Gapped-inductor foil windings with low AC and DC resistance

A new configuration for foil windings in gapped inductors reduces AC resistance while maintaining very low DC resistance. Thus, it is particularly valuable for current waveforms composed of a large DC component with high-frequency ripple. The new technique is applied to an example 50 μH inductor in which several different winding cross sections are compared. Finite-element simulations confirm that losses can be reduced by a factor of five relative to standard foil windings.