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Tesla Coil Help

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LAN_403

interloper

Wed Apr 21 2010, 04:53PM

Registered Member #2801 Joined: Wed Apr 14 2010, 12:02PM
Location:
Posts: 9

Goodchild wrote ...

lpfthings wrote ...

Those salt water caps look like they don't even have an internal electrode! That could be the cause of your problems ..

ya it looks like you don't even have wire or any thing inside the bottle.

lol, those pics are from before we wired them. Here are more pics-

We changed the primary coil. We switched the positions of the capacitors and the spark gap but still nothing happened. We used a can instead of the toroid, still nothing happened. So nothing is wrong with the toroid. The capacitors are working because every time we run the coil, we get a smell from em which I THINK is due to the salt water. Btw, we put a little canola oil in each capacitor. Its supposed to reduce the corona discharge and hence make them more efficient. I think the spark gap might be too wide. Here are our new calculations-

J A V A T C version 12.4 - CONSOLIDATED OUTPUT

Units = Inches
Ambient Temp = 68Â°F

------------------------------------------- ---------
Surrounding Inputs:
------------------------------------------ ----------
100 = Ground Plane Radius
100 = Wall Radius
100 = Ceiling Height

------------------------------------------ ----------
Secondary Coil Inputs:
------------------------------------------ ----------
Current Profile = G.PROFILE_LOADED
1 = Radius 1
1 = Radius 2
0 = Height 1
19.65 = Height 2
900 = Turns
0.019685 = Wire Diameter

---------------------------------------- ------------
Primary Coil Inputs:
------------------------------------------ ----------
Round Primary Conductor
4 = Radius 1
9.375 = Radius 2
0 = Height 1
0 = Height 2
7 = Turns
0.375 = Wire Diameter
0 = Ribbon Width
0 = Ribbon Thickness
0.00178 = Primary Cap (uF)
0 = Total Lead Length
0 = Lead Diameter

---------------------------------------- ------------
Top Load Inputs:
------------------------------------------ ----------
Toroid #1: minor=1.65, major=6, height=22.75, topload
Toroid #2: minor=1.65, major=8, height=24.25, topload

----------------------------------------- -----------
Secondary Outputs:
----------------------------------------- -----------
734.66 kHz = Secondary Resonant Frequency
90 degÂ° = Angle of Secondary
19.65 inch = Length of Winding
45.8 inch = Turns Per Unit
0.00215 inch = Space Between Turns (edge to edge)
471.2 ft = Length of Wire
9.82:1 = H/D Aspect Ratio
12.509 Ohms = DC Resistance
16522 Ohms = Reactance at Resonance
0.55 lbs = Weight of Wire
3.579 mH = Les-Effective Series Inductance
4.001 mH = Lee-Equivalent Energy Inductance
3.986 mH = Ldc-Low Frequency Inductance
13.112 pF = Ces-Effective Shunt Capacitance
11.729 pF = Cee-Equivalent Energy Capacitance
23.819 pF = Cdc-Low Frequency Capacitance
3.4 mils = Skin Depth
8.111 pF = Topload Effective Capacitance
70.1519 Ohms = Effective AC Resistance
236 = Q

----------------------------------------------- -----
Primary Outputs:
----------------------------------------- -----------
863.56 kHz = Primary Resonant Frequency
14.93 % low = Percent Detuned
0 degÂ° = Angle of Primary
24.51 ft = Length of Wire
1.81 mOhms = DC Resistance
0.393 inch = Average spacing between turns (edge to edge)
2.803 inch = Proximity between coils
1.1 inch = Recommended minimum proximity between coils
19.083 ÂµH = Ldc-Low Frequency Inductance
0.00246 ÂµF = Cap size needed with Primary L (reference)
0 ÂµH = Lead Length Inductance
15.192 ÂµH = Lm-Mutual Inductance
0.055 k = Coupling Coefficient
0.123 k = Recommended Coupling Coefficient
18.18 = Number of half cycles for energy transfer at K
10.51 Âµs = Time for total energy transfer (ideal quench time)

------------------------------------------- ---------
Transformer Inputs:
------------------------------------------ ----------
220 [volts] = Transformer Rated Input Voltage
9000 [volts] = Transformer Rated Output Voltage
30 [mA] = Transformer Rated Output Current
50 [Hz] = Mains Frequency
220 [volts] = Transformer Applied Voltage
0 [amps] = Transformer Ballast Current
0 [ohms] = Measured Primary Resistance
0 [ohms] = Measured Secondary Resistance

-------------------------------------- --------------
Transformer Outputs:
----------------------------------------- -----------
270 [volt*amps] = Rated Transformer VA
300000 [ohms] = Transformer Impedence
9000 [rms volts] = Effective Output Voltage
1.23 [rms amps] = Effective Transformer Primary Current
0.03 [rms amps] = Effective Transformer Secondary Current
270 [volt*amps] = Effective Input VA
0.0106 [uF] = Resonant Cap Size
0.0159 [uF] = Static gap LTR Cap Size
0.0277 [uF] = SRSG LTR Cap Size
18 [uF] = Power Factor Cap Size
12728 [peak volts] = Voltage Across Cap
31820 [peak volts] = Recommended Cap Voltage Rating
0.14 [joules] = Primary Cap Energy
122.9 [peak amps] = Primary Instantaneous Current
23.7 [inch] = Spark Length (JF equation using Resonance Research Corp. factors)
10.5 [peak amps] = Sec Base Current

I just noticed that our coupling coefficient is low. (0.055). That could be one problem. Another thing I just noticed is our spark gap. This is the JAVATC data-

---------------------------------------------- ------
Static Spark Gap Inputs:
------------------------------------------ ----------
2 = Number of Electrodes
0.15748 [inch] = Electrode Diameter
0.590551 [inch] = Total Gap Spacing

----------------------------------------- -----------
Static Spark Gap Outputs:
----------------------------------------- -----------
0.591 [inch] = Gap Spacing Between Each Electrode
12728 [peak volts] = Charging Voltage
23573 [peak volts] = Arc Voltage
31430 [volts] = Voltage Gradient at Electrode
39916 [volts/inch] = Arc Voltage per unit
185.2 [%] = Percent Cp Charged When Gap Fires
1.648 [ms] = Time To Arc Voltage
607 [BPS] = Breaks Per Second
0.49 [joules] = Effective Cap Energy
290394 [peak volts] = Terminal Voltage
300 [power] = Energy Across Gap
31 [inch] = Static Gap Spark Length (using energy equation)

It says "Gap Distance is too wide ( ref arc vs chg value).
One more thing-
the reference value given in JAVATC which is required for resonance is 0.00246 uF. Our calculated capacitance is 0.00178 uF which has a large probability of being wrong.
Now, I think I have SOME idea as to what I should fix. Suggestions?

Mads Barnkob

Wed Apr 21 2010, 06:43PM

Registered Member #1403 Joined: Tue Mar 18 2008, 06:05PM
Location: Denmark, Odense C
Posts: 1968

A word about your capacitors... capacitors are usually made from even sized plates with a isolating layer between them, you only seem to have a thin enamelled wire going down in the water, the surface of this "plate" is very small, even if you did remove the varnish from the piece in the water.

raff

Wed Apr 21 2010, 10:20PM

Registered Member #2315 Joined: Tue Aug 25 2009, 02:35AM
Location: Leyte, PH
Posts: 161

too much connecting wires.. poorly designed caps...possibly too wide spark gap..

Coronafix

Wed Apr 21 2010, 10:52PM

Registered Member #160 Joined: Mon Feb 13 2006, 02:07AM
Location: Melbourne, Australia
Posts: 938

Mads Barnkob wrote ...

A word about your capacitors... capacitors are usually made from even sized plates with a isolating layer between them, you only seem to have a thin enamelled wire going down in the water, the surface of this "plate" is very small, even if you did remove the varnish from the piece in the water.

With salt water caps, the water acts as one plate, the foil on the outside as the other.

Herr Zapp

Thu Apr 22 2010, 05:50AM

Registered Member #480 Joined: Thu Jul 06 2006, 07:08PM
Location: North America
Posts: 644

interloper -

OK, your photos are starting to provide some clues to start the debugging process.

1. What is the electrolyte in your capacitors, and how did you prepare it? Most commonly used is a SATURATED solution of table salt in tap water. Dissolve as much salt as possible in boiling water, and pour this into your bottles. As the solution cools, some salt should precipatate out of solution, becoming visible on the bottom of the bottles. This is a good indication that the solution is truly saturated. If no salt is visible, add another 1/2 teaspoon or so to each bottle.

2. Replace ALL of your primary wiring with #12 AWG wire, either solid or stranded will do. This includes ALL the wiring associated with your capacitors. Strip at least 10" of insulation off the wire going into the salt water of each cap, and make sure that all 10" are submerged in the electrolyte.

3. Your photo of your "completed" capacitor bank doesn't seem to show any electrical connections to the outer foil of each botttle. Can you describe exactly how the outer foils are connected together, and how they are connected to the rest of the primary circuit? You DO have some electrical connection to the foils, correct? A photo of the connections to the foils would be useful .....

4. If you haven't already done so, relocate your spark gap and capacitors as close to the primary coil as possible, and make all the wiring between primary, spark gap, and capacitor bank as short and direct as possible. Any excess wire length in the primary circuit add inductance, and further lowers the primary's resonant frequency.

5. Borrow or purchase a multimeter with a capacitance scale, and measure the capacitance of your primary capacitor. The meter can be a cheap imported model, as you don't need a high level of accuracy. Plug this measured capacitance value into JAVATC, and see where your primary resonant frequency is, relative to your secondary system's resonant frequency.

Regards,
Herr Zapp

lpfthings

Thu Apr 22 2010, 09:38AM

Registered Member #1361 Joined: Thu Feb 28 2008, 10:57AM
Location: Cairns, Australia
Posts: 305

Does your spark gap fire? Could you possibly take a video while you are trying to operate it? if the spark gap is more of a continuous, quiet(ish) buzzing arc, then your capacitors aren't working properly. When running, the spark gap should be extremely loud with bright blue sparks jumping between the 2 eelctrodes.

Coronafix

Sat Apr 24 2010, 02:43AM

Registered Member #160 Joined: Mon Feb 13 2006, 02:07AM
Location: Melbourne, Australia
Posts: 938

You need an adjustable tap on your primary.

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