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 was found in old documentation. PUTs are uncommon components today. The circuit...
This circuit was obtained in a 1991 Electronics Handbook. The publication no longer exists, but...
This crystal oscillator generates a 20 MHz signal. Equivalent transistors such as BF494 and 2N2222...