A transformer assembly includes a vertical bobbin and a shrouding element. The vertical bobbin includes a first winding portion, a second winding portion, and a flange. The flange is disposed between the first winding portion and the second winding portion. The flange includes a flange edge. The shrouding element, which substantially covers the first winding portion or the second winding portion, includes a shrouding edge that is operatively coupled to the flange edge. The flange edge and the shrouding edge have at least one complementary corrugation. In one example, the flange edge includes at least one groove and the shrouding edge includes at least one protrusion that is complementary to the groove. In another example, the shrouding edge includes at least one groove and the flange edge includes at least one protrusion that is complementary to the groove.