Transformer or choke coil with strip winding - uses metal foil, firmly connected to each polymer film of strip, all turns of strip coil interconnected by respective polymer films

摘要

The strip coil consists of a number of layered turns of a band, consisting of a metal foil (16) with a polymer film coating, at least on one side. The metal foil is connected firmly to each abutting polymer film (19, 21) and each turn of the band is also firmly connected with the turn underneath. Between the metal foil-polymer film layers and/or between polymer film layers only are provided cavities (62, 63) open for liquid dielectric surrounding the strip coil for the coil complete saturation. Preferably the metal foil and polymer film connection is provided by a binder applied in spots, islands, lines etc. Each band turn may be similarly connected to the turn underneath. The binder thickness may be preferably 1 to 10 microns. The choke coil may contain another strip coil of the same type, concentrically mounted round the first coil, with a cooling element between the two coils. The latter may contain several channels, through which flows the transformer, of choke insulating liquid or gas.