Re: [CAD_CAM_EDM_DRO] 470uf capacitor for Geckos,,,Polarity??

R Rogers wrote:

>Dan, I just checked the voltage coming off of my Caps and it is 64 volts :-). Do you think I could still use them as they are rated for 63 volts?
>
>Ron
>
>

You shouldn't.

Usually, you want a cap that's rated for 20% (on a precision designed
system, with all sorts of other safeties in place) to 100% (for
something that you threw together in your spare time :) ) over the
expected operating voltage.

There are (at least) two reasons for this. First, there may be
overvoltage situations - the power company may actually output anything
from 110V to 130V, possibly more. Not for very long, but it doesn't
take too long. Second, the dielectric in an electrolytic cap degrades
over time. High quality caps are rated to run for between 1000-2000
hours at their rated voltage and temperature. Since you want yours to
last longer, you have to over-spec it. Conversely, if it's too hot or
over voltage, its lifetime decreases exponentially.

- Steve