RE: Secondary size

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

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

Not that I intend to but if a very small dia secondary were used would
there be any damage to anything?  Or is it only a matter of low out put
based on the inductance ratio issue?

Luke Galyan
Bluu-at-cox-dot-net

-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Wednesday, January 14, 2004 3:30 PM
To: tesla-at-pupman-dot-com
Subject: Re: Secondary size

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


Keep your coilform dia as large as practical.  An 8-10 inch dia for even
a
small coil will give much longer sparks due to it's overall higher
inductance ratio (sqr (Ls/Lp).  A 2 inch dia. coil won't cut it --- too
low
inducance ratio because IR goes up as the square of the radius.

Dr. Resonance

Resonance Research Corporation
E11870 Shadylane Rd.
Baraboo   WI   53913
  >
  > 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
  >   >
  >   >
  >   >
  >   >
  >
  >
  >