CIRCUIT FOR DETECTING MAGNETIC IMPEDANCE EFFECT ELEMENT

PROBLEM TO BE SOLVED: To simplify a winding work and a winding structure, and miniaturize a circuit by reducing exciting coils to be wound to an MI(magnetic impedance effect) element. SOLUTION: The detect circuit has a magnetic impedance effect element 2a arranged in an external magnetic field, an element drive circuit 1 for supplying a high frequency current to the magnetic impedance effect element 2a, a coil 2b for impressing a magnetic field to the magnetic impedance effect element 2a, and an amplifier 5 for outputting a detect voltage corresponding to a voltage appearing to both ends of the magnetic impedance effect element 2a. The detect circuit generates a bias magnetic field to the coil 2b based on a bias voltage different from the detect voltage and, generates a negative feedback magnetic field in an opposite direction to a direction of the external magnetic field based on the detect voltage.