Magnetic resistance sensor

Magnetic resistance effect sensors are made based on the magnetic resistance effect of magnetic materials. Magnetic materials (such as Permalloy) have anisotropy, and when magnetized, their magnetization direction will depend on the easy magnetization axis of the material, the shape of the material, and the direction of the magnetization field. When a current I is applied to a strip like perovskite alloy material, the resistance of the material depends on the angle between the direction of the current and the magnetization direction. If a magnetic field B (measured magnetic field) is applied to the material, it will cause the original magnetization direction to rotate. If the magnetization direction turns perpendicular to the direction of the current, the resistance of the material will decrease; If the magnetization direction turns parallel to the direction of the current, the resistance of the material will increase. The magneto resistive effect sensor generally consists of four such resistors, which are connected into a bridge. Under the action of the measured magnetic field B, the resistance values of the two resistors located in relative positions in the bridge increase, while the resistance values of the other two resistors decrease. Within its linear range, the output voltage of the bridge is proportional to the measured magnetic field.