Re: compact oil insulated secondaries?

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Jolyon Vater Cox by way of Terry Fritz <teslalist-at-qwest-dot-net>" <jolyon-at-vatercox.freeserve.co.uk>


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Wednesday, April 23, 2003 6:42 PM
Subject: Re: compact oil insulated secondaries?


 > Original poster: "Jim Lux by way of Terry Fritz <teslalist-at-qwest-dot-net>"
<jimlux-at-earthlink-dot-net>
 >
 > At 08:06 AM 4/23/2003 -0600, you wrote:
 > >Original poster: "Jolyon Vater Cox by way of Terry Fritz
 > ><teslalist-at-qwest-dot-net>" <jolyon-at-vatercox.freeserve.co.uk>
 > >
 > >Dear List,
 > >I am considering building an oil filled secondary
 > >to improve durability and increase compactness in a small TC in which I
am
 > >currently using a secondary of 880t of 32swg enamelled copper wire wound
 > >on a former measuring 10.875" long x 2.98 diameter.
 > >
 > >My reason for doing this is because I am planning to double the number of
 > >turns by winding a new secondary using 40swg wire on the same former
 > >and there may be insulation issues to be considered here.
 > >
 > >What is envisaged here is a double-walled cylinder made from two
 > >plastic  tubes of dissimilar diameter the winding wound on the smaller
 > >inner tube with the oil contained between this and the larger outer tube.
 > >the ends of the tubes plugged with rings cut from a polythene chopping
 > >board and sealed with silicone.
 > >
 > >I am anticipating cutting the rings from the board using a  hole saw
 > >driven by an electric drill with cutting blades of different diameters-
 > >will this be OK?
 >
 > This works fairly well, but the cut isn't always the smoothest in the
 > world, and the "as cut" sizes available may not nicely nest.  Silicone
 > doesn't stick all that well to PE (nothing does!). You might want to
 > contemplate some other material.

Would it be possible to use silicone with PE to seal the gap if two tightly
fitting rings were used per seal; the former ring  (in contact with the oil)
being caulked around the edge with silicone to prevent leakage with the
latter,outer ring behind it to provide mechanical support by way of screws
passing through the wall of the outer tube?

Jolyon
 >
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