Patent ID: 8067910
Filing Date: 2011-11-29
Classification: H02P

Abstract:
1. A brushless motor, comprising: a permanent magnet; a driving coil moving relative to the permanent magnet; a sensor coil disposed to the permanent magnet so as to generate a sensor coil induced voltage having a same phase of a driving coil induced voltage generated in the driving coil; and a driving circuit applying a driving voltage to the driving coil, the driving voltage having a same phase of the sensor coil induced voltage generated in the sensor coil, wherein the driving coil has m poles and is energized by a p-phase driving method where p≧1, and m≧p, the sensor coil induced voltage includes a plurality of sensor coil induced voltages, and the sensor coil has n poles and generates p number of the sensor induced voltages where m≧n≧p, the driving coil induced voltage includes a plurality of driving coil induced voltages and the sensor coil is disposed such that each phase of the p number of the sensor coil induced voltages is equal to a phase of one of the p number of driving coil induced voltages generated in the driving coil, and the driving circuit applies the driving voltage having the same phase of the sensor coil induced voltage to the driving coil such that each of the sensor coil induced voltages has the same phase of one of the driving coil induced voltages.