A magnetic structure comprising: an electrically insulating carrier comprising a base portion and a plurality of upstanding sidewalls forming a regularly shaped cavity and including a front wall portion, a left side wall portion, a right side wall portion and a rear wall portion extending upwardly normally from the base portion; a plurality of substantially planar dielectric spacers (12a-12m) configured for nesting disposition within said cavity; a plurality of substantially planar windings (14, 16) configured for disposition within said cavity, with each said planar winding interstitially disposed between an adjacent pair of said dielectric spacers; and a ferrite core operative to magnetically couple said windings, said carrier and said windings forming first and second spaced-apart sets of cooperating registration features operative to maintain said windings in fixed alignment with said carrier, said plurality of windings comprise a plurality of primary windings (14a-14d) and a plurality of secondary windings (16a-16h) wherein said base portion further comprises a plurality of upstanding inner walls forming an inner structure with an axial through passage and extending through corresponding openings in each of said dielectric spacers and windings (14,16); wherein each of said windings comprises a first termination portion, an intermediate portion including at least one turn, and a second termination portion, characterised in that said first spaced-apart set of cooperating registration features comprise posts (80a, 80b) proximal to said inner structure and positioned between a rear wall of said inner structure and the rear wall portion of the carrier and the second termination portion of the primary windings includes a single opening cooperatively receiving one of said posts (80a, 80b) proximal to said inner structure to mechanically secure said second termination portion to the carrier and to electrically connect the second termination portion with the one of said posts (80a, 80b) proximal to said inner structure for electrical interconnection with other winding terminals within the device; wherein said posts (80a, 80b) proximal to said inner structure are integrally formed as part of the carrier. an electrically insulating carrier comprising a base portion and a plurality of upstanding sidewalls forming a regularly shaped cavity and including a front wall portion, a left side wall portion, a right side wall portion and a rear wall portion extending upwardly normally from the base portion; a plurality of substantially planar dielectric spacers (12a-12m) configured for nesting disposition within said cavity; a plurality of substantially planar windings (14, 16) configured for disposition within said cavity, with each said planar winding interstitially disposed between an adjacent pair of said dielectric spacers; and a ferrite core operative to magnetically couple said windings, said carrier and said windings forming first and second spaced-apart sets of cooperating registration features operative to maintain said windings in fixed alignment with said carrier, said plurality of windings comprise a plurality of primary windings (14a-14d) and a plurality of secondary windings (16a-16h) wherein said base portion further comprises a plurality of upstanding inner walls forming an inner structure with an axial through passage and extending through corresponding openings in each of said dielectric spacers and windings (14,16); wherein each of said windings comprises a first termination portion, an intermediate portion including at least one turn, and a second termination portion, characterised in that said first spaced-apart set of cooperating registration features comprise posts (80a, 80b) proximal to said inner structure and positioned between a rear wall of said inner structure and the rear wall portion of the carrier and the second termination portion of the primary windings includes a single opening cooperatively receiving one of said posts (80a, 80b) proximal to said inner structure to mechanically secure said second termination portion to the carrier and to electrically connect the second termination portion with the one of said posts (80a, 80b) proximal to said inner structure for electrical interconnection with other winding terminals within the device; wherein said posts (80a, 80b) proximal to said inner structure are integrally formed as part of the carrier.