| 摘要 |
<P>PROBLEM TO BE SOLVED: To rotate a brushless DC motor at high speed without lowering a voltage drop rate and enable speed control over a wide range. <P>SOLUTION: A brushless DC motor 1 includes: a rotor formed by arranging a plurality of magnets plurally divided around a rotation axis around which the rotor is rotationally driven; and an armature placed around the rotor with the rotation axis at the center and whose coils are supplied with currents corresponding to the respective phases. When a motor drive unit drives this motor, its output control unit 9 performs the operation of: selecting armature coils in two phases that change and control the on/off state of switching elements of a PWM inverter 3 based on the rotational position detected by a position detector 4 and a position detector 5; supplying the magnetic flux produced by the armature coils in two phases from the armature to the rotor to control the number of rotations; and selecting the armature oil in the other phase to PWM-control the switching elements of the PWM inverter 3 connected with the phase. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
