Planar transformer for energy transfer

Abstract

A planar transformer for power transmission, having vertical and horizontal extents, includes a circuit board having a sandwich-type structure with at least three layers to form electrical conductors. First and second layers of these layers form outer layers of the circuit board, and each additional one of these layers forms an inner layer of the circuit board. An insulation material with a minimum thickness is arranged between all of these layers, with a number of at least three mutually galvanically isolated circuits. A first circuit forms a primary circuit and each additional circuit forms an equally entitled secondary circuit, having a magnetic core assembled from two interconnected magnetic core parts. A first core part with a central part and two outer legs forms a U shape. The circuit board has two recesses, and the two outer legs of the first core part are inserted into these recesses and connected to the second core part at their ends remote from the central part. A conductor is formed on at least one of the outer layers for exactly one single circuit of the at least three circuits, and a conductor of at least one circuit of the at least three circuits is wound around a first outer leg, and conductors of at least two additional circuits of the at least three circuits are wound around the second outer leg.