RE: More THOR Expts

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

Original poster: "Denicolai, Marco" <Marco.Denicolai-at-tellabs-dot-com> 

Hi Malcolm,

The ROC can be easily kept constant as I use an extra metal ball (25 mm 
o.d.) to draw streamers from the toroid.

One extra thing I pulled out from my data a moment ago was (from Fig.3) the 
distance reached with the same average number of bangs vs. the bang 
voltage. I tried for 8 bangs and for 14 bangs. The dependance was LIMEAR, 
not quadratic. This indicates that the distance reached is linearly related 
to the charging voltage, not to the secondary charge accumulated.

I'm surely going to perform some of your mentioned experiments when the 
suitable time comes.

Best Regards

 > -----Original Message-----
 > From: Tesla list [mailto:tesla-at-pupman-dot-com]
 > Sent: 30. heinäkuuta 2004 17:05
 > To: tesla-at-pupman-dot-com
 > Subject: More THOR Expts
 >
 > Original poster: "Malcolm Watts" <m.j.watts-at-massey.ac.nz>
 >
 > Hi Marco, all,
 >                 A question that needs to be answered is "what
 > determines what the useful maximum breakrate is?", "useful"
 > being defined as the breakrate beyond which no further
 > increase in spark length results. Some thought led to the
 > hypothesis that the useful breakrate will scale with
 > secondary charge storage (i.e. capacitance).
 > I devised some expts which will hopefully prove or disprove this.
 > There is weak evidence already that supports this hypothesis,
 > mainly the results obtained by Richard Hull in his extensive
 > work. My own observations with a range of coil sizes also
 > suggests this might be true.
 >
 > Noting the highest useful breakrate for the current THOR
 > configuration:
 >
 > #1 - increase Ctop while maintaining the same ROC, and
 > maintain the same theoretical Vout by suitably increasing Cp
 > or Vp (i.e. Ep). An increased useful BPS would indicate a
 > charge-available dependence.
 >
 > #2 - decrease Ctop while maintaining the same ROC and same
 > Vout (reducing Ep to maintain this). If the useful BPS
 > increases, that would throw my hypothesis out. If useful BPS
 > decreases, there is supporting evidence for
crease Ctop while maintaining Ep to increase Vout (at
 > this point, I am not sure whether increasing or maintaining
 > the same ROC is the way to go - for completeness' sake it
 > would be worth doing both). Does the useful BPS change and if
 > so, higher or lower?
 > If higher, it again negates the hypothesis.
 >
 > #4 - increase Ctop while maintaining Ep to reduce Vout (ROC
 > may have to be reduced to allow breakout). If useful BPS
 > remains the same, it would provide more support for the hypothesis.
 >
 > This list is by no means complete but should be a useful
 > guide to devising a complete set of tests. Some of these
 > questions may already have been answered but what I would
 > like to see is the full gamut of tests and results presented
 > all at once. A key question I would like to see answered is
 > the degree to which sparklength depends on output voltage
 > and, separately, charge availability. My guess is that there
 > is a dependence on both but that charge availability is the
 > more dominant of the two. The enormous discharge from the 5MV
 > Russian Marx bank plus the behaviour of lightning seems to
 > indicate this also.
 >
 >      The purpose of all this is to refine the design criteria
 > for a spark-producing coil, a goal I'm sure we'd all welcome
 > being reached.
 > The general approach at present seems to be equivalent to
 > grabbing whatever components one has available and building
 > something that works. In the engineering world however, one
 > does as much as is needed to fulfil a design goal and no more
 > (safety margins nothwithstanding), size, weight and economics
 > being the arbiters.
 >      This is also what I'd consider to be a rigorous
 > (scientific if you like) approach to coil building. Why throw
 > a 20 x 5" toroid on top of a coil just because it happens to
 > be lying around if it makes the finished product bulkier and
 > heavier without actually contributing to the performance? I
 > think anyone building coils for commercial gain (I a
) would appreciate this way of doing things.
 >
 > Malcolm
 >
 >
 >
 >