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Re: Capacitors.........



    Tantlum capacitors use a solid block of carbon, encased in tantlum.
Can=Tatlum, Contents=Carbon  one connection to the can, and one connection
to the carbon.  There is nothing else to a tantlum capacitor.

    Which proves that a solid, or a semi solid has it's own stray
capcitance, but the question is still un-answered.  Which summed up was is
there a table in reference to the table of elements that refers to ability
of an element to store a charge by weight?
I know how standard capacitors are built, but extreemly high voltages are a
totally different story.  So, if by volume of a material, a high voltage is
better stored without a negative plate using one element, or without a
positive plate using another by volume to capacitance, I want to know.

The Flavored Coffee Guy.





>Original Poster: Gary Lau  04-Nov-1998 1307 <lau-at-hdecad.ENET.dec-dot-com>
>
>>Original Poster: "James" <elgersmad-at-email.msn-dot-com>
>>
>>    Well, I already know about the internal construction, and they look
like
>>a can, filled with carbon.  Somewhere after the dielectric isolation,
there
>>is a layer of tantalum foil.  It is really looking like solid carbon's
>>reaction to tantalum.  It is that strange, and I was wondering, if anyone
>>has done any measurements, because Nikola Tesla did.  He measured the
>>capacitance of the Earth in respect to, a what I don't know, but his
>>determination was that the Earth's capacitance was at .1 uF or .01uF if I
>>don't remember rightly.  So, if tantlum is way up there just because of
it's
>>chemical response to carbon, is there another metal that can do similar?
>
>The choice of metals in the construction of a capacitor makes no
>difference, it's just the geometry of the plate conductor that matters.
>The reason tantalum is used is that it can be formed as a sponge-like
>mass of particles with a very high surface area per volume.  An oxide
>layer is then grown over this sponge, and it is this oxide layer that is
>the dielectric.  Again there's nothing magical about this oxide layer, it
>just has a very high surface area to volume ratio.  In any event, the
>oxide layer's maximum voltage is very limited in tantalum caps, is valid
>only for DC applications, and these are TOTALLY WORTHLESS in a Tesla coil.
>
>See http://www.avxcorp-dot-com/tech/tantalum.htm for a very detailed
>explanation of tantalum capacitor construction.
>
>>I was once doing experiments with charging a 30 ft long piece of wire,
>>and I place some foil onto my tv screen before it warmed up.  Then I let
>>it warm up, when I hung a weight from the middle of the 30 ft piece of
>>wire strung with a little slack between two tacks.  It contracted when I
>>shorted it to earth ground as though the electrons were just occupying
>>space.  So, there must be a static value for any given element on the
>>table of elements, and I was wondering if there was a way to measure
>>that.  Between earth ground, and the block of metal itself being isolated
>>from earth ground?
>
>What you did was to create a capacitor using your foil as one plate, the
>CRT glass as the dielectric, and the CRT's anode as the other plate.  You
>charged up the foil plate, not the wire.
>
>By "static value", I assume you must mean dielectric constant.  This is a
>property only of insulators when forming the dielectric layer between two
>conductive plates, and in your case, the CRT glass face.  The choice of
>insulator will affect the capacitance.  The choice of conductive plate
>material has NO effect on capacitance, assuming plate geometry stays the
>same.  Tables of dielectric constants for all reasonable capacitor
>dielectrics have appeared recently on this list and are in the archives,
>no need for anyone to measure them again.
>
>>I guess I'll have to do something pretty soon. Possibly with a roll of
>>quaters, because they're all the same size, and I can get allot of em'.
>
>You mean use quarters for plates in a capacitor?  Why do you want to use
>something so small and expensive?
>
>Gary Lau
>Waltham, MA USA
>
>