Hybrid winding concept for toroids

Abstract

This paper proposes a hybrid winding concept for toroids using the traces in a printed circuit board to make connection to bended copper foil cutouts. In a final product a number of strips with a certain thickness would be held by a former and the whole assembly could be placed by pick and placement machinery. This opens up the possibility for both an automated manufacturing process and an automated production process of toroidal magnetics such as power inductors, filtering inductors, air core inductors, transformers etc. Both the proposed hybrid and the common wire wound winding implementation is simulated using finite element modeling and the DC and AC resistance of the inductors are verified with experimental measurements on prototypes. It is found that commercial available layer thickness of printed circuit boards is a bottleneck for high power applications. Furthermore, the winding configuration is crucial for performance.