This circuit was found in the September 1972 issue of Radio Electronics magazine. The circuit uses an operational amplifier of the time and a symmetrical 9 V source.
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...