Patent ID: 8040090
Filing Date: 2011-10-18
Classification: H02P

Abstract:
1. A brushless motor controller that performs rotation control for a brushless motor by detecting a rotational position and a rotation speed of a rotor based on a detection signal from a rotation sensor and determining an energizing timing of a three-phase stator coil based on the detected rotational position and rotation speed of the rotor, the brushless motor controller comprising: a normal timing generation unit which generates a normal energizing timing determined by the rotational position of the rotor; an advancing angle timing generation unit which generates an advancing angle energizing timing determined by the rotational position of the rotor and advanced by a predetermined amount from the normal energizing timing, generates a delay amount that changes in correspondence with the rotation speed of the rotor, and generates a final advancing angle energizing timing delayed by the delay amount from the advancing angle energizing timing; and a control switching unit which switches rotation control of the motor between a first rotation control executed when the rotation speed of the rotor is less than a predetermined value and a second rotation control executed when the rotation speed of the rotor is greater than or equal to the predetermined value, wherein the motor is controlled in accordance with the normal energizing timing in the first rotation control, and the motor is controlled in accordance with the final advancing angle energizing timing in the second rotation control.