PURPOSE: To freely set the rate of opening of a valve correspondingly to a control voltage by driving a motor in response to information about the position of a potentiometer which is operated in association with the valve and the control voltage for controlling the rate of opening of the valve.
CONSTITUTION: When a control voltage is supplied to a differential amplifier 22 the output of the differential amplifier 22 is supplied as a driving current to a motor 26 via an absolute value circuit 27. The motor 26 drives a valve 23 and a potentiometer 24 which is operated in association with the valve 23. A voltage caused by information about the position of the potentiometer 24 and applied to the differential amplifier 22 comes close to the control voltage and finally equals the control voltage and then the motor 26 is stopped. Then a predetermined rate of opening of the valve 23 is obtained. A mark judging circuit 28 determines whether the output of the differential amplifier 22 is positive or negative to decide whether the motor 26 is rotated in its normal or reverse direction.
UESAWA TOSHIYUKI
SHUDO TOSHIO
MATSUBARA KAZUO
| JPH01120495A | 1989-05-12 | |||
| JPS58182719A | 1983-10-25 |