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Re: dielectric constants


rom: 	David Huffman[SMTP:huffman-at-FNAL.GOV]
Sent: 	Friday, November 07, 1997 8:29 AM
To: 	Tesla List
Subject: 	Re: dielectric constants

CRC 53rd Edition
beeswax, white dielectric constant -2.75-3.0 Loss factor - 0.025
beeswax, yellow dielectric constant -2.90 Loss factor - 0.029
Loss factor=power factorXdielectric constant
sucrose dielectric-3.32-at-300Mhz this is the only sugar I could find.
D. Huffman


>
>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.)
>
>