摘要 |
In a motor driver, based on driving waveforms of respective phases generated by a driving waveform generator, a power feeder feeds respective phase-coils with an alternating current consecutively changing in sine wave. Further, a phase advancing controller adjusts phases of the driving waveform, and performs phase-advancing control such that each phase of back electromotive forces induced in respective phase-coils generally coincides with a phase of the ac running through the coils. In phase-advancing controlling, a phase current is detected with a common current. The structure discussed above can reduce torque ripples, vibrations and noises, and a motor thus can be driven efficiently. |