Motor control circuit
AssigneeSankyo Seiki Mfg. Co., Ltd.
InventorsKimio Kitajima, Hiroyuki Kiuchi
Life of this patent
Estimating the term…
Abstract
A motor control circuit provides reduced stopping time. The circuit utilizes n rotational signals whose relative phase differences are proportional to the rotational speed of the motor. Inverted logic signals are formed of these n signals. Circuitry for discriminating the direction of the motor and for determining from the n signals n-1 and/or n inverted signals, the initial change of any of the signals following a reversal of the motor. Upon determining the initial change, a signal is supplied to the motor drive circuit to cause the motor to de-energized. A specific circuit for holding the motor in a stopped condition is disclosed.
Claims12
A motor control circuit for causing a motor to have a reduced stopping time comprising:
- means for supplying first and second rotational signals whose phase difference is proportional to the rotational speed of said motor;
- means for forming an inverted signal of said first rotational signal;
- means for supplying a signal to stop the motor;
- a first discrimination circuit for discriminating a rotational direction of the motor in response to said first and second rotational signals and for providing an output signal representative thereof;
- a second discrimination circuit for discriminating the rotational direction of the motor in response to said inverted signal and said second rotational signal for providing an output signal representative thereof;
- a motor drive circuit;
- rotational direction instruction means for controlling said motor drive circuit so that said motor is reversely rotated when said signal to stop said motor is supplied;
- a stop circuit for supplying a signal to said motor drive circuit to de-energize said motor, said stop circuit responsive to the output signals from said first and second discrimination circuits, which circuits, after said motor has been rotated reversely, detect a predetermined initial change of said first rotational signal and said inverted signal;
- and
- a hold circuit for resetting said first and second discrimination circuits by a stop signal provided by said stop circuit for holding the stopped state of the motor.
A motor control circuit for causing a motor to have a reduce stopping time comprising:
- means for supplying n rotational signals whose relative phase differences are proportional to the rotational speed of a motor and are nominally related by 360.degree./n;
- means for forming inverted signals from n-1 of said rotational signals;
- a motor drive circuit;
- means for supplying a signal to stop the motor;
- rotational direction instruction means for controlling said motor drive circuit so that said motor is reversely rotated when said signal to stop said motor is supplied;
- means for discriminating the direction of said motor and for determining, from said n signals and from said n-1 inverted signals, a predetermined initial flange of said n signals and n-1 inverted signals following a reversal of said motor and for supplying a signal to said motor drive circuit to de-energize said motor upon determining said initial change;
- and
- means for holding said motor in a stopped condition following stopping of said motor.
A method for reducing the time for a motor to come to a complete stop comprising:
- supplying a plurality of n rotational signals related to the rotational speed of a motor by the relative phase difference therebetween, the signals nominally being related by 360.degree./n;
- forming n-1 inverted signals from said n rotational signals;
- reversing the rotational direction of said motor in response to a signal to stop the motor;
- determining, from said n signals and n-1 inverted signals, a predetermined initial change of any of said n rotational signals and n-1 inverted signals following a reversal of said motor;
- de-energizing said motor upon determining said initial change;
- and
- positively holding the motor in a stopped state after said motor has come to a complete stop.
Dependencies are inferred from the claim text.