This circuit consists of an electrostatic sensor that can check if a cable is energized by simply approaching it. The circuit is from an Electronics Now from December 1998.
Found in Popular Elecronics, this configuration also appears in this section, but obtained from other...
This circuit was obtained in an old French publication from the 80s. The maximum power of the lamp...
Found in a 1966 American publication, this circuit invert the phase of a low frequency signal. The...