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470 uf cap 10v vs a 470 uf cap 100v? Answered

If the specs call for a 470uf 10v cap. Would everything still work properly with a 470uf 100v cap? What might change? 



Best Answer 6 years ago

YES ! !

Energy stored in a capacitor ( condenser ) = C × V × V ÷ 2...

Given the same Capacitance  ;

A 100V Capacitor can store 100 Times the stored Energy of
a 10V Capacitor :-)

Higher voltage capacitors are more expensive and bigger.


Will be Ok nothing will change from your perspective. the 10v is a minimum rating.

Then what is the advantage of making a 10v cap. Why not make them all 100v so it would be easier?

It's not that simple. I work on tube radios so I often need 160 volt or 300 volt or 600 volt caps. I assume it's harder to make a 100 volt cap rather than 10 v. They are a little larger and cost more. May just be a racket.

For the higher voltage, the insulation between the plates has to be thicker. That means a bigger cap and more money for the materials. Of course any manufacturer of electronic devices wants to save money, so they go for the cheapest. And designers always want the smallest parts to make the appliances as tiny as possible.

The voltage rating on an electrolytic capacitor is the maximum safe working voltage BEFORE it may incur damage. If you take both these capacitors and put 50 volts to them, the 10 volt capacitor will go POOF, let out the magic smoke, most likely throw sparks and probably leak electrolyte goo. The 100 volt capacitor will happily sit there and charge up to the supply voltage. Running a capacitor at or close to it's WVDC will stress the capacitor to the point of failure, over time.

There are other differences, such as physical size (the higher the WVDC, the larger the cap), ESR (important in critical timing situations) and many other things that designers look for in their specific applications. If you look at a site such as Mouser Electronics, there is a long list of criteria to sort by, most of which you probably need not worry about.

Long story short, you want to have a voltage rating of around twice what you would expect the voltage to be at the point where you need the capacitor. In the case of the 2 you mentioned, 5V (max.) average for the 10V cap, and 50V (max.) average for the 100V cap. This is called your safety margin. That will insure your caps live a long and healthy life.

In summary, the caps are basically the same, just 1 can handle more voltage than the other. When in doubt, more WVDC is better than less. There is a point where you are in diminishing returns and going over about 2.5 times the circuit voltage is overkill and you are needlessly spending money and losing PCB real estate.