| 摘要 |
PURPOSE:To eliminate the effects due to temperature drift and secular change by calculating the output signals from two position sensing means whose phases are different and performing feedback control of said position sensing means so that the calculated result becomes constant. CONSTITUTION:Hall elements 2 and 3 are arranged at the positions whose phases are different by 90 deg. so that said element faces a rotating permanent magnet 1. The Hall voltage of the Hall elements 2 and 3 are amplified, and the absolute voltages of the output voltages Vc and Vs are added in an operating circuit 6. Its output voltage and a voltages Vo of a reference voltage source 7 are compared in a comparator 8, and the signal corresponding to the deviation is outputted. A transistor 9 is operated by said output, and the Hall elements 2 and 3 are controlled. |
