| 摘要 |
PROBLEM TO BE SOLVED: To reduce the driving sound and striking sound produced when a stepping motor is returned to its origin by chopping the driving current which is supplied when the motor is driven to stop toward a stopper by means of a zero-returning means and, at the same time, lowering the on-duty ratio of the chopping signal as the motor approaches the stopper. SOLUTION: In step 201, whether or not the zero-returning process of a stepping motor is completed is judged and, when the process is not completed, step 202 is started. In step 202, the driving current of the motor is chopped when the motor is driven in steps toward a stopper and, at the same time, the on-duty ratio of the chopping signal is gradually lowered as the motor approaches the stopper. When the zero-returning process is completed, step 203 is started and the zero-returning process is terminated. Therefore, the driving sound and striking sound which are produced when the motor is drive to return its origin can be reduced. |
