Patent ID: 9742323
Date: 2017-08-22
CPC Classifications: H02K,H02P

Claim:
1. A phase control circuit for a brushless motor, comprising: a signal output unit that outputs M signals, whose phases differ from each other, in response to a change in a magnetic field resulting from a rotation of a magnet placed in a rotor; a control signal generator that generates two or more different kinds of group of phase control signals, based on at least the M signals, wherein the group of phase control signals is used to control drive voltages, whose phases differ from each other, which are supplied to each phase of an N-phase coil (N being an integer greater than or equal to two); and a drive unit that supplies the drive voltages to each phase of the N-phase coil, based on the group of phase control signals, wherein the control signal generator is configured such that a first phase control signal group and a second phase control signal group are generated, the first phase control signal group controls drive voltages, which are supplied to each phase of the N-phase coil, in a first drive mode of the brushless motor, the second phase control signal group, whose phase differs from that of the first phase control signal group by a predetermined phase of a degrees (α>0), controls drive voltages, which are supplied to each phase of the N-phase coil, in a second drive mode of the brushless motor, and wherein the control signal generator includes