Patent ID: 8269440
Filing Date: 2012-09-18
Classification: H02P

Abstract:
1. A motor control system comprising: a power control module that controls power applied to a first stator coil and a second stator coil of a motor to rotate a rotor, wherein the rotor induces voltages in the first stator coil and the second stator coil when the rotor is rotating; and a detection module that i) determines a first time when a first voltage is induced in the first stator coil, ii) determines a second time when a second voltage is induced in the second stator coil after the first voltage is induced, and iii) determines a speed of the rotor based on a difference between the first time and the second time, wherein the power control module applies current through the second stator coil a predetermined period after the second time, and wherein the power control module determines the predetermined period based on the speed of the rotor.