How to Testing Cermaic Capacitors?

hello, I heard that Ceramic Capacitors rarely fail nevertheless how can one be sure? Is there a way to test them to know if they are good? Is it important to test these or not? Any help would be appreciated!

Reply to
mikuzj5
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ive never tested them before but thay can shortout sumtimes. had a shorted one in a rotel amp in the phono stage on the power rail, it took out a fuse, i have hered that if you apply to much heat soldering them thay can short as well.

Reply to
crazy frog

ceramics are known to have a problem with high resistance instead of infinite ohms, tolerance on some are really wide, temp stability -v- cap is shocking

Reply to
Ed /:-}

On 12 Sep 2005 08:37:39 -0700, snipped-for-privacy@yahoo.com put finger to keyboard and composed:

I've seen S/C, low capacitance, and temperature drift problems. To test for the latter, measure the capacitance while subjecting the cap to a hair dryer or spray freeze.

-- Franc Zabkar

Please remove one 'i' from my address when replying by email.

Reply to
Franc Zabkar

You heard wrong.

If in doubt, replace them.

Reply to
The Real Andy

I have seen quite a few short-circuit "little blue" 100nF bypass caps. When there is a few hundred on a board to pick from, this can be less than fun to fix.

all Z5U and Y5V dielectric caps will "fail" the freeze-spray/hair dryer test, because the dielectrics themselves have seriously ratshit performance over temperature. see the first graph of:

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Z5U are even worse with temperature.

The 2nd graph is interesting too - capacitance *plummets* with rising Vdc above 10%. Any more than 40% Vrated and capacitance has dropped to about 1/10 its rated value!

Cheers Terry

Reply to
Terry Given

hello,

** On 5 volt rail digital stuff, ceramics sometimes go short - especially tiny blue monolithics - and pull the supply rail right down.

My favourite trick is to substitute a 5 volt, 6 amp bench DC supply and

*smoke the sucker* out.

........ Phil

Reply to
Phil Allison

On Thu, 15 Sep 2005 11:00:52 +1200, Terry Given put finger to keyboard and composed:

I take your point. The capacitor failures that I verified with a heat test were in horizontal oscillators. I recall one in a 13" IBM monitor, others were in high end CADCAM systems. I believe they were NPO types which should have been relatively stable. Another common choice for this type of application used to be silvered mica. I had drift problems with those also.

-- Franc Zabkar

Please remove one 'i' from my address when replying by email.

Reply to
Franc Zabkar

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