Gentlemen the reasons for my question are;
1. I am new at this so am trying to understand how these things work. They
are obviously complicated so getting into details is important.
2. In reading past post I remember some discussion on strike rings that
included some reference to open and closed loop rings but I was not clear
on the issue.
3. In the video of the damage to the secondary one of the captions
indicated an open loop strike ring so I wondered if there was any
significance to specifying that it was open loop. If no one runs closed
loop why say it was open?
Teddy
On Jul 6, 2018 5:22 PM, "Steve White" <steve.white1@xxxxxxxxx> wrote:
> If it is heating then it is absorbing energy. Heat takes energy to
> generate. A closed loop that is grounded would be just as effective as an
> open loop that is grounded but why would you even want to consider that
> unless this is just casual interest? It is simple enough to cut a gap in
> the ring.
>
> Steve
>
> ----- Original Message -----
> From: "Tedd Dillard" <tedd.dillard@xxxxxxxxx>
> To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
> Sent: Friday, July 6, 2018 8:16:04 AM
> Subject: Re: [TCML] Fixing secondary strikes Re: Bad strike to a 12 inch
> traditional coil (somewhat terminal)
>
> Carl thank you for your quick response.
> In a closed loop does the energy going in to heating the loop detrack from
> the energy going into the primary or is the heating the only issue?
> Is there any effect on the effectiveness of the loop to protect the primary
> if it is an open loop.
> Teddy
>
> On Jul 5, 2018 10:15 PM, "Carl Noggle" <cn8@xxxxxxx> wrote:
>
> Hey--
>
> A closed loop ring will act like a single shorted turn coupled to the
> primary. If it has a much bigger radius than the primary, it probably
> won't absorb too much power. But is it's close, it will absorb a lot of
> power just heating up the ring. Putting a small gap in the ring eliminates
> this problem.
>
> --- Carl
>
>
>
>
>
> On 7/5/2018 5:51 PM, Tedd Dillard wrote:
>
> > Gentlemen this may not be best place to ask this question but I noticed
> in
> > the vedio that it was an open loop strike ring. Comments on the
> difference
> > in an open loop vs closed loop strike ring please.
> > Teddy
> >
> > On Jul 5, 2018 1:31 PM, "Bert Hickman" <bert@xxxxxxxxxxxxxxxxxxxxx>
> wrote:
> >
> > Phil, Steve, and all,
> >>
> >> Sorry for the damage to your secondary, Phil. The videos were excellent
> >> and will hopefully lead to good discussion here and effective
> preventative
> >> measures for higher power systems.
> >>
> >> A thick coating of 2-part epoxy or polyester may accomplish a similar
> >> function as PMMA tubing at significantly lower cost. When uniformly
> >> coated,
> >> errant strikes to the secondary will "splash" outward across a
> relatively
> >> wide area of the outer surface of the coated secondary. The coating
> >> dissipates spark energy by spreading it out and capacitively conducting
> it
> >> to the secondary without creating damaging hot spots. In practice, I've
> >> seen hot primary-secondary flashovers that left NO permanent or visible
> >> effect on thickly-coated secondaries. These would have undoubtedly
> caused
> >> melting and turn-turn shorts on an unprotected secondary.
> >>
> >> Your system also has a comparatively large topload OD compared to
> primary
> >> OD. You may want to consider adding one or two additional,
> >> larger-diameter,
> >> strike rails to spread out the E-field "footprint" of the base. These
> will
> >> alter the E-field between the topload and base, making it more vertical
> >> (in
> >> the space between the two) helping to reduce strikes to the secondary.
> The
> >> larger strike rails could be an add-on that can be removed before
> >> transporting the coil, and they would would require any changes to your
> >> existing primary winding.
> >>
> >> You may also want to consider adding a smaller toroid under the top
> >> toroid. By elevating the top toroid, you'll increase the outward "throw"
> >> of
> >> sparks while further reducing hits to the strike rail. In the latest
> video
> >> there were a number of hits to the strike rail that came quite close to
> >> flashing over to the lower half of the secondary even at 100 BPS. The
> >> hotter 200 BPS strikes combined with thermal rise seems to have tipped
> the
> >> balance, unfortunately.
> >>
> >> Good luck and best wishes,
> >>
> >> Bert
> >>
> >>
> >> Steve White wrote:
> >>
> >> I have also had this idea for some time. I would love for somebody to
> try
> >>> this but even if it works I don't know if any of us could stand the
> >>> expense.
> >>>
> >>> Steve
> >>>
> >>> ----- Original Message -----
> >>> From: "Phillip Strauss via Tesla" <tesla@xxxxxxxxxx>
> >>> To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
> >>> Sent: Wednesday, July 4, 2018 4:02:13 PM
> >>> Subject: Re: [TCML] Fixing secondary strikes Re: Bad strike to a 12
> inch
> >>> traditional coil (somewhat terminal)
> >>>
> >>>
> >>>
> >>> Hello Jim,
> >>> Although very costly in the UK, I was considering a 350mm diam cast
> >>> acrylic 1 metre long tube (that's how it comes) with 5mm wall thickness
> >>> to
> >>> go over my 300mm (12") diam secondary, it would cover about the first
> two
> >>> thirds of the tube, a good few inches higher than the previous strikes.
> >>> Your comment on a dissipative tube caught my eye for that particular
> >>> reason
> >>> but I don't understand the concept of loading or that my idea would
> work,
> >>> any explanation and/or prediction would be much appreciated.I'm
> >>> contemplating your other suggestions (which are totally novel
> >>> <https://maps.google.com/?q=her+suggestions+(which+are+
> totally+novel&entry=gmail&source=g>
> >>> to me) with
> >>> interest.
> >>> Regards,Phillip.
> >>>
> >>>
> >>>
> >>> ____________________________________________________________
> >>> _________________
> >>>
> >>> 14 Broad Street, Stamford, Lincs PE9 1PG
> >>>
> >>> Tel: 01780 753008
> >>>
> >>> On Wednesday, 4 July 2018 21:26:39 BST, jimlux <
> >>> jimlux@xxxxxxxxxxxxx>
> >>> wrote:
> >>> On 7/4/18 11:40 AM, David Rieben wrote:
> >>>
> >>> Hi Phil,
> >>>>
> >>>> My deepest condolences for your loss. I know it's JUST a secondary
> coil,
> >>>> but as a fellow coiler, I most assuredly feel your pain. On the bright
> >>>> side, at least you did manage to capture some truly spectacular
> footage
> >>>> of this secondary coil mishap. I have had this happen on rare occasion
> >>>> with the operation of my big coil, though fortunately, none of my
> >>>> mishaps turned out quite that severe! Only once did I actually have to
> >>>> repair some damage to the side of my coil and was able to get it back
> >>>> into full functioning mode via the repair. Since I must operate mine
> >>>> outside, I did have one occasion where the wind actully "blew" one of
> >>>> the streamers back into the side of my secondary coil, too. Lesson
> >>>> learned - although refraining from outdoor operation during rainfall
> is
> >>>> an obvious good rule, non-starters in windy conditions are also well
> >>>> advised.
> >>>>
> >>>> I suppose this is a risk, that although may be small with a well-tuned
> >>>> and efficiently operating coil, is never completely absent. :^/
> >>>>
> >>>>
> >>>>
> >>> I wonder if we could figure out a way to segment a large coil
> >>> vertically, so if a segment gets damaged, you can just rewind that
> >>> segment. Just off the top of my head, I'm thinking about something like
> >>> segments with a hundred turns or so. Could we come up with a way of
> >>> making the connections in a "good" way. I'm almost thinking about how
> >>> you using field grading rings on a Van de Graaff. You don't want a
> >>> complete shorted turn, but you could terminate the winding in some sort
> >>> of flat terminal on the "mating face" of a segment. You'd stack the
> >>> segments, and then put some compression on it (threaded fiberglass
> rod?)
> >>>
> >>> The other idea that comes to mind is if there is some way to "spread"
> >>> the energy of the secondary strike.. Say your secondary were coated
> with
> >>> a resistive (but still conductive) coating. Would that spread the
> >>> current density enough to prevent burning through the insulation? Or a
> >>> dissipative tube covering the secondary - not enough to "load" the
> >>> secondary, but enough to "take the hit".
> >>>
> >>> OR, what about a second helix, space wound, that extends the length of
> >>> the secondary, with some suitable resistive conductor, so the voltage
> >>> profile matches that of the secondary (so no protective helix to
> >>> secondary arcs), but so it doesn't enter into the resonant circuit. The
> >>> protective helix would be mostly capacitively coupled to the secondary,
> >>> establishing the voltage.
> >>>
> >>> What about something like a helix wound with wire, but with small gaps
> >>> along the length.. the gaps don't break down normally, but if a
> streamer
> >>> strikes, the gaps break down and provide a conductive (but lossy) path
> >>> to the base.
> >>>
> >>>
> >>>
> >>>
> >>> _______________________________________________
> >>> Tesla mailing list
> >>> Tesla@xxxxxxxxxxxxxxxxxx
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> >>> _______________________________________________
> >>> Tesla mailing list
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> >>> Tesla mailing list
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> >>>
> >>>
> >>> _______________________________________________
> >> Tesla mailing list
> >> Tesla@xxxxxxxxxxxxxxxxxx
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> >>
> >> _______________________________________________
> > Tesla mailing list
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> >
> >
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