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 16:33:34 -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!)

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
> >>
> >>
> >>
> >>
> >
> >
> > 
> 
> 
> 
>