[R-390] Capacitors - Testing and identification

[Drew P.]

Barry wrote:

"Vaguely on this subject, I'm wondering what folks recommend for small electrolytics.  Is Nichicon a trusted brand now?  I've used them a few times but don't know much about them.  Is Vishay better (as far as reliability)?  Others?"

There was a big problem with electrolytic capacitors a few years back, from Taiwan, at least.  This caused failure of many computer motherboards and other products.  More can be found here: 

http://en.wikipedia.org/wiki/Capacitor_plague

>From the above-referenced page:

"In one case, the reason for the manufacture of faulty electrolytic capacitors was industrial espionage gone wrong: several Taiwanese electrolyte manufacturers began using a stolen formula that was incomplete, and lacked ingredients needed to produce a stable capacitor.[7]"

As far as present electrolytics from Taiwan and China are concerned, one would think that the problem would be corrected by now, but who knows?  I have seen exploding Chinese electrolytics in recent low cost fluorescent lights having integrated electronic ballasts, but this could just be a matter of poor application. 

I used Xicon (Taiwanese) electrolytics from the referenced time period in my '67 EAC and they have not caused any trouble.  Perhaps the aforementioned problem was mainly in applications having high ripple current; the R-390A (choke input filter) is definitely not a high ripple current application. 

Drew