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Inductance, h/d ratio
Subject: Re: Toroid Question (fwd)
Date: Sat, 3 May 1997 17:28:46 +0500
From: "Alfred A. Skrocki" <alfred.skrocki-at-cybernetworking-dot-com>
To: Tesla List <tesla-at-pupman-dot-com>
On Fri, 2 May 1997 18:53:30 +1200 Malcolm Watts
<MALCOLM-at-directorate.wnp.ac.nz> wrote;
> Hi Alfred, all,
> I wrote a program to calculate the optimum former h/d
> ratio for a given length of wire. Method: start with a length of wire
> and h/d = 50, then increase d as l is decreased. The answer the
> program gave me was just under 0.5. Not great for coiling except with
> a gigantic coil because of the height. Not the same as maximum Q
> (without terminal) either. That turned out to be h/d=1, confirmed by
> measurement.
What were you using as your determinant of optimum? I remember back
in college that the largest inductance for a given length of wire was
something close to a h/d ratio of 3. It's not talked about in modern
text but if you have access to the older radio enginering handbooks
say from 1910 through 1950 I'm sure you will see it's close to 3 .
Sincerely
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Alfred A. Skrocki
alfred.skrocki-at-cybernetworking-dot-com
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