Re: Re: Power supply question.....

On 22 Apr, CAD_CAM_EDM_DRO@yahoogroups.com wrote:

>
> have seen several pwr supply questions about caps....and it seems to me
> that if they are being used as brute filter caps people are using way to
> low a working voltage....in this case i would feel much better with a
> 80-100v rating....and yes you can put them in parallel

This not good advice for electrolytics.

There is some charge thing that goes on related to the chemistry of an
electrolytic cap, such that a cap used below its rated voltage loses
capacitance, almost in direct proportion to the rated voltage / applied
voltage.

That is, a 100 volt electrolytic cap used at 50 volts will, within a
short period of time, have only half the capacitance.

Therefore, against all good engineering instincts, a person should use
an electrolytic cap rated for a voltage as close as possible to the
expected DC voltage.

Alan

--

Alan Rothenbush | The Spartans do not ask the number of the
Academic Computing Services | enemy, only where they are.
Simon Fraser University |
Burnaby, B.C., Canada | Agix of Sparta