[TCML] Runaway breakdown" for creating *really* long sparks

[johnbrooks@xxxxxxxxxxx]

4HV.org::Forums::High Voltage
"Runaway breakdown" for creating *really* long sparks

This was written 1973.Fascinating!
Merry Christmas To All

Joe in Texas


	

On Thu, 24 Dec 2009 12:20 -0600, "Steve Ward" <steve.ward@xxxxxxxxx>
wrote:
> Dex,
> 
> Perhaps this is because a single VTTC spark event is equivalent to a
> series
> of burst spark events at extremely high pulse rate and duty cycle.  Just
> as
> we suspect that the effect on spark growth vs burst rate reaches an
> ultimate
> limit, i think the pulse of a VTTC may very well define that limit.
> 
> I do know that with my SSTCs running long spark times (in the mS regime)
> the
> spark does not grow much at all (in length) after about 1-2mS, the next
> 5-6mS just make it appear "thicker" or "bushier" but not longer.
> 
> Thoughts?
> 
> I also did try running high pulse rates at low bang energy with my
> DRSSTC.
> I need to expand on my pulse rate capability (currently limited to
> 500pps)
> to see if even lower energies will grow long sparks at these rates.
> Eventually the line between a sequence of short pulses, or a CW coil
> thats
> interrupted, becomes blurred.
> 
> Steve
> 
> On Wed, Dec 16, 2009 at 1:24 PM, Dex Dexter <dexterlabs@xxxxxxxxxxx>
> wrote:
> 
> > Yes,but please explain me why VTTC sparks don't successively
> > extend in multiple pulses regime through a previously
> > ionized channel?Ionization of the previous channel is not
> > high enough or?I would say an average temperature of VTTC
> > channel is even higher than that of SGTC spark.
> >
> > Dex
> >
> >
> > --- jimlux@xxxxxxxxxxxxx wrote:
> >
> > From: jimlux <jimlux@xxxxxxxxxxxxx>
> > To: Tesla Coil Mailing List <tesla@xxxxxxxxxx>
> > Subject: Re: [TCML] Re:Pros and cons
> > Date: Tue, 15 Dec 2009 20:01:42 -0800
> >
> > Steve Ward wrote:
> > > Hi Dex,
> > >
> > > Glad you could chip in here a bit, i was having trouble finding any good
> > > references for coils with discharges much longer than the top voltage
> > would
> > > suggest.  More comments
> >
> > I suspect that most coils are in this category. at 30kV/cm, 200-300kV
> > (which is probably a typical topload voltage for a small NST coil) would
> > only support a spark of 7-10cm, and sparks much longer than that are
> > common.
> >
> > The difficulty is multifold:
> >
> > The field is very non-uniform, which tends to lead to longer sparks,
> > even in a single shot environment (Bazelyan and Raizer's book talks
> > about this a lot, in connection with EHV and UHV transmission systems
> > and switchgear)
> >
> > you have multiple pulses which can successively extend the spark through
> > a previously ionized channel.
> >
> > As an obvious indication of unusual behavior, a lot of coils have sparks
> > longer than the distance from topload to base, without arcing over the
> > secondary coilform.
> > _______________________________________________
> > Tesla mailing list
> > Tesla@xxxxxxxxxx
> > http://www.pupman.com/mailman/listinfo/tesla
> >
> >
> >
> >
> > _____________________________________________________________
> > Washington DC's Largest FREE Email service. ---> http://www.DCemail.com---> A Washington Online Community Member --->
> > http://www.DCpages.com
> > _______________________________________________
> > Tesla mailing list
> > Tesla@xxxxxxxxxx
> > http://www.pupman.com/mailman/listinfo/tesla
> >
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxx
> http://www.pupman.com/mailman/listinfo/tesla
-- 
  
  johnbrooks@xxxxxxxxxxx

-- 
http://www.fastmail.fm - The way an email service should be

_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla