Re: Tesla coil formula

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Shaun Epp <scepp@xxxxxxx>

The actual equation for Inductance that is written in physics books 
that I've seen is:

L = u N^2  A              which clearly shows that inductance is 
proportional to
     ------------           the the area of the coil (A), the number 
of turns squared (N),
            l                     and inversely proportional the the 
lenght of the seleniod (l)
                                  u = 4 PI 10^-7 (mu)

A = PI r^2                  r is radius of coil

so --- r N is approaximatly wire length, if you ignoring the length 
of the selenoid.
         wr^2 = (r N)^2 + l^2   is probably more accurate.

But your misssing PI in your equation too.

It just doesn't add up

Shaun Epp


----- Original Message ----- From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Monday, December 05, 2005 4:59 PM
Subject: Re: Tesla coil formula


> Original poster: Jared E Dwarshuis <jdwarshui@xxxxxxxxx>
>
> I'd like to respectfully suggest that that may be because you have
> to effectively introduce a fiddle factor by adding a specific amount
> of terminal capacitance to make it work (and what's worse, adjust
> that capacitance for a specific coil geometry). We have come full
> circle. Discovering that hidden factor in a plethora of wire length
> equations (all of which were sworn as gospel by their proponents)
> back in the eighties was where I began my investigations which led
> to my adopting the now popular L and C approach.
>
> Malcolm
>
> Hi: Malcolm
>
> For an air cored inductor, the inductance, as derived by Maxwell's
> equations can be written as:
>
> L = u ( wire length )Sqrd / (4pi l )
>
> Prominent is the wire length, a sadly neglected geometry.
>
>
> Jared Dwarshuis