Re: dielectric constants

To: "'Tesla List'" <tesla-at-poodle.pupman-dot-com>
Subject: Re: dielectric constants
From: Tesla List <tesla-at-stic-dot-net>
Date: Thu, 6 Nov 1997 21:39:57 -0600
Approved: tesla-at-stic-dot-net

From: 	Alfred C. Erpel[SMTP:aerpel-at-op-dot-net]
Sent: 	Thursday, November 06, 1997 6:31 PM
To: 	'Tesla List'; Tesla List
Subject: 	Re: dielectric constants

  Kevin,

    No suggestions on the high reading, but I'd be curious about the
dielectric strength and constant of honey.  After you stop laughing, it
might not be a bad idea.  Clover honey might be a good choice to try because
it is readily available and very consistant.  All honey has an indefinite
shelf life.  But I don't know what would happen to it inside of a high
voltage capacitor.  You could try beeswax too, but it would ruin your
capacitor. (you'd never get every bit off of the laminations unless you
found a solvent for it).

    I am real curious if anyone can tell me about the efficacy of using
beeswax as a dielectric material in building a plate capacitor.  How about
DC vs. AC use?





>>  After hearing of different oils and dielectric constants for capacitor
>> building, I ran a simple experiment.  Using a variable capacitor from an
old
>> tube type radio and measuring its capacitance with air as the dilectric,
and
>> then immersing in different oils I have come up with a list of dielectric
>> constants.
>>
>>   The capacitor had a full mesh reading of .96 nF.  The capacitor was
cleaned
>> in solvent & air blowed dry between each oil immersion.  For the 90w oil
>> test, the oil was heated to 100 deg.F. to saturate the capacitor plates
>> better.
>>
>>
>>                                                    capacitance
>>                       diel. constant
>>
>> begining capacitance in air.                  .96 nF
>>                                  1
>>
>> In pharmaceutical mineral
>> oil (or baby oil)                                  2.08 nF
>>                                   2.17
>>
>> In canlola cooking oil                         3.28 nF
>>                                   3.42
>>
>> in 90w mineral gear oil
>> at 100 deg F                                     18 nF
>>                                    18.75
>>
>> in 30w motor oil                                 55 nF
>>                                    57.3
>>
>>  As can be seen there is a wide range, can't figure the high motor oil
>> reading though, possible additives causing high readings?  Any comments
or
>> suggestions?
>>  I'll perform break down voltages for each oil on another day.  Of coarse
a
>> high dielectric constant does not necessarily make it a good choice for
>> capacitor construction.  The flash points may make some dangerous to use
if a
>> spark occured in a sealed capacitor with any air in the enclosure.  Also
the
>> thicker the oil the more easily the high voltage electric field will
force it
>> away from the foil edges of a capacitor as noted in other experiments of
>> past.
>>
>> Kevin E.



	( Sounds like a sticky wicket to me.  S.C.)