This circuit comes from a Gernsback Publications of the 90s. The circuit uses a general-purpose transistor as a sensor. The power supply must be symmetrical.
This is the conventional configuration of an astable multivibrator with operational, found in a...
This 1969 Electronics World power supply has 5 V to power digital circuits and a 170 V output for...
The Texas TL783 integrated circuit is a three-terminal high voltage regulator with a wide range of...