[sdiy] "Boutique" capacitors

[Ralph]

Hi All,

Sorry to jump in like this late, but-

Electrolytics, even cheap ones, should not be failing in 5 years. More like 12 or so. But you do see them go, because often the designer has not really bothered to rate the cap for the ripple currents involved, and the cap runs a bit of a temperature. If the temperature is only a few degrees (hardly noticable), it will probably last a few years, the hotter it runs the shorter the life, and the hotter it runs the hotter it will try to run as time goes by. Best to have them rated right in the first place before they spew something. 

You don't really need a boutique part like a Muse or Black Gate (especially for a computor), but it does pay off to check the ripple current specs in the book before installing the part. If you are replacing a part this is what I would do.

This is a particular problem with high capacitance parts (+2,200 uf) where the ripple currents can be quite high. An alternative solution is to choose a part with a higher voltage rating. Size could be an issue...

Have fun!

-Ralph


On Sun, 6 Feb 2005 14:38:38 +1100
sasami at hotkey.net.au (Ken Stone) wrote:

> >Where does this electrolyte go?
> >
> 
> usually it leaks all over your circuit board and makes a royal mess, or if
> you've made the mistake of salvaging it, it leaks all over the other
> capacitors in the storage box. I think I have learned - brown electros,
> frequently 105 degrees, are not worth salvaging - they leak, almost
> guarenteed. Maybe there are a brand or two that don't but considering how
> many I have found that do, I bin them.
> 
> >Does it just break down into other compounds under heat stress or does it 
> >vent and evaporate?
> >
> >Are dipped electrolytics any better at retaining theirs?
> >
> >
> >
> _______________________________________________________________________
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