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Little help figuring out my primary values?

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LAN_403

magnet18

Thu Sept 01 2011, 03:06AM

Registered Member #3766 Joined: Sun Mar 20 2011, 05:39AM
Location:

Posts: 624

Alright, on my secondary I have 1000 turns of 24ga wire, 4.5" in diameter, with a spun aluminum toroid, 3" minor 12" major, which should give me a secondary inductance of 21mH and a capacitance of 21.8 pF which gives me a resonant frequency of 235.2 khz.

However, whenever I try to lay out a primary coil and tank capacitor, I get the javatc message that the tank capacitor is too large for the 15/30 transformer to charge, and if the capacitor is small enough, I need too much wire for the coil, am I making a dumb mistake somewhere?

MRacerxdl

Thu Sept 01 2011, 03:31AM

Registered Member #989 Joined: Sat Sept 08 2007, 02:15AM
Location: SÃ£o Paulo, Brazil
Posts: 476

No, it just you made a coil that will not work easy. The maximum current that your HV Supply can source limits how much time the capacitor will need to charge. If the current is low enough it will take too much to charge it, and the coil will not work properly. Just choose a higher current power supply or decrease the capacitance (increasing the primary coil as you said)

magnet18

Thu Sept 01 2011, 11:20AM

Registered Member #3766 Joined: Sun Mar 20 2011, 05:39AM
Location:

Posts: 624

so I should lower the resonant frequency then?
increase the windings on the secondary, and maybe add more topload?

MRacerxdl

Thu Sept 01 2011, 03:46PM

Registered Member #989 Joined: Sat Sept 08 2007, 02:15AM
Location: SÃ£o Paulo, Brazil
Posts: 476

You should increase the ressoant frequency to lower the capacitor/indutor size.
You can try to reduce the toroid size or decrease secondary windings. I think the toroid is what will affect it more.

Herr Zapp

Thu Sept 01 2011, 04:09PM

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

m18 -

Please post your entire JAVATC design file so we can see what your preliminary concept looks like. It's impossible to perform a design critique if you only provide a few of the parameters.

Herr Zapp

magnet18

Thu Sept 01 2011, 11:33PM

Registered Member #3766 Joined: Sun Mar 20 2011, 05:39AM
Location:

Posts: 624

this, or the load file?
Essentially, I have a 15/30 transformer, a 3/12 toroid, a 4.5" diameter secondary with 24awg wire, which isn't finished and can end between 800 and 1100 turns, and everything else is up in the air

[EDIT]
Wait, I think I got it tuned, does this look right?
Gimme a minuet and I'll attach the load file

J A V A T C version 12.5 - CONSOLIDATED OUTPUT
Thu Sep 01 2011 20:36:16 GMT-0400 (Eastern Daylight Time)

Units = Inches
Ambient Temp = 68Â°F

------------------------------------------- ---------
Surrounding Inputs:
------------------------------------------ ----------
5 = Ground Plane Radius
0 = Wall Radius
0 = Ceiling Height

------------------------------------------ ----------
Secondary Coil Inputs:
------------------------------------------ ----------
Current Profile = G.PROFILE_LOADED
2.25 = Radius 1
2.25 = Radius 2
16 = Height 1
38 = Height 2
1000 = Turns
24 = Wire Awg

--------------------------------------------- -------
Primary Coil Inputs:
------------------------------------------ ----------
Round Primary Conductor
3 = Radius 1
12.501 = Radius 2
16 = Height 1
16 = Height 2
13.002 = Turns
0.25 = Wire Diameter
0 = Ribbon Width
0 = Ribbon Thickness
0.00528 = Primary Cap (uF)
12 = Total Lead Length
0.125 = Lead Diameter

---------------------------------------- ------------
Top Load Inputs:
------------------------------------------ ----------
Toroid #1: minor=3, major=12, height=40, topload

----------------------------------------- -----------
Secondary Outputs:
----------------------------------------- -----------
280.22 kHz = Secondary Resonant Frequency
90 degÂ° = Angle of Secondary
22 inch = Length of Winding
45.5 inch = Turns Per Unit
0.0019 inch = Space Between Turns (edge to edge)
1178.1 ft = Length of Wire
4.89:1 = H/D Aspect Ratio
29.9932 Ohms = DC Resistance
34397 Ohms = Reactance at Resonance
1.44 lbs = Weight of Wire
19.536 mH = Les-Effective Series Inductance
21.589 mH = Lee-Equivalent Energy Inductance
21.284 mH = Ldc-Low Frequency Inductance
16.512 pF = Ces-Effective Shunt Capacitance
14.942 pF = Cee-Equivalent Energy Capacitance
29.986 pF = Cdc-Low Frequency Capacitance
5.46 mils = Skin Depth
10.572 pF = Topload Effective Capacitance
116.5099 Ohms = Effective AC Resistance
295 = Q

----------------------------------------------- -----
Primary Outputs:
----------------------------------------- -----------
280.22 kHz = Primary Resonant Frequency
0 % = Percent Detuned
0 degÂ° = Angle of Primary
52.77 ft = Length of Wire
8.76 mOhms = DC Resistance
0.481 inch = Average spacing between turns (edge to edge)
0.615 inch = Proximity between coils
1.52 inch = Recommended minimum proximity between coils
60.777 ÂµH = Ldc-Low Frequency Inductance
0.00528 ÂµF = Cap size needed with Primary L (reference)
0.317 ÂµH = Lead Length Inductance
140.9 ÂµH = Lm-Mutual Inductance
0.124 k = Coupling Coefficient
0.131 k = Recommended Coupling Coefficient
8.06 = Number of half cycles for energy transfer at K
14.25 Âµs = 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
1.19 [joules] = Primary Cap Energy
197.7 [peak amps] = Primary Instantaneous Current
30.7 [inch] = Spark Length (JF equation using Resonance Research Corp. factors)
153.1 [peak amps] = Sec Base Current

----------------------------------------- -----------
Static Spark Gap Inputs:
------------------------------------------ ----------
5 = Number of Electrodes
0.25 [inch] = Electrode Diameter
0.354 [inch] = Total Gap Spacing

----------------------------------------- -----------
Static Spark Gap Outputs:
----------------------------------------- -----------
0.089 [inch] = Gap Spacing Between Each Electrode
21213 [peak volts] = Charging Voltage
15000 [peak volts] = Arc Voltage
33365 [volts] = Voltage Gradient at Electrode
42373 [volts/inch] = Arc Voltage per unit
70.7 [%] = Percent Cp Charged When Gap Fires
3.651 [ms] = Time To Arc Voltage
274 [BPS] = Breaks Per Second
0.59 [joules] = Effective Cap Energy
281973 [peak volts] = Terminal Voltage
163 [power] = Energy Across Gap
32 [inch] = Static Gap Spark Length (using energy equation)

magnet18

Fri Sept 02 2011, 12:51AM

Registered Member #3766 Joined: Sun Mar 20 2011, 05:39AM
Location:

Posts: 624

heres the load file of what I think should work, but I'm not 100%
the primary cap value looks awful close to the resonant value of the transformer, I'm not sure how bad that is

TeslaCoil

Sat Sept 03 2011, 05:56AM

Registered Member #4020 Joined: Thu Jul 21 2011, 06:40PM
Location:
Posts: 30

Does your mmc capacity there account for resonant rise?

magnet18

Sat Sept 03 2011, 02:19PM

Registered Member #3766 Joined: Sun Mar 20 2011, 05:39AM
Location:

Posts: 624

I believe so
javatc is fairly advanced

TeslaCoil

Sat Sept 03 2011, 05:58PM

Registered Member #4020 Joined: Thu Jul 21 2011, 06:40PM
Location:
Posts: 30

It auto adjusts for resonant rise?

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