A new contact amorphous torque sensor with wide dynamic range and quick response

A Torque sensor is described, which uses amorphous ribbons in contact with a sensor head, with a wide dynamic range. A uniaxial magnetic anisotropy Kuo was induced in the (Fe1-xCox)78Si8B14amorphous alloy ribbons by magnetic field annealing. These amorphous ribbons, with various Kuo/λsvalues, were used in order to examine the torsional stress detection characteristics. As expected, a larger Kuo/λsresulted in a wider dynamic range. The wide dynamic range, 1000 μ strain, was obtained in which the detecting torque sensitivity reached a value ten times as high as that for a strain gage torque sensor, using metal resistance film, where exciting frequency (subcarrier wave frequency) f = 5.4 kHz and the exciting current Ip= 5 mA.