| 摘要 |
PURPOSE:To improve starting characteristics by conducting plural times reverse excitations from forward to reverse or vice versa during a starting step in a plurality of phases, and repeating plural times the step. CONSTITUTION:The sensorless polyphase DC motor has a stator to be applied to a spindle motor for a magnetic disk apparatus to generate a magnetic field in an excited state and a rotor for obtaining a rotary force by electromagnetic interaction with the stator to sequentially supply driving currents (iu, iv, iw) for rotating the rotor in a predetermined direction to the stator. A starting step to be conducted by energizing the stator is repeated a plurality of times. And, reverse excitations for supplying currents from normal to reverse or vice versa during the starting step are included a plurality of times in a plurality of phases. |
