Re: Win tesla

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Barton B. Anderson by way of Terry Fritz <twftesla-at-qwest-dot-net>" <tesla123-at-pacbell-dot-net>

Hi Gary,

WinTesla was close according to my calcs: We were told 8 gaps, 0.178" total gap
width, but not told the electrode diameter. For the specified distance of
0.178, the electrodes should be about 0.225" diameter or near. Thus, 0.0225"
per gap.

In your example, (two 1" spheres separated by 0.228" & assuming equal spheres)
yield a 14,986 arc voltage using the equations below.
This is lower than than the chart predicts. Obviously, there are differences
either in the electrode shape, the pressure, the air, the tests, or something.
Someday I'd like to do a large range of arc tests electrode sizes, shapes, and
distances. I would bet they stay real close to North's equations. I believe
Antonio has made several of his own tests which North predicted well.

Take care,
Bart
PS: Here's a post from Antonio showing some of these equations:

----------------------------------------------
Spark length to a grounded ball with the same curvature of the terminal
(another terminal) gives a good value, provided that the spark is not 
too long compared to the radius of the ball. Use the formula:

V=E*4*d/(d/R+1+sqrt((d/R+1)2+8));

Where E=30000 V/cm, d is the spark length (cm), and R is the radius 
of the ball (cm).

Or, using a small ball, with radius R much smaller than the radius 
of the terminal :

V=E*4*d/(2*d/R+1+sqrt((2*d/R+1)2+8));

The same formula applies (more exactly) to a spark to a large plane,
with R being the radius of the terminal.

Formulas from the "North Report".




Tesla list wrote:

>
> Original poster: "Lau, Gary by way of Terry Fritz
<mailto:twftesla-at-qwest-dot-net><twftesla-at-qwest-dot-net>"
> <mailto:Gary.Lau-at-hp-dot-com><Gary.Lau-at-hp-dot-com>
> 
> 8400V/inch sounds too low.  From the sphere breakdown voltage chart on
> Terry's site,
>
<http://hot-streamer-dot-com/TeslaCoils/Misc/SGapVolt.jpg>http://hot-streamer.co
m/TeslaCoils/Misc/SGapVolt.jpg, two 2.5cm (1")
> spheres 0.58cm (0.228") apart would break down at 20kV peak.  Assuming
> voltage vs. distance is linear (which does not seem to be the case from the
> chart), that comes out to 87.7kV per inch.  Maybe a decimal place error?
> 
> Gary Lau
> MA, USA
> 
>    
>>
>> Original poster: "by way of Terry Fritz
>> <mailto:twftesla-at-qwest-dot-net><twftesla-at-qwest-dot-net>"     
>
> <mailto:Rscopper-at-aol-dot-com><Rscopper-at-aol-dot-com>   
>>
>> That WinTesla value is based on 8400 volts per inch. 12000/8400=1.43in     
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>>>> I've just started using the WinTesla program and I've noticed that the
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> fixed   
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>>>> spark gap calculator is not giving the numbers that I would expect. I
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> entered   
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>>>> 8 > gaps for a 12000 volt NST and it responded with 0.178 in/gap. This
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> is far too   
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>>>> large.         
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