 multiply the current amplitude command value with the U-phase and W-phase current phase command values. The resultant two outputs from respective multipliers 00U, 00W are, then, fed to two D/A converters 00U, 00W so as to generate U-phase and W-phase current commands, respectively. These U-phase and W-phase current commands are, subsequently, fed to current amplifiers 00U, 00W in which drive currents to be supplied to the U-phase winding 0 and the W-phase winding 0 are generated in response to the U-phase and W-phase current commands, respectively. The