This 4-voltage power supply using zener diodes has a maximum recommended current of 25 mA. The circuit was found in the May 1966 Radio Electronics magazine.
This circuit for 12 V x 2.2 W lamps was found in a documentation from the 70's. The circuit uses...
This voltage inverter allows you to raise the voltage of a battery to values as high as 140 V...
Using the 709 integrated circuit, one of the first operational, this circuit was found in the...