Re: formulas (fwd)

---------- Forwarded message ----------
Date: Mon, 13 Jul 98 12:04:17 EDT
From: Jim Monte <JDM95003-at-UCONNVM.UCONN.EDU>
To: tesla-at-pupman-dot-com
Subject: Re: formulas (fwd)


The formulas you gave are accurate, but not exact.  If you compute
the arc lentgh for the wire, you come up with a log term.  The
program I sent in an earlier post uses the exact formula and works
for soleniodal coils, pancakes, or anything between these, including a
straight piece of wire.

Jim Monte

>Date: Sun, 12 Jul 1998 21:56:24 -0700
>From: "Antonio Carlos M. de Queiroz" <acmq-at-compuland-dot-com.br>
>To: Tesla List <tesla-at-pupman-dot-com>
>Subject: Re: Formula's (fwd)
>Shaun wrote:
>> Also I can't remember how to find the length of a spiral. I also need
>> to find the length for the primary.
>Length of wire for a solenoid coil with n turns, radius r, and length m:
>Wire length=sqrt((n*2*pi*r)^2+m^2)
>Length of wire for a flat spiral coil with n turns, internal radius r1 and
>external radius r2:
>Wire length=sqrt((n*pi*(r1+r2))^2+(r2-r1)^2)
>All the distances consider the center of the wire. The second squared
>terms are usually negligible, but with them the expressions are exact.
>"sqrt" is square root, pi=3.1416.
>Antonio Carlos M. de Queiroz