Patent ID: 8487564
Filing Date: 2013-07-16
Classification: H02P

Abstract:
1. A brushless motor controller that performs rotational control for a brushless motor by detecting a rotational position and a rotational 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 rotational speed of the rotor, the brushless motor controller comprising: a load state detecting unit for detecting a load state of the motor; 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 detected load state of the motor and the rotational 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 rotational control of the motor between a first rotational control executed when the rotational speed of the rotor is less than a predetermined value and a second rotational control executed when the rotational 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 rotational control, and the motor is controlled in accordance with the final advancing angle energizing timing in the second rotational control.