On Sun, 02 Mar 2008 17:09:01 GMT, wrote:

thank you for the info and your help

On Sun, 02 Mar 2008 10:22:22 -0600, jakdedert
wrote:

wrote:
can I replace a 4.7 uf 250 volt cap with a 4.7 uf 350 volt capacitor
without doing damage or does it have to be the same voltage?forgive my
ignorance but i am just getting into this...thanks

Yeah, no problem. It 'used to be', but apparently modern electrolytics
don't have to be 'formed' at near their working voltage anymore.

jak
To add a little more info for the novices: the voltage rating of a
capacitor is just that, a rating, not a value. The difference is that
a rating is a maximum useage value. A capacitor rated at 250 volts
should not be used in a circuit that will see more than 250 volts, but
use in circuits with lower voltages is fine. Therefore a 350 volt
capacitor can be used in place of a 250 volt capacitor without
difficulty.

Good design practice calls for derating components, for instance to
not use a 250 volt capacitor in any circuit that applied 125 volts to
it. That would be a 50 percent voltage derating to improve the
reliability of the circuit. The same principle could be applied to
resistor and semiconductor power ratings, etc.

John