I am building a one-shot monostable oscillator using 555 Timer. Trigger pulse is controlled by a pushbutton, and thus can be long. I don't want output pulse to stay high for that long (simulated by V2 and voltage-controlled switch in schematic below). For that reason, I want to use reset pin to reset cycle after,say, 50ms. I simulated circuit but I am not sure how to execute in reality control of reset pin (this is simulated by V3 in schematic).