Re: [CAD_CAM_EDM_DRO] Re: 67 Amp 5 Volt Regulated Supply

ballendo@... wrote:

> Hello all,
>
> While we're talking 'bout large surplus elctrolytic filter caps...
>
> There is a tendency for these caps to go bad over time, and more so
> if not used. So, if you are buying surplus, be careful. Most caps of
> this type have a mfr. date which can be puzzled out. Try to use newer
> ones if possible.
>
> It is a good idea to "check out" the older ones. I use a variable DC
> supply and set it to a low voltage. I put the capacitor(s) under a
> cover (5 gallon pail) so if they "blow" I can contain the mess...
> Believe me, you DON'T want to experience the smell and mess
> of "exploded" filter caps more than once :-) Then, over a period of a
> couple days, I gradually turn the voltage up towards the
> intended "use" voltage. Let 'em cook at this for at least several
> hours...
>
> THEN, they can be checked to see if they are holding a charge and put
> into use.

I have been using old, large electrolytic caps for years. I have a number
that are over 30 years old, and they still work FINE! Now, if they've been
in some piece of equipment running for 30 years in 50+ C temperatures,
they are ready to retire. But, otherwise, I've VERY rarely had a problem
with them.

Jon