by Dennis Feucht, Innovatia Laboratories, Cayo, Belize, How2Power Today, Jul 15 2020
Focus:
In power supply magnetics, one of the limitations on winding efficiency is the packing
factor, kp, the fraction of winding area that is conductor. Ideally the conductive
part of a winding—the copper or aluminum part of the wire turns—would completely fill
the area allotted to a particular winding, and the current and power density would
then be maximum. However, gaps between round wires result in areas not conducting
current. This article proposes a way to reduce gaps and thus increase the winding fill
factor, kf by filling these gaps with smaller wires. After reviewing the various
packing factor components that quantify winding density, the article analyzes how to
determine the optimum wire size for the smaller wire in square-layered and hexagonal-
layered winding configurations. It also determines the improvement in fill factor
obtained in each case, and assesses the relative benefit of adding the extra wire in
one winding configuration versus the other.
What you’ll learn:
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