Patent ID: 8054033
Filing Date: 2011-11-08
Classification: H02P

Abstract:
1. A method for operating a motor, wherein the motor comprises a plurality of electromagnets, the method comprising: calculating a pulse-width modulation (PWM) duty cycle; sampling a voltage induced by rotation of the rotor at a first expected zero crossing value, wherein said sampling produces a first sampled voltage value; calculating an average of a plurality of sampled voltage values, wherein the plurality of sampled voltage values comprise voltage values sampled at a plurality of prior expected zero crossing values and the first sampled voltage value; subtracting the first sampled voltage value from the calculated average to produce a delta zero crossing error; multiplying the delta zero crossing error by a first constant, wherein the first constant represents electromechanical properties of the motor, to produce a representation of an angular velocity; generating one or more time values based on the representation of the angular velocity; controlling operation of the motor based on the one or more time values and the PWM duty cycle.