| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress rotation unevenness of a motor drive using a sine wave drive system, and to perform optimum motor driving that corresponds to the rotational speed. <P>SOLUTION: A motor drive is provided with an inverter 20 having a plurality of sets of switching elements; a waveform generating part 31 for generating a waveform signal WF for AC-driving a motor 10; a pulse width modulating part 32 for generating a pulsed signal whose pulse width is modulated by the waveform signal WF; a polarity discriminating part 33 for discriminating the polarity of the induced voltage generated in drive winding; and a drive-mode selecting part 34 for selecting a high-speed drive mode for generating a drive signal which complementarily switches the switching element and a low-speed drive mode for generating a drive signal turning off the switching element of positive electrode side or of negative electrode side, according to the polarity determined by the polarity discriminating part 33. <P>COPYRIGHT: (C)2009,JPO&INPIT |
