Re: BIG coil project

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Original poster: "Dr. Resonance" <resonance@xxxxxxxxxx>




Dave:

Our Big Bruiser design is similar to the coil you are proposing.  The only
difference is our 24 inch dia. sec coil.  We used 0.3 uFd with a 9 turn
primary.  We will run at 220 VAC @ 120 Amps (our main breaker rated at 125
Amps).  We plan on trying 0.4 uFd next summer.

Your coil should run better with 0.2 uFd with the available power you have,
but with less wire length, you could get away with 0.1 uFd.  If you have the
extra cap, use it.  Do an O-scope/sig gen tuning to see which value works
best.  You might get down to 4-5 turns with the 0.2 uFd cap.

Dr. Resonance

Resonance Research Corporation
E11870 Shadylane Rd.
Baraboo   WI   53913


>
> I'm starting to get together some of the basic parts for my biggest coil
> project to date. I have just completed a 12 x 56 toroid made from 4
> pieces of 12" aluminum flex-duct that each had a compressed length
> of 24". The secondary is ~897 turns of non-spaced # 17 AWG heavy
> build, Essex magnet wire, wound on a 12.75" OD form for a total wind-
> ing length of 44". It's a little short for the spark length that I'm
shoot-
> ing for, but with that massive toroid, it should work. Looks like a mini-
> ature Wardencliffe :^) The power transformer will be either a 10 or a
> 15 kVA, 14,400 volt pole transformer unit and the control/ ballast as-
> sembly is (2) paralleled 1256D powerstats in series with the core of
> a 225 amp stick welder, set at maximum current. I can get a little
> over 100 amps current flow if I turn the variacs all the way up (280
> volts input to either pole pig, that's set for a Jacob's ladder) for a
short
> run. I have (2) .1 uFd, 50 kV commercial pulse caps that I can use
> for the primary cap and I was thinking of starting off with just one
> (.1 uFd). The primary is 12 turns of 1/2" copper tubing and it sets
> a 2 to 3" below the plain of the lowest secondary turn. The outer-
> most primary turn is about 40" in diameter. I will be using a G-10/
> tungsten rotary gap that I still have yet to aquire. I was wondering if
> maybe a few of you guys with the coiling programs could run the
> numbers and tell me how well this will work and what I could expect
> as far as spark legth output and where the primary coil would be tapped.
> I was hoping to be able to make up to 15 foot sparks with this setup
> and I know that R. Hull's Nemesis had a 14" dia x 46" tall secondary
> with a really large top-load and it made 15 foot sparks. I can't recall
> the size of his top-load, but it looked to be in the size range of my
> 12 x 56 one. Should I use just one of the .1 uFd caps or both with
> for .2 uFd with this massive of a top load? Any comments appreciated.
>
> Thanks,
> David Rieben
>
> PS- The bottom of the toroid is only about 6" above the upper-most
> turn of the secondary, so I don't think that I will need a smaller second
> toroid underneath the big one. What do you guys think?
>
>
>
>