Re: Oil insulated secondaries (fwd) (Aluminum plate under coil. Does it waste power? No!) (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Sun, 9 Sep 2007 18:40:57 -0700 (PDT)
From: J. Aaron Holmes <jaholmes@xxxxxxxxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: Oil insulated secondaries (fwd)  (Aluminum plate under coil.  Does
    it waste power?  No!)

Regarding the use of copper tubing for a ground
conductor within the circumference of the
primary/secondary:  I can, however, see where this
might be problematic, if not for power "waste", then
for power reflected down and away from the secondary
above (since the base of the secondary will be
somewhat above the primary).  Perhaps some flat copper
busbar or else a number of small-diameter rods would
be best.  Or perhaps simply cutting a notch down the
side of the copper tubing.  That would certainly be a
breeze.  ...?

Cheers,
Aaron, N7OE

--- "J. Aaron Holmes" <jaholmes@xxxxxxxxxxxxxxxxxx>
wrote:

> Hey, Peter:
> 
> This was discussed quite a bit on 4HV a short while
> back, and almost universally contradicted (to my
> surprise, I'll admit).  However, IIRC, it can be
> easily explained like this:  Because copper and
> aluminum are great conductors, it's extremely
> difficult to induction heat them (i.e., cause them
> to
> "waste" power).  Rather, when placed under a coil,
> they'll tend simply to reflect power.  A number of
> folks conducted exeperiments which agreed with this,
> basically showing that large copper and aluminum
> sheets under coils raised the primary-secondary
> coupling by way of reflected power, and did not
> "waste" power.
> 
> ...but we shall see!  There will be a few
> interesting
> experiments going on simultaneously here.  There
> will
> be some clearance between the end cap and the
> primary,
> obviously; I'm not planning on having the primary
> wrapped right around a big aluminum block!  If the
> clearance seems intuitively a bit small, I may play
> with a shorter coil form.
> 
> And of course, if it all fails miserably, I promise
> to
> still share the results immediately in case it
> should
> prevent anybody from following me down a dead end!
> :-)
> 
> Cheers,
> Aaron, N7OE
> 
> --- Tesla list <tesla@xxxxxxxxxx> wrote:
> 
> > 
> > ---------- Forwarded message ----------
> > Date: Mon, 10 Sep 2007 01:38:16 +0800
> > From: Peter Terren <pterren@xxxxxxxxxxxx>
> > To: Tesla list <tesla@xxxxxxxxxx>
> > Subject: Re: Oil insulated secondaries (fwd)
> > 
> > I see a problem.  The aluminum end cap near the
> > toroid has very low coupling 
> > and is not a problem. The cap at the other end
> will
> > be right on your primary 
> > and will absorb most of your power.  Also you
> can't
> > suspend a coil on a 
> > copper tube, particularly if the copper tube is
> near
> > the primary for the 
> > same reason but I am not quite sure what you
> > planned.
> > I am planning an oil insulated secondary for my
> > polypancake coil
> >
>
http://tesladownunder.com/Tesla_coils_intro.htm#Multilayer%20Tesla%20coil
> > 
> > Peter
> > 
> > >
> > > ---------- Forwarded message ----------
> > > Date: Sat, 8 Sep 2007 16:22:58 -0700 (PDT)
> > > From: J. Aaron Holmes
> > <jaholmes@xxxxxxxxxxxxxxxxxx>
> > > To: Tesla list <tesla@xxxxxxxxxx>
> > > Subject: Re: Oil insulated secondaries (fwd)
> > >
> > > Hey there, Dave!  I'd be interested in any tips
> > here,
> > > too, however I suspect the number of amateur
> > coilers
> > > who have built oil-insulated secondaries can be
> > > counted on one hand, maybe less ;-)  The only
> > > functioning amateur oil-insulated coil I've ever
> > seen
> > > pictures of is Terry Blake's:
> > >
> >
>
http://www.tb3.com/tesla/teslathon2003/tb_tc/tb_tc.htm
> > >
> > > It was his coil that inspired me to start
> building
> > my
> > > own oil-insulated coil.
> > >
> > > I've also heard of a few oil-insulated research
> > coils,
> > > and seen drawings illustrating their
> construction.
> > >
> > > For about the last year, I've been slowly
> > gathering
> > > the pieces for a medium-sized oil-filled
> > secondary.
> > > For lack of any real guidance on oil-insulated
> > > construction, I've decided to strike out in what
> > seems
> > > like a new direction:  I'm building the
> secondary
> > > inside an oil-tight ceramic insulator that used
> to
> > > house a 115kV capacitor:
> > > http://silicon-arcana.com/cap/cap.jpg
> > > (on left)
> > >
> > > It's about 4' tall and will accomodate a 6" x
> 30"
> > coil
> > > form quite nicely.
> > >
> > > The insulator has aluminum end caps with rubber
> > seals.
> > > If the end caps were steel, I'd worry about
> > losses,
> > > but aluminum should be fine.  The bottom of the
> > coil
> > > form will be stood off from the bottom cap, too.
> > >
> > > The secondary winding itself will also be
> > something
> > > unusual; a friend with a lathe has cut threads
> > into a
> > > piece of clear acrylic tubing, such that the
> > secondary
> > > windings will actually lie in a groove, held
> very
> > > slightly apart so that the oil almost completely
> > > surrounds them.  I will not be coating the
> winding
> > at
> > > all; the threaded form will keep the windings in
> > > place.  Within the ceramic insulator, the coil
> > form
> > > will be suspended from both ends by 2" OD copper
> > > tubing.  I'll also be installing a pressure
> > release
> > > valve on the top cap.  The top cap will then be
> > > completely hidden inside a 6"x24" spun toroid
> > which
> > > I've cut most of the center out of.  A larger
> > 8"x30"
> > > toroid will comprise the main topload above
> this.
> > >
> > > All this, it is hoped, will look extremely cool
> > when
> > > finished, not to mention being almost
> > indestructible.
> > > The biggest missing piece right now is the time
> to
> > > actually finish it!  But as I have so little
> time
> > in
> > > general, I'm being patient about collecting all
> > the
> > > best stuff.  I can't bank on any second chances!
> > > We'll see what happens.  I'm hoping to actually
> > have
> > > something working by mid 2008.
> > >
> > > Cheers,
> > > Aaron, N7OE
> > >
> > >
> > > --- Tesla list <tesla@xxxxxxxxxx> wrote:
> > >
> > >>
> > >> ---------- Forwarded message ----------
> > >> Date: Sat, 08 Sep 2007 02:08:24 +0000
> > >> From: Sparktron01@xxxxxxxxxxx
> > >> To: Tesla List <Tesla@xxxxxxxxxx>
> > >> Subject: Oil insulated secondaries
> > >>
> > >> Folks
> > >>
> > >> Are there some links to construction techniques
> > to
> > >> build a oil insulated Tesla Coil or
> > >> Magnifier secondary (or extra coil)?  Please
> > advise.
> > >>  Thanks
> > >>
> > >> Regards
> > >> Dave Sharpe, TCBOR/HEAS
> > >> Chesterfield, VA. USA
> > >>
> > >>
> > >>
> > >>
> > >
> > >
> > > 
> > 
> 
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