The circuit, shown in figure 2, is a monostable multivibrator with two NAND ports out of the 4 available on 4001. In this circuit, a positive input pulse activates the circuit, obtaining a pulse whose duration depends on capacitor C1. Note that the duration of the output pulse is independent of the input pulse. This circuit can be used to obtain a pulse of constant duration at the output, regardless of the output pulse. Note that the input pulse must have an amplitude compatible with the characteristics of the C-MOS 4001 circuit and its supply. This means that, for a 5 V supply, the trigger pulse H1 must have an amplitude between 3.5 and 5 V; for a 10 V supply, this pulse must be between 7 and 10 V and for 15 V, between 10.5 and 15 V. The minimum duration of the output pulse must be greater than 20 ns.
