Re: Safety Gap

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

Original poster: "Gary  Weaver" <gary350-at-earthlink-dot-net> 

Forget the safety gaps.  I tried them and decided they are a waste of time
and effort.  I have not used a safety gap on any of my coils in probably 4
years.  http://home.earthlink-dot-net/~gary350/tc10-4.jpg
Gary Weaver



----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Sunday, February 08, 2004 9:45 AM
Subject: RE: Safety Gap


 > Original poster: "Luke" <Bluu-at-cox-dot-net>
 >
 > The gap I used was not for use as the safety gap.  I was just trying to
 > get an idea as to what spacing I did need for the gap.  I knew shape had
 > a little to do with it but didn't think that much.
 >
 > But for the sake of getting the feel of it, let me ask this.
 >
 > If I were to use
 > 1: standard style main static spark gap consisting of copper pipe
 > parallel to each other and spaced at about 0.29" as JavaTC says is about
 > right.
 >
 > 2: Used a needle gap for a safety gap set at just over 3/4" so gap
 > was just large enough to prevent the NST from arcing.
 >
 > Would the safety gap still perform its task?
 > I would assume yes but what are some thoughts on this.
 > I do intend to use rounded electrodes in the safety gap but what would
 > be the input on the above?
 >
 > Luke Galyan
 > Bluu-at-cox-dot-net
 >
 > -----Original Message-----
 > From: Tesla list [mailto:tesla-at-pupman-dot-com]
 > Sent: Saturday, February 07, 2004 3:35 PM
 > To: tesla-at-pupman-dot-com
 > Subject: Re: Safety Gap
 >
 > Original poster: Bart Anderson <classi6-at-classictesla-dot-com>
 >
 > Hi Luke,
 >
 > Absolutely! What you basically have is a needle gap. The influence of
 > electrode shape and size plays a major role defining the arc voltage for
 > a
 > given gap width. For larger electrodes and the narrow gap spacing used
 > for
 > the typical spark gap configuration, the numbers should be pretty close.
 >
 > The reason is that the electrodes appear planar. But as you start
 > decreasing the electrode size where the gap width is larger than the
 > electrode size, the shape and curvature come into play. And with that,
 > if
 > the gap width is "much" larger, the electrodes begin to appear like a
 > point
 > or needle gap.
 >
 > Dr. Resonance last year tested flat electrodes with a 30kV supply
 > varying
 > the gap width and measuring the voltage at which the gap conducted.
 > Javatc
 > follows those actual arc voltage measurements pretty darn close
 > throughout
 > it's range. Thanks to Dr. R's measurements, I had some actual data to
 > work
 > with. However, if a needle gap such as you have set up is used, then all
 >
 > bets are off. However, what you have provided here is another good piece
 > of
 > information that can be jotted down for review regarding a needle gap
 > setup
 > with a 15/30 NST could arc across 3/4", which is certainly believable.
 >
 > Take care,
 > Bart
 >
 > Tesla list wrote:
 >
 >  >Original poster: "Luke" <Bluu-at-cox-dot-net>
 >  >Yup no caps.
 >  >Just an NST and a Spark gap.
 >  >The spark gap in this case was nothing more than two pieces of copper
 >  >wire cut and pointed toward eachother. So it wasn't rounded balls or
 >  >anything like that. Does that make a huge difference?
 >  >
 >  >Luke Galyan
 >  >Bluu-at-cox-dot-net
 >  >
 >  >-----Original Message-----
 >  >From: Tesla list [mailto:tesla-at-pupman-dot-com]
 >  >Sent: Friday, February 06, 2004 6:34 PM
 >  >To: tesla-at-pupman-dot-com
 >  >Subject: Re: Safety Gap
 >  >
 >  >Original poster: Bart Anderson <classi6-at-classictesla-dot-com>
 >  >
 >  >Hi Luke,
 >  >
 >  >What are using as electrodes and what are the dimensions of the
 >  >electrodes?
 >  >BTW, is this test with only the NST and the sparkgap? (no cap in
 >  >there?).
 >  >
 >  >Let me know.
 >  >Thanks,
 >  >Bart
 >  >
 >  >Tesla list wrote:
 >  >
 >  > >Original poster: "Luke" <Bluu-at-cox-dot-net>
 >  > >I was working out how I wanted to make my safety gap and happened
 >  >across
 >  > >something that has me confused.
 >  > >Using the JavaTC program with a static spark gap and a 15KV NST, if I
 >  >set
 >  > >the total gap spacing to anything over 0.3" I am informed that the
 >  >voltage
 >  > >needed to jump the gap is greater than the peak voltage of the NST.
 >  > >
 >  > >I was assuming that the safety gap would be set at close to this
 >  >distance
 >  > >as well. I started playing with a 15KV 30mA NST. I can set a gap of
 >  >almost
 >  > >¾" and still get an arc when I energize the NST. This seems to be
 > close
 >  >to
 >  > >the cut off point since it sometimes will and sometimes will not jump
 >  >the
 >  > >¾" gap.
 >  > >
 >  > >Yes I know the peak voltage is around 21 or 22KV. And just to avoid
 > the
 >  >
 >  > >questions no I am not using a variac. I just have a cord with a cord
 >  >cap
 >  > >on it and I plug it in, then poof an arc jumps the ¾".
 >  > >
 >  > >Is JavaTC telling me something other than what I think it is? Is
 > there
 >  > >something I am missing? Any comments.
 >  > >
 >  > >Luke Galyan
 >  > >Bluu-at-cox-dot-net
 >  > >
 >  > >
 >  > >
 >  > >
 >  > >
 >  >
 >  >
 >  >
 >  >
 >
 >