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.
Found in a 90s Silicon Chip documentation this circuit is intended to protect a speaker system in...
The circuit shown is a reference of -10 V with a maximum current of 50 mA obtained from the Linear...
Found in a 1980s American documentation, this circuit can use a SCR and a general-purpose transistor....