Re: Tesla turns ratio ?

Subject:  Re: Tesla turns ratio ?
  Date:   Sun, 15 Jun 1997 07:33:32 +0500
  From:   "Alfred A. Skrocki" <alfred.skrocki-at-cybernetworking-dot-com>
    To:   Tesla List <tesla-at-pupman-dot-com>

On Fri, 13 Jun 1997 00:11:11 -0400 Owen Lawrence
<owen-at-iosphere-dot-net> wrote;

> > 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).

YES, I goofed on the origional post! I sent out a correction but it 
was too late!

> > 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).

Yes, there are any ways to increase the output of a Tesla coil;
increase the primary voltage, increase the primary capacitance, 
decrease the primary inductance, increase the secondary inductance 
and decrease the secondary capacitance. But realize you can only go 
so far with any of these changes on a given coil and then you hit a 
point of deminishing returns. 

> > 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:

Well, then I'm doing a good job!

> How much power can theoretically be transferred to  the  secondary?

That is something to still be determined.

> 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?

Again this is an area that has not recieved much theoretical or 
practical treatement! We do know that energy is transfered from the 
primary to the secondary by the primarys fluctuating magnetic field 
cutting through the turns of the secondary but that can't be the only
thing going on or else a Tesla coil would follow the turns ratio 
which it does not! It is also known that resonators spaced far abart 
will respond to their resonant frequency so there is a strong 
possibility that energy is ariving at the secondary from the primary 
in the same way radio waves are propigated. Tesla himself got into a 
lot of theorization on this matter and came up with terms like 
longitudinal waves. There is a sizable aount of discusson on 
longitudinal waves but it is difficult to seperate the B.S. from the 
facts, since this seems to be a favorite with the fringe groups and 
their claims of faster than light transission, ect.

> 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"?

Probably, one could use one of the ferrites to concentrate the fields 
close to the secondary and probably increase the efficiency BUT then 
core saturation could occur and we would now have to contend with 
historesis losses as well. Dr.Resonance sited a nuber of references 
for you that are good starting points to answers to all these
questions and their worth while investigating.


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                           Alfred A. Skrocki
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