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Re: Newbie cap and topload questions



Original poster: "Barton B. Anderson" <bartb@xxxxxxxxxxxxxxxx>

Greetings Hank,

Ok, 30mA is even better. Because of that, I would recommend 0.15uF Cornell Dublier 942C20P15K. The reason is you can build a .0079uF cap using 19 with a single string with fair voltage stand off (38kV), which is decent for an MMC. Because of the single cap value (0.15uF), this particular cap/string scenario would be the least expensive.

Dr. Resonance is the person you should contact with a direct email (resonance@xxxxxxxxxx). Dr. Resonance is very active on this list with great advice to coilers and has produced professional coils to organizations for many years.
http://www.resonanceresearch.com/

The good Dr. is an amazing man! He's been a major factor for list members in supplying all sorts of goodies like the toroid bulk buys, CD caps, coils, wire, electrodes, caps, all the gizmo's we need for this very fun, mysterious, and learned hobby. The generosity of time Dr. R. puts into these things, well, I personally feel you will not find a better person. I would also highly recommend taking advantage of the toroid bulk buy he recently proposed, if finances are workable.

Take care,
Bart

Tesla list wrote:

Original poster: jvillecheesehead@xxxxxxxxxxxxxxxx
I noticed I made a typo in my NST specs, it is 30mA, not 20. I actually
had been going off the resonant cap frequency and didn't realize the LTR
value was what is recommended and this happened to be the same as the LTR
for a 20mA transformer.

The LTR value for a 15/30 is .008uF. The capacitor I was referring to at
Electonrics Goldmine is a Phillips cap (.047uF 1600V) that looks very much
like thier 376 MMKP series that is on the good caps list but the pic isn't
clear enough to tell for sure. I will try calling to verify this. In
order to achieve the desired cap size I would need 3 strings of 18 of these
which would total .0078uF 29kv at $56.

If I were to use one of the CD caps the .1uF 942 series would require 1
string of 13 for .0077uF 26kV or the .15uF cap would require 1 string of 19
for .0079uF 38kV. Out of these configurations, do any seem to have a
better price/reliability combination then the others? If you suggest the
CD caps, where do you get these (RELL as suggested by Dave has a minimum
order or 67)?

Thanks again for all the help!
Hank

On Sun, 08 Jan 2006 6:19:47 -0500 (EST), "Tesla list" <tesla@xxxxxxxxxx> wrote:
> Original poster: "Barton B. Anderson" <bartb@xxxxxxxxxxxxxxxx>
>
> Hi,
>
> The coil looks fine. The NST can drive the coil,
> but you will probably want to upgrade the NST at
> some point in the future. A 15/60 NST would be
> ideal here (of course, that would change the cap
> size for an equivalent LTR ratio).
>
> I would probably increase the width of the toroid
> to 3" x 15". Your gap looks good and I like the
> slotted holes you added there. It can be
> difficult to produce parallel spacing between
> electrodes using a bolt on method, but I can see
> how the slotted holes would help. I personally use epoxy (quick and easy).
>
> Unsure about the caps you showed. I would
> recommend sticking with known good caps list.
> http://hot-streamer.com/TeslaCoils/MMCInfo/good-bad.txt
>
> I see your using the static gap LTR value of
> 0.005uF. Due to that, I think using the 0.1uF
> Cornell Dublier 942C20P10K would be the cheapest
> route (1 string of 20). The 0.15uF CD caps would
> require 1 string of 30 to achieve the 0.005uF value.
>
> I ran Javatc as well on your specs here except
> using the 15" toroid option while looking at your
> coil. Thought I would just share that data. Below
> Javatc data is Javammc data for the 1 string of
> 20. BTW, many of us have a very similar coils.
> Those dimensions are common and they work well.
>
> Take care,
> Bart
>
> J A V A T C v.10 - CONSOLIDATED OUTPUT
> Sunday, January 08, 2006 11:14:48 AM
>
> Units = Inches
> Ambient Temp = 68ã??
>
> ----------------------------------------------------
> Surrounding Inputs:
> 100 = Ground Plane Radius
> 100 = Wall Radius
> 100 = Wall Height
> 100 = Ceiling Radius
> 100 = Ceiling Height
>
> ----------------------------------------------------
> Secondary Coil Inputs:
> Current Profile = G.PROFILE_LOADED
> 2 = Radius 1
> 2 = Radius 2
> 20 = Height 1
> 40 = Height 2
> 800 = Turns
> 23 = Wire Awg
>
> ----------------------------------------------------
> Primary Coil Inputs:
> 3 = Radius 1
> 8.922 = Radius 2
> 20.5 = Height 1
> 20.5 = Height 2
> 11.83 = Turns
> 0.25 = Wire Diameter
> 0.005 = Primary Cap (uF)
> 0 = Desired Coupling (k)
>
> ----------------------------------------------------
> Top Load Object Inputs (dimensions & topload or ground connection):
>
> Toroid #1: minor=3, major=15, height=41, topload
> Disc #1: inside=0, outside=9, height=41, topload
>
> ----------------------------------------------------
> Secondary Outputs:
> 341.15 kHz = Secondary Resonant Frequency
> 90 degã??= Angle of Secondary
> 20 inch = Length of Winding
> 40 inch = Turns Per Unit
> 0.00243 inch = Space Between Turns (edge to edge)
> 837.8 ft = Length of Wire
> 5:1 = H/D Aspect Ratio
> 17.05 ohms = DC Resistance
> 24709 ohms = Forward Transfer Impedance
> 24297 ohms = Reactance at Resonance
> 1.29 lbs = Weight of Wire
> 11.335 mH = Les-Effective Series Inductance
> 10.964 mH = Lee-Equivalent Energy Inductance
> 11.834 mH = Ldc-Low Frequency Inductance
> 19.201 pF = Ces-Effective Shunt Capacitance
> 17.958 pF = Cee-Equivalent Energy Capacitance
> 31.122 pF = Cdc-Low Frequency Capacitance
> 4.98 mils = Skin Depth
> 14.84 pF = Topload Effective Capacitance
> 80.9 ohms = Effective AC Resistance
> 300 = Q
>
> ----------------------------------------------------
> Primary Outputs:
> 341.15 kHz = Primary Resonant Frequency
> 0 % = Percent Detuned
> 0 degã??= Angle of Primary
> 36.94 ft = Length of Wire
> 0.25 inch = Average spacing between turns (edge to edge)
> 1 inch = Primary to Secondary Clearance
> 43.529 ã?? = Ldc-Low Frequency Inductance
> 0.005 ã?? = Cap size needed with Primary L (reference)
> 99.262 ã?? = Lm-Mutual Inductance
> 0.138 k = Coupling Coefficient
> 7.25 = Number of half cycles for energy transfer at K
> 10.49 ã?? = Time for total energy transfer (ideal quench time)
>
> ----------------------------------------------------
> Transformer Inputs:
> 120 [volts] = Transformer Rated Input Voltage
> 15000 [volts] = Transformer Rated Output Voltage
> 20 [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:
> 300 [volt*amps] = Rated Transformer VA
> 750000 [ohms] = Transformer Impedence
> 15000 [rms volts] = Effective Output Voltage
> 2.5 [rms amps] = Effective Input Current
> 300 [volt*amps] = Effective Input VA
> 0.0035 [uF] = Resonant Cap Size
> 0.0053 [uF] = Static gap LTR Cap Size
> 0.0092 [uF] = SRSG LTR Cap Size
> 55 [uF] = Power Factor Cap Size
> 21210 [peak volts] = Voltage Across Cap
> 74977 [peak volts] = Recommended Cap Voltage Rating
> 1.12 [joules] = Primary Cap Energy
> 227.3 [peak amps] = Primary Instantaneous Current
> 25 [inch] = Spark Length (JF equation using Resonance Research Corp. factors)
>
> ----------------------------------------------------
> Static Spark Gap Inputs:
> 5 = Number of Electrodes
> 1 [inch] = Electrode Diameter
> 0.28 [inch] = Total Gap Spacing
>
> ----------------------------------------------------
> Static Spark Gap Outputs:
> 0.07 [inch] = Gap Spacing Between Each Electrode
> 21210 [peak volts] = Charging Voltage
> 20390 [peak volts] = Arc Voltage
> 34333 [volts] = Voltage Gradient at Electrode
> 72822 [volts/inch] = Arc Voltage per unit
> 96.1 [%] = Percent Cp Charged When Gap Fires
> 7.923 [ms] = Time To Arc Voltage
> 126 [BPS] = Breaks Per Second
> 1.04 [joules] = Effective Cap Energy
> 340233 [peak volts] = Terminal Voltage
> 131 [power] = Energy Across Gap
> 30.2 [inch] = Static Gap Spark Length (using energy equation)
>
>
>
------------------------------------------------------------------------------
> ------------
> J A V A M M C v.1.06 - CONSOLIDATED OUTPUT
> Sunday, January 08, 2006 11:03:07 AM
>
> Capacitor Data Inputs:
> .1 [uF] = Single Capacitor value
> 2000 [volts] = Rated DC Votlage Rating
> 22 [C/watts] = Capacitor Dissipation Factor
> 10 [%] = Capacitor Rated Tollerance
> .005 [uF] = Desired Total MMC Capacitance
>
> ----------------------------------------------------
> Coil Data Inputs:
> 400 [kHz] = Coil Resonant Frequency
> 20 [caps] = Desired Capacitors per String
> 15000 [volts] = Transformer Output Voltage
> 20 [mA] = Transformer Output Current
> 120 [BPS] = Spark gap Breaks Per Secondd
> 2 [ohms] = Primary Coil Resistance
>
> ----------------------------------------------------
> JAVAMMC Outputs:
> 0.005 [uF] = Cap Bank Total Capacitance
> 0.005 [uF] = Capacitance Per String
> 1 [strings] = Number of Strings Required
> 20 [caps] = Total Number of Caps Required
> Fair = Reliability: Cap Bank Standoff Voltage
> Excellent = Reliability: Cap Temperature Rise
> 40000 [volts] = Cap Bank Rated Voltage
> 1.13 [joules] = Cap Bank Discharge Energy
> 135 [watts] = Cap Bank Nominal Power
> 21213 [volts] = Transformer Peak Voltage
> 0.0036 [TANd] = Dielectric Loss Factor
> 0.0563 [joules] = Single Cap Discharge Energy
> 0.0145 [ohms] = Single Cap Internal Resistance
> 0.0485 [watts] = Single Cap Power Dissipation
> 1.067 [Cã?? = Single Cap Temperature Rise
> 1.83 [amps] = Capacitor String RMS Current
>
>
>
> Tesla list wrote:
>
> >Original poster: jvillecheesehead@xxxxxxxxxxxxxxxx
> >Hi,
> >I'm a first time coiler and it took until now for me to finally discover how
> >useful this list was. Anyhow, I am using a 15kv 20mA nst and have wound my
> >secondary of 4" diameter 20" height with 800 turns of 23 gauge wire. My
> >question is about a couple options with
> >caps. First, I am assuming this 35,000V
> >.005uf cap from Electronics Goldmine for $2.75 is not suitable for tesla
> coils
> >as the site claims and wanted to confirm this. Here is a link:
>
&gt;http://www.goldmine-elec-products.com/prodinfo.asp?number=G15589&amp;variation=&amp;-
> aitem=72&mitem=91
> >
> > My other plan was to use this Phillips 1600V
> > .047uf cap that runs for a buck a
> >piece at the same site:
>
&gt;http://www.goldmine-elec-products.com/prodinfo.asp?number=G14832&amp;variation=&amp;-
> aitem=67&mitem=91
> >
> > According to an excel calculator, I believe
> > using Terry Fritz's data, the best
> >reliability/price point would be 2 strings of 19 of these caps. Upon
> reading
> >some other posts it sounds like some people push
> >them harder without any issues
> >and was wondering if anyone had an opinion on this.
> >
> >I also had another quick question about the topload. For some reason in my
> >planning (which was a few months ago, couldn't work on the coil while I was
> at
> >college) I decided to use a toroid with 3" diameter Al ducting with a total
> >diameter of about 10 inches. Using Barton
> >Anderson's JavaTC calculator this in
> >combination with my other components results in a 390kHz resonant frequency.
> >The size and frequency differs from many of the
> >coils I have seen online and was
> >wondering if there is any problem with using it.
> >
> >Lastly, I thought I would share a picture of my
> >spark gap that includes a simple
> >modification to the Richard Quick design that allows for increased
> >adjustability. Thanks for the help!
> >
> >
> >
> >
> >