The coil that is installed on a lever is obtained from a flat coil, which is wound flat so as to generate upper and lower winding regions that are parallel to the direction that the lever extends along a vertical surface that is parallel to the direction that the lever extends. The magnetic circuit is provided with multiple plate-shaped permanent magnets that face the upper and lower winding regions of the flat coil and are magnetized in a direction that is orthogonal to the vertical surface, and yoke members that induce lines of magnetic force of the permanent magnets so that a magnetic flux of an orientation that is orthogonal to the vertical surface is generated.