Re: BIG coil project

["Tesla list" <tesla@xxxxxxxxxx>]

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

Hi Dr,

Yes, I doubt that my coil will be able to compete with your "Big Bruiser"
but I am hoping to be able to achieve up to 15 foot point-to-point sparks
with it once it's completed and tuned in. It's interseting that you suggest
using the total .2 uFd with both of my .1 uFd caps as Scot D (aka Bunny-
killer) suggested seriesing the to 14.4 kV pigs for around 30 kV of pri-
mary voltage and using both of the .1 uFd caps as well, only in series for a
.05 uFd @ 100 kV combo. This would still give me the same joules/bang
as with .2 uFd at  14.4kV and would allow for using more primary turns.
The resultant increase of primary L should allow for lower gap losses.
The one big drawback with this is that 30 kV is a real pain in the butt
to stand off w/out flashover in the primary circuit. Scot can tell you all
about that, too. So, it's gonna be a somewhat difficult decision to de-
cide on exactly how I'm going to wire this thing, but I'll probably start
out with 14.4 kV at .1 uFd and see what kind of sparks that I can get
from that setup and go from there ;^)

Unfortunately, I don't have an O-scope or a signal generator. I've been
spending too much of my money on the coil parts themseleves to worry
about getting the fancy test equipment.... It'll be a lot of trial and error
for tuning it in, just like it was all of the times before ;^))

David Rieben


----- Original Message -----
From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Saturday, December 04, 2004 2:55 PM
Subject: Re: BIG coil project


> 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?
>  >
>  >
>  >
>  >
>
>
>