Re: [TCML] First (or maybe 2nd) light on my medium-sized SG coil, PT current rating?

["DC Cox" <resonance@xxxxxxxxxxxx>]

Dave:

Try running two separate 120 VAC circuits using separate ballasts on each
120 vac circuit.  They you can set the current draw at 16 Amps on each
circuit, have 32 Amps total on the PT primary, even run your gap blower fan
or rsg off one of the 20 vac lines, and never trip your 120 vac circuit.  I
also do this with MOTs and it works great!

Dr. Resonance




On Tue, Apr 15, 2008 at 10:21 AM, David Rieben <drieben@xxxxxxxxxxx> wrote:

> Hi Jim,
>
> My PT is just a regular run-of-the-mill 1.5 kVA rated (@ 30*C)
> 120:1 GE potential transformer. However, I have found PTs to
> be VERY conservatively rated since they are rated to put out
> their rated VA output with essentially zero voltage drop. After
> all, they are designed for metering a known fraction of primary
> line voltage so voltage accuracy is important. For this reason,
> most PTs can put out several times more VAs than their name-
> plate rating suggests. Of course my PT is made for 120 volt
> input, unlike your monster 5 kVA unit with a 240 volt input.
> Turth be told, you could probably run up to 20 kVA+ through
> that 5 kVA PT of yours if you kept the uninterrupted  run times
> within reason! BTW, if you want to go even bigger on the
> transformer, why not just upgrade to a pole pig as they usually
> run much cheaper than equivalent sized PT combos?
>
> With that being said, my PT is running fine but I am finding it dif-
> ficult to "hold the reins" on it to keep the current draw within the
> limits of a standard 20 amp line service. I suppose running with
> 2 paralleled MOTs with their secondaries shorted as a ballast
> is what's taxing the electric service. You have to remember too
> that I have done gotten spoiled to the 12 to 14 ft. super bright
> discharges of my Green Monster coil running of up to 90 amps
> at 240 volts input and fired with a pole pig. I took on this project
> to have a coil that I could run off a standard 120 volt service
> but I still want to get all of the "bang for my buck" that I can
> muster ;^) I am already getting 50 to 60" arcs with the variac
> only set at about 50 to 60 on the dial but if I try to roll it outside
> and push it further, it will pretty quickly trip the 20 amp panel
> breaker. That's why I was wondering about how much PFCs
> would help to hold down the current draw. I suppose that I could
> also cut back to one MOT and then be able to turn my variac knob
> up higher.
>
> I also think that my .08 uFd primary C along with a relatively
> monsterous 6 x 30 top-load is also really sucking the amps for
> a standard 120 volt service :^) It seems that a 6" coil is about
> at the size limit for firing at its full potetntial from a standard 120
> volt, 20 amp electrical service.
>
> --
> David Rieben
>
>
>
> -------------- Original message --------------
> From: "Jim Mora" <wavetuner@xxxxxxxxx>
>
> > Hi David,
> >
> > -----Original Message-----
> > Hello David,
> >
> > What is the current output of the PT? I have a 5KVA GE that I am
> planning on
> > running on my 8" coil also wound with #22 to 35.5" so your results are
> > interesting to me! I plan to use a smaller sat reactor and a combo
> static
> > and dc motor rotary gap. This PT runs on 240v. I wish I had two of em!
> >
> > Jim Mora
> >
> > From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On
> Behalf
> > Of David Rieben
> > Sent: Monday, April 14, 2008 5:25 PM
> > To: Tesla list
> > Subject: [TCML] First (or maybe 2nd) light on my medium-sized SG coil
> >
> > Hi all,
> >
> > I have finally gotten my mid-sized SG coil project up and running
> > A quick rough-up of the specs are about 28" of #22 AWG magnet
> > wire wound on a 6" ID (6.5" OD) white PVC pipe for the secondary
> > coil. The primary is 11 turns of 3/8" copper tubing wound in the
> > classic Archemdian spiral with between 3/8" and 1/2" spacing be-
> > tween each turn and the outermost turn has about a 12.5" radius
> > (25"diameter). After initial tuning, the primary has been tapped at
> > approx. 8 3/4 turns. The transformer is a 120:1 GE potential trans-
> > former (14,400 volt output).
> >
> > _______________________________________________
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