We found this sensitive high input impedance voltage amplifier in the November 1970 Radio Electronics magazine. The circuit is powered by 18 V power source.
This commercial NEC radio circuit from Japan has an audio power of 300mW and uses 7 germanium...
This sophisticated timer has several activation modes and operation monitoring through sequential LEDs....
This simple circuit from a 1987 documentation can be used in robotics and automation, as well as...