trigger pulse generator circuit

trigger pulse generator circuit

Shown is a trigger pulse generator circuit. The circuit consists of shuttle key switch, double D flip-flop SN7474 and NAND gate.
D flip-flop works in shift mode. Each time the button is pressed, a low level is sent to the Dl terminal in the figure, and the Dl state is shifted to the right bit by bit under the action of the clock signal CP
. When the second rising edge of CP arrives, the NAND gate forms a single pulse output from the Q1 and Q2 states. The voltage shown in the figure moves into a low level,
so the output is a negative single pulse .