Coil device, power supply device, and detection device

A coil device comprising:

• a coil generating a magnetic field;
• a casing accommodating the coil;
• a conductive part including an input part, an output part, and a conductive pattern connecting the input part to the output part, the conductive part being provided on the casing, and electrically insulated from the casing;
• and
• a detection part electrically connected to the input part and the output part, energizing the conductive pattern via the input part and the output part, and detecting deformation in the casing based on an energized state of the conductive pattern,
• wherein the conductive pattern includes a first portion and a second portion arranged side by side on a pattern arrangement surface of the casing, and wherein electric currents in the first portion and in the second portion flow in opposite directions when energized,
• wherein the conductive pattern includes a plurality of first linear portions extending in one direction of in-plane directions of the pattern arrangement surface, and a plurality of second linear portions extending in an other direction of the in-plane directions intersecting the one direction,
• wherein the first linear portions and the second linear portions are alternately connected,
• wherein the first portion is an outward path extending from the input part to a turn-back position,
• wherein the second portion is a return path extending from the turn-back position to the output part,
• wherein the outward path and the return path each include the plurality of first linear portions and the plurality of second linear portions, and
• wherein at least three pairs, each pair comprising one of the first linear portions of the outward path and an adjacent one of the first linear portions of the return path, are arranged side-by-side on the pattern arrangement surface.