The invention relates to a method of energizing a polyphase motor by means of a plurality of coils (E1, E2, E3), each coil intended to be excited by means of a control signal (I1, I2, I3). The method in accordance with the invention comprises the following steps: identifying the control signal having the largest absolute value, and connecting the corresponding coil to a reference-potential terminal (VCC or GND). The invention enables the losses caused by switching operations in the power stages energizing the coils to be reduced, and to increase the efficiency of the power supply device of the motor.