[time-nuts] HP 3586B Power Supply Failures
attila at kinali.ch
Thu Mar 22 11:04:30 UTC 2012
On Wed, 21 Mar 2012 22:33:49 -0700
"John Miles" <jmiles at pop.net> wrote:
> I did this for a while, but I eventually realized that new
> "computer grade" electrolytic capacitors no longer have the same
> quality levels that they must have had in the 1970s and 1980s.
> Back then, orders of magnitude more of them would have been used in
> production than are used today, and the manufacturers would have paid
> more attention to what they were doing. After my first few encounters
> with high-ESR parts out of the retail box, I stopped replacing good ones.
That's not really true. More electrolytics are used today than were in the
70s and 80s, mostly because a lot more electronics is build today.
What is different though is that those electrolytics are more optimized
to be cheap than they were before. Which means that you have to more
carefully select the capacitor you are going to use. Main stuff you have
to look for is: ESR, maximum ripple current, operating temperature.
Especially the ripple current is important as this is what kills most
electrolytics in "cheap" or not well designed circuits these days.
Or to put it short:
Just using a electrolytics you found somewhere in a switched power supply
is asking for the capacitor to fail. And it doesn't matter whether it's
a brand capacitor or not.
The trouble with you, Shev, is you don't say anything until you've saved
up a whole truckload of damned heavy brick arguments and then you dump
them all out and never look at the bleeding body mangled beneath the heap
-- Tirin, The Dispossessed, U. Le Guin
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