CURRENT TRANSFORMER

PROBLEM TO BE SOLVED: To provide a current transformer having a structure which can be miniaturized while sufficiently insulating a single winding coil and a multilayer winding coil and which can use a bobbin in a versatile manner irrespective of the specification of the single winding coil side.SOLUTION: In a current transformer 1a formed by laminating a single winding coil 11a under a multilayer winding coil 12 wound around a winding shaft 100 extending in the vertical direction, the multilayer winding coil is wound around a bobbin 10a, and the single winding coil is composed of wirings 34 formed in the inner layer of a substrate 30 having insulating layers on the upper and lower surfaces, and the substrate is laminated on the lower end surface of the bobbin.SELECTED DRAWING: Figure 4 【課題】一巻きコイルと多層巻きコイル間を十分に絶縁しつつ、小型化が可能で、一巻きコイル側の仕様に依らず、ボビンを汎用的に使用できる構造を有するカレントトランスを提供する。【解決手段】上下方向に延長する巻軸１００に巻回された多層巻きコイル１２の下方に一巻きコイル１１ａが積層されてなるカレントトランス１ａであって、前記多層巻きコイルは、ボビン１０ａに巻回されてなり、前記一巻きコイルは、上下両面に絶縁層を有する基板３０の内層に形成された配線３４からなり、前記ボビンの下端面に前記基板が積層されている。【選択図】図４