Electricity generating sensor

A power generation sensor comprising:

• a magnetic wire configured to exhibit a large Barkhausen effect by an alternating magnetic field applied in an axial direction thereof;
• a coil wound around the magnetic wire;
• and
• a pair of magnetic flux conducting pieces that include a pair of magnetically-soft components respectively magnetically coupled to opposite end portions of the magnetic wire and are symmetrical with each other with respect to a symmetry plane defined at an axially middle position of the magnetic wire;
• wherein the pair of magnetic flux conducting pieces include:
• a pair of axis-orthogonal portions respectively fixed to the opposite end portions of the magnetic wire and respectively extending parallel to each other orthogonally to the axial direction from the opposite end portions of the magnetic wire;
• and a pair of axis-parallel portions extending toward each other in the axial direction from distal ends of the axis-orthogonal portions with their adjacent ends opposed to each other and spaced a gap from each other in the axial direction;
• wherein a distance of the gap as measured in the axial direction is 5% to 50% of a distance between magnetic wire coupling positions of the axis-orthogonal portions as measured in the axial direction;
• wherein the axis-orthogonal portions of the magnetic flux conducting pieces respectively have wire placement portions each formed with a hole or a groove extending therethrough in the axial direction;
• wherein the magnetic wire extends through the wire placement portions of the axis-orthogonal portions and is fixed to the axis-orthogonal portions;
• and
• wherein the power generation sensor is configured to have a detection region located on a side of the axis-parallel portions opposite from the magnetic wire.