Another simple question, cap voltage values

[ryanf]

Sorry i am asking all these questions but this should be a quick answer.

For electrolytic capacitors' voltage ratings, I am assuming that these are maximum voltages. Is this correct?

Secondly, how important is it that these exact voltage ratings are used? Will it hurt to use higher voltage caps than reccomended?

[oldhousescott]

Yes, they are rated maximum values. Yes, you can use higher voltage rated caps, but physical size can become a problem.

[sliberty]

When selecting capacitors, always try to match the capacitance values fairly closely, and always select the rated or higher voltages. So for example, if a circuit calls for a 50uF @450V cap, you can certainly use a 47uF@500V or 47uF@600V without a problem. 47uF is less than 10% off on the capacitance value, and if the cap can handle more voltage than the circuit will present, it will handle the presented voltage easily.

[David Root]

Generally good advice. I would go a bit higher voltage rating on the first cap after the rectifier, if possible, just for insurance against voltage spikes. Depends on your rectifier, soft hexfreds are so much better in SS rectification.

Doesn't hurt to do this with tube rectification either, but you can't go nuts with the uF value with tube rectification.