RE: the cure for racing sparks

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

Original poster: "Steven Ward by way of Terry Fritz <twftesla-at-qwest-dot-net>" <srward16-at-hotmail-dot-com>

I think ive already confused you Gary.  What i meant is that the extra layer 
of polyurethane PREVENTED the arcs from jumping down the entire lenght of 
the coil.  Im sorry if i ruined any breakthrough that you thought i might 
have seen with my coil and DC build up.  Although i may note that there 
SEEMED to be LESS static buildup on the coil after the run was over.  I 
didnt get any of the usual zaps that i normally get.  Maybe the extra 
insulation stopped me from getting the normal zaps, i cant really say.  But 
its ineresting that when the coil was not coated at all, i had the sparks 
inside and out of the secondary, and no static build up.  Then i sprayed it 
with layers of acrylic spray.  Then i only got the racing sparks on the 
outside, but more static charge afterward.  Now with a thick later of poly 
on the coil, ive gotten rid of the racing sparks, and can not DETECT any DC 
build up(yet it may be inside the insulation).  I will run the coil again to 
confirm the last situation i wrote(no build up).

Steve Ward.



>From: "Tesla list" <tesla-at-pupman-dot-com>
>To: tesla-at-pupman-dot-com
>Subject: RE: the cure for racing sparks
>Date: Thu, 11 Jul 2002 12:04:08 -0600
>
>Original poster: "Lau, Gary by way of Terry Fritz <twftesla-at-qwest-dot-net>" 
><Gary.Lau-at-hp-dot-com>
>
>Are you saying that by adding only the polyurethane coating to your
>secondary and changing NOTHING else, this increased the tendency to develop
>racing arcs?  The DC (static) charge that accumulates on the secondary
>surface has long been suspected of being a factor in the creation of this
>nasty phenomenon, but I don't think there's ever been a controlled
>experiment changing only the secondary coating to investigate this.
>
>Regards, Gary
>
>  -----Original Message-----
>From: 	Tesla list [mailto:tesla-at-pupman-dot-com]
>Sent:	Thursday, July 11, 2002 10:03 AM
>To:	tesla-at-pupman-dot-com
>Subject:	Re: the cure for racing sparks
>
>Original poster: "Steven Ward by way of Terry Fritz <twftesla-at-qwest-dot-net>"
><srward16-at-hotmail-dot-com>
>
>Hi Doc,
>
>Im not positive that you understand all of the circumstances.  Im using the
>9 turns with the extra inductor, but i need such a small extra inductance
>the just running wire to the inductor and back brings it in tune(no extra
>turns added).  So this would suggest that i only need to add at most 1 more
>turn to bring it into tune.  So does the primary still seem to be the
>culprit??  There is a tad roughness on the base of the sphere, but the
>sparks that jump down do not appear to come from the sphere, but the last
>few turns on top, and travel all the way down the coil.
>
>But you know what, i just realised that the last time i ran it, it didnt
>have any problems for a good few minute runs.  GEEZE!  ive been so busy
>lately that i totally forgot that i added a layer of polyurethane, and ran
>the coil again!!!  I dont even know why i wrote the above paragraph!!  The
>mind is a strange thing (especially mine lately).  I suppose the above
>paragraph may hold since im not sure how long my quick fix may last, and i
>may run into the same problems.  Sorry to anyone i confused with this
>email!!
>
>Steve Ward
>
>
> >From: "Tesla list" <tesla-at-pupman-dot-com>
> >To: tesla-at-pupman-dot-com
> >Subject: the cure for racing sparks
> >Date: Wed, 10 Jul 2002 19:30:51 -0600
> >
> >Original poster: "D.C. Cox by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> ><DR.RESONANCE-at-next-wave-dot-net>
> >
> >
> >
> >Steve:
> >
> >Two things come to mind.  First, racing sparks are usually caused by 
>either
> >too small a toroid on top which provides ineffective electostatic field
> >control down the coil and second, the usual culprit, not enough available
> >inductance in the primary (too few turns) to hit the proper tuning point.
> >You are tuning at the wrong primary resonance point.
> >
> >A 12 inch sphere is adequate, but keep it as close to the winding as
> >possible, ie, no more than 1/4-1/2 inch away.
> >
> >A second note is that you may be "overcoupled" which causes the
> >"double-hump" on the freq, ie, splitting the res. freq. into two 
>different
> >freqs which beat against each other.  Try elevating your sec. coil. or
> >moving your primary further out.  With this size coil we get 28 inch 
>sparks
> >(our model M-20).  The sec. is elevated 1 full inch above the primary 
>coils
> >horizontal plane and the pri to sec coilform spacing is also 1 inch.
> >
> >The first thing to do is get rid of your present primary and set up some
> >scrap 12 AWG house wiring on cardboard (cut slits for the wire).  Set up
> >this test with about 30 turns and adjust tuning with variac at 30 % and
> >your
> >spark gap set close together.  In many cases the racing sparks are caused
> >because you simply do not have enough available primary turns to find the
> >tuning point.  After tuning carefully with scrap wire you will find the
> >correct tuning point and then it's time to replace it with your beautiful
> >primary.
> >
> >I would be willing to bet when you do this you will hit the proper tunig
> >point and then the racing sparks will go away totally.  Remember, they 
>only
> >occur when you are grossly out of tune.
> >
> >Dr. Resonance
> >
> >
> >
> >
> >----- Original Message -----
> >From: "Tesla list" <tesla-at-pupman-dot-com>
> >To: <tesla-at-pupman-dot-com>
> >Sent: Tuesday, July 09, 2002 12:18 PM
> >Subject: sparks along secondary
> >
> >
> > > Original poster: "Steven Ward by way of Terry Fritz
> ><twftesla-at-qwest-dot-net>"
> ><srward16-at-hotmail-dot-com>
> > >
> > > Hi everybody
> > >
> > > Does anyone know how to cure those pesky arcs that travel over the
> >entire
> > > length of the secondary coil??  Ive coated my coil several times with
> > > acrylic spray, and its helped a little.  My problem is that i use a
> >sphere
> > > (12" diameter) because its the coolest damn thing ive ever used for a
> > > topload!  My coil is powered with a 12000v 40ma(modified) NST.  My cap
> >is
> >a
> > > GE bank for a total of .0136uf at 30000vdc.  I have a 9 gap static gap
> >with
> > > a blower.  A 9 turn flat spiral primary(12" outer diameter) and an off
> >axis
> > > tuning inductor.  My secondary is wound on some kind of HDPE (i think)
> >tube
> > > that is only about 1/32" thick(low losses!).  Its 3" in diameter, and
> >wound
> > > 14" with some 28g magnet wire.  Atop sits a 12" sphere about .5" from
> >the
> > > windidng.  At times the arcs reach about 30" or so!  This sphere has 
>the
> > > coolest breakouts ive seen yet.  It takes a few seconds, then 
>WHAMMM!!!
> >a
> > > huge 28" arc will jump out into the air.  But lately ive been
> >experimenting
> > > and it seems that it likes to just jump down the side of the secondary
> >coil
> > > if it cant breakout of the sphere.  Anyone know how to fix this??  
>Would
> > > putting plexiglass discs around the coil help??  Ive seen this on big
> >coils
> > > but not on anything my size.  Any thoughts are welcome,
> > >
> > > Thanks,
> > >
> > > Steve Ward.
> > >
> > >