Choke coil for e.g. multiple mains filter drive system, has primary winding, where choke coil is coupled with coupling coil and choke coil inductivity is adjusted by coupling coil that is realized as air core coil, which does not have core

摘要

The choke coil (10) has a circular core (3) and a primary winding (2), where the choke coil is magnetically coupled with a coupling coil (1) by a secondary winding (5) and inductivity of the choke coil is adjusted by the coupling coil. The coupling coil is realized as an air core coil, which does not have a core, and the inductivity of the air core coil is adjusted by varying number of turns of the air core coil and/or by varying either a cross-section or a length of the air core coil.