| 摘要 |
PROBLEM TO BE SOLVED: To prevent the mean value of the operating speed of a load from extraordinarily exceeding a set value when the load that may be brought into a negative state is driven by a motor. SOLUTION: A load 2 the roller 2c of which is energized by a spring 2d and is in contact with a drum 2a and a cam 2b is driven using a motor 1. A motor drive control means 7 exercises control so that the rotational speed of the motor 1 is kept at a set value. Since the drum 2a is driven by the spring 2d, a timing detector 8 generates a timing detection signal Vt with a timing a set time ahead of the timing with which the load is brought into the negative state. When a timing detection signal Vt is generated, a drive stop command signal generating circuit 9 generates a drive stop command signal Vst that last for a certain length of time, and thus the drive of the motor 1 is kept in a stop as long as the drive stop command signal is generated. |
