| 摘要 |
PROBLEM TO BE SOLVED: To control a motor speed on the basis of a safety signal, without provision of a special speed sensor on the motor.SOLUTION: A control unit 11 generates a control signal on the basis of a speed command signal or a safety signal, to output to a main circuit 13 through a drive circuit 12. Also, the control unit 11 calculates a speed estimation value of a motor 4, on the basis of the drive current of the motor 4 detected by a current sensor 14. Based on the speed estimation value, the control unit 11 determines whether or not the speed control of the motor 4 is normally performed according to the safety signal, and generates a halt signal when determining that the speed control of the motor 4 according to the safety signal is not normally performed, to intercept the supply of the drive current from the main circuit 13 to the motor 4 to halt the motor 4.SELECTED DRAWING: Figure 1 |
