This two-port configuration of the 4001 was found in the April 1988 issue of Radio Electronics magazine. The timings are given by R1 and C1 as a function of the desired behavior of the circuit.
This circuit makes use of a diac to stop the activation of a sensitive reed relay 1 mA. The trip...
The circuit found in a documentation from the 90s allows capacitance measurements to be carried out...
This signal injector and tracer (follower) was found in an old American documentation. The...