Re: 81" Continuous Arcs!

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

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

In a message dated 6/11/01 10:18:30 AM Eastern Daylight Time, 
tesla-at-pupman-dot-com writes:

> 
>  > Original poster: "Christopher Boden by way of Terry Fritz
>  <twftesla-at-qwest-dot-net>" <chrisboden-at-hotmail-dot-com>
>  > What is the longest realistic streamer length for a bipolar twin coil 
> system
>  > at 10kVA 13.8kV?
>  
>  With John Freau's NST formula 14.2 ft. With John's Potential Transformer
>  formula 17.5 ft. So I'd say
>  somewhere in between, and if your not hitting at least 14 ft., there will
>  be some efficiency work to be done
>  (These numbers consider 120 bps and in John's testing, less spark length
>  for higher bps.  These are
>  considered rather optimum spark length efficiency's. Although spark length
>  can exceed these numbers,
>  typically they don't).
>  
>  Bart Anderson

Bart, Chris, all,

Twin coils give longer sparks than single coils for a given input
power.  To calc the spark length for a twin, first take 1/2 the
input power.  Use the formula on it, then double the result.

Thus, for 10kVA,  1/2 of 10kVA = 5kVA.  The sqrt of 5000 = 
70.71 x 1.7 = 120" or 10 feet.  Double this result to give the
expected spark length of 20 feet for a twin.

The reason that twins give longer sparks is because they must
be thought of as two smaller coils each of half the power, 
each giving a spark length according to the formula.  The
result is doubled since the sparks meet at the center.

Cheers,
John Freau