Patent ID: 7168677

Claim:
A motor-operated valve apparatus comprising: a flow control valve provided in a fluid channel for controlling a fluid flow and having its motion range mechanically restrained; a stepping motor for driving the flow control valve; and control means for supplying pulses to the stepping motor via a motor drive circuit and controlling the amount of displacement of the flow control valve by the stepping motor according to the number of pulses supplied, wherein said control means comprises: motor standby operation controlling means for supplying pulses to said stepping motor so that the flow control valve is displaced to a predetermined position closer to a first end of both ends of the motion range of said flow control valve when said fluid channel is interrupted while said motor drive circuit and control means receive electric source power; and shift-to-home position controlling means for supplying to said stepping motor a predetermined number of pulses capable of displacing the flow control valve from said first end to a home position to displace the flow control valve to the home position, with the home position of the flow control valve being a second end of both ends of the motion range of said flow control valve, when the supply of electric source power is restarted after the supply of the electric source power to at least said motor drive circuit and control means is stopped.