Provided is a coil assembly comprising a magnetic core and a coil having a wound portion in which a rectangular wire is wound in an edgewise fashion. In the coil assembly, both ends of the rectangular wire extend in the same direction from the wound portion, and the ends form a connector junction portion that is connected to a reception-side connector. This coil assembly is conductively connected to a circuit board provided with the reception-side connector, and is housed in an outer case.
