1, the lamp turns on smoothly in a time determined by...
This circuit consists of an amplifier for signals from the FM band. We found it in an old...