Abstract: A detector for the rotational angle of a motor and a small brushless or stepping motor having the detector built therein are disclosed. A sensor probe of the detector is provided with a wire configuration comprising a giant magnetoresistive element (sensor element) enabled to read a change in magnetic field up to at least 10 kOe, a first sensor lead and a second sensor lead connected one each to the opposite terminals of the magnetoresistive element, and an insulating layer interposed between the two sensor leads. The sensor probe of the detector is disposed inside a motor housing as approximated closely to the magnetic teeth of a rotor of the motor. The giant magnetoresistive element is formed of a magnetic particle dispersion type giant magnetoresistive material, an artificial lattice type giant magnetoresistive material, or a colossal magnetoresistive material.

Abstract: A detector for the rotational angle of a motor and a small brushless or stepping motor having the detector built therein are disclosed. A sensor probe of the detector is provided with a wire configuration comprising a giant magnetoresistive element (sensor element) enabled to read a change in magnetic field up to at least 10 kOe, a first sensor lead and a second sensor lead connected one each to the opposite terminals of the magnetoresistive element, and an insulating layer interposed between the two sensor leads. The sensor probe of the detector is disposed inside a motor housing as approximated closely to the magnetic teeth of a rotor of the motor. The giant magnetoresistive element is formed of a magnetic particle dispersion type giant magnetoresistive material, an artificial lattice type giant magnetoresistive material, or a colossal magnetoresistive material.

Abstract: Disclosed are a method and apparatus for detection of a magnetic substance erroneously included in a non-magnetic product. The non-magnetic product such as a sewn product is passed through a high magnetic field in which a magnetic field is applied to the product. The residual magnetization of a magnetic substance such as a broken needle mingled in the product is detected by a sensing unit and a signal of detection is transmitted to a measuring unit to measure the magnitude of detected residual magnetization. The presence or absence of the magnetic substance in the product is determined by a control unit based on the output from the measuring unit. Alternatively, a magnetic field may be preparatorily applied to a magnetic substance having the possibility of being mingled in the non-magnetic product thereby causing the magnetic substance to assume a state of possessing residual magnetization.