| 摘要 |
PURPOSE:To stably operate a motor even at phase difference displacing time by securing to a low voltage until switched to a signal from rotating magnetic field generating means and a signal of comparator group from starting time. CONSTITUTION:A brushless motor 3 having a magnet rotor 5 is rotated by controlling the energization of an armature winding 4 by semiconductor switching group 2. When started by starting command means 14, a period signal of the prescribed frequency is input from generating means 8 to rotating magnetic field generating means 9 to form 3-phase synchronizing signals 9-U-W phases displaced at 120 deg., and the group 2 is controlled through switching means 11 and controlling means 12. Further, the drive power source 1 of the motor 3 is secured to low voltage to forcibly rotate a magnet rotor 5. Thus, after the prescribed time is elapsed, the means 11 is switched by the means 10, the position detection signal of the rotor 5 is input from comparator group 7 to the means 12 to normally rotate the motor 3. |
