Re: Charging Inductor Construction (fwd) / Induction Coils; brothers of TC's (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Mon, 29 Oct 2007 04:48:34 +0100
From: Kurt Schraner <k.schraner@xxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: Charging Inductor Construction (fwd) / Induction Coils; brothers
    of TC's

Hi Ed

comments interspersed...

Tesla list wrote:
> ---------- Forwarded message ----------
> Date: Sun, 28 Oct 2007 10:39:17 -0700
> From: Ed Phillips <evp@xxxxxxxxxxx>
> To: Tesla list <tesla@xxxxxxxxxx>
> Subject: Re: Charging Inductor Construction (fwd) / Induction Coils
> (fwd)
>
> Hello Ed,
>
> thanks for the answer and for giving me the term "scramble wound",
> correcting my very limited english-vocabulary  :-) . "
>
> "Wild wound" conveys the thought just as well.  Your english
> vocabulary is infinitely better than my german one and all of you
> notes are perfectly clear to us so please don't apologize for it!

Well..., thank you! ;-)
>
> One thing that isn't clear to me is how you hold the windings
> together when you impregnate with paraffin.  If you've explained this
> I've missed it in reading what you've written.  Are the cardboard
> former pieces part of the assembly you place in the molten paraffin?
> I notice that you take the wise precaution of heating the paraffin in
> hot water rather than over an open flame.  That is a more complicated
> procedure than just placing the paraffin container on the heater but
> far safer!!!

True: in a "balneum-Mariae"(waterbath) the temperature of the paraffin can 
be kept easier within some temperature limits. This (appart from safety 
considerations), appears also to be of some relevance, 'cause insulating 
properties of the paraffin: when getting yellowish those properies decrease, 
which is easily the case, when heating paraffin more than 80C over extended 
time, as needed to impregnate all the coils.
The cardboard formers _are_ part of the assembly I place in the molten 
paraffin, in order to keep the windings together. The choice of cardboard 
for the formers was (in part), decided in the hope, they would be permeable 
for the liquid paraffin, which I "think" has a fairly low viscosity, 
comparable to water at room temperature. The results seem to confirm this.
>
> Another question has to do with the arrangement of your pies.
> Apparently all are assembled with the windings in the same direction.
> Some very old plans [~ 1910-1920] for making induction coils seem to
> assemble alternate pies with the windings in opposite directions so
> that the connections are top to top and bottom to bottom on adjacent
> pies.  Have you considered this?

Yes, I know this from Codd's relly nice textbook about "Induction Coil 
Design", obtainable from Jim Harvesty of "PV-Scientific Instruments" at:
http://www.arcsandsparks.com/reprintpage.html#HVPA
...and I "think", if making a next coil (...not very propable, considering 
my laziness), I would do it that way. I had a very nice contact to a german 
induction-coil builder, Georg-Wilhelm Schulze, who is an 
"Orgelsachverständiger" and catholic-church man (...not _my_ case ;-) ), who 
sent me detailed information how to make such a winding. His coil was not at 
all impregnated, and seems to work like a champ (Could send his concise 
description (in german), of how the winding was realized, - off-list).

BTW: the best textbook about theory of induction coils, I've met until now, 
is available in the net, Taylor Jones book:
http://www.archive.org/details/inductioncoil032158mbp
Part of his investigations I was able to verify by means of the fairly 
controlled way, operating an induction coil, by means of the Andiruptor. To 
be seen on:
http://twfpowerelectronics.com/%7Ekurt/InductionCoils/induction_coils2.html
specifically:
http://twfpowerelectronics.com/%7Ekurt/InductionCoils/Andiruptor/19_oscillograms_01.jpg

Sorry for getting a little OT.

>
> Thanks for sharing your work with us,
>
> Ed

Best regards
Kurt