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, which can be used as a shield, was found in American documentation from the 1970s....
This circuit for low frequency data transmission was found in the May 1977 issue of Radio...
This circuit activates a relay that has a lamp as a load. The circuit is from a Radio Electronics from...