| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem wherein, in performing AD conversion of a motor voltage signal with a sampling signal in a constant period, unnecessary signal components are generated, in a drive unit for a stepping motor. SOLUTION: In the drive unit for a stepping motor, AD conversion sections 90, 91 have: an AD converter 90 which converts an AC analog signal to a digital value in a constant period; a digital accumulator which accumulates the AC signal converted into the digital value for one waveform period; a data holder which holds the digital value; and a limiter which outputs a specified value when an input signal exceeds a specified range and outputs the value of the input signal when the input signal remains within a specified range. The output of the AD converter is input into the digital accumulator, the accumulated value equivalent to the one period of the AC signal obtained is one input value of the data holder, the output of the data holder is the input of the limiter, the difference between the output of the limiter and the output of the data holder is the other input value of the data holder, and the output of the limiter as a correction value is output after deducting it from the digital value of the AD converter. COPYRIGHT: (C)2007,JPO&INPIT |
