| 摘要 |
<P>PROBLEM TO BE SOLVED: To significantly reduce the noise and vibration of a brushless motor during a period from the startup of the brushless motor until the brushless motor reaches a steady rotational frequency. <P>SOLUTION: A calculation sequencer 32 executes current-control calculation when detecting rising of a clock signal CARYCLK during a period from the stop of a brushless motor until the brushless motor reaches a steady rotational frequency. Subsequently, when the fall of the clock signal is detected, a calculation sequence 32b determines whether or not a division control signal DIVCNT is changed and executes soft switch calculation if it is changed. After it is determined that the division control signal is not changed or after the end of the soft switch calculation, the calculation sequencer 32 determines whether or not rising of a mask signal MASK occurs within one period of a PWM carrier signal CARYCLK. When the rising of the signal does not occur, processing is returned to first processing. When a rise of the signal occurs, PLL control calculation is executed, and then the processing is returned to the first processing. <P>COPYRIGHT: (C)2009,JPO&INPIT |
