| 摘要 |
PURPOSE:To suppress a torque ripple of high order by controlling the amplification factor of an amplifier and magnetoelectric transducers by the average value of the sum of the outputs of the transducers, and the output combined by the average value and the output of a control amplifier. CONSTITUTION:A magnetic field of a rotor magnet is detected by Hall elements 1-3, and the outputs are respectively amplified by amplifiers 30, 40, 50. The outputs of the amplifiers 30, 40, 50 are respectively amplified by power amplifiers 60, 70, 80, and currents are respectively supplied to stator windings 7, 8, 9. A control amplifier 130 and current mirror circuits 110, 140 control the amplification factors of the amplifiers 30, 40, 50 so that the average value of the sum of the outputs of positive or negative direction from the amplifiers 30, 40, 50 to the amplifiers 60, 70, 80 becomes proportional to the control voltage input to a control voltage input terminal 20. The amplification factors of the amplifiers of the amplifiers 60, 70, 80 are controlled by the combined output of the sum of the outputs of positive or negative direction from the amplifiers 30, 40, 50 to the amplifiers 60, 70, 80 and the output of the amplifier 130. |
