| 摘要 |
PURPOSE:To achieve the enhancement of insulation strength between a primary coil and a secondary coil using a simple constitution, by making the number of turns of the coil at both the ends of the primary coil, opposed to both the ends of the secondary coil, smaller than that in the center of the primary coil, opposed to the center of the secondary coil. CONSTITUTION:A primary coil 151 consists of a large diameter portion 151a in the center and small diameter portions 151b at both ends. The first layer of the primary coil 151 is wound to the end of winding width of a primary spool 50, and made to turn back from there. The second layer is made to turn back halfway without returning to the start point, and the third layer is also make to turn back halfway without returning to the end. Thus the fourth layer is formed until the coil reaches the turning point of the second layer, and from the point the coil sinks by two stages. That is, the height of the small diameter portions 151b on both sides is smaller by a value equal to the height of two of the layers than that of the large diameter portion 151a in the center. This provides a large distance between the primary coil and a secondary coil, and thus ensures insulation there. |
