Re: line current for primary?

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

Original poster: "Laurence Davis by way of Terry Fritz <twftesla-at-qwest-dot-net>" <meknar-at-hotmail-dot-com>

Got to play with it last night.  It =IS= a nst powered coil.  nice little 
science project.  6kv/20ma, 5nf/10kv pulse cap (no mfg on it).
got to see spark racing on the secondary. woohoo!  and after we played with 
it for 20-30mins.... I found out what a pulse cap sounds like when it pops. 
;)  I feel partially responsible... i kept thinking of fun things to use as 
a topload.  I guess I'm gonna build him an mmc to replace the blown cap.  
neat thing i didn't expect was the coil kept running after the cap blew.  I 
shut it off after 2 or 3 secs after it popped.  he also learned that pulse 
caps hold a charge without a bleeder.  also: don't play with a tesla coil 
next to the cash register while working (at mcdonalds.)  (they tend to lock 
up. :)

basic coil specs: 6kv/20ma nst (actown), 5nf/10kv pulse cap(1.25"x3" 
cylinder w/radial leads), 3inch secondary wrapped w/30awg to a height of 
maybe 10-12", primary using 3 or 4 turns of aluminum wire, single point 
adjustable tungsten carbide electrodes. all housed in a nice little aluminum 
expermenters box.

larry d.


>From: "Tesla list" <tesla-at-pupman-dot-com>
>To: tesla-at-pupman-dot-com
>Subject: Re: line current for primary?
>Date: Sun, 30 Jun 2002 21:30:35 -0600
>
>Original poster: "Daniel McCauley by way of Terry Fritz 
><twftesla-at-qwest-dot-net>" <dhmccauley-at-spacecatlighting-dot-com>
>
>Doesn't sound right.  If he is indeed running his coil at 120vac, 60 hz
>(neglecting spark gap operation), the impedance of the primary coil at that
>frequency would pretty much be a "short circuit", or better yet, a nice
>wirewound heater.
>
>My guess is that he is running 120vac to power a NST or something which 
>then
>in turn powers the primary.
>
>Dan
>
>
>
>
>
> > I'm going to see someone tonight that has a coil running 120vac
> > on the primary.  static gap w/tungsten contacts.  generates about 18inch
> > arcs.  Is this possible?  I understand that the voltage multiplying 
>affect
> > of tesla coils is by inductance ratio rather than turns ratio, so... I
>guess
> > this could work.  but the gap has to be very small.  I think the 
>breakdown
> > of air is 50v/mil, right?  so that would be 2 or 3 mils.  then its going
>to
> > be interesting to quench with such a small gap distance.  The owner of 
>the
> > coil told me it is "unstable."  Perhaps the gap is getting hot or it is
>hard
> > to quench?  He also said there wasn't any (intentional) current limiting
> > from the line current.
> > I mean if you were to use a specific wire size to the primary, smaller
> > diameter wires would offer resistance, although I don't think i'd want 
>to
>go
> > that route to limit current.
> >
> > I'll let you all know what I find out. maybe even some pics, if I can 
>get
>it
> > to my house. ;)
> >
> > lar.
> > (coiling in pittsburgh)
> >
> >
>