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 a Popular Electronics from the 90s, this circuit triggers an indicator when these lights...
This common circuit using a multivibrator causes two lamps to alternately flash at a frequency and active...
This 80s signal follower makes use of an audio amplifier of the era. The circuit can be adapted to...