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Primary tube diameter

Subject:  Re: More rotary gap questions... (fwd)
  Date:   Tue, 22 Apr 1997 07:37:43 -0700
  From:   "DR.RESONANCE" <DR.RESONANCE-at-next-wave-dot-net>
    To:   "Tesla List" <tesla-at-pupman-dot-com>


Hello All

Tom's points are well taken.  We use 1/4 in. ID tubing only on systems
running .02 MFD caps or smaller.  Larger systems with values above .02
to
0.1 should consider only 1/2 in. ID tubing.  Copper strap is fine for
smaller systems but should not be considered on large systems with
sparks
of 48 in. or longer as the sharp edges tend to produce easier ionization
of
the pri-sec coil area.  Copper tubings smaller radius of curvature and
lack
of sharp points help minimize these problems.

The larger copper tubing is also required to handle the relatively large
pulse currents produced.  We have measured these currents on a .06 MFD
cap
at over 2,200 peak Amperes.  Even though it's only there for a few
microseconds (or less) it is a very high value and really doesn't
"enjoy"
snaking its way thru stainless steel or other poor conductors of RF
(200-400 KHZ) currents.  Who said electrons don't think???

DR.RESONANCE-at-next-wave-dot-net


----------
 
> 
> 
> snip
> > 
> > Hello Dr Resonance, all,
> >                          I just had to ask a question about this 
> > statement:
> > 
> > <snip>
> > > Even though most coilers use copper tubing primarys,
> > > good
> > > grade caps, etc. they sometimes forget that the most circuit
resistance
> > > is
> > > thru the stainless steel or steel electrodes in their sparkgaps.
> > 
> > Leaving aside the cap and primary inductor, which component apart 
> > from the ionized air in the gap itself has some 200V across it while 
> > passing the primary current?
> > 
> > Malcolm
> > <snip - points about burning stainless noted>
> 
> Malcolm,
> The wiring that links the tank circuit together can easily have several
> hundreds of volts across it. The voltage drops will be particularly
> large
> at the junctions unless they are soldered or made with a good
> compression
> joint that includes lots of connective surface area. The wiring is an
> often
> overlooked source of energy loss. For some strange reason people can't
> get
> it though their heads that the primary tank circuit is a CIRCUIT (a
> circle)
> that includes the inductance of the connecting wires as well as the
> inductance of the primary coil. I have seen Tesla circuits in which the
> inductive losses due to the twists and turns in the wiring must have
> been
> substantial... say 10 to 15% as large as the primary inductance. That
> affects the tuning too! Use conductors with large surface areas, smooth
> surface areas, and as short and straight as possible. Ideally if your
> primary is 1/4 inch copper tubing, the entire tank wiring should be at
> least as robust. Sometimes you will touch a connection joint after a
> long
> run and you can feel the difference in temperature between the wiring
> and
> the junctures. This is especially true at points where the metals are of
> different kinds.
> 
> Fr. Tom McGahee