This circuit was found in the September 1972 issue of Radio Electronics magazine. The circuit uses an operational amplifier of the time and a symmetrical 9 V 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...