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Re: [TCML] DIY Tank Capacitor - Plate configuration confusion



Hey Grant....

considering that you have 2 metal plates in contact with each other with no dielectric between them, wouldnt that constitute as a single metal plate? In your "diagram"
below you have shown t-m-d-m-m-d-m-m-d-m-m-d-m-t.

Lets look at it this way

T+/M+/D/M-/M-/D/M+/M+/D/M-/M-/D/M+/T+

If you have in a condensed form as above but considering that the 2 adjacent plates are in contact with each other...
T+/M+/D/M-/D/M+/D/M-/D/M+/T+

you now have no potential created across the dielectric throughout the whole cap but only in the center and that is only going to occur if you have voltage applied to the center plates...

if you apply voltage to the 2 end terminals, you produce at some point 2 plates that will repell the electrostatic? forces thus resulting in a null field...

an odd thought here but consider series sets of batteries....

+-/+-/-+/+-   or even   +-/+-/-+/-+
both above shouldnt give a voltage reading on a meter...

Scot D


Grant Visser wrote:

Hi and thank you all for taking the time to have a look at my mail!

Brian, thank you, yes I am definitely going to do as you suggested and
get hold of Jeff to see if I can get a definitive answer on this one!
lol

Dave, Scot, and William ... I do see what you are saying but my
leftover 2% is still fighting *grin*

If we look at the normal process of connecting capacitors in series,
we put power into the string, let it travel through the string, to our
other power lead. The effect (apart from the charging component) is
that Vtotal is now split across the caps, ie. each cap only has to
deal with it's portion of Vtotal which in our case is exactly what we
want as Single MEGAVTOTAL caps are horribly expensive! Yes?

OK, now strip off the outer sheathing of each of the caps so we can
see all there is to see there.

If William doesn't mind, I'm going to borrow his method here, thus T
indicateds the terminal, D means Dielectric, and M neans a metal foil
conductor.  It would look like this:

t-m-d-m-m-d-m-m-d-m-m-d-m-t    right?

Now what we have inbetween each dialectric is a metal foil conductor
connected directly to another metal foil conductor (via the outer
legs). The point is that a metal foil conductor connected straight to
another metal foil conductor, in my thinking, is exactly equal to one
metal foil conductor with two sides/faces ......

If that is the case then what I depicted in D4 is exactly the same as
the above as the aluminum foil plate which "seems" to be floating in a
single capacitor is in fact doing exactly what we have above. It has
two sides and it will therefore have a positive charge on the one side
and a negative on the other allowing charge to build up on either side
of it.

Or ... not! ...... lol

All the best
Grant

2008/9/25 William Noble <william_b_noble@xxxxxxx>:
without reviewing the diagrams, the following thought experiment might be helpful

let's imagine a series stacked plate capacitor - where T indicateds the terminal, D means Dielectric, and M neans a metal foil conductor.  It would look like this:

t-m-d-m-d-m-d-m-d-m-t   right?

ok, now think about the foil (m) layers in the middle - they don't actually do anything - they aren't connected to anything - all they do is lie between two dielectric plates (d).   So, when you think about htat capacitor, it really is the same as:

t-m-dddd-m-t

So, what you are doing by putting capacitors in series is really the same as what you get by increasing the gap between the plates/thickening hte dielectric.  So, if you were using 1/8 inch glass, for example, you couild go to 1 inch glass, keeping hte metal foil plates the same size, and you would get the same effect as putting 8 of the 1/8 glass capacitors in series.

does this help a little?


Date: Wed, 24 Sep 2008 17:11:02 -0400
From: ka1bbg@xxxxxxxxxxx
Subject: Re: [TCML] DIY Tank Capacitor - Plate configuration confusion
To: tesla@xxxxxxxxxx
CC:

HI, Grant, first there are no idiots on this list.....some have much less
knowlege of coils, some have extensive physics, electrical, engineering
backgrounds, math background who often give regularly of the
knowledge....write programs, and might even be a ham radio operator as i
am.....so skip the idiots...Jeff Behary who runs
www.eletrotherapymuseum.com/
has a huge stack of older information, and i bet he would be able to point
you to some information, despite how busy he is..
for stacked capacitors.......cul brian f.


www.genapro.com
----- Original Message -----
From: "Grant Visser"
To:
Sent: Wednesday, September 24, 2008 1:26 PM
Subject: [TCML] DIY Tank Capacitor - Plate configuration confusion


Hi all,

I have held off on asking this question for many many MANY hours because I
was :
1. 98% convinced that my memory of the theory was correct so didn't
want to embaress myself by seeming just plain stupid.
2. 100% convinced that a few seconds research on the net would not
only confirm my theory but also give me a bunch more ideas to play
with!

Well, following many many MANY hours of searching the net and reading
way too many articles/papers/tutorials/etc. on capacitors, my
conviction regarding my theory has dropped to around 2%, which is low
enough to be extremely depressing but not low enough to allow me to
simply give up, so here I am ..... ready to embaress myself! LOL

I have built a few smaller stacked plate caps in the past, have also
blown a few so no problem there. Am certainly no guru in the field of
amateur electronics but am also no .... idiot .... or at least I
didn't think I was until today!

Capacitors can be wired in parallel to increase capacitance or in
series to decrease capacitance and to spread the voltage load (as in
an MMC array).

When constructing a stacked plate capacitor the cells are hooked up in
parallel thus this type of DIY cap is often referred to as a "Parallel
Plate Capacitor" and bunches of these can be strung together in series
to build up a tank capacitor suitable for the intended use.

Don't 'think' I have made any mistakes yet so so far so good!

My theory, which I was convinced was ELEMENTARY, is the source of my
confusion at this stage because I have been completely unable to find
any reference to it in my hours and hours and HOURS of searching!

ALL I wanted to do was to use a SERIES STACKED PLATE configuration in
each of my capacitor modules to increase the Voltage Capacity of each
individual module. I could then wire these modules externally in
parallel or indeed in any configuration required for my application.

I really didn't think that using a series stack configuration would
pose any challenges but now I am not so sure!!!

I have put together a diagram simplifying what I wanted to do for clarity.


http://i238.photobucket.com/albums/ff108/FreeekyG/FreakyTesla/FreakyCaps.jpg
PLEASE, I would be most grateful if you would take a moment and let me
know if (D4) and (D5) are workable as I thought or if I am indeed ...
an IDIOT! *grin*
If my concept of the Series Stacked Plate Capacitor doesn't work or
has "issues", PLEASE could you explain why or maybe point me to some
reference material so that I can figure this one out!

Very best regards
Grant
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