Second , a single steady-state circuitMonostable circuit has only one stable state. The effect of external trigger pulse , the circuit from the steady-state turn to the transient , the transient for some time, then return to steady state , and generates a rectangular output pulse . 1 , a single steady state circuit It is constituted by the CC7555 timing circuits , circuit diagram as follows: Figure in (1) It features the work of : Circuit is only one steady state ; When the external trigger pulse , the circuit turn to the transient from the steady state and transient residence time , and at the output produces a rectangular pulse width TW . Its application : In digital systems, commonly used in the shaping monostable circuit . Namely: the irregular wave into the width of the same wave amplitude .