Re: Jonathon's 6" Coil (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Sat, 30 Jun 2007 23:45:18 -0500
From: resonance <resonance@xxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: Jonathon's 6" Coil (fwd)




Good info Bart.  Nice to see math works sometimes!!

D.C. Cox
Resonance Research Corp.
www.resonanceresearch.com


----- Original Message ----- 
From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Saturday, June 30, 2007 9:22 PM
Subject: Re: Jonathon's 6" Coil (fwd)


>
> ---------- Forwarded message ----------
> Date: Tue, 26 Jun 2007 21:05:24 -0700
> From: Barton B. Anderson <bartb@xxxxxxxxxxxxxxxx>
> To: Tesla list <tesla@xxxxxxxxxx>
> Subject: Re: Jonathon's 6" Coil (fwd)
>
> Hi DC,
>
> I didn't read any of these emails until now. Guess I came in on the tail
> end of things (man, you guys are quick)!
>
>>To test the true peak output of a resonance transformer, it must be 
>>operated
>>in a "single-shot" mode.  I use 1 pulse every 120 seconds which gives any
>>residual ions time to clear the previous spark channel.
>>
>>The peak potential is then a function of the spark's distance between two
>>standard 1/2 inch dia. rod gaps.  I think chip has posted this information
>>in the archives for reference.
>>
>>In short summary:
>>
>>60 cm = 332 kV     70 cm = 382 kV     80 cm = 435 kV     90 cm = 488 kV
>>100 cm = 537 kV
>>
>>40 cm = 225 kV     30 cm = 172 kV     20 cm = 124 kV     15 cm = 102 kV
>>
>>
>>
> Rod Gaps? Then these numbers look very good. Javatc uses sphere gap
> geometry where the voltage between spheres required for surface corona
> is twice as great as rod gaps with planar geometry. When sphere
> electrodes are close, they act like planar electrodes, but as they are
> separated, their spherical geometry becomes a factor and increases the
> voltage required for surface corona (up to a self-limiting max where
> further separation will no longer increase this value). The gap
> separation above is great compared to the gap to curvature ratio.
>
> In Javatc (static gap section), I looked at 1/2" spheres at same
> distances as above:
> 10 cm = 129 kV / 2 =  64.5 kV
> 15 cm = 187 kV / 2 =  93.5 kV
> 20 cm = 243 kV / 2 = 121.5 kV
> 30 cm = 352 kV / 2 = 176.0 kV
> 40 cm = 458 kV / 2 = 229.0 kV
> 50 cm = 562 kV / 2 = 281.0 kV
> 60 cm = 665 kV / 2 = 332.5 kV
> 70 cm = 766 kV / 2 = 383.0 kV
> 80 cm = 867 kV / 2 = 433.5 kV
> 90 cm = 966 kV / 2 = 483.0 kV
> 100 cm = 106.5 kV / 2 = 532.5 kV
>
> So, your measurements look great from my calculated view of the world.
> Looks like I need to update Javatc's spark length predictions in the
> static gap table to include planar gaps. I list quite clearly in the
> help files that Javatc is looking at sphere electrodes only. But, it
> would be easy enough to equate the planar geometry (not as I've done
> above, there is actually equations for planar electrodes). Javatc uses
> derivations from Electrode geometry equations of the L.A.N.L. report
> "High-Power Microwave-Tube Transmitters, chapter 7, by William North"
> (the North Report). It's an enlightening readers who haven't yet studied
> this chapter:
> http://www.classictesla.com/download/north7.pdf
>
> BTW, Field Strength used in Javatc is from the web site of our
> illustrious member Jim Lux.
> Field Strength = p * ( B / ( C + ln ( p * d)))
>
> where
>
> p = pressure in Torr (mm Hg). For air, this value is 760
> B = 365 Vcm-1 Torr-1
> C = ln( A / ln ( 1 + 1 / gamma))
> d = gap width
>
> where
> gamma = 0.095 (secondary ionization coefficient)
> A = 14.6 cm-1 Torr -1
>
> I set the gamma value at 0.095 myself as I compared Jim's equations to
> other equations. After a complex time consuming study, I realized Jim's
> equation was right on the mark. I then compared the gamma factor through
> several exercises and found my way to 0.095 (this occurred a long time
> ago and I don't remember all the details at how I ended up there, but I
> do remember I spent a lot of time deciphering a "real" gamma factor.
>
>>Actually, you were around 560 kV output.  You can also check this value by
>>using the equation:
>>
>>Vsec = Vpri x 80% x SQR(Lsec/Lpri).  This equation is very close, usually
>>within a few percent.
>>
>>
> When discussing output voltage, we should remember that we are talking
> about the top terminal maximum voltage (not a spark voltage as it can
> confuse when coilers don't consider spark impedance). The max voltage
> occurs for a quick moment in the cycle and the capacitance storing that
> energy at that moment is denoted as Cee in Javatc (secondary outputs). I
> use this value to define the "peak" (not rms) top terminal voltage in
> both the RSG and Static Gap tables where Vtop = Vpri x sqrt(Cpri/Cee)
> and is therefore a decent top voltage prediction for that moment in the
> cycle where it is maximum. Spark length is not related to this value.
>
> Note that in the Transformer table I show a spark length based on John
> Freau's empirical (tried and tested) equation. This value will always be
> less than my equation shown in the RSG and Static Gap tables. The reason
> other than different but similar equations, is that in the Transformer
> section, there is an efficiency factor included based on Dr. R's posted
> secondary diameter efficiency. All of these spark length equations are
> empirical and derived from helical solenoid secondary coils only. Most
> coilers would fall into an 85% efficiency factor due to diameter of
> coil. Here is a write up by Dr. Resonance showing the factors used.
> http://www.classictesla.com/download/resonance_tips.pdf
>
> Take care,
> Bart
>
>
>
>