The invention relates to a power converter (1) comprising a magnetic core (3) and a plurality of sub-converters each having a primary winding (17. 19) and a secondary winding. The magnetic core (3) comprises an inner leg (7) and a plurality of outer legs (5, 9), each of the outer legs (5, 9) having a gap (11, 13) formed therein. The primary winding (17) of one sub-converter is wound around an outer leg and the primary winding (19) of another sub-converter is wound around another outer leg. The primary windings (17, 19) are formed from a unitary winding (21) which is wound around the legs (5, 7, 9) in a continuous fashion. The primary windings (17, 19) are mounted on a printed circuit board (PCB) (15) and interconnects between turns of the primary windings are achieved using vias (27, 29) at the ends (23, 25) of the unitary winding. The vias may be conveniently placed in the corner sections or the PCB (15).