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Why we use capacitors with same capacitance and diff. volt ?

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a_tek7

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capacitor voltage

why we need capacitors with same capacitance and different voltage?
 

Re: capacitor voltage

Hi,

For a given capacitance, you usually pay more for a higher voltage rating, so you want to try to keep your ratings not too far above your peak voltages.
There are many different ways of making capacitors, resulting in differences in voltage sustainability, ESR (Equivalent Series Resistance) and other parameters. You usually need to choose the one that suits your needs best without being too expensive or large mechanically.
The value of capacitance is usually dictated by your application, but the type you want to use will depend, among other things, on the voltages it will be subjected to.
Regards,

Samuel
 

Re: capacitor voltage

would you classify all kind of capacitors and their applications?
 

capacitor voltage

The reason is for higher voltage you need better insulation and bigger size.
 

Re: capacitor voltage

Dear a_tek7

Letme give you very simple comparison....you have watch cells, "pensil" cells, Battery cells, all with the same 1.5v rating. but what is the difference..? the difference lies in how "Big" a circuit that each one can drive....One cannot expect watch cell to drive a FM/AM radio.... like wise battery cell would damage a watch completely......

In summary, the key word here is "Current Ratings". we know

Power= Current* Voltage

Even though in all the above said cases voltage was same yet their current drive levels were different.

Similar arguments hold for a capacitor in terms of the "Charge" that is stored and therefore its "Wattage"

I guess this answers your queiry.

Sai
 

Re: capacitor voltage

but I think in a specific kind of capacitors for example ceramic and in a specific range of voltage ,the difference of size and isolation is small(my english is bad)
 

Re: capacitor voltage

Dear a_Tek7,

what you said is true......all ratings (wattage etc) depends purely on the dielectric used within the capacitor, b'cos that is what finally stores charge. Ofcourse cost and criticality of applications also come into picture. For example there are lead capacitors as well SMD (surface mount devices) capacitors. In SMD there is what is called a,b,c,d-cases (size or casing of the capacitors).

Now, similar cased capacitors manufactured by different manufacturers differ in their ratings (and ofcourse cost also...!) b'cos each one would have used different dielectric material and casing material(s).

sai
 

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    a_tek7

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Re: capacitor voltage

a_tek7 said:
but I think in a specific kind of capacitors for example ceramic and in a specific range of voltage ,the difference of size and isolation is small(my english is bad)
Click to expand...
Do you know a manufacturer that mass produces e.g. 100nF 62V and 100nF 63V and 100nF 64V at the same time when you have 63V and 100V then it is a lot of difference and consider that capacitor is not just one layer so size can meaningfully differ.
 

Re: capacitor voltage

Dear fala,Do you know how a capacitance is made
 

Re: capacitor voltage

I guess i can only give you a partial reply, based on my experience.
For small signal circuits, we tend to use ceramic SMD capacitors, mostly because they have low ESR (cheap too). For bias circuits, a combination of electrolytic (large capacity) and ceramic works well.
For power circuits, electrolytics are good (capacitance/size/maxV) but one needs to watch out for polarity. AC capacitances have been more tricky in my experience.
As you can see capacitors are not my specialty !
Hope this helps.
 

capacitor voltage

a-Tek7, There are different capacitors, ceramic, multilayer, electrolyte. Each have their own manufacturing process it is too complicated to be answered in one post. use google you will find plenty of information.
 

Re: capacitor voltage

fala said:
a-Tek7, There are different capacitors, ceramic, multilayer, electrolyte. Each have their own manufacturing process it is too complicated to be answered in one post. use google you will find plenty of information.
Click to expand...


Well said sir.


to thread starter:"the answers is on your finger tip."

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