[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Fw: Tesla coil formula -- oops correction



Original poster: Shaun Epp <scepp@xxxxxxx>

Oops I made a error on my first post,  Here's the correction

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
            l                      (A), the number of  turns squared (N),
                                  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 --- 2 pi r N is approaximatly wire length, if you ignoring the length of the
                       selenoid.

(wire length)^2 = (2 pi r N)^2 + l^2   is probably more accurate.

Your equation works, but It wasn't designed to show that wire length was proportional to resonance. A person could stuff anything into an equation if they divide out what doesn't belong. (4 pi)

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