Magnetic sensor apparatus, current sensor apparatus and magnetic sensor element

摘要

A magnetic sensor apparatus comprises a magnetic detector (101) that outputs a signal responsive to a magnetic field and a magnetic substance (110) having a cavity (111) in which the magnetic detector (101) is placed. The magnetic detector (101) is placed in the cavity (111) of the magnetic substance (110). The ratio between a magnetic field (H) to be measured and a magnetic field applied to the magnetic detector (101) is set to a specific value, based on at least one of a first demagnetizing factor depending on the shape of the magnetic substance (110) and a second demagnetizing factor depending on the shape of the cavity (111). The magnetic sensor apparatus further comprises a feedback coil (112) that applies a negative feedback magnetic field to the magnetic detector (101) and a reference magnetic field coil (113) that applies a reference alternating magnetic filed to the magnetic detector (101) for controlling the property of the magnetic detector (101).