Monostable trigger timing circuit

The monostable trigger timing circuit is shown in the figure below. This circuit connects the 555 time base circuit into a monostable form. Normally, the button switch S is in the normally open state, and the 3rd pin of the 555 time base circuit outputs a low level. At this time, the internal discharge switch is closed, and the voltage on the capacitor C is zero. When the button switch S is pressed, the trigger circuit flips, and the 3rd pin of the 555 time base circuit changes from a low level to a high level, and the circuit enters a temporary stable state. At the end of the temporary stable state, the output terminal 3rd pin of the 555 time base circuit changes from a high level to a low level. The temporary stable state time tD is the timing time tW, that is, tD=tW=1.1RC. This circuit will enter the timing working state once every time the switch S is pressed, so this circuit is suitable for occasions where manual control of timing work is required.