1. Core: selection of 0.3mm thick of high performance of magnetic silicon steel sheet, 45° wide ramp joints, three-step lap, no punching, the surface is coated with epoxy resin, and therefore rust-proof, low loss and low noise. 2. Coil: High-voltage coil: it applies the continuous structure of high mechanical and good cooling, and then through the impregnation of the H-class solvent-free varnish and the high ...