Originally suitable for photography applications, this circuit from a Popular Electronics from the 90s can also be used to time plate baths. The components are common, and the sensor is remote.
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...