RE: Liquid Layered Capacitors

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Dave Halliday" <dh@xxxxxxxxxxxxxx>

Cool idea but it will not work.

Vegetable oil will absorb moisture and cause leakage, it can also turn
rancid over time.

Even if the oil had no water in it, the normal action of the cap would heat
it up to the point where the Olive Oil would turn liquid.

Your best bet for an easy to make, cheap cap is the Geek Group Beer Bottle
capacitor.  They designed this specifically to be a cheap but RELIABLE cap
for small Tesla Coils.

You will need to get a gallon or so of Mineral Oil or new motor oil and five
pounds of salt but the rest of the components can be scrounged by asking
around.

http://www.thegeekgroup.org/geekwiki/index.php/Geek_Group_Bucket_Capacitor




> -----Original Message-----
> From: Tesla list [mailto:tesla@xxxxxxxxxx]
> Sent: Sunday, November 26, 2006 12:47 PM
> To: tesla@xxxxxxxxxx
> Subject: Liquid Layered Capacitors
>
>
> Original poster: "Breneman, Chris" <brenemanc@xxxxxxxxxxxxxx>
>
> Hello,
>
> I'm new to building tesla coils, and am trying to get my first one
> built.  The problem is that I have very little money available to
> spend on materials.  The main thing I'm trying to get now is a
> capacitor for the primary circuit, and it looks like my best option
> is to build one.  I've seen a number of designs for homemade
> capacitors, but came up with one myself, and was wondering if anyone
> has tried it, or if there is any inherent problem in the design.
> I was thinking that the most efficient and easy-to-build designs were
> liquid capacitors where at least one of the plates is a liquid such
> as salt water.  The most common design of a liquid capacitor seems to
> be filling bottles with the solution and putting them all in a vat
> with another conductive solution.  But isn't this wasting space due
> to the large plates?  The best space-savers seem to be layered
> capacitors, which also seem to be pretty efficient (from what I've
> read), but the recurring problem is apparently that the solids don't
> get extremely close contact with each other.  So I got thinking ...
> what if a layered liquid capacitor could be built?  Or more like
> liquids that could dry.
> Here's one specific design idea that I had: Inside of some kind of
> bottle, put a small amount of salt water, then a layer of olive oil
> as a dielectric.  Olive oil will float on top of the water and
> generally has a higher freezing point than water
> (http://www.oliveoilsource.com/olive_chemistry_freezing.htm) so it
> should be possible to freeze this or at least make it harden somewhat
> without causing the water to freeze and expand - this could
> potentially be done in a refrigerator.  After the layer of oil
> hardened, a small layer of hot glue could be placed on top of it to
> prevent it from mixing with above layers.  Then more salt water could
> be added, and the process repeated, until there were enough layers to
> fill the bottle.
> One problem with this is that I can't find the breakdown voltage of
> olive oil.  Does anyone happen to know this?  Also, is there any
> mechanical or other problem with this design that would prevent it
> from working?
>
> Thanks,
> Crispy
>
>