| 摘要 |
<p>PURPOSE: To improve a voltage conversion efficiency by setting each plate thickness of a plurality of magnetic body steel plates to the specific ratio or less of a specific diameter of a circumscribed circle and setting the plate thickness to, at least a specific type, the number to, at least a specific number, and the ratio of the area of a circle to, at lead, a specific ratio for the area of the circumscribed circle. CONSTITUTION: An iron core 502 is formed in cylindrical shape with its sectional area being nearly circular using, at least, 12 magnetic body steel plates where the dimension in longitudinal direction consisting of silicon steel plate is made constant and a plate width dimension differs. The diameter of the column-shaped and nearly circular circumscribed circle is set to 15mm or less, at least six ranges of the plate width are set, and lamination is made successively from a steel plate 501b where the plate width gradually becomes wider from the minimum plate width 501a to the maximum plate width 501m, thus achieving 8% or less of the diameter of the circumscribed circle 500. Then, a ratio where nearly circular area occupies for the area of the circumscribed circle 500 is set to, at lead, 90%, thus improving a voltage conversion efficiency and reducing manufacturing cost.</p> |
