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 traditional doubler configuration with the 555 IC can be found in other articles on the...
This traditional circuit with a neon lamp is a flip-flop that draws which of the two lamps will...
This sophisticated circuit is from old Motorola documentation, using common integrated devices...