ROTATION ANGLE DETECTION DEVICE

• Main Authors: MITSUMATA CHIHARU, OKADA YASUYUKI, AIMUTA KYOHEI
• Format: Patent
• Language: English; French; German
• Published: 23.10.2013
• Subjects: ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVEREDIN A SINGLE OTHER SUBCLASS; MEASURING; MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR; PHYSICS; TARIFF METERING APPARATUS; TESTING

A rotation-angle-detecting apparatus comprising a magnet rotor, a magnetic sensor detecting the direction of magnetic flux from the magnet rotor, a correction circuit, and an angle-calculating circuit, the magnetic sensor having bridge circuits X and Y each comprising four connected magnetoresistive devices, each magnetoresistive device comprising a spin-valve, giant-magnetoresistive film, the correction circuit calculating difference (Vx - Vy) and sum (Vx + Vy) from the output voltage Vx of the bridge circuit X and the output voltage Vy of the bridge circuit Y, and making their amplitudes equal to each other, and the angle-calculating circuit determining the rotation angle of the rotor by arctangent calculation from a signal (Vx - Vy)' and a signal (Vx + Vy)' supplied with the same amplitude from the correction circuit.