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.
This simple optical alarm circuit was found in the 1991 Electronics Experimenter Handbook. The...
This broadband amplifier was found in an Elektor from the 90's. The gain is 10 dB with a noise...
A recreational application of the 4018 is shown in the figure in which we have electronic dice....