[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Conical and Pancake Coil Arguments... (fwd)



---------- Forwarded message ----------
Date: Mon, 18 Jun 2007 20:52:55 +0800
From: Peter Terren <pterren@xxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: Conical and Pancake Coil Arguments... (fwd)

Your comments on pancake coils are of interest to me. I still have (in the 
loungeroom for the last 2 years or so) the materials for a 20 layer pancake 
coil to be immersed in oil.  What has been stopping me going further is the 
concern about air voids as you say.  I can see the rationale for cotton 
covered wire here but oil soaked cotton is not going to let air out easily 
either so it may not be the complete answer.
Peter 
http://tesladownunder.com/Tesla_coils_intro.htm#Multilayer%20Tesla%20coil


---------- Forwarded message ----------
Date: Sun, 17 Jun 2007 23:26:16 +0000
From: Jeff Behary <jeff_behary@xxxxxxxxxxx>
To: tesla@xxxxxxxxxx
Subject: Conical and Pancake Coil Arguments...
....
Tesla stated in 1897 that he used quadruple cotton covered wire to insulate
his Pancake Coils, and later used normal magnet wire wound with a required
thickness of string to achieve the proper distances in his coils. Tesla Coil
X-Ray pioneer T. B. Kinraide used silk-covered magnet wire that was covered
EIGHT times in order to insulate his coils properly.

Today we have rubber and PVC coated wire.  These work great for Cylindrical
and Conical Tesla Coils,
no argument there, but for Pancake Coils they are useless.  The original
cotton and silk covering allows insulation to flow THROUGH the windings and
saturate all interstices of the coil up to the wire itself.  When plastic
covered wire is used (even under vacuum impregnation) small voids and air
pockets result from the tension of turns next to each other.  Sections of
the coil can become "vacuum-tight" as it were though still have air trapped
within these voids found between turns.  The result is a coil that works
really well for a split second and then pours out black smoke from within.

......
Jeff Behary, c/o
The Turn Of The Century Electrotherapy Museum
http://www.electrotherapymuseum.com