| 摘要 |
PURPOSE:To simplify lead treatment, by composing a position detecting means of a magnetoresistance element having a bias magnet and auxiliary members. CONSTITUTION:Of two-phase stator windings 1, 2, 3, 4, current is alternately conducted to windings 1, 2 via a switching element 7, and is alternately conducted to windings 3, 4 via a switching element 6 to rotate a rotor 5 having four poles. Electrical conduction is changed-over by detecting the electrical angle of the rotor 5 with a magnetoresistance element 8. In other words, the magnetic fields at two points at the angle of 90 deg. against the rotor 5 are induced to the magnetoresistance element 8 by auxiliary members 12, and the difference is detected. As the magnetoresistance element 8 has no magnetic-field-direction- discriminating property, a bias magnet 11 is added to detect the direction of the magnetic field. The resistance of the magnetoresistance element 8 is converted to voltage, which is compared with reference voltage by means of a comparator 9, and by the output, the switching elements 6, 7 are turned ON/ OFF. As a result, it is possible to form the wirings to the magnetoresistance element 8 of two wirings. |
