Using a 106 series SCR, this circuit was found in the May 1971 Radio Electronics magazine. The quiescent current is very low and is given by the value of R1.
This circuit trips when a negative pulse is applied to its input or when the voltage drops below a...
This is an old 1988 circuit consisting of a timer or time control for exposing silk-screen arrays. The...
This circuit was taken from an old American documentation. It can be built with modern op amps. The...