| 摘要 |
PURPOSE:To always start a sensorless spindle motor even if a load of a rotor is largely increased due to an irregularity in solid matters, aging change, etc. CONSTITUTION:A motor controller 11 initializes a rotating speed of an exciting phase for coils 13a, 13b, 13c of a motor 13, and outputs a phase control signal 15 responsive to the initialized value to a driving circuit 12. The circuit 12 switches an exciting phase at a speed responsive to the signal 15, generates a 3-phase motor drive signal 16, and forcibly rotatably drives the motor 13. The controller 11 sequentially decelerates the speed of the exciting phase if the motor 13 is not started, and starts the motor 13 to a suitable speed. When the controller 11 detects the rotation of the rotor from a rotor position signal 18 as the motor is forcibly rotated, it is shifted to a control rotation for exciting a suitable phase based on the signal 18 from a rotor position detector 14. |
