| 摘要 |
PURPOSE:To produce an output voltage and to prevent dropped of motor efficiency and production of vibration by subtracting the average value of voltage signals from a voltage signal fed from a magnetic sensor, further splitting thus obtained voltage signal into a plurality of components and weighing the voltage components thereby synthesizing a vector. CONSTITUTION:Average value -A(V) of voltage is obtained through an average voltage operating circuit 3a, but since it is an offset amount it is processed through a subtractor 5a such that -A(V) is always subtracted from a magnetic pole signal 2a thus eliminating the offset component at all times. Feedback signals 11a, 11b, 11c are fed to phase operating circuits 7a, 7b, 7c so that the operation result of subtractors 8a, 8b, 8c will be 0. By such arrangement, offset or phase shift is eliminated. |
