The purpose of this circuit is to monitor the output voltage of a power supply. The under and over voltage indicator was found in the August 1991 Radio Electronics magazine.
This trigger uses two switching transistors that can still be found with some ease. The circuit is from...
This circuit was obtained in old documentation, but it is valid for modern triacs that must be...
This circuit was found in a Japanese magazine from 1971. The circuit uses Japanese transistors of the time,...