Magnetostrictive torque sensor with read-out circuitry and earth magnetic field compensation

摘要

A magnetostrictive torque sensor (1) of the present invention is provided with: a magnetostrictive film (3, 4); a detection coil (5, 6, 7, 8); a current direction switching device (11, 26, 27); and an inversion device (23, 25), wherein: when the current flows in a direction from one side to another side of the detection coil (5, 6, 7, 8) by the current direction switching device (11, 26, 27), the torque acted to a shaft (2) is detected based on an input signal of the inversion device (23, 25); and when the current flows in an inverse direction from another side to one side of the detection coil (5, 6, 7, 8) by the current direction switching device (11, 26, 27), the torque acted to the shaft (2) is detected based on the output signal of the inversion device (23, 25).