Re: oil for caps (fwd)

To: tesla-at-pupman-dot-com
Subject: Re: oil for caps (fwd)
From: Tesla List <mod1-at-pupman-dot-com>
Date: Mon, 12 Jan 1998 18:46:01 -0700 (MST)
Approved: mod1-at-pupman-dot-com


---------- Forwarded message ----------
Date: Mon, 12 Jan 1998 17:25:29 -0700
From: "D.C. Cox" <DR.RESONANCE-at-next-wave-dot-net>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: oil for caps (fwd)



to: Ralph

Sounds like excellent performance in a small system.  What is your upper HV
terminal type and size??  Also, is 25 inches the sec winding length (wire
gauge??) or total sec coil form length??

DR.RESONANCE-at-next-wave-dot-net

----------
> From: Tesla List <tesla-at-pupman-dot-com>
> To: tesla-at-pupman-dot-com
> Subject: Re: oil for caps (fwd)
> Date: Monday, January 12, 1998 4:46 PM
> 
> 
> 
> ---------- Forwarded message ----------
> Date: Mon, 12 Jan 1998 16:58:51 -0500
> From: Thomas McGahee <tom_mcgahee-at-sigmais-dot-com>
> To: Tesla List <tesla-at-pupman-dot-com>
> Cc: Esondrmn-at-aol-dot-com
> Subject: Re: oil for caps (fwd)
> 
> 
> 
> ----------
> > From: Tesla List <tesla-at-pupman-dot-com>
> > To: tesla-at-pupman-dot-com
> > Subject: Re: oil for caps (fwd)
> > Date: Monday, January 12, 1998 1:48 PM
> > 
> > 
> > 
> > ---------- Forwarded message ----------
> > Date: Mon, 12 Jan 1998 13:27:33 EST
> > From: Esondrmn <Esondrmn-at-aol-dot-com>
> > To: tesla-at-pupman-dot-com
> > Subject: Re: oil for caps (fwd)
> > 
> > In a message dated 98-01-09 02:01:20 EST, you write:
> >    -  snip  -
> > << 
> >  Fellow Coilers.
> >  I made the original post re SUNISO oil and its apparent effect of
> >  increasing the expected capacitance of a stacked plate cap (aluminium
> >  litho plates and polystyrene dielectric).
> >  I was concerned that possibly my findings were in error, so I set up a
> >  small test as follows:-
> >  I built a very rudimentary cap consisting of 4 aluminium litho plates 
> >  7" x 5" separated with 3 sheets of polystyrene 1/16" thick.
> >  The unit was taped together and the capacitance measured with a
> >  Parameters 7060 multimeter as .000635 uF.
> >  I then lowered the unit still connected to the multimeter into a
> >  container full of Suniso 3GS refrigeration oil.
> >  The capacitance steadily rose as the capillary action sucked the oil
> >  between the plates to .000747uF. But stopped there due to air trapped
in
> >  the centre of each plate.
> >  I dismantled the stacked plate and reassembled wet (painted each plate
> >  with oil) and the measured capacitance was .000859uF.
> >  This was only a quick and dirty experiment which you can all duplicate
> >  with virtually no expense.  The results show quite clearly that the
> >  Suniso 3GS oil does in fact increase the expected capacitance.  This
> >  particular test did not show an increase of 100%, but never the less
> >  there is an increase.
> >  My original cap ((.02uF) - which should have been .01uF using the
TESLAC
> >  program) is still functioning and hasn't missed a beat in 2 years! is
> >  used with 4 x 10kv 30mA neon trannies in parallel driving a 9" x 25"
> >  secondary, with a 1/4" copper flat spiral primary - 9 turns tapped at
> >  7.5 - produces 4 foot streamers consistently using a single spark gap
> >  (brass coach bolts - about 1/4" gap).
> >  Regards
> >  Ralph Down
> >  Keyboard Electronics
> >  Gold Coast
> >  Australia
> >   >>
> > Ralph,
> > 
> > I thought the original question here was whether or not one type of oil
will
> > yield a higher capacitance value (significantly higher, like double)
when
> > compared to say mineral oil.  Your test shows that a cap with
polystrene and
> > oil produces more capacitance than a cap with polystrene and air.  No
> argument
> > here, I would expect that.  I calculate that your test cap should
produce
> > about 978 pf - and you measure a little less, which is also expected as
the
> > caps we normally build end up with a spacing between plates a little
more
> than
> > the measured thickness of the dielectric due to everything not being
> perfectly
> > flat and insuffecient pressure holding the plates together.
> > 
> > Once again, I maintain that the selection of the type of oil will not
> > dramatically affect the capacitance value achieved.
> > 
> > Ed Sonderman
> 
> Ed & Ralph,
> I have to agree with Ed here. The air with a constant of 1 is being
> displaced by the SUNISO oil, and the increase is as we would expect
> with just mineral oil. To lay the thing to rest once and for all
> would be simple: perform the exact same experiment, but use mineral
> oil this time. If the results are about the same, then that would show
> that there is little or nothing to be gained by using oils of
> higher dielectric constant.
> 
> HOWEVER, I believe that the looked-for increase probably WOULD show up
> if the cap was made using 6 mil poly!!! The reason here is that the 
> thickness of the oil interface will now be much larger in proportion
> to the poly thickness. Note that this would imply TWO things at least:
> Higher dielectric constant oil COULD be used to increase the capacitance
> of caps made using THIN poly, AND such use of high dielectric constant
> oil WOULD put greater electric stress on the poly, because the
> proportion of thickness would be quite different with thin poly.
> 
> Ralph, was your cap built using THIN poly? That would account for its
> increase.
> 
> Hope this helps the discussion.
> Fr. Tom McGahee