Found in the September 1972 issue of Radio Electronics magazine, this signal injector is based on the HEP580. The circuit is powered by two batteries and its frequency is basically given by C1.
Found in American documentation from the 1980s, this circuit operates in the frequency range 0.5...
This circuit was found in an American 1980s documentation. The transistors admit equivalents and the...
This circuit consists of an electrostatic sensor that can check if a cable is energized by simply...