Maintaining electrolytic capacitor
Spehro Pefhany email (remove spam text)
At 08:54 PM 12/18/02 +1300, you wrote:
> > .... all being well I'd like to see the units run for many
> > trouble-free years.
>In which case, if using tantalum fuses be CERTAIN that the applied voltage
>NEVER exceeds their voltage ratings for any reason. Tantalums have their
>place but they have to be protected against their great weakness of failing
>spectacularly when over-volted.
I've never personally experienced it, but unfortunately they can stand up
long enough under REVERSE bias in a power supply situation to explode,
burn etc. later after the product has been tested and shipped. As the markings
are the reverse of aluminum caps, this has caused problems for some.
Smoke is bad.
They are also quite limited in terms of transient current capability, and
some manufacturers tell you to put an xx ohm resistor in series, which
practically kills their major application as a bypass capacitor. You
MUST never connect them to a low impedance source without some limiting
of the current. More recent ones are better, but the limitation is there
in the fine print.
Nasty and expensive little things, but they are small.
Spehro Pefhany --"it's the network..." "The Journey is the reward"
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In reply to: <014001c2a66a$d18cb940$2301a8c0@Paradise>
See also: www.piclist.com/techref/index.htm?key=maintaining+electrolytic
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