RE: Desktop Bipolar Coil

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

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

Hi Gary, John,

On 30 Jun 2003, at 7:35, Tesla list wrote:

 > 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.

I cannot agree with that assertion and further I'd state that to
assume that the length of sparks produced in a repetitively operating
machine is intimately mirroring input power overlooks a major
operating parameter - plasma dynamics. The random long spark is a
cumulative effect. Why? Because it does not happen in single shot
mode. QED.

Malcolm


 > 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
 >
 >
 >