Re: Streamer loading effect

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

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

Steve,

The answer to your question is that a 12/30 NST (or any NST) can
deliver more than its rated power in a TC application, especially if
powered by a 140 volt variac, as I do.  My 12/30 NST actually
draws about 800 watts, and probably delivers 700 watts or so to
the coil.  I don't think the JavaTC calculator allows for this effect.
It's something you just have to know about, and then type in
700 watts, instead of 360 watts, into the JavaTC program.  
Bart may wish to add a notice in his program that NST's can
draw more than their rated power under certain conditions, to
eliminate the confusion.  It's a question that comes up often.
Six foot arcs from 1800 watts is an efficient coil.  If you're using
NST's with a combined rating of 1800 watts, the system may
actually be drawing 3600 watts.  Some coils do well with the
RQ type spark gap, others don't do as well.  A lot has to do
with the value (uF) of the capacitor, etc.  If the NSTs can
deliver 3600 watts, then perhaps an 8.5 foot spark should be
expected.

Also, I think large coils may be more efficient than small coils
(I know John C doesn't agree). 

Cheers,
John 


>
> I have a question about efficiency with my coil.  On the classic tesla java 
> TC calculator, they say my coil with a rotary gap, could produce a 6 foot 
> arc.  This makes me wonder about how helpful rotary gaps really are.  Im 
> using a somewhat undersized RQ gap, and getting close to the theoretical, 
> optimal output for my coil.  Am i missing something here, or is my coil 
> quite efficient for the spark gap that i have?  Or would perhaps a RSG boost 
> my output beyond 6 feet?  This 6 foot figure that the calculator gave me is 
> somewhat puzzling.  If John F. can get 42" (or 44" now) from a 12/30, why on 
> earth would a figure for 6 feet on a 1800w coil make sense for high 
> efficiency?  I know larger coils loose efficiency per power.  Oh well, i 
> should just be happy with what i have, and what i have is good enough for me 
> :)
>
> Steve Ward
>