Re: BIG coil project

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Barton B. Anderson" <tesla111@xxxxxxxxxxxxx>

Hi David,
An invitation to model a coil like this is hard to pass up! Dave, I'll post 
my JavaTC specs below. I hope you don't mind, but I set the coefficient of 
coupling to 0.153 (it would have been at 0.147 with the secondary bottom 
winding at 2" above the primary).

I set the primary turn to turn spacing at 0.5", the same as the primary 
wire diameter (not sure what reality is in that area). I also set your RSG 
to 10kva and with my SRSG 240 BPS G10/tungsten gap dimensions. JavaTC's 
default coil surroundings input values are the dimensions of my garage 
(probably a good estimate for most coilers). All the rest are your specs as 
given. Looks like your capable of spark between 153" and 168.6" (12 and 14 
feet of hot white streamers). Refer to my JavaTC specs for the misc. details.

For those who don't know David, let me tell you that Dave is fully capable 
of achieving these spark lengths. Dave is experienced in the art of 
coiling. He, like myself, is your everyday garage coiler, but Dave has 
shown me though video that he has the ability to make big sparks. Dave, 
this particular coil is nearly identical to my old retired coil which was 
12.75" x 43.25", except wound with 18g wire. Your toroid size is larger 
than anything I used on that coil. To date, it was my best coil for power 
and sparklength. These days, when I do get to play, it's with this 1789 
turn, 24g, 8.5" coil, which runs great, but just doens't have the wild hot 
arcs which I my old coil gave. Interestingly, your only 1kHz away from old 
coil in frequency (your sort of building my old coil). As I have the video 
you sent me a few years ago,I have no doubt you'll achieve greater 
sparklengths than I ever could.

All my very best,
Barton B. Anderson



J A V A T C v.10 - CONSOLIDATED OUTPUT
Friday, December 03, 2004 6:47:31 PM

Units = Inches

----------------------------------------------------
Surrounding Inputs:
103 = Ground Plane Radius
103 = Wall Radius
150 = Wall Height
103 = Ceiling Radius
150 = Ceiling Height

----------------------------------------------------
Secondary Coil Inputs:
Current Profile = G.PROFILE_LOADED
6.375 = Radius 1
6.375 = Radius 2
20 = Height 1
64 = Height 2
897 = Turns
17 = Wire Awg

----------------------------------------------------
Primary Coil Inputs:
7.875 = Radius 1
16.171 = Radius 2
18.695 = Height 1
18.695 = Height 2
8.3 = Turns
0.5 = Wire Diameter
0.1 = Primary Cap (uF)
0 = Desired Coupling (k)

----------------------------------------------------
Top Load Object Inputs (dimensions & topload or ground connection):


Toroid #1: minor=12, major=56, height=70, topload


Disc #1: inside=0, outside=12, height=70, topload


----------------------------------------------------
Secondary Outputs:
69.78 [kHz] = Secondary Resonant Frequency
90 [deg°] = Angle of Secondary
44 [inch] = Length of Winding
20.4 = Turns Per inch
0.0038 [inch] = Space Between Turns (edge to edge)
15 [awg] = Recommended Wire Size
2994.1 [ft] = Length of Wire
3.45 = H/D Aspect Ratio
15.16 [ohms] = DC Resistance
29412 [ohms] = Reactance at Resonance
29831 [ohms] = Forward Transfer Impedance
18.56 [lbs] = Weight of Wire
67.082 [mH] = Les-Effective Series Inductance
67.821 [mH] = Lee-Equivalent Energy Inductance
66.278 [mH] = Ldc-Low Frequency Inductance
77.548 [pF] = Ces-Effective Shunt Capacitance
76.215 [pF] = Cee-Equivalent Energy Capacitance
107.291 [pF] = Cdc-Low Frequency Capacitance
9.848 [mils] = Skin Depth
68.041 [pF] = Topload Effective Capacitance

----------------------------------------------------
Primary Outputs:
69.78 [kHz] = Primary Resonant Frequency
0.01 [%] = Percent Detuned
0 [deg°] = Angle of Primary
52.25 [ft] = Length of Wire
0.499 [inch] = Average spacing between turns (edge to edge)
1.5 [inch] = Primary to Secondary Clearance
52.022 [uH] = Ldc-Low Frequency Inductance
284.717 [uH] = Lm-Mutual Inductance
0.153 [k] = Coupling Coefficient
6.54 = Number of half cycles for energy transfer at K
46.14 [uS] = Time for total energy transfer (ideal quench time)

----------------------------------------------------
Transformer Inputs:
120 [volts] = Transformer Rated Input Voltage
14400 [volts] = Transformer Rated Output Voltage
694 [mA] = Transformer Rated Output Current
60 [Hz] = Mains Frequency
120 [volts] = Transformer Applied Voltage
0 [amps] = Transformer Ballast Current

----------------------------------------------------
Transformer Outputs:
9994 [volt*amps] = Rated Transformer VA
20749 [ohms] = Transformer Impedence
14400 [rms volts] = Effective Output Voltage
83.3 [rms amps] = Effective Input Current
9994 [volt*amps] = Effective Input VA
0.1278 [uF] = Resonant Cap Size
0.1918 [uF] = Static gap LTR Cap Size
0.3333 [uF] = SRSG LTR Cap Size
1841 [uF] = Power Factor Cap Size
20362 [peak volts] = Voltage Across Cap
71978 [peak volts] = Recommended Cap Voltage Rating
20.73 [joules] = Primary Cap Energy
889.6 [peak amps] = Primary Instantaneous Current
153 [inch] = Spark Length (JF equation using Resonance Research Corp. factors)

----------------------------------------------------
Rotary Spark Gap Inputs:
1 = Number of Stationary Gaps
8 = Number of Rotating Electrodes
1800 [rpm] = Disc RPM
0.375 = Rotating Electrode Diameter
0.375 = Stationary Electrode Diameter
10.6 = Rotating Path Diameter

----------------------------------------------------
Rotary Spark Gap Outputs:
8 = Presentations Per Revolution
240 [BPS] = Breaks Per Second
56.8 [mph] = Rotational Speed
4.17 [ms] = RSG Firing Rate
10.375 [ms] = Time for Capacitor to Fully Charge
2.01 = Time Constant at Gap Conduction
0.75 [ms] = Electrode Mechanical Dwell Time
86.58 [%] = Percent Cp Charged When Gap Fires
17629 [peak volts] = Effective Cap Voltage
15.54 [joules] = Effective Cap Energy
638917 [peak volts] = Terminal Voltage
3729 [joule*seconds] = Energy Across Gap
168.6 [inch] = RSG Spark Length (using energy equation)

Tesla list wrote:

> Original poster: "David Rieben" <drieben@xxxxxxxxxxxxxxx>
>
> Hi all,
>
> 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?