Re: Power output

["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 3/13/02 10:26:37 AM Eastern Standard Time, 
tesla-at-pupman-dot-com writes:

Jim,

If you're interested in calcing the spark length output for your coil.
I like to use the equation:

   spark length (inches) = 2.2*sqrt rated VA

A 9/30 nst is rated at 270 VA.  Sqrt 270 = 16.43.  2.2*16.43 = 36".

My website is at:

  http://hometown.aol-dot-com/futuret/page3.html

So an optimally designed TC could perhaps give 36" sparks using
that NST.  Usually the sparks are somewhat shorter for a number
of reasons.  The equation above is an empirical one that I found
works well for my coils.  You didn't mention the type of spark
gap you're using.  The gap often has a limiting effect on the
coil's performance.

I'm building a new small 120 bps sync rotary for my new TT-32
TC which gives 32" sparks from a 9/25 NST.  This new rotary
has a 3.25" diameter rotor.  The rotor can be rotated relative
to the hub to set the phase.  

Cheers,
John