RE: The PING Test

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

Original poster: "Malcolm Watts by way of Terry Fritz <twftesla-at-qwest-dot-net>" <m.j.watts-at-massey.ac.nz>

Hello John,

On 25 Sep 2002, at 12:01, Tesla list wrote:

> Original poster: "John H. Couture by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <couturejh-at-mgte-dot-com>
> 
> 
> Malcolm -
> 
> I cannot agree with you about the Q factor and the overall efficiency. It
> does make sense and I showed in my post how any coiler can make the test and
> do the calcs. Note that a Q factor of 300 would be about 183 cycles to 10%
> using the ping test. This would give a very low resistance and a very high
> secondary voltage which appears to be contrary to the actual test voltage.

It actually says nothing about the voltage that is developed and 
everything about how quickly the secondary loses what energy is 
imparted to it. The voltage, as Dr de Queiroz says, is dictated by 
the amount of energy that ends up in the coil and coils effective 
self-capacitance at Fr. If Q is infinite, the secondary rings forever 
but it cannot develop a voltage higher than that allowed by 
conservation of energy.
 
> What do you think about my question at the bottom of my post. Should I
> increase or decrease the turns to increase the secondary voltage and spark
> length for the same H/D coilform? There apparently aren't many coilers that
> wish to comment on that question. It's certainly a very important decision
> that ever coiler is confronted with when he builds a Tesla coil. It is
> obvious that there is an optimum number of turns for a certain H/D coilform.

I am more than happy to comment. My first reaction is to ask "how 
long is a piece of string?". If the secondary coilform is the same, 
the self-capacitance of the coil is pretty much invariant (we most 
certainly do know this) and for a given quantity of energy, the 
output voltage will be the same. 

 
> Most coilers use 1000 turns for that particular H/D coilform but what
> happens if you increase or decrease the turns? I haven't heard of any coiler
> that has researched this problem. With big coils this type of research can
> be expensive. However, with the 4KV/20ma contest this can be easily and
> inexpensively researched. It will be interesting to see how this contest
> develops.

Indeed! I am hoping to participate through a proxy or jointly with 
one of my friends on the list.
     The "problem" has been thoroughly quantified. Or has the TSSP 
project all been in vain? Sad if it has.

Regards,
Malcolm