Re: first non NST coil questions

["Tesla list" <tesla@xxxxxxxxxx>]

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

Gerry,

O yea, it IS quite a resistor! It is coiled up nichrome type resistance
ribbon that's about 3/8" wide and around 1/16" thick and wound
probably some 50 to 75 turns around a 14" long ceramic rod core.
Definitely a POWER resistor. I used 2 fans blowing directly across
the ribbon and they still develop a cherry red glow when pullling
this kind of power. It also doubles as a nice shop heater on cold
winter days ;^)

David

----- Original Message -----
From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Monday, March 26, 2007 8:19 PM
Subject: Re: first non NST coil questions


> Original poster: "Gerry  Reynolds" <gerryreynolds@xxxxxxxxxxxxx>
>
> Hi David,
>
> That must be quite a resister.  I^2R = 7000watts.  I must be missing
something.
>
> Gerry R
>
> >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"
> > > > >  >
> > > > >  >
> > > > >
> > > >
> > > >
> > >
> > >
> > >
> > >
> >
> >
>
>
>
>