| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To accurately detect ripple components included in current signals of a motor without using a cutoff frequency variable type filter. <P>SOLUTION: A ripple extractor 3 extracts ripple components including in current signals of a motor 2. The ripple extractor 3 includes: a current/voltage converter 10 for converting the current signals of the motor 2 to voltage signals; a filter 40 for filtering the voltage signals converted by the current/voltage converter 10 and attenuating the ripple components; and a differential amplifier 50 for taking a difference between the voltage signals converted by the current/voltage converter 10 and output signals of the filter 40. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
