| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an abnormality judging device which can judge abnormality quickly and accurately even in condition that the rotation of a brushless servo motor is continuous when abnormality occurs in the driving circuit of the brushless servo motor. <P>SOLUTION: An abnormality judging part 13 monitors the motor current detected with a current detector 4 and the duty ratio computed with a duty ratio computing part 11, and in case that the value of the motor current is not more than a specified current value and that the duty ratio is not less than a specified ratio, it judges that the supply system of a motor current is temporarily abnormal. The abnormality judging part 13 executes this monitoring treatment a specified number of times, and in case that the rate of the number of times it has judged the supply system temporarily abnormal to the number of times of judgement is at or over a specified rate, it judges that the supply system of the motor current is abnormal. <P>COPYRIGHT: (C)2008,JPO&INPIT |
