RE: Secondary size

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

Original poster: "Luke" <Bluu-at-cox-dot-net> 

To: Dr. Resonance
I have already understood (to some degree) the information you just
posted.
You seem to have missed what I was asking.
I know 4.5:1 works very well.  Since this is true I could then use my
15KV 60Ma NST, give it a SRSG and a MC of .028 micro farads.  Then my
optimal coil height would be 9" tall right?  Providing I use a secondary
dia. of 2" I would still be in the 4.5:1 ratio and poof I should fall
into a good rule of thumb for my coil height.  I got it!  Thanx!

Ok that was not meant to be sarcastic.  I was trying to show you that
the ratio was not my question as stated in the original question.  There
were actually a few questions I had.  but in reference to the one you
answered I was aiming somewhere else.

Assuming I use your recommended 4.5:1 ratio.  What is a good height to
use based on the anticipated arc length?  Obviously the 9" tall coil
might have some problems if say 50" arcs were created.

The question is based on a particular anticipated arc length, what is a
good rule of thumb to decide on the HEIGHT of the coil?

After I get this under my belt ill re ask the other questions.
Thanx

And again I do not mean to sound sarcastic just trying to make a point
in order to address my real question.

Luke Galyan
Bluu-at-cox-dot-net

-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Tuesday, January 13, 2004 9:01 PM
To: tesla-at-pupman-dot-com
Subject: Re: Secondary size

Original poster: "Dr. Resonance" <resonance-at-jvlnet-dot-com>


An optimum coil height to dia ratio is approx 4.5:1.  At values less
than
4.5:1 arcing to primary or strike rails occur on a regular basis.  If
the
coil is too high the coeff. of coupling is lower and less energy is
transferred.
4.5 : 1 seems to work very well.

The potential output of a resonance transformer is equal to it's gain
times
the potential input, ie,

Vout = Vinput peak (1.4 x Erms) x sqr (Ls/Lp)    ----    this is called
system gain.

Also inductance of a coil is proportional to n^2 (high number of turns
works
good because of this square factor) and also to r^2 (this is the radius
of
the coils geometry).  This r squared factor rapidly increases the
inductance
(Ls) in big coils so the gain (voltage multiplication factor) is high
and
output potential is high.

It's important to note that spark length is more of a function of
current
(system power) than potential.  To double the spark length in most
systems
the power has to be increased by a factor of 4 (2 ^2).

Hope this answers your question.

Dr. Resonance

Resonance Research Corporation
E11870 Shadylane Rd.
Baraboo   WI   53913
  >
  > I would assume that the height would be based on anticipated arc
length
and
  > the dia would simply fall into using what you can to stay in the
suggested
  > height to width ratio.
  > How do you go about deciding how tall the coil should be based on the
arc
  > length?
  > Other than aesthetics what is the method for choosing a secondary
size?
  > What is the cut off for deciding how short a coil can be with a given
  > anticipated arc length?
  >
  > It seems there are coils that generate longer arcs than the coil is
  > high.  And since the arcs are referenced to ground it seems that is
putting
  > the top load very close to ground with respect to its output.  I know
that
  > the toroid slash secondary top will be at the same positive or
negative at
  > any one time as the arc and like charges repel so that is what keeps
the
  > arcs from going straight down.
  >
  >
  > Ok also if a height is determined what are the advantages /
disadvantages
  > for going with the larger diameter coil verses the smaller diameter?
Keep
  > in mind that when I say large or small diameter I am talking about
staying
  > close to the excepted rule of thumb for height to dia. ratio.
  >
  > Thanx
  >
  > I will be asking lots more questions so bare with me.  J
  > Luke Galyan
  > Bluu-at-cox-dot-net
  >
  >
  >
  >