In an apparatus, a first control unit performs current-feedback control, and a second control unit performs torque-feedback control. The torque-feedback control samples values of each output current at phases. The sampled values of each output current at the phases are referred to as phase-related sampled values of the corresponding output current. The apparatus causes the second control unit to sample values of each output current at the predetermined phases while the first control unit is performing the current-feedback control when switching the current-feedback control to the torque-feedback control. The second control unit uses the values of each output current sampled by the first control unit as the phase-related sampled values of the corresponding output current to start the torque-feedback control when the current-feedback control is switched to the torque-feedback control.