Re: Practical limit to number of turns on primary ? ? ?

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Barton B. Anderson by way of Terry Fritz <teslalist-at-qwest-dot-net>" <classictesla-at-netzero-dot-com>

Hi Marc,

Even if the space charge is intense around the coil, and leaders are longer 
than normal, there is still something unique here to permit the efficiency 
of the coil discharge. Dave and Malcolm both have interesting quandry's 
about the coil. I am personally curious on the rate of change in efficiency 
with voltage and impedance. For example, if the coil was compared to a 
similar 1000 turn coil run through the same inputs, regardless of 
individual stats, did the change in efficiency with voltage remain constant 
or increase with the higher impedance coil. Would make an interesting graph 
to look at. Not asking you to jump and do this, but it might be a neat 
quick and easy observation to make sometime in the future (assuming it 
hasn't already been done).

I'll be waiting to see those "food for thought" images.

Take care,
Bart

Tesla list wrote:

>Original poster: "marc metlicka by way of Terry Fritz 
><teslalist-at-qwest-dot-net>" <mystuffs-at-orwell-dot-net>
>
>Bart,
>  I personally believe the extended length of the discharge is due to the
>space charging of the system itself. in the 120" strike to the aluminium
>ladder, the ladder itself glowed with a corona extending toward the
>discharge just before contact.
>  also, as i noted previously, our bodies themselves were charges to the
>point that after shut down we could touch a neon tube which would light
>for an inch or two?
>
>  yes i input 37kv into the primary capacitor, but the massive charge of
>the huge primary, secondary and topload charges the surrounding space
>immensely.
>
>  I have finally sorted out my web page problems so i will be adding some
>very interesting images for food for thought.
>
>  Thank you for the complement and i think more coilers should study
>pauls work. especially the voltage profiles along a given coil, this
>explains much on racing arcs.
>Take care and keep up the good work,
>Marc
>
>Tesla list wrote:
> >
> > Original poster: "Barton B. Anderson by way of Terry Fritz 
> <teslalist-at-qwest-dot-net>" <classictesla-at-netzero-dot-com>
> >
> > Marc buddy!,
> >
> > 2kva at 120"! All I can say is WOW!!  I knew this coil was running 90" at
> > one time, but never would I have expected spark lengths at 120"! Is this a
> > record of sorts? This is typically a 75" to 80" spark length on a good
> > running coil. You know, your coil has some unique characteristics as Paul
> > as modeled with available data (mm3p). There are quite a few differences
> > your coil exhibits beyond the norm. I truly like the way you've gone out
> > there with this coil.
> >
> > You know, I still have yet to open up ba0 to see what it can throw out (as
> > it's a rather high turn coil and low Fres for it's size). I've been firing
> > it up all week and it's running sweet right now. The only thing I've
> > changed since those models is pounding an 8 ft rf-rod in the middle of the
> > garage directly below the coil (drilled through cement, pounded, sealed),
> > but everything else is unchanged. As soon as the weather dry's up, I'll
> > roll it out in the backyard and let it go (think I saw a minute or two of
> > sun today).
> >
> > The "myths" as stated have to be used in context. For example, your firing
> > voltage is up around 34kV and near 30j bang energy, very high top volts,
> > low freq (38.4kHz), and many other values that are outside the typical
> > coil. I think too often, turns and their performance are stated without
> > stating the other parameters for what makes those statements true, and it
> > then quickly becomes a global thought based on many coils that really
> > aren't that different. Obviously, one can go outside the "norm" and do
> > better. Great job with this coil. A true pioneering development of which
> > I'm very happy Paul has been able to get measurements and models on from
> > time to time.
> >
> > Take care,
> > Bart
> >
> > Tesla list wrote:
> >
> > >Original poster: "marc metlicka by way of Terry Fritz
> > ><teslalist-at-qwest-dot-net>" <mystuffs-at-orwell-dot-net>
> > >
> > >
> > >
> > >Tesla list wrote:
> > > >
> > > > Original poster: "by way of Terry Fritz <teslalist-at-qwest-dot-net>"
> > > <FutureT-at-aol-dot-com>
> > > >
> > > > In a message dated 1/27/03 1:34:26 AM Eastern Standard Time,
> > > > tesla-at-pupman-dot-com writes:
> > > >
> > > > Steve, all,
> > > >
> > > > I've found the best efficiency when using a rather large number
> > > > of primary turns on a small coil.  For example my old research
> > > > coil used about 18 to 22 turns, and gave 42" sparks from a normal
> > > > 12/30 NST.  By using a lot of primary turns, the surge impedance
> > > > is raised, and the gap losses are reduced as a result.  Also, coils
> > > > with a lot of primary turns probably also have a lot of secondary
> > > > turns, and this tends to result in a coil which operates at a low
> > > > frequency.  There is evidence that a lower frequency is effective
> > > > in producing longer sparks also.  Using a lot of turns may be less
> > > > important in larger coils which tend to have high surge impedances,
> > > > and lower frequencies even when using fewer turns, but this seems
> > > > to be unknown at this time.  Of course if too many turns are used
> > > > on any coil, it will increase the wire losses due to the high 
> resistance
> > > > of the thin wire, and the losses will increase too much.  I discuss
> > > > these issues at my website
> > > > at:
> > > >
> > > 
> <http://hometown.aol-dot-com/futuret/page3.html>http://hometown.aol-dot-com/futuret/page3.html 
>
> > >
> > > > click on the link for "efficiency theory".
> > >
> > >
> > >  I'm not sure this is the case here? when i built the 3000 turn coil it
> > >uses 24 turns of 1/8" inch primary, the 3' wide primary form assures
> > >coupling to the top of the 42" coil. I'm very impressed with the 2kva
> > >120" discharges compared with the 4' discharges of a 4"-1300 turn coil
> > >placed on the same psu. Also with using many turns of wire will
> > >distribute sharp voltage grandaunt lows over a much broader area, thus
> > >cutting down on mid coil breakout.
> > >  The whole myth of the 1200-1800 turns being optimal only show that not
> > >many coilers are willing to try more!
> > >  With a 6000 turn secondary combined with, a proper primary
> > >construction, could very well surpass my ten footers at 2kva.
> > >
> > >By the way, i have never felt secondary heating along the coils.
> > >
> > >http://members.fortunecity-dot-com/marcmet/index.htm
> > >
> > >Marc M.
> > > >
> > >
> > >
> > >
>
>
>