Energy harvesting derived from magnetization reversal in FeCoV wire

A fast magnetization reversal accompanied by a large Barkhausen jump in a magnetic wire is utilized in speed sensors, rotation sensors, and other applications. This magnetization reversal induces a pulse voltage in a pick-up coil. The sensor structure consists of the magnetic wire attached directly to a movable object, the pick-up coil, and a single magnet separately located outside the object. In this structure, the excitation source is a single magnet. There are certain advantages of this sensor structure; for example, it is less stressful for the vibratory or rotating object because of the small and light wire attached to the object. Multiple output signals can be obtained for each movement cycle by simply adding a number of wires to the object without the need for any additional pick-up coils or magnets. These advantages are expected to widen the scope of application. In this paper, the dependence of the area in the output pulse was measured, and the derivation of the domain wall displacement was clarified.