Re: Power versus Spark Length

From: 	John H. Couture[SMTP:couturejh-at-worldnet.att-dot-net]
Sent: 	Wednesday, July 16, 1997 11:47 PM
To: 	Tesla List
Subject: 	Re: Power versus Spark Length

At 01:19 PM 7/13/97 +0000, you wrote:
>From: 	FutureT-at-aol-dot-com[SMTP:FutureT-at-aol-dot-com]
>Sent: 	Saturday, July 12, 1997 3:20 AM
>To: 	tesla-at-pupman-dot-com
>Subject: 	Power versus Spark Length

  John -

  Note that the square law relationship may only hold for a particular coil
at a certain wattage. This relationship would vary when the following
parameters are changed:

  1. Increasing/decreasing the Tesla primary voltage would increase/decrease
the spark length.

  2. Increasing/decreasing the secondary coil inductance would
increase/decrease the spark length.

  3. Increasing the length of the secondary wire beyond a certain length
would overload the power transformer and reduce the spark length.

  4. The spark length is longer with pole type transformers compared to neon
transformers because the pole type can be changed to produce a variety of
short circuit wattage outputs.

  There are other parameter changes that affect the spark length. The JHCTES
TC computer program changes the spark length to agree with these
possibilities. The program uses  more complex equations than the square law
so it will agree with the different combinations of TC parameters. The
program is based on empirical data and needs to be updated so your research
is helpful. To my knowledge this is the only program available to date that
shows spark length with the above 

  John Couture 


>Recent work with disruptive coils, and old work with tube coils, suggest
>that the power required for a given spark length follows (more or less) a 
>simple direct square law.
>Two coils were built, each optimized for its input power level.  One drew
>680 watts and gave a 42" spark, the other drew 2100 watts and gave a
>65" spark.   The tube coil results followed a similar trend.
>I'll chart some hypothetical and actual results, based on square law
>  watts (wallplug)           spark length
>       10.6                           5 1/4"
>       42.6                         10 1/2"
>       170                             21"
>       680                             42"   (actual)
>     2100                              65"   (actual)
>     8400                             134"
>      33.6 kW                       268"   (22 feet)
>      67.2 kW                                 (30.8 feet)
>     134.4 kW                                (44 feet)
>      537.6 kW                               (88 feet) 
>These results seem reasonable to me, and appear to agree to
>a large extent with real-world results.  
>Comments welcomed.
>John Freau