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Im really just trying to not buy more then 50ft of copper tubing but i cant seem to get the primary length down under 50 enough where i can add 2 more turns, anyone have any input?
J A V A T C version 12.5 - CONSOLIDATED OUTPUT Wed 07 Sep 2011 06:31:33 AM CDT
-----------------------------------------
----------- Secondary Outputs: -----------------------------------------
----------- 246.58 kHz = Secondary Resonant Frequency 90 deg° = Angle of Secondary 23 inch = Length of Winding 39.1 inch = Turns Per Unit 0.00298 inch = Space Between Turns (edge to edge) 1060.3 ft = Length of Wire 5.11:1 = H/D Aspect Ratio 21.4071 Ohms = DC Resistance 25252 Ohms = Reactance at Resonance 1.64 lbs = Weight of Wire 16.299 mH = Les-Effective Series Inductance 16.982 mH = Lee-Equivalent Energy Inductance 16.54 mH = Ldc-Low Frequency Inductance 25.56 pF = Ces-Effective Shunt Capacitance 24.532 pF = Cee-Equivalent Energy Capacitance 38.338 pF = Cdc-Low Frequency Capacitance 5.92 mils = Skin Depth 21.767 pF = Topload Effective Capacitance 85.0672 Ohms = Effective AC Resistance 297 = Q
-----------------------------------------------
----- Primary Outputs: -----------------------------------------
----------- 246.58 kHz = Primary Resonant Frequency 0 % = Percent Detuned 0 deg° = Angle of Primary 48.79 ft = Length of Wire 8.1 mOhms = DC Resistance 0.537 inch = Average spacing between turns (edge to edge) 0.864 inch = Proximity between coils 75.92 inch = Recommended minimum proximity between coils 52.208 µH = Ldc-Low Frequency Inductance 0.008 µF = Cap size needed with Primary L (reference) 0.055 µH = Lead Length Inductance 110.444 µH = Lm-Mutual Inductance 0.119 k = Coupling Coefficient 0.131 k = Recommended Coupling Coefficient 8.4 = Number of half cycles for energy transfer at K 16.89 µs = Time for total energy transfer (ideal quench time)
-------------------------------------------
--------- Transformer Inputs: ------------------------------------------
---------- 120 [volts] = Transformer Rated Input Voltage 15000 [volts] = Transformer Rated Output Voltage 30 [mA] = Transformer Rated Output Current 60 [Hz] = Mains Frequency 120 [volts] = Transformer Applied Voltage 0 [amps] = Transformer Ballast Current 0 [ohms] = Measured Primary Resistance 0 [ohms] = Measured Secondary Resistance
--------------------------------------
-------------- Transformer Outputs: -----------------------------------------
----------- 450 [volt*amps] = Rated Transformer VA 500000 [ohms] = Transformer Impedence 15000 [rms volts] = Effective Output Voltage 3.75 [rms amps] = Effective Transformer Primary Current 0.03 [rms amps] = Effective Transformer Secondary Current 450 [volt*amps] = Effective Input VA 0.0053 [uF] = Resonant Cap Size 0.008 [uF] = Static gap LTR Cap Size 0.0138 [uF] = SRSG LTR Cap Size 83 [uF] = Power Factor Cap Size 21213 [peak volts] = Voltage Across Cap 53033 [peak volts] = Recommended Cap Voltage Rating 1.8 [joules] = Primary Cap Energy 263.1 [peak amps] = Primary Instantaneous Current 30.7 [inch] = Spark Length (JF equation using Resonance Research Corp. factors) 14.8 [peak amps] = Sec Base Current
-----------------------------------------
----------- Rotary Spark Gap Inputs: ------------------------------------------
---------- 0 = Number of Stationary Gaps 0 = Number of Rotating Electrodes 0 [rpm] = Disc RPM 0 = Rotating Electrode Diameter 0 = Stationary Electrode Diameter 0 = Rotating Path Diameter
----------------------------------------
------------ Rotary Spark Gap Outputs: -----------------------------------------
----------- 0 = Presentations Per Revolution 0 [BPS] = Breaks Per Second 0 [mph] = Rotational Speed 0 [ms] = RSG Firing Rate 0 [ms] = Time for Capacitor to Fully Charge 0 = Time Constant at Gap Conduction 0 [µs] = Electrode Mechanical Dwell Time 0 [%] = Percent Cp Charged When Gap Fires 0 [peak volts] = Effective Cap Voltage 0 [joules] = Effective Cap Energy 0 [peak volts] = Terminal Voltage 0 [power] = Energy Across Gap 0 [inch] = RSG Spark Length (using energy equation)
---------------------------------------
------------- Static Spark Gap Inputs: ------------------------------------------
---------- 2 = Number of Electrodes 0.25 [inch] = Electrode Diameter 0.524 [inch] = Total Gap Spacing
-----------------------------------------
----------- Static Spark Gap Outputs: -----------------------------------------
----------- 0.524 [inch] = Gap Spacing Between Each Electrode 21213 [peak volts] = Charging Voltage 21203 [peak volts] = Arc Voltage 31862 [volts] = Voltage Gradient at Electrode 40465 [volts/inch] = Arc Voltage per unit 100 [%] = Percent Cp Charged When Gap Fires 10.723 [ms] = Time To Arc Voltage 93 [BPS] = Breaks Per Second 1.8 [joules] = Effective Cap Energy 382899 [peak volts] = Terminal Voltage 168 [power] = Energy Across Gap 32.1 [inch] = Static Gap Spark Length (using energy equation)
Registered Member #480
Joined: Thu Jul 06 2006, 07:08PM
Location: North America
Posts: 644
TC -
I gotta ask, are you paying attention to the inputs you are getting on this forum?
You're trying to get your primary coil length less than 50' so you can use a readily-available 50' coil of 1/4" diameter copper refrigeration tubing. This is a reasonable goal.
Now that you've been playing with JAVATC, do you see the relationship between the length of the primary and secondary conductors and their inductance? And how topload capacitance and secondary inductance determine the resonant frequency of the secondary circuit? And how primary inductance and tank capacitor value determine the resonant frequency of the primary circuit? And how changing the value of any of these parameters affects the other parameters? And that to maintain a given resonant frequency of a tuned circuit, you can increase the capacitance and reduce the required inductance (e.g. reduce the length of the conductor), and vice versa?
In your latest JAVATC file, you have input the total length of all the interconnecting wiring of your primary circuit as 10 inches, with a conductor diameter of 10 inches (!!!). Is this what you really intended? It was suggested that you make a scaled sketch of your complete Tesla coil with all its components in place so you could get some idea of the length of all the wiring needed to connect primary coil, spark gap, tank capacitor, and adjustable tap lead. Have you done that? If so please post a copy of that sketch showing how you achieved a total of 10-inches of interconnecting wiring.
More typically, the total length of interconnecting wiring in a simple spark gap TC will be somewhere around 2-3 feet. The inductance of this wiring is part of the primary circuit, and will reduce the length of the copper tubing needed in the primary coil.
You're trying to do some simple electrical engineering here, and it takes a little understanding and a little attention to detail. Go back and fix your lead length inputs, and see what happens to your primary coil length. Then, see what additional "tweaking" of tank cap value or secondary resonant frequency would be required to get your primary tap point at less than 50', allowing at least one additional turn for tuning. JAVATC makes this easy to make these changes and immediately see the results.
The additional primary length beyond the theoretical tap point is needed to allow you to compensate for construction variables that cause your primary and/or secondary resonant frequency to be slightly different from your calculated values. The closer you are to the calculated values, the less "extra" primary turns are required. You can always tap further into the primary if you need a resonant frequency higher than calculated, but you can't tap further out if there is no conductor there.
Alright Herr Zap :) im hearing what your saying, the trick was to change the diameter of my secondary coil to raise the resonant frequency which left my primary winding at only 32 feet leaving plenty of room for adding a few extra turns!
i used dummy lead lengths for now based off of what you told me and in the morning i will use inventor to plane out the layout of it to get the real numbers!
here are the new numbers, thank you so much!
J A V A T C version 12.5 - CONSOLIDATED OUTPUT Wed 07 Sep 2011 10:44:50 PM CDT
-----------------------------------------
----------- Secondary Outputs: -----------------------------------------
----------- 334.36 kHz = Secondary Resonant Frequency 90 deg° = Angle of Secondary 21 inch = Length of Winding 42.9 inch = Turns Per Unit 0.00323 inch = Space Between Turns (edge to edge) 824.7 ft = Length of Wire 6:1 = H/D Aspect Ratio 20.9953 Ohms = DC Resistance 22488 Ohms = Reactance at Resonance 1.01 lbs = Weight of Wire 10.704 mH = Les-Effective Series Inductance 11.353 mH = Lee-Equivalent Energy Inductance 11.1 mH = Ldc-Low Frequency Inductance 21.167 pF = Ces-Effective Shunt Capacitance 19.958 pF = Cee-Equivalent Energy Capacitance 31.77 pF = Cdc-Low Frequency Capacitance 5.15 mils = Skin Depth 16.841 pF = Topload Effective Capacitance 83.2829 Ohms = Effective AC Resistance 270 = Q
-----------------------------------------------
----- Primary Outputs: -----------------------------------------
----------- 334.36 kHz = Primary Resonant Frequency 0 % = Percent Detuned 0 deg° = Angle of Primary 32.34 ft = Length of Wire 5.37 mOhms = DC Resistance 0.582 inch = Average spacing between turns (edge to edge) 0.865 inch = Proximity between coils 1.52 inch = Recommended minimum proximity between coils 27.404 µH = Ldc-Low Frequency Inductance 0.008 µF = Cap size needed with Primary L (reference) 1.026 µH = Lead Length Inductance 58.277 µH = Lm-Mutual Inductance 0.106 k = Coupling Coefficient 0.128 k = Recommended Coupling Coefficient 9.43 = Number of half cycles for energy transfer at K 14.01 µs = Time for total energy transfer (ideal quench time)
-------------------------------------------
--------- Transformer Inputs: ------------------------------------------
---------- 120 [volts] = Transformer Rated Input Voltage 15000 [volts] = Transformer Rated Output Voltage 30 [mA] = Transformer Rated Output Current 60 [Hz] = Mains Frequency 120 [volts] = Transformer Applied Voltage 0 [amps] = Transformer Ballast Current 0 [ohms] = Measured Primary Resistance 0 [ohms] = Measured Secondary Resistance
--------------------------------------
-------------- Transformer Outputs: -----------------------------------------
----------- 450 [volt*amps] = Rated Transformer VA 500000 [ohms] = Transformer Impedence 15000 [rms volts] = Effective Output Voltage 3.75 [rms amps] = Effective Transformer Primary Current 0.03 [rms amps] = Effective Transformer Secondary Current 450 [volt*amps] = Effective Input VA 0.0053 [uF] = Resonant Cap Size 0.008 [uF] = Static gap LTR Cap Size 0.0138 [uF] = SRSG LTR Cap Size 83 [uF] = Power Factor Cap Size 21213 [peak volts] = Voltage Across Cap 53033 [peak volts] = Recommended Cap Voltage Rating 1.8 [joules] = Primary Cap Energy 363.2 [peak amps] = Primary Instantaneous Current 30.7 [inch] = Spark Length (JF equation using Resonance Research Corp. factors) 18.6 [peak amps] = Sec Base Current
-----------------------------------------
----------- Rotary Spark Gap Inputs: ------------------------------------------
---------- 0 = Number of Stationary Gaps 0 = Number of Rotating Electrodes 0 [rpm] = Disc RPM 0 = Rotating Electrode Diameter 0 = Stationary Electrode Diameter 0 = Rotating Path Diameter
----------------------------------------
------------ Rotary Spark Gap Outputs: -----------------------------------------
----------- 0 = Presentations Per Revolution 0 [BPS] = Breaks Per Second 0 [mph] = Rotational Speed 0 [ms] = RSG Firing Rate 0 [ms] = Time for Capacitor to Fully Charge 0 = Time Constant at Gap Conduction 0 [µs] = Electrode Mechanical Dwell Time 0 [%] = Percent Cp Charged When Gap Fires 0 [peak volts] = Effective Cap Voltage 0 [joules] = Effective Cap Energy 0 [peak volts] = Terminal Voltage 0 [power] = Energy Across Gap 0 [inch] = RSG Spark Length (using energy equation)
---------------------------------------
------------- Static Spark Gap Inputs: ------------------------------------------
---------- 9 = Number of Electrodes 0.5 [inch] = Electrode Diameter 0.42 [inch] = Total Gap Spacing
-----------------------------------------
----------- Static Spark Gap Outputs: -----------------------------------------
----------- 0.053 [inch] = Gap Spacing Between Each Electrode 21213 [peak volts] = Charging Voltage 21213 [peak volts] = Arc Voltage 32693 [volts] = Voltage Gradient at Electrode 50507 [volts/inch] = Arc Voltage per unit 100 [%] = Percent Cp Charged When Gap Fires 10.728 [ms] = Time To Arc Voltage 93 [BPS] = Breaks Per Second 1.8 [joules] = Effective Cap Energy 424704 [peak volts] = Terminal Voltage 168 [power] = Energy Across Gap 32.1 [inch] = Static Gap Spark Length (using energy equation)
How do I go about making the primary coil a perfect spiral? I'm not to sure how to wind it so that it has perfect spacings and everything. Can anyone help??
Registered Member #4107
Joined: Sun Sept 25 2011, 07:30PM
Location: London
Posts: 53
Hi TeslaCoil. Don't use PVC piping. It will cook inside the coil, degrade and melt at high enough powers.
Alternatives aren't necessarily expensive. One of the best I ever made was a simple cardboard postage tube, coated with -- wait for it -- 25 coats of gloss varnish, each baked on.
Registered Member #4107
Joined: Sun Sept 25 2011, 07:30PM
Location: London
Posts: 53
Hey TeslaCoil, I don't mean to sound critical but your last post, just like your first, was MASSIVE and virtually impossible to read through.
Perhaps think about the impact on your readers if you want good responses - break 'em up, keep them short and to the point. Masses of information like that just looks like spam. I doubt if anyone will read through it.
Registered Member #480
Joined: Thu Jul 06 2006, 07:08PM
Location: North America
Posts: 644
astralhighway -
You wrote: "Don't use PVC piping. It will cook inside the coil, degrade and melt at high enough powers."
This is totally incorrect. Possibly 90+ percent of modern Tesla coils are built using PVC pipe as the secondary coilform. This includes spark gap, solid-state, and vacuum-tube coils, many operating at multi-kilowatt input power levels.
Also: " .....but your last post, just like your first, was MASSIVE and virtually impossible to read through."
It sounds like you've never designed a Tesla coil using design software like JAVATC, don't recognize a JAVATC output file, and don't understand the data contained therein.
In attempting to design his first TC, Tesla Coil encountered a problem where his initial design needed a large primary inductance value, which would have required a very long piece of copper tubing. BY using JAVATC to simulate various combinations of primary inductance and capacitance, he was able to refine his design to enable use of a single 50' coil of copper tubing.
It's common practice in this forum to post a JAVATC output file for peer review BEFORE starting to actually build a coil. Forum members will provide a "design review" to help uncover any weaknesses or problem areas before its too late. The file may seem long, but all the information is valuable.
If you don't understand the data presented in a JAVATC output file, you might want to study JAVATC and get some understanding of the information contained in the file. Use of TC design software like JAVATC allows a highly efficient, high-performance coil to be designed and built quickly, as opposed to a slow, laborious "trial and error" method.
JAVATC and instructions on how to use it can be found at:
Registered Member #4107
Joined: Sun Sept 25 2011, 07:30PM
Location: London
Posts: 53
Herr Zapp,
Thanks for pulling me up on the PVC issue. My bad. I did have a very poor experience once using a very lossy black plastic drainpipe l that I assumed was PVC, but I note that as you say, the bulk of deigns suggest it as a former for the secondary coil.
On the JAVATC, my response wasn't because I'm unfamiliar with this approach or don't understand these parameters. I've used several online tools over 12 years and sure, there's a place for this analysis at the design stage and for tweaking during the build.
My objection (which wasn't personal) was to the presentation of the data with no analysis by the OP.
But also, as the OP declares him/herself to be doing this for the first time, I'm very aware of the gap between theoretical values and what's experienced during a build. I never got close to the design capacitance of the top-load in my first SGTC, and in two VTTCs, found the self-resonant frequency of the secondary to be widely adrift of the theoretical figure.
I'm not slamming data or theory - love it- just aware that although some is good / essential, idealised conditions do not materialise during a build. Hope that's okay? Hope that gives a better impression of where I'm coming from?
Registered Member #480
Joined: Thu Jul 06 2006, 07:08PM
Location: North America
Posts: 644
astralhighway -
" .......idealised conditions do not materialise during a build."
That's why it's so beneficial to use a design tool like JAVATC to determine what the "idealized conditions" (exact electrical parameters) are that are required for the system to achieve resonance, and then MAKE them materialize. Careful attention to detail when actually building the coil so that the hardware actually meets the target electrical parameters in both the primary and secondary circuits will guarantee that the coil will "run" when first powered up, and will require only relatively minor tuning to obtain peak performance.
You mention that in two VTTCs you built, you " found the self-resonant frequency of the secondary to be wildly adrift of the theoretical figure". That's not because of any flaw in the physical laws defining the electrical characteristics of a solenoidal coil, but because of some construction or measurement error on the part of the coil builder.
When I originally obtained good quality test equipment that allowed me to make accurate measurements of inductance, capacitance and frequency, I was amazed at how closely carefully constructed hardware matched the "theoretical" values.
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My first tesla coil (SGTC)
