[Lowfer] Litz Wire Resistivity

Sat, 23 Nov 2002 11:28:06 -0700

Lyle,
    Thank you.  I managed to find the web page that I had previously lost,
and then went digging for Sullivan's papers.  The NEEWC page URL that you
provided has exactly what I was looking for.

Chris

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----- Original Message -----
From: "Lyle Koehler" <[email protected]>
To: <[email protected]>
Sent: Saturday, November 23, 2002 9:41 AM
Subject: Re: [Lowfer] Litz Wire Resistivity


> The New England Wire and Cable Company has apparently changed its name to
> New England Electric Wire. Their Litz wire information page is at
> http://www.neewc.com/litz/litz.htm
>
> The formulas they give on the succeeding pages may be correct, but I think
> they screwed up their arithmetic someplace in the following example, which
> was for 450 strands of #40 wire at 100 kHz:
>
> "The A.C. resistance is, therefore, 1.0344 x 2.70 or 2.79 ohms/1000 ft.
>
> The value of Litz can easily be seen if the above example is compared with
a
> solid round wire with equivalent cross sectional area, 65.8 mils in
> diameter. Using the same operating parameters, the D.C. resistance is
2.395
> ohms/1000 ft. However, the A.C./D.C. ratio increases to approximately 21.4
> making the A.C. resistance 51.3 ohms/1000 ft."
>
> This says that Litz wire has 18 times less resistance than a solid wire of
> the same cross section. I seem to recall that when I went through the
> arithmetic, the actual advantage was somewhere around 2 or 3 to 1. And be
> prepared for sticker shock if you can't find Litz wire on the surplus
market
> and have to order a batch of it!
>
> Lyle, K0LR
>
>
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