This SCR timer was found in an old English documentation. The SCR can be the TUIC106 and modern equivalent transistors like the BC557 for TR1 and BC547 for the others.
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...