| 摘要 |
PROBLEM TO BE SOLVED: To provide a core for a low-noise wound transformer, which realizes low noise effectively and has little vibration, and a manufacturing method therefor by having a resin intermediate layer for restarting vertical vibration in a copper plate surface and finding manufacturing conditions for eliminating deterioration of a resin intermediate layer after final strain relief annealing. SOLUTION: In the manufacturing of an iron core of a wound transformer, a bilayered electromagnetic steel plate having a 10 to 100 μm-thick resin layer between laminations of two electromagnetic steel plates is used as a part of a core sheet forming a core without strain relief annealing, and resin layers are provided to a plurality of places each having a thickness of 1% or more of a core thickness and combined with a core sheet obtained by annealing an electromagnetic steel plate of a single layer in core formation. Thereby, a core of a low-noise wound transformer can be manufactured. |
