Several embodiments of a circuit device using principles of planar Litz wire construction are disclosed using flexible printed circuit boards on which a given set of conductors is located on one surface only. The FPCBs are folded at strategic locations to effectively cause conductors in adjacent parallel planes to effectively cross one another to realize the advantages of braided Litz wire conductors, but without the use of vias or circuit interconnections between opposite sides of any given FPCB or between different sections of a continuous FPCB wherein each section defines its own coil or coil set.