Abstract: A flow control device includes an opening part through which an upstream side of a fluid flow passage is in communication with a downstream side of the fluid flow passage. A valve element closes the opening part and includes a large flow rate controlling valve element capable of adjusting an opening degree of the opening part, a sealing member provided with a valve hole having an open area smaller than the opening part and formed to be capable of being brought into tight contact with a peripheral wall part of the opening part and a small flow rate controlling valve element capable of adjusting an opening degree of the valve hole. A valve drive device rotates to drive the valve element in a closed direction for closing the opening part or in an opened direction for opening the opening part.

Abstract: A motor control device for a flow control device includes an opening part through which an upstream side of a fluid flow passage is in communication with a downstream side of the fluid flow passage, a valve element that controls a flow of a fluid which passes through the opening part, a motor which includes a rotor and a stator that relatively moves the valve element with respect to the opening part and a drive control section by which the motor is rotationally driven and controlled. Drive pulses are outputted from the drive control section for rotationally driving the rotor of the motor and a stop pulse is outputted from the drive control section and set to be a period width longer than that of the drive pulse for stopping the rotor of the motor at a prescribed position. The stop pulse is applied to the motor and the rotor stops at the prescribed position by a magnetic detent torque between the rotor and the stator.

Abstract: A flow control device includes an opening part through which an upstream side of a fluid flow passage is in communication with a downstream side of the fluid flow passage. A valve element closes the opening part and includes a large flow rate controlling valve element capable of adjusting an opening degree of the opening part, a sealing member provided with a valve hole having an open area smaller than the opening part and formed to be capable of being brought into tight contact with a peripheral wall part of the opening part and a small flow rate controlling valve element capable of adjusting an opening degree of the valve hole. A valve drive device rotates to drive the valve element in a closed direction for closing the opening part or in an opened direction for opening the opening part.

Abstract: A motor control device for a flow control device includes an opening part through which an upstream side of a fluid flow passage is in communication with a downstream side of the fluid flow passage, a valve element that controls a flow of a fluid which passes through the opening part, a motor which includes a rotor and a stator that relatively moves the valve element with respect to the opening part and a drive control section by which the motor is rotationally driven and controlled. Drive pulses are outputted from the drive control section for rotationally driving the rotor of the motor and a stop pulse is outputted from the drive control section and set to be a period width longer than that of the drive pulse for stopping the rotor of the motor at a prescribed position. The stop pulse is applied to the motor and the rotor stops at the prescribed position by a magnetic detent torque between the rotor and the stator.