Motor brake control circuit for reducing motor stopping time
First Claim
1. A motor brake control circuit comprising:
- a first discriminator circuit for detecting the sense of rotation of the motor by applying a rotational signal having a value proportional to the rate of rotation of the motor;
a second discriminator circuit for detecting the sense of rotation of the motor by applying an inverted signal of said rotational signal;
a sense-of-rotation directing circuit for controlling the motor drive circuit and reversing the sense of rotation of the motor whenever a brake command is given to the motor;
a brake circuit for turning off the power being supplied to the motor coil whenever a change in the signals from the first and second discriminator circuits is detected for the first time after the reversal of the sense of rotation of the motor; and
coil short circuit means for short-circuiting power terminals of the motor coil the instant the brake signal is issued from the brake circuit.
1 Assignment
0 Petitions
Accused Products
Abstract
A motor brake control circuit is provided with a coil short circuit for short-circuiting the power terminals of the coil once a brake signal is issued from its brake circuit so that the brake is forcibly and continuously applied to the motor. With such an arrangement, the time required for the motor to come to a complete stop after the issuance of a brake command signal is considerably reduced as compared with a motor that does not have such a coil short circuit and, therefore, comes to a complete halt only by natural deceleration. Further, since the motor is braked by the short-circuited motor coil when the brake control circuit is activated, there is virtually no affect on the motor by external force such as vibration to shift its rotary position in a braked condition.
-
Citations
10 Claims
-
1. A motor brake control circuit comprising:
-
a first discriminator circuit for detecting the sense of rotation of the motor by applying a rotational signal having a value proportional to the rate of rotation of the motor;
a second discriminator circuit for detecting the sense of rotation of the motor by applying an inverted signal of said rotational signal;a sense-of-rotation directing circuit for controlling the motor drive circuit and reversing the sense of rotation of the motor whenever a brake command is given to the motor; a brake circuit for turning off the power being supplied to the motor coil whenever a change in the signals from the first and second discriminator circuits is detected for the first time after the reversal of the sense of rotation of the motor; and coil short circuit means for short-circuiting power terminals of the motor coil the instant the brake signal is issued from the brake circuit. - View Dependent Claims (2, 3, 4, 7, 8, 9, 10)
-
-
5. The motor brake circuit of claim I including a third discriminator circuit developing a further rotational signal, said first, second and third discriminator determining the sense of rotation of the motor by a combination of two of the rotational signal, the inverted signal and the further rotational signal;
- a change in signal from at least two of the discriminator circuits being detected for the first time after reversal of motion of the motor.
-
6. The motor brake control circuit of claim wherein said inverted signal is an inverted logic signal.
Specification