Discussion in 'General Electronics Chat' started by greenpeace, Nov 20, 2007.

1. ### greenpeace Thread Starter Active Member

Sep 22, 2007
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hello everybody ,

before I introduce the problem , I have to tell you that I'm not an electrical engineer ,
but I have a problem related to your major & I hope someone can help me !

suppose that we have to insert a capacitor in a circuit

but for that capacitor = instead of consisting of to adjacent plates

it consists of many plates ( say 8 or 10 or any other )

( I don't know if it is called multi-capacitor or not )
The question is / how these plates will be connected ?
& what is the benefits of using many several plates instead of just 2 ?

hope someone can help me & give me as more information as possible

Jan 10, 2006
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-|-|-|-|-|-|-|-|-|-|----------- terminal 1
--|-|-|-|-|-|-|-|-|-|---------- terminal 2

By interleaving the plates a greater plate surface area is achieved in a small space meaning more capacitance. Commonly seen in Tuning gangs.

3. ### greenpeace Thread Starter Active Member

Sep 22, 2007
30
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but can you explain how the plates are connected more please

( keep in mind that my knowledge in this field is very poor )

I'm mechanical engineer

just explain it in words
& if you can / explain that illustration about terminals !

4. ### Papabravo Expert

Feb 24, 2006
10,338
1,850
The metalic plates are soldered or welded to a metalic conductor. One set of plates is connected to one of the two terminals. The other set of plates is connected to the other set of terminals. In this configuration there is no way for a DC current to flow. Only an AC current can flow through a capacitor. That concept may be beyond your understanding at the moment, but you can take it on faith for the time being until you have a chance to investigate the matter further.

5. ### greenpeace Thread Starter Active Member

Sep 22, 2007
30
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I didn't understand how each plate is connected to the plate next to it ??

6. ### greenpeace Thread Starter Active Member

Sep 22, 2007
30
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I will try to illustrate my imagination of that capacitor
and you tell me which configuration is the right one !

7. ### greenpeace Thread Starter Active Member

Sep 22, 2007
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if this configuration is considered , what is the answer to that question ?

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8. ### greenpeace Thread Starter Active Member

Sep 22, 2007
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here is illustrated question :

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9. ### greenpeace Thread Starter Active Member

Sep 22, 2007
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here is illustrated question about the charge :

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10. ### greenpeace Thread Starter Active Member

Sep 22, 2007
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* the way of connecting each plate to the plate next to it .

* charge distribution in the plates .

* the separation between the plates ( whether the plates are equally separated , or there is separation between two sets of plates < beside the separation between each plate > )

Sep 22, 2007
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12. ### thingmaker3 Retired Moderator

May 16, 2005
5,072
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Your drawings are capacitances in series. They are solved using 1/C1 + 1/C2 + 1/C3... + 1/Cn = 1/Ct where Ct is the equivalent capacitance. Ergo, if you have eight plates instead of two, and they are all the same size and same distance apart with the same dielectric, you have 1/8 the Farads you would have with a "normal" capacitor of the same specification.

There is no reason to do this, of course. Much less costly would be to simply make a smaller capacitor.

13. ### greenpeace Thread Starter Active Member

Sep 22, 2007
30
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nice to shear knowledge

by this configuration we increase the cross-sectional area
and therfore increasing the capacitance .

but the problem is , how each plate is connected to the plate next to it ?
and what about the charge ditribution in each plate ?

14. ### thingmaker3 Retired Moderator

May 16, 2005
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I've often been accused of "cutting up."

By any method cost-effective to the manufacturer. The plates would not be connected to the next plate, though, rather to the one beyond. See the "variable tuning capacitor" in this reference: http://encyclopedia2.thefreedictionary.com/capacitor
Even, equal, and pretty much uniform.

15. ### greenpeace Thread Starter Active Member

Sep 22, 2007
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I told you before that i cannot imagine its shape
that's why i draw it , so you can tell me if I'm right or wrong

see the attachement and answer my question

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16. ### thingmaker3 Retired Moderator

May 16, 2005
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The gray plates are connected electrically as one plate. The white plates are connected electrically as the other plate. When the gray plates rotate into the spaces between the white plates, capacitance is increased.

17. ### greenpeace Thread Starter Active Member

Sep 22, 2007
30
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can this be done without rotation ?

I mean is there any type of capacitors with many plates
where the two sets are stationary ?

18. ### thingmaker3 Retired Moderator

May 16, 2005
5,072
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They're not "many plates." They're "many sections of the same plate."

19. ### greenpeace Thread Starter Active Member

Sep 22, 2007
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so the vertical plates are sections of the horizontal plate ?

20. ### greenpeace Thread Starter Active Member

Sep 22, 2007
30
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see what the doctor draw

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