We found this circuit in a Radio Electronics from April 1965. The components are from the time and the power supply is for 12 V cars. The transistor must be equipped with a good heat radiator.
This circuit was found in an American documentation from the 90s. It can be implemented with...
This 2-terminal regulator was obtained from a 1990s National Semiconductor manual. The components admit...
This circuit uses a photocell as sensor and a sensitive relay according the power supply voltage....