| 摘要 |
PURPOSE:To obtain a sensor which has no variation in output voltage with the fitting angle and provides high-accuracy detection even when the gap between an MR element and a magnetic material is wide by arranging a ferromagnetic thin-film resistance element so that its film surface is in a plane which contains the movement trace of a detection magnetic body and a bias magnet and the direction of a main current almost at right angles to the magnetic field of the detection magnetic field. CONSTITUTION:The detection magnetic body 6 is made of a permeable material and the magnet 8 biases the MR element 7. The bias magnet 8 and MR element 7 constitute a magnetic sensor and the MR element 7 is so arranged that its film surface is in the plane which contains the movement trace of the detection magnetic body 6 and the bias magnet 8 and the main current direction of the magnetism sensitive part 9 of the MR element 7 is at right angles to the magnetic field Hs of the bias magnet 8. A detecting means has the detection magnetic body 6 fitted to a rotary disk 5 and the magnetic sensor is fitted to a fitting base 10 by fixing the MR element 7 and an alnico magnet 8. The MR element 7 is connected in series with a resistor 11 and a battery 12 is connected across the element. An amplifier 14 and a waveform shaper 15 are connected to the connection point of the MR element 7 and resistor 11 through a capacitor 13 and rotation information is obtained from an output terminal 16.
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