Use the links below to view specifications, and to generate a product request. Description of Film Insulatations Description of Fiber Serve Insulations Round Litz-Type 1 Round Litz-Type 2 Round Litz-Type 3 Round Litz-Type 4 Round Litz-Type 5 Round Litz-Type 6 Braided Litz-Type 7 Rect. Litz-Type 8 Rectangular Litz Back to Litz Back to Products Product Request

Litz Cable Design

The word litz is derived from the German word "Litzendraht", and refers to constructions consisting of a number of separately insulated strands woven or bunched together, so that each strand tends to take all possible positions in the cross-section of the entire conductor. The reason for this random bunching of conductors is to reduce losses caused by the tendency of currents to flow only on the outside surface of wires at high frequency, which is known as "skin effect losses".

Litz cable is primarily used in resonant circuits where high efficiency is required. Efficiency of a coil or transformer is designated as "Q", which is expressed as the ratio XL/R where XL equals 2 P FL (F equals operating frequency and L equals inductance at that frequency) and R equals effective resistance.

In considering the above ratio XL/R, it is obvious that for any given conductor R should be minimal, and therefore the ideal "Q" would be infinity. Typical values of "Q" however, range from ten for certain air core coils to five hundred or over for toroidal coils using litz wire and ferrite cores.

The following outline briefly describes design and construction techniques for various litz conductors.

1. Required information from customer:
   
   
   1. Operating frequency.
   2. Current carrying capacity and operating voltage required.
   3. Environment in which cable will be used and insulation required (both single end wire and overall).
   4. Maximum overall diameter and bending radius.
      
      
2. Determine wire size to use from the following table:

3. Current carrying capacity should be based on one thousand circular mils per amp for minimum heating of the conductor. If space is a factor and some heating of the conductor is permissable, eight hundred circular mils per amp can be used.
   
   
   1. Voltage is sometimes important, especially if the litz cable is being used in a resonant circuit where one end of the coil would be much higher potential than the other end, and therefore would have a large voltage gradient between turns. Servings such as nylon, cotton, silk, etc., only provide insulation values equivalent to the same spacing in free air. If greater insulation values are required, a taped or extruded jacket can be provided in accordance with the customers specifications.

The formula for computing number of single end wires required for a given cable size is as follows: