| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a transformer which can be made smaller in size and thickness, while keeping a desired dielectric strength. SOLUTION: A coil bobbin 10, which is provide with flanges 10b and 10c on both ends of a winding shaft 10a, is used, and the winding shaft 10a is wound by an electric wire for attaching a winding 11. When the coil bobbin 10 is mounted to a circuit board, a sheet coil 12 is arranged on the outer side (lower side in the figure) or the flange 10c, located on the side of the circuit board. The sheet coil and winding constitute the transformer. The sheet coil itself is a plate-like coil, having a desired dielectric strength, and the wall thickness of the flange 10c can be made small, because the sheet coil does not cause a problem even if it is in contact with the winding, and no barrier tape is needed between the winding and sheet coil, so that dead space can be reduced and a transformer as a whole can be made small in size.</p> |
