Patent ID: 8237392

Claim:
A motor control apparatus that drives a motor with n phases, wherein n is a natural number equal to or larger than 3, the motor control apparatus comprising: a controller that determines a level of a command voltage used to drive the motor; a motor drive signal generator that generates a pulse width modulation signal having a predetermined pulse width in each unit period, using a voltage whose level is equal to the level determined by the controller; and a motor drive circuit having a plurality of upper and lower switching elements that drive the motor based on the pulse width modulation signal from the motor drive signal generator, and a switching circuit that supplies a current to the motor when the pulse width modulation signal turns the plurality of switching elements on/off, wherein the controller corrects the level of the command voltage to compensate for a change in voltage applied to the motor drive circuit in accordance with on/off states of the switching element, wherein the voltage applied to the motor drive circuit changes based on a number of the upper switching elements that is turned on.