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Re: Secondary internal arcing (fwd)



---------- Forwarded message ----------
Date: Wed, 12 Sep 2007 17:34:21 -0700
From: Barton B. Anderson <bartb@xxxxxxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: Secondary internal arcing (fwd)

Hi Nick,

Those small external rings won't do much. Robert had 20 times the 
creepage distance with his discs and he did like them (boy, haven't 
heard from him in a long time). In any event, it's my opinion that if 
coupling is tight enough to cause racing sparks on a secondary without 
creepage discs, then it's simply too tight - period. I don't use them 
and never found the need to. It does make for a cool looking secondary 
however.

Oh, the radius thing Aaron mentioned; I agree with that sort of. Tesla 
made mention of this but it was also in a completely different 
application. It's pretty simple. If the voltage gradient at any point on 
the secondary is large enough to cause corona and breakout, it will 
certainly try to do so on the secondary form and usually near the top 
(and then race directly downward all the way to the bottom). May even 
arc out to the primary periodically. However, this voltage gradient is 
also dependent on the topload shielding. If the topload is too high, 
this situation would be more prone. But if the topload is low/wide 
enough, even larger radius's than the secondary work very well without 
the racing spark events. Of course, you don't want to get it too low either.

On my little coil, I run a 6.25" radius on a 4.5" secondary. It see's a 
racing spark now and then also, but I could easily stop that with a 
little k adjustment (you could have done the same). Once we get going 
with sparks we just want to let it go. And then when it's over, it's 
tear down time. Par for the course I think.

Take care,
Bart



Tesla list wrote:

>---------- Forwarded message ----------
>Date: Tue, 11 Sep 2007 21:43:20 -0700
>From: seanick <edgarsbat@xxxxxxxxxxx>
>To: Tesla list <tesla@xxxxxxxxxx>
>Subject: Re: Secondary internal arcing (fwd)
>
>I can say from personal experience that a sealed baffle works great to 
>prevent internal arcing. After an internal arc developed in my current 
>secondary, once not long after I first made it, I put in a 4" spaced baffle 
>in the approx. center, covered with plexi and fiberglass, and it hasnt had 
>any trouble (internally) since.
>
>also, I can say that hot-gluing clear vinyl tube to the outside of the 
>secondary every foot or so does NOT prevent racing external arcs. take a 
>glance at this (from last saturday):
>http://picasaweb.google.com/calumet45/TeslaCoilSeptember8th2007/photo#5108069972092515458
>
>This is the one picture where I didn't have a breakout point on the topload.
>Aaron said something about the secondary being a smaller diameter than the 
>minor diameter of the toroid might make it look like a better breakout 
>point. Makes sense to me, but maybe he was joking, I don't know....
>
>anyway I promptly re-attached the breakout point (a drywall screw pushed 
>through the sticky side of a scrap of the metal tape) and resumed the 
>controlled arcing with no further trouble. check out the rest of the set 
>while you're at it. was a fun time, except for the rotor of my spark gap 
>catching fire from the epoxy repairs I put on it after a previous run....
>
>heheh
>-NICK
>
>ps. anyone want to sell/machine a new rotor?
>required specs in case anyone's interested:
>1/2" thick G10,
>9" dia,
>4x3/8" electrode holes spaced every 90 degrees at approx. 4" from center
>3/4" center hub
>:)
>
>
>
>----- Original Message ----- 
>From: "Tesla list" <tesla@xxxxxxxxxx>
>To: <tesla@xxxxxxxxxx>
>Sent: Sunday, September 09, 2007 10:54 AM
>Subject: Re: Secondary internal arcing (fwd)
>
>
>  
>
>>---------- Forwarded message ----------
>>Date: Sun, 9 Sep 2007 10:58:50 -0700
>>From: huil888 <huil888@xxxxxxxxxxxx>
>>To: Tesla list <tesla@xxxxxxxxxx>
>>Subject: Re: Secondary internal arcing (fwd)
>>
>>David -
>>
>>No, the function of a sealed baffle is slightly different from a creepage
>>disk.
>>
>>A properly sealed baffle is a solid wall of insulating material separating
>>two areas at different voltage potentials.
>>
>>A creepage disk is a piece of material placed between two areas at 
>>different
>>potential that increases the effective distance across which surface 
>>arcing
>>or tracking must take place. Therefore, when creepage disks are installed 
>>it
>>increases the voltage at which surface tracking begins to take place.
>>
>>Regards,
>>Scott Hanson
>>
>>
>>----- Original Message ----- 
>>From: "Tesla list" <tesla@xxxxxxxxxx>
>>To: <tesla@xxxxxxxxxx>
>>Sent: Sunday, September 09, 2007 9:29 AM
>>Subject: Re: Secondary internal arcing (fwd)
>>
>>
>>    
>>
>>>---------- Forwarded message ----------
>>>Date: Sun, 09 Sep 2007 04:20:34 +0000
>>>From: david baehr <dfb25@xxxxxxxxxxx>
>>>To: tesla@xxxxxxxxxx
>>>Subject: Re: Secondary internal arcing (fwd)
>>>
>>>
>>>Hmmm, these 'internal  baffles'  , could be called creepage  disks ?
>>>Why not use 'em on the outside of the coil also ?
>>>
>>>________________________________________________________________________________
>>>
>>>     From:  "Tesla list" <tesla@xxxxxxxxxx>
>>>     To:  tesla@xxxxxxxxxx
>>>     Subject:  Re: Secondary internal arcing (fwd)
>>>     Date:  Thu, 6 Sep 2007 22:01:11 -0600 (MDT)
>>>     >
>>>     >---------- Forwarded message ----------
>>>     >Date: Thu, 6 Sep 2007 22:57:28 -0500
>>>     >From: resonance <resonance@xxxxxxxxxxxx>
>>>     >To: Tesla list <tesla@xxxxxxxxxx>
>>>     >Subject: Re: Secondary internal arcing (fwd)
>>>     >
>>>     >
>>>     >
>>>     >Use two internal baffles of 1/4 inch clear acrylic sheet
>>>     (plexiglass) approx
>>>     >5-8 inches in from each end.  Use generous amounts of
>>>     silicone (GE Silicone
>>>     >II) to seal the baffles in place.
>>>     >
>>>     >Also, before winding, be sure to sand a PVC tube thoroughly
>>>     both inside and
>>>     >outside prior to applying --- again, both inside and outside
>>>     --- 3 generous
>>>     >coats of AC-43 or equivalent.
>>>     >
>>>     >With these treatments it should hold up for dozens of years.
>>>     >
>>>     >Dr. Resonance
>>>     >
>>>     >Resonance Research Corp.
>>>     >www.resonanceresearch.com
>>>     >
>>>     >
>>>     >----- Original Message -----
>>>     >From: "Tesla list" <tesla@xxxxxxxxxx>
>>>     >To: <tesla@xxxxxxxxxx>
>>>     >Sent: Thursday, September 06, 2007 10:22 PM
>>>     >Subject: Secondary internal arcing (fwd)
>>>     >
>>>     >
>>>     > >
>>>     > > ---------- Forwarded message ----------
>>>     > > Date: Thu, 06 Sep 2007 22:47:22 -0400
>>>     > > From: Rich Winders <rwinders_3@xxxxxxxxxxx>
>>>     > > To: tesla@xxxxxxxxxx
>>>     > > Subject: Secondary internal arcing
>>>     > >
>>>     > >
>>>     > > Okay quick question.
>>>     > >
>>>     > > I was having arcing inside my secondary. it is a white
>>>     pvc pipe 4In di and
>>>     > > wound
>>>     > > with 27 awg wire 16 inchs tall . From the what I could
>>>     tell from the arc
>>>     > > marks
>>>     > > they began (punctured) at the bottom or lv end of the
>>>     secondary and
>>>     > > traveled to
>>>     > > some where up my coil. i tried many differnt things to
>>>     decrease this
>>>     > > arcing.. ..
>>>     > > Increase coupling, varnish on the inside, and even
>>>     stuffing the coil with
>>>     > > bubble
>>>     > > wrap and sytrofoam nothing really seemed to work.. so i
>>>     bought 4 lbs of
>>>     > > wax and
>>>     > > melted it on my stove and poured the wax into the form of
>>>     my secondary and
>>>     > > let it
>>>     > > harden.. after running my coil i dont see any signs of
>>>     arcing, melted wax
>>>     > > or arc
>>>     > > marks.. or any kind of ozone or burnt smell. i was
>>>     wondering was i right
>>>     > > to go
>>>     > > with wax or should i have maybe filled with with a
>>>     transformer oil?
>>>     > >
>>>     > > Rich w
>>>     > >
>>>     > >
>>>     > >
>>>     > >
>>>     > >
>>>     > >
>>>     > >
>>>     >
>>>
>>> >_______________________________________________________________________________
>>>     ________
>>>     > >
>>>     > > Windows Live Hotmail. Even hotter than before Get a
>>>     better look now.
>>>     > >
>>>     > >
>>>     > >
>>>     >
>>>     >
>>>     >
>>>     >
>>>
>>>
>>>________________________________________________________________________________
>>>
>>>A place for moms to take a break!
>>>
>>>
>>>
>>>      
>>>
>
>
>
>
>
>
>  
>