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 circuit delivers at its output a voltage that proportional to the amplitude of the input...
This circuit can be used to listen for SSB signals on receivers that do not have the built-in...
We found this circuit in a 1970 General Electric manual. The circuit uses components that are...