The circuit shown, with the printed circuit board, was found in an article in the June 1990 issue of Radio Electronics magazine. Integrated circuits must be equipped with heat sinks.
Using a capacitor as a sensor, this circuit was found in the 1989 Radio Electronics Experimenter magazine....
Using bipolar, FETs and unijunction this long-lasting timer can reach 10 hours with good quality...
This circuit is found in an American documentation from the 80's. The circuit measures the power of...