The differnce between 100uF 25V and a 100uF 630V capacitors? (on circuit of 9v dc)?

Question

If I was to use a capacitor of a value of 100uF, would the voltage make any difference?

Will it change the time it takes to charge up?

Thanks for your help in advance

Tom

Answer 1

No it shouldn't make much difference.   You might find the tolerence on the 630V part is wider, say +40%/-20%, compared to say +/-10% on the 25V part.   To make a full comparison its necessary to look at the specific part data sheets. Also look at parameters like ESR, ripple current, operating temperature.

But the 630V cap would be MUCH larger/expensive , so pointless for use on 9V in a production item.  If its all you have for a hobby construction, its not important.

I expect you are talking about cheap electrolytic caps.  There are several other types, tantalum and aluminium for example. Both are more expensive.

Look on sites like www.farnell.com, rswww.com for data.

The difference in working voltage reflects the amount of energy that the device can store. i.e. 0.5 x capacitance * voltage^2.  Work it out for the 2 caps.

Answer 2

They have the same capacitance, which is what determines how they work in the circuit. As long as the rated voltage is greater than 9V, either will do. But the 630V capacitor is overkill, it'll be much too big and expensive -- unless you happen to have one lying around.

If it were me, I'd look for a 10V or 16V part.

Answer 3

sos is correct, there is little or no difference between the two caps when used at 9 volts. One is a lot physically larger than the other.