# Re: Tesla turns ratio ?

```Subject:  Re: Tesla turns ratio ?
Date:  Fri, 13 Jun 1997 00:11:11 -0400
From:  "Owen Lawrence" <owen-at-iosphere-dot-net>
To:  "Tesla List" <tesla-at-pupman-dot-com>

> related to the ratio of primary to secondary turns! For the benefit
> of anyone who is not familiar with the derevation of the ratio of
> trasformation in a Tesla coil here it is:
>
>               E = .5 x C x V^2  :energy stored in a capacitor
>          Eprimary = Esecondary  :conservation of energy law
>
> combining the two equations gives;
>
>   .5 x Cprimary x Vprimary^2 = .5 x Csecondary x Vsecondary^2
>
> dividing both sides by .5 gives;
>
>        Cprimary x Vprimary^2 = Csecondary x Vsecondary^2
>
> Solving in terms of Vsecondary gives;
>
>                   Vsecondary = SQRT (Cprimary / Csecondary)

Thank you for your very clear explanation.  However, if CpVp^2 = CsVs^2,
then Vs = VpSQRT(Cp/Cs).

> Realize this is a theoretical maximum and many factors effect it such
> as resistive losses, dialectric losses, coronal leakage, ect.
> Examining the above equations should clearly show that ones goals are
> to make the secondary capacitance as small as possible while at the

Looking at these equations, it can't hurt to start out with a higher
primary voltage, either.  With a Cp to Cs ratio of 10000 every kilovolt
increase of input is another hundred kilovolts of output
(theoretically).

> small as is practical. I say practical because a one turn wide
> diaeter primary may give minimum inductance but it may not transfer
> all the primary energy to the secondary and using too large a primary

Now you've gone and said too much, because you make me think of a whole
bunch of questions:  How much power can theoretically be transferred to
the
secondary?  Can someone please explain exactly how the transfer takes
place, anyway?  With the large currents in the primary coil there is a
big
magnetic field.  This will induce currents in the secondary.  But there
is
also a large electric field about the primary conductor, too, isn't
there?
How does it affect the currents in the secondary?  Does the energy
driving
the secondary arrive like radio waves to the antenna of my TV (which
means
exactly WHAT? by the way) or does it arrive like a moving magnet next to
a
charge?  Since these fields must be spreading out from the primary coil
away from the secondary, I assume power is lost.  Is there any way to
shape
the fields in such a way as to focus them on the secondary coil
"target"?

Thanks for any and all responses.

- Owen -

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