| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a drive circuit for a multi-speed DC brushless motor that can be driven with high efficiency, in response to a large number of speed commands using a simple configuration, such as only one set of a magnetic detector. <P>SOLUTION: In the drive circuit, one set of the magnetic detector is arranged at the position of leading phase, the time when an energization current waveform reaches a peak value and a 1/2 the time of an energization block are compared, and a phase shift circuit of an energizing control signal is controlled so as to eliminate the difference of the comparison, thus enabling drive control at high efficiency, in response to the multi-speed by only one set of the magnetic position detector. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
