Re: [TCML] inductance Vs diameter Vs height

[DC Cox <resonance@xxxxxxxxxxxx>]

It works out to 0.9.

I you build coils this way they will definitely flashover top to base.

Dr. Resonance





On Wed, Aug 11, 2010 at 12:34 PM, Phil Tuck <phil@xxxxxxxxxxx> wrote:

> Scott:
>
> I came across this post the other day while looking for something related:
>  http://www.pupman.com/listarchives/2009/Mar/msg00178.html
> I do not know if it is correct though !!
>
> Phil
>
> It says "The ABSOLUTE MAXIMUM Inductance from a given length of wire, the
> section should be circular and the with a ratio of a = 2.575r where a is the
> radius of the circular axis of the coil and r is the radius of the
> cross-section - eg a torus...
> The inductance is  L = 5.35 * PI * N² * a * 10-³ microhenries
> where N = total turns
>
> For a SINGLE LAYER coil (ie classic tesla coil) where the turns are close
> wound, the maximum inductance for a given wire length is:
> diameter/ breath = 2.415
> which is probably why tesla's magnifier was so fat and squat - maximum
> inductance and hence maximum coupling and energy transfer to the secondary
> before being fed to the extra coil...?
>
> For a FLAT CIRCULAR COIL - the lowest resistance - and hence max time
> constant/maximum inductance of a flat circular coil is is obtained when
> inner radius r1 is about 0.4 of the outer radius r2.
> This coil has 99% of the maximum efficiency when r1/r2 < 0.7.
>
> I have not verified these sizes and shapes and equations personally - but
> they should be easy enough to plot on a spreadsheet.. the best way to do
> this would be to have a constant turns per inch ration and this simplifies
> the terms need to plot. then the basic inductance equation adopts the form
> D²*Length with everything else being constant..... "
>
>
>  From: Scott Bogard
>  Sent: Tuesday, August 10, 2010 9:01 PM
>  To: Tesla Coil Mailing List
>  Subject: [TCML] inductance Vs diameter Vs height
>
>
>  Hey all,
>  Off the top of your heads can anybody tell me the most efficient
>  surface area to inductance ratio of single winding solenoids?  What I
>  mean is the most efficient surface area to volume ratio for cylinders is
>  1 to 1 diameter to height, I am wondering if this applies to inductors
>  also, or if a single turn of huge diameter is better, or perhaps zero
>  diameter and infinite turns or somewhere in between.  So for a given
>  wire length, what configuration yields the highest inductance for single
>  layer I guess is what I am asking, just curious and thought someone
>  might know a short answer, and have any thoughts as to if this could
>  apply to coiling in any way.
>
>  Scott Bogard.
>  _______________________________________________
>  Tesla mailing list
>  Tesla@xxxxxxxxxx
>  http://www.pupman.com/mailman/listinfo/tesla
> Regards
> Phil Tuck
>
> www.hvtesla.com
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxx
> http://www.pupman.com/mailman/listinfo/tesla
>
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla