Re: first non NST coil questions

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "David Rieben" <drieben@xxxxxxxxxxxxxxx>

Hi Scot,

My rotary gap uses 3/8" diameter x 1.75 long solid tungsten flying
electrodes and (2) 1/2" diameter x 3" long solid tungsten stationary
electrodes, so that would probably explain why I can run more cur-
rent before quenching begins to fail. However, even with my "beefy"
electrodes, I still found that I needed to commutate the arc by series-
ing the rotary gap with a forced-air cooled RQ style gap when I started
pushing around 75 to 80 amps! I also needed to add a .7 ohm power
resistor in series with my "humungus" 232 lb. inductive ballast, which
would allow over 110 amps of current draw with the variac dial at 90!
My rotary gap would start "popping" with the purplish-yellow "halo"
around the blue-white plasma core and the output would start
"missing" with the "pops". That's how I could tell that my quneching
was beginning to fail. Even with the resistive ballast and the seriesed
RQ gap, my rotary gap can only handle about a 90 to 100 amp draw
before the quenching starts to fail and the tell-tale popping and missing
begins. The added resistance helps to keep the current draw down
to sane levels with the variac turned up to max.

David


----- Original Message -----
From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Saturday, March 24, 2007 8:53 PM
Subject: Re: first non NST coil questions


> Original poster: BunnyKiller <bunnikillr@xxxxxxx>
>
> When I was running my BIGPIG coil on forced air gap, I began having
> quenching problems at about 40 amps draw on a 240 line feed...ehhh
> approximately 9.5 - 10 kVA. The gap was 2 @ 1/4" dia. tungsten
> electrodes inside a 2" PVC pipe driven by my 1.5 HP shop vac...(
> yupperz the industrial sized unit)  the arc would extend about 2"
> beyond the electrodes. Once I started pushing the pig beyond 40 amps,
> the streamers would get shorter and erratic in output. I switched
> over to a rotory gap and still need something better....   the arc
> will jump to the electrodes and follow them for about an inch pre,
> during and post direct line up. Having it run like this extends my
> active arc time quite a bit...  but Im getting 10 - 15 foot streamers
> depending on weather moon phase if the tree is leafy or not...  :)
>
> Scot D
>
>
>
> Tesla list wrote:
>
> >Original poster: "David Rieben" <drieben@xxxxxxxxxxxxxxx>
> >
> >Hi Justin, all,
> >
> >I'm not sure what the "magic number" is to where
> >the power levels become too great for forced air
> >cooling alone to adequately quench a spark gap.
> >However, I do think that there comes a point to where
> >it's more practical and economical to just upgrade to
> >a quality rotary gap than to employ the draconian mea-
> >sures that would be required to properly quench an
> >air cooled stationary gap system. IIRC, Richard Hull
> >used to state that anything over 3 kVA required a
> >rotary gap but I think there are a few coilers that have
> >built successful RQ style gaps running power levels
> >up to 5 or 6 kVA. IMHO, with really large coils (>
> >10 kVA) it is sometimes necessary to use a combi-
> >nation of rotary and air cooled stationary gaps in series
> >to help commutate the generated heat. That's what I do
> >with my Green Monster that runs as high as 15 to 20
> >kVA power levels and Cameron Prince also does this
> >with his large coil.
> >
> >http://www.teslauniverse.com/members/drieben/
> >http://www.teslauniverse.com/gallery/v/coils/polepig/
> >
> >My $.02,
> >David
> >
> >
> >----- Original Message -----
> >From: "Tesla list" <tesla@xxxxxxxxxx>
> >To: <tesla@xxxxxxxxxx>
> >Sent: Thursday, March 22, 2007 10:05 PM
> >Subject: Re: first non NST coil questions
> >
> >
> > > Original poster: Justin <rocketfuel@xxxxxxxxxxxxx>
> > >
> > >
> > > Hi Jared,
> > >
> > > What do you mean by high power levels?  A friend in town showed me his
> > > design which he claimed could withstand 5kVA pretty well.
> > >
> > >
> > > Justin
> > >
> > >
> > >  > Original poster: "Jared Dwarshuis" <jdwarshuis@xxxxxxxxx>
> > >  >
> > >  > Hi: Justin
> > >  >
> > >  > It is nearly impossible to get high power levels to quench with a
> >sucker
> > >  > gap.
> > >  >
> > >  >
> > >  > Sincerely: Jared Dwarshuis
> > >  >
> > >  > "If Tesla coils are outlawed, only outlaws will have Tesla coils"
> > >  > "They will get my pole pig when they pry it from my cold dead
fingers"
> > >  >
> > >  >
> > >
> >
> >
>
>
>
>