Re: Secondary insulation; Racing sparks

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

Original poster: "Bert Hickman by way of Terry Fritz <twftesla-at-qwest-dot-net>" <bert.hickman-at-aquila-dot-net>

Hi John,

I have little doubt that this technique would work quite well. At an
East Coast Teslathon many years ago, one coiler brought a great
performing little coil that had a 1" diameter secondary. Surrounding the
secondary was a larger diameter tube made from clear acrylic or
polycarbonate. The space between was filled with mineral oil. The
winding could easily be seen through the outer tube an mineral oil. The
little 1" winding was magnified by the optics of the system, making the
winding look significantly bigger than it really was. 

This little coil had no problem generating 24"+ streamers with no signs
of overcoupling or racing sparks. The presence of the oil (k~2.3)
immediately next to the winding should dramatically reduce the voltage
stress at the outer surface of the winding's insulation versus air
(k=1). The overall impact of the wire, oil, and outer clear dielectric
layer should permit the system to run at a significantly higher coupling
coefficient without racing sparks than if it the secondary winding was
simply surrounded by air alone...

Best regards,

-- Bert --
-- 
Bert Hickman
Stoneridge Engineering
"Electromagically" (TM) Shrunken Coins!
http://www.teslamania-dot-com

Tesla list wrote:
> 
> Original poster: "John Richardson by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <jprich-at-up-dot-net>
> 
> Hi,
> After reading the latest thread concerning methods to insulate secondary
> windings, I was wondering the feasibility of obtaining a piece of  PVC with
> an i.d. slightly larger than the o.d. of the secondary winding, slipping the
> coil in and filling the gap with mineral or transformer oil, after proper
> sealing measures have been taken.  Seems to me that this would eliminate
> insulating difficulties and protect the secondary from flashovers.  Thoughts
> would be appreciated.
> 
> John Richardson
> 
> (Terry, sorry for sending this to the wrong address.)  > No problem ;-) <