To reset the timer the voltage on t

To reset the timer the voltage on the reset must be pulled under 0.4 V The reset in put will override other inputs and set the output to low if the reset input is not going to be used it should be wired to Vcc to prevent false signals In its initial state the 555 timers internal flipflop connects the discharge to the ground and sets the output to low Each time the trigger voltage is pulled down under 1/3 Vcc the flip-flop will break the discharge pin’s connection to ground and set the output to high It will hold this state until something forces the threshold pin’s voltage equal to 2/3 Vcc which will reset the flip-flop.