Re: [CAD_CAM_EDM_DRO] Re: CNC power supply question

Tony Jeffree wrote:

>Ken -
>
>The following extract from a spec sheet chosen at random, for a range of
>"long life" screw terminal electrolytics:
>
> Shelf life 2000 h at 0V +85°C, or
> 4 years at 0V +40°C
> Operational life time 60000 h at +85°C
>
>Seems to indicate pretty clearly that the lifetime is severely shortened if
>stored at 0V.
>
>

But, it may well mean that if you only charge it up once a year, it will
last
for a long time. Only by shorting it for 4 years continuously do you
degrade
it. I have large electrolytic caps that are over 30 years old (260,000 hrs)
that are still working fine. The ones in my CNC power supply are drained
to zero by the wound fields in the servo motors. I seem to have no problem
with the caps over the last 6 years, and these caps were used when I got
them.

Jon