Re: TESLA MAP UPDATED

["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 7/6/01 3:17:38 PM Eastern Daylight Time, tesla-at-pupman-dot-com 
writes:

Bart, all,

I've posted a few times in the past regarding the possible optimal
toroid sizes for various power inputs.  I don't have a copy of my
posting, but I may have been refering to 120 bps operation which 
requires larger toroids for a given power input and spark length due
to the larger bang size.  My various equations do not usually make 
much of a distinction between NST or pig power, since power is power.  
I may have given some examples of toroid sizes for higher breakrates,
but I don't really remember what I said in the old postings.  In general,
toroid sizes will fit a square law similar to the power input vs spark
length equation, but using a different factor of course.  If the input
power is quadrupled, the toroid size should be doubled.  I use a 4" x
13" toroid on my 600 watt coil, so a 2400 watt coil should use an
8" x 26" toroid from this point of view at 120 bps.  This is just a 
rough guide of course.

I just did some quick calcs, and the Tesla Map results you
cite do indeed fit the quidelines above for 120 bps, and result
in a 17" by 60" toroid or so, and a larger overall diameter toroid
could probably be used.   The toroid should be smaller for 
higher bps systems.  Richard Hull used a 13" or 15" by 60"
toroid on his 10kVA Nemesis TC, which ran at about 500 bps,
and was probably an actual 320 bps or so, considering missed
firings of the async rotary.  

I have no idea if Tesla Map uses the chord concept or simply the
overall size for the toroid sizes (I didn't look at the program). 
I always use the overall sizes, never the chord concepts.  When 
I speak of a 60" toroid, I mean 60" overall major diameter.

120 bps operation likes big toroids, both to control breakout,
and to help keep the streamers coalesced.

John Freau
---

> Screen #2: The toroid calculated optimum still shows 17" x 68" toroid? You
>  show this is from J.F.'s
>  formula to match toroid to voltage and current. Can you or John comment
>  here? I assume this is based on
>  the transformer since this is the data input thus far. This would be a 17"
>  x 88" toroid (major diameter
>  edge to edge)? Seems a bit big, don't you think? This isn't right. I know
>  optimum toroid is always a
>  challenge, but I really don't think we've managed a correct method for
>  calculating optimum toroid size
>  (based off transformer ratings - at least not for 14.4kv, 694mA pole pigs).
>  Maybe this is "strictly" low
>  current NST's?