RE: TC Spark Energy

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

Original poster: "Malcolm Watts" <m.j.watts-at-massey.ac.nz> 

On 16 Mar 2004, at 11:26, Tesla list wrote:

 > Original poster: "John H. Couture" <couturejh-at-mgte-dot-com>
 >
 >
 > Malcolm -
 >
 > What transfer efficiency are you referring to?
 > What is an energy trade?

Energy trade between the primary and secondary.

 > The overall efficiency I am referring to is the
 >
 >     OA Eff = energy out/energy in
 >
 > The "energy out" is the spark energy. The "energy in" is the energy
 > going into the NST.

Since the various transformers and transformer/ballasting setups have
differing losses I don't think there is much point in trying to
derive a wallplug to output spark efficiency figure as there is no
discrimination between what gets lost in the transformer and what
gets lost in the gap (i.e. there is no way of telling *where* the
losses are occurring). So OK, my prime interest is the efficiency of
the system *discounting* the transformer. That way, knowing that with
a high Q secondary losses are insignificant, factors affecting gap
losses are brought into focus. So, knowing Ep accurately and
capturing ringdowns and energy trades between primary and secondary
on the oscilloscope, you can calculate (for example) what proportion
of primary energy is being lost in the gap between secondary maximums
and finally sum those losses together to get a final result.

 > How do you find these two energies for your TCs? Any examples from
 > your coils?

I measured a 12% loss in one very small coil (discounting charging
circuit losses) and somewhere around 30% in a much larger coil with
attached streamers and, (interestingly enough) a rather low X primary.

Malcolm

 > John Couture
 >
 > --------------------------------------
 >
 >
 > -----Original Message-----
 > From: Tesla list [mailto:tesla-at-pupman-dot-com]
 > Sent: Tuesday, March 16, 2004 10:25 AM
 > To: tesla-at-pupman-dot-com
 > Subject: RE: TC Spark Energy
 >
 >
 > Original poster: "Malcolm Watts" <m.j.watts-at-massey.ac.nz>
 >
 > On 15 Mar 2004, at 16:50, Tesla list wrote:
 >
 >   > Original poster: "John H. Couture" <couturejh-at-mgte-dot-com>
 >   >
 >   >
 >   > Malcolm -
 >   >
 >   > I agree the TC voltage is one of the dependencies when talking
 >   about > spark length. However, this problem is to find the TC energy
 >   in and > the energy out to determine the overall efficiency. The TC
 >   voltages > are another problem. > > John Couture
 >
 > John, below you distinctly say:
 >
 >   > On 11 Mar 2004, at 22:56, Tesla list wrote:
 >   >
 >   >   > Original poster: "John H. Couture" <couturejh-at-mgte-dot-com>
 >   >   >
 >
 > "The problem is to
 >   >   find the energy to produce a spark of a certain length with a >
 >    certain TC of a certain design. > >
 > John Couture"
 >
 > I've cut the various headers out for brevity.
 >
 > I know you are particularly interested in matters of efficiency. It is
 > not difficult to calculate transfer efficiency and I won't repeat the
 > procedure since it must appear any number of times in the archives.
 > Since you can know the primary energy when the secondary is empty, you
 > can do it for any number of energy trades and sum the partial results
 > to find an overall figure for a particular bang (and whatever spark it
 > might produce.
 >
 > However, you do say something about sparklength also and I am simply
 > pointing out that when you do talk about sparklength, you cannot
 > ignore parameters other than energy shot size (and BPS if relevant).
 >
 > Malcolm
 >
 >
 >