Re: Oil insulated secondaries (fwd) (Are they worth it?) (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Tue, 11 Sep 2007 09:58:50 -0500
From: resonance <resonance@xxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: Oil insulated secondaries (fwd) (Are they worth it?) (fwd)




Epoxy works well if it is vacuum impregnated, otherwise it is not a good 
choice as it just provides a cover not an imbedded insulator.

Using only a cover, the seemingly tight fit actually looks like the Grand 
Canyon to an electron.  Very small critters indeed!





Dr. Resonance

Resonance Research Corp.
www.resonanceresearch.com


----- Original Message ----- 
From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Tuesday, September 11, 2007 7:25 AM
Subject: Re: Oil insulated secondaries (fwd) (Are they worth it?) (fwd)


>
> ---------- Forwarded message ----------
> Date: Mon, 10 Sep 2007 21:11:57 -0700
> From: huil888 <huil888@xxxxxxxxxxxx>
> To: Tesla list <tesla@xxxxxxxxxx>
> Subject: Re: Oil insulated secondaries (fwd) (Are they worth it?) (fwd)
>
> Aaron -
>
> I've got to disagree with your position that epoxy coatings don't provide
> effective electrical insulation. I've been using epoxy to coat every
> secondary I've wound over the last 8 years or so, and I can assure you 
> that
> a heavy (.050" or thicker) epoxy coating provides extremely effective
> electrical insulation, as well as providing the mechanical protection you
> mention.
>
> Since I started using epoxy coatings, I have never had a secondary damaged
> by external arcing or flashover, even when used with  helical primaries 
> with
> very high coupling factors. Exactly how much electrical insulation is
> provided can be seen when there is a tiny pinhole or near-microscopic 
> bubble
> in the coating anywhere in the upper 1/2 of the secondary. Once the coil 
> is
> tuned and operating at near peak power, corona and thin spidery arcs will
> flow out of the pinhole like a leak in a pressurized garden hose.
>
> I fully agree that aside from the novelty factor, its hard to justify the
> additional complexity and probability oil seepage with an oil-insulated
> secondary for a conventional Tesla coil.. A correctly applied epoxy 
> coating
> will give the appearance that the secondary is encased in a perfect glass
> sleeve, an effect that you just can't get with concentric acrylic tubes 
> with
> oil in between.
>
> The only place that I can think of where this additional complexity is
> likely to provide any real benefits is in a magnifier setup, where the
> extremely tight pri-sec coupling makes it very hard to prevent corona and
> flashover.
>
> Regards,
> Scott Hanson
>
>
>
> ----- Original Message ----- 
> From: "Tesla list" <tesla@xxxxxxxxxx>
> To: <tesla@xxxxxxxxxx>
> Sent: Monday, September 10, 2007 7:37 PM
> Subject: Re: Oil insulated secondaries (fwd) (Are they worth it?) (fwd)
>
>
>>
>> ---------- Forwarded message ----------
>> Date: Mon, 10 Sep 2007 09:53:09 -0700 (PDT)
>> From: J. Aaron Holmes <jaholmes@xxxxxxxxxxxxxxxxxx>
>> To: Tesla list <tesla@xxxxxxxxxx>
>> Subject: Re: Oil insulated secondaries (fwd) (Are they worth it?)
>>
>> Epoxy coating is not about electrically insulating,
>> it's about physically protecting and preventing the
>> windings from sliding off.  That's it, really.  Oil
>> does neither of these things, and is instead all about
>> electrical insulation.  HOWEVER, whether it's any
>> advantage at all depends on what other aspects of your
>> design you hold constant, and given that most of these
>> other aspects are usually controllable in such a way
>> as to avoid the necessity of oil insulation, I'd have
>> to agree that oil insulated secondaries are moderately
>> to extremely silly in most cases.  They are
>> undoubtedly "interesting" and "cool", though.  I loved
>> the look of Terry Blake's coil, and decided to add my
>> own twist".
>>
>> All else being equal, I'd expect oil insulation would
>> make the secondary less susceptible to secondary
>> breakout, primary-secondary strikes, racing arcs, and
>> internal arcing.  This, in turn, might permit the use
>> of higher-than-average coupling, larger toploads
>> (which would otherwise tend to encourage secondary
>> breakout), and generally a bit more power, achieving a
>> higher-than-average streamer-to-secondary length
>> ratio.  But we'll see!!  Again, I doubt if it's a very
>> practical way to accomplish these things, but it is
>> nonetheless a fun twist.
>>
>> Cheers,
>> Aaron, N7OE
>>
>> --- Tesla list <tesla@xxxxxxxxxx> wrote:
>>
>>>
>>> ---------- Forwarded message ----------
>>> Date: Sun, 9 Sep 2007 18:22:33 -0700 (PDT)
>>> From: Yurtle Turtle <yurtle_t@xxxxxxxxx>
>>> To: Tesla list <tesla@xxxxxxxxxx>
>>> Subject: Re: Oil insulated secondaries (fwd)
>>>
>>> I'm just curious why oil would be better than simply
>>> potting it in epoxy. I realize it would look cooler.
>>> Seems like an oil tight seal would be harder to
>>> accomplish than one that only needs to hold up until
>>> the epoxy hardens.
>>>
>>> Adam
>>>
>>> --- Tesla list <tesla@xxxxxxxxxx> wrote:
>>>
>>> >
>>> > ---------- 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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