Re: Questions about current

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

Original poster: "Peter Lawrence by way of Terry Fritz <twftesla-at-uswest-dot-net>" <Peter.Lawrence-at-Sun-dot-com>

Matt,
     I'm still figuring NSTs out, but here goes
     
1, corona is lossage, unless it is comming out of the top, in which case
we call it streamers
     
2, an NST rated at for example 12kv-30ma will put out 12kv when the output is
open circuit (no load), and 30ma when the output is a short circuit. You can
draw a graph of volts vs amps if you connect various (resistive) loads and
you will get a straight line (thats why their called "linear output") like
this:

	12-kv*
	     |  *
	8   |    *
	     |      *
	4   |        *
	     |          *
	0   +-------------*
	     0   10   20   30-ma
	     
so its definately not "constant current"!


(no one seems to _really_ know what happens to a current-limited
xfrmr with a reactive rather than resistive load).


3, you have to be careful when measuring NST outputs or you will blow your
meter. Terry has a good suggestion for current, put a 1kohm/25watt resistor
across the NST output (thats a short circuit for all practical purposes
since the internal res of the NST is 20k-50k) and measure the volts across
the resistor, 1 volt across 1kohm => 1-ma. Terry recommends a 130vac meter
for NSTs up to 120-ma.

http://hot-streamer-dot-com/TeslaCoils/Misc/meter.jpg

to measure volts, make a hugh voltage divider with a long string of very high 
valued resistors (like 10 * 1MegOhm for 10:1, or 10*1MegOhm + 100KOhm for
100:1, or 10*1MegOhm + 10KOhm for 1000:1).


4, plan ahead, way far ahead...!


-Peter Lawrence.




>Original poster: "Matt S. by way of Terry Fritz <twftesla-at-uswest-dot-net>" 
<matt777777-at-hotmail-dot-com>
>
>Hi,
>I have a couple of questions I was wondering if someone could possibly 
>answer for me.
>(I am in the process of launching off my first coil and am hoping to learn 
>as much as possible as I go).
>I am fully aware of the basic nature of these questions an appreciate any 
>indulgence.
>
>1.  Is there any current 'lost' to corona?
>
>2.  I understand that an NST is current limited.  Is it also a constant 
>current kind of thing  -  i.e. when I'm only putting 80 volts to my 12/60 
>NST, is it still supplying 60 ma?
>
>3.  Is it out of the question to toss an old common analog current  meter in 
>the output of my NST (before powering it up that is)-- (I'm trying to grasp 
>the nature/% of the voltage drop across the internal components of the meter 
>in relation to the nst/gap circuit... .......and probably missing some key 
>point).
>
>Thanks,
>Matt.
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