| 摘要 |
<P>PROBLEM TO BE SOLVED: To conduct stable driving by detecting accurate rotational position information by shortening a time for detecting a self-induction counter electromotive force, and by sufficiently securing a time for measuring a voltage of an induced electromotive force. <P>SOLUTION: The time for detecting the self-induction electromotive force of one phase can be shortened such that, by cutting off energization at electric angles of 120° to the other phase of a three-phase armature winding for a prescribed time, at timing when energization to the one phase of the three-phase armature winding is cut off by 120° square-wave energization, and also at timing when the self-induction voltage is generated, the self-induction electromotive force having polarity reverse to that of the self-induction voltage of the other phase is generated at the other phase. By this configuration, the time for detecting the self-induction electromotive force is shortened at electric angles of 60° at which the 120° square-wave energization is cut off, thus sufficiently securing the time for measuring the voltage of the induction electromotive force, and the accurate rotational position information is detected, thus providing a brushless motor that can stably be driven. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
