CURRENT SENSING DEVICE

The present invention relates to a current sensing device, comprising: a substrate (40); and one or more coil elements (30). The substrate comprises a plurality of holes (100) projecting at least part way through the substrate from a first surface of the substrate, wherein prior to a coil element being mounted to the substrate each of the plurality holes has a circular or polygonal cross section. The coil element comprises: a winding body (10, 20); a length of wire (80); and a plurality of locating pins (60). The winding body has an outer surface around an axis of the winding body, and wherein at least a portion of the length of wire is wound multiple times around the outer surface of the winding body in a generally circumferential direction with respect to the axis of the winding body. A first locating pin of the plurality of locating pins projects from the coil element in a direction parallel to a pin axis that is perpendicular to the axis of the winding body, and wherein a second locating pin of the plurality of locating pins projects from the coil element in the direction parallel to the pin axis. Prior to the coil element being mounted to the substrate a cross section of the first locating pin perpendicular to the pin axis comprises first and second outer vertices facing away from the second locating pin, and a cross section of the second locating pin perpendicular to the pin axis comprises third and fourth outer vertices facing away from the first locating pin, and wherein the four outer vertices form a first quadrangle. When the coil element is mounted to the first surface of the substrate the first locating pin is located in a first hole of the plurality of holes such that the first and second outer vertices are in contact with first and second regions on the inside of the first hole and the second locating pin is located in a second hole of the plurality of holes such that the third and fourth outer vertices are in contact with third and fourth regions on the inside of the second hole. Prior to the coil element being mounted to the substrate, first and second circumferential or perimeter points of the first circular or polygonal cross section hole correlate with the first and second regions, and third and fourth circumferential or perimeter points of the second circular or polygonal cross section hole correlate with the third and fourth regions, and wherein the four circumferential or perimeter points form a second quadrangle smaller than the firs