RE: Desktop Bipolar Coil

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

Original poster: "Lau, Gary by way of Terry Fritz <teslalist-at-qwest-dot-net>" <gary.lau-at-hp-dot-com>

It's not clear why "Watt-seconds" are being discussed.  The power to a coil 
is measured in simple Watts.  If one was operating in a single shot mode, 
the cap is charged over an interval of time for an essentially 
instantaneous release, but then the power in the cap is typically measured 
in Joules, a.k.a. Watt-seconds. But performance with single shot operation 
won't equal that of normal operation where successive bangs propagate the 
streamer length.

As to the suitability of "random TC sparks" for quantifying performance, 
that simply is the nature of the beast.  Every streamer is a slightly 
different length, as a multitude of variables interact over the course of 
time.  It you really wanted to be accurate, you could somehow measure every 
streamer over some very long time interval and perform some weighted 
averaging to arrive at an average length.  But it's far easier to simply 
choose the best result and identify that as the maximum result achieved.

Gary Lau
MA, USA


Original poster: "John H. Couture by way of Terry Fritz 
<teslalist-at-qwest-dot-net>" <couturejh-at-mgte-dot-com>


John F. -

This is what I mean by nonsense engineering when using random TC spark
outputs. This possibility also occurs with other engineering systems. Your
spark 36 inch length can be real, however, the exact watt second input to
produce this spark cannot be determined and the spark length should not be
compared to other spark lengths with an assumed same watt second input. Keep
in mind that the random spark length also has a random watt second input for
that particular spark. With most engineering systems random outputs can lead
to over unity energy.

For example -

7500 x .03 = 225 watts

John Freau equation -

     spark inches = 1.7 sqrt(watts)
                  = 1.7 x sqrt(225)
                  = 25.5 inch spark

John Freau 36 inch spark -

     watts = (inches/1.7)^2
           = (36/1.7)^2
           = 448 watts

     unity eff = 448/225
               = 3.96 = 396% over unity energy

It is amazing what you can do with numbers using random sparks!

This is the penalty that coilers must pay for using random TC spark lengths.
Hopefully, in the future TC spark lengths and watt second inputs will be
better defined.

John Couture

--------------------------------


-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Saturday, June 28, 2003 9:18 PM
To: tesla-at-pupman-dot-com
Subject: Re: Desktop Bipolar Coil


Original poster: "by way of Terry Fritz <teslalist-at-qwest-dot-net>"
<FutureT-at-aol-dot-com>

In a message dated 6/28/03 1:00:09 PM Eastern Daylight Time,
tesla-at-pupman-dot-com writes:

  >. It is my understanding the John Freau's equation for
  >spark length is only good for NSTs when the NST is modified.
  >
  >John Couture


John,

My equation is good for NST's whether they are modified or not.
One should use the measured input wattage for the calc, or at
least the PF corrected VA which should be a reasonably accurate
approach too.  Consider for example John Morawa's beautiful
15/30 NST coil which gave 40" sparks from an unmodified NST,
at 120 volts input.

John