litz

Litz wire is a type of electrical conductor designed to minimize the skin effect and proximity effect in alternating current. It consists of many thin insulated strands that are individually coated and then woven, braided, or twisted into a single conductor. The arrangement is chosen so that each strand occupies different positions along the cross-section, helping to equalize current distribution.

In construction, the strands are usually copper or aluminum with a thin enamel or polymer insulation. The strand diameters are much smaller than those of a solid wire, and the total number of strands can range from a few dozen to several hundred. The specific lay pattern—such as braided or interleaved configurations—helps reduce eddy currents within the conductor when exposed to AC fields.

Litz wire is used primarily to reduce AC resistance and heating in high-frequency applications. It is common in components such as inductors, transformers, and switching power supplies, where skin effect would otherwise concentrate current near the surface of a solid conductor. It is also found in some radio frequency coils and certain audio and telecommunications equipment.

Limitations include higher cost, greater complexity in manufacture, and physical size that may be larger than equivalent solid wires. The benefits are most pronounced when the skin depth is larger than the strand diameter; at very high frequencies, the advantage diminishes. Litz wire is typically specified by overall conductor diameter, the number and diameter of strands, insulation type, and intended frequency range.