To provide a small magnetic detector capable of detecting a variable magnetic field with high sensitivity without influence from the earth's magnetism.
A magnetic detector includes a magnetic impedance element which applies a pulse current or a high-frequency current to an amorphous wire and generates, in a detector coil wound around the amorphous wire, a voltage corresponding to the strength of a peripheral magnetic field. The number of turns of the detector coil falls within a range of 10 to 500. The ratio of the diameter of the detector coil to the diameter of the amorphous wire falls within a range of 1.05 to 10. The ratio of the length of the coil to the diameter of the detector coil falls within a range of 10 to 200. Further, in the magnetic detector, the magnetic impedance element is connected to an input terminal of a differential amplifier via a high-frequency filter.
COPYRIGHT: (C)2008,JPO&INPIT
Michiharu Yamamoto
Kotani Yoshiaki
Takeshi Kono
Genban Hiroe
Kazumi Tadashi
Toyota Central R & D Labs.
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