Re: [TCML] tcml primary self c

["David Rieben" <drieben@xxxxxxxxxxx>]

Hi all,


Since I have not built a fully successful coil with a ribbon primary
coil, I'm probably jumping in out of line line here, but it seems to
me that a multiple turn ribbon primary coil wouldn't have as much
of a corona issue as would a SINGLE sharp ribbon edge, as the
neighboring ribbon windings should sort of electrostatically shield
each other, shouldn't they? Just like a rough surfaced large toroid
can still hold off breakput until some decent high potentials are
reached because of this effect.

I know for a fact that Cameron Prince runs his big coil with
a ribbon primary and he has had no issues, that I know of, with
excessive primary/ secondary corona. The only issue he had
with this original primary coil is that the ribbon would get really
hot during operation. This was due to the fact that it was that
bronze weather stripping. It was not very robust for pig power,
plus bronze is relatively poor conductor compared to pure cop-
per. Once he changed over to 3" wide pure copper ribbon, the
output improved and the new primary stayed much cooler during
operation.

David Rieben



----- Original Message ----- 
From: "DC Cox" <resonance@xxxxxxxxxxxx>
To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
Sent: Monday, July 28, 2008 8:44 PM
Subject: Re: [TCML] tcml primary self c


> No myth here --- I am sticking to the facts. Physics is physics and it
> doesn't change.
>
> If you look at some photos of Wysock's earlier coils using copper ribbon 
> you
> see a generous amount of corona off the sharp edges.
>
> I also experienced this in photos I shot.
>
> My advise is:  if you are running a coil with ribbon shoot your own photos
> and check for corona.  Make your own determination.  But, if you are
> designing from scratch, why not use good engineering practice in the first
> place?
>
> Anytime you run a coil at 200-400 kV (or more) and put a sharp edge near 
> the
> secondary (12-24" away), it will definitely produce corona.  Just do the
> physics or look at some electrostatic plots of ribbon coils and you will 
> see
> what I mean.
>
> I urge future coil builders to use copper tubing --- it's rounded edges 
> help
> retard corona.  A better solution than burying your head in the sand and
> pretend the corona doesn't exist.
>
> Dr. Resonance
>
> On Mon, Jul 28, 2008 at 6:39 PM, <dr.hankenstein@xxxxxxxxxxxxx> wrote:
>
> > I agree with Finn. Here is a long time exposure taken at 1600ASA of a 
> > small
> > coil with a flat ribbon primary:
> > http://www.audiotesla.org/images/Corona%20Experiment/DSC_0155.JPG  I 
> > don't
> > see any evidence of the ribbon causing corona worth worrying about. I am
> > using "high voltage buss" on my larger coil. The difference between high
> > voltage buss and low voltage buss is that the corners are rounded on the 
> > HV
> > buss to help reduce the effects of corona when the buss is in close
> > proximity of each other. Over 69kv the buss is usually round and the 
> > edges
> > are all smoothed down.
> >
> > Woo
> >
> >
> > > [Original Message]
> > > From: Finn Hammer <f-h@xxxx>
> > > To: Tesla Coil Mailing List <tesla@xxxxxxxxxx>
> > > Date: 7/28/2008 5:23:25 AM
> > > Subject: Re: [TCML] tcml primary self c
> > >
> > > DC Cox skrev:
> > > > After I saw all the corona in B&W asa 400 photos I shot with 4-8 sec
> > > > exposure time,
> > > Even posting this picture would not add much credit to your point of
> > > view. Pictures taken with the same film, and exposure times, of similar
> > > sized tubular coils excited by the same primary bang energy would have
> > > to be produced.
> > > Then a long term study of the effects on the secondary (Which I have
> > > already done) would also have to be produced
> > > >  I realized the sec coil would be slowly degraded using sharp
> > > > edged copper ribbon and quit this procedure.
> > > >
> > > Oh, so you _assumed_, in the stead of actually _observed_, that a
> > > degradation would take place.
> > >
> > > A lot of newbies are listening. Let`s stick to facts instead of adding
> > > to the list of coiling myths, shall we? Doc?
> > >
> > > Cheers, Finn Hammer
> > >
> > >
> > > _______________________________________________
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> > > Tesla@xxxxxxxxxxxxxx
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