Transformers and cores for transformers

摘要

A transformer having a core having a butt-lap-step joint. The laminations of the core are the turns of a spiral into which a web of very thin amorphous magnetic material is wound. At the joint, the core is cut producing opposite folds whose ends are aligned. The purpose of the joint is to enable the core to be opened by pealing off the folds defining the cuts and converted into a U-shaped structure; coils are telescoped on the arms. The core is closed by refolding the folds and aligning the ends of the opposite folds. At the joint the laminations, subdivided into successive groups, are cut at an angle of the order of 87 DEG to the center line of the laminations; alternate groups being cut inclined in one direction and the intervening groups being cut inclined oppositely. The oppositely inclined cuts preclude mismatching and mislocating the groups when the core structure is closed after the coils are telescoped on the arms.