Sorry to perpetuate the OT discussion, but there is an excellent series of articles by capacitor design engineer Cyril Bateman called Understanding Capacitors, published in EW&WW magazine in the late '90s. The article on electrolytics covers almost anything you might want to know about them, and is a very worthwhile read. I highly recommend the whole series.
Cyril had the articles posted on his own website some time ago, which I can no longer find. But, they are still available online if you search around. - Chad. On Jun 23, 2011, at 9:10, "Dr. David Kirkby" <[email protected]> wrote: > On 06/21/11 08:39 PM, Poul-Henning Kamp wrote: >> In message<[email protected]>, Chuck Harris writes: >> >>> and yet, I find that some electrolytic >>> capacitors that have been run at lower than normal voltage improve markedly >>> when "reformed" by applying rated voltage through a 10K resistor for a >>> couple of hours. >> >> I noticed in a datasheet at one point, that the capacity only was >> warranted above a certain percentage of rated voltage. No explanation >> was given. >> > > Note on the link posted by Robert LaJeunesse: > > > http://www.cde.com/catalogs/AEappGUIDE.pdf > > > it says voltage derating gives better reliability: > > > ====================================== > "Aluminum electrolytic capacitors made with formation voltages > at least 35% higher than rated voltage and with rated tempera- > tures of 85 oC or higher, don’t require much voltage derating. In > applications operating at less than 45 oC no derating is needed, > and with up to 75 oC, 10% is sufficient. For higher temperatures > and with high ripple current, 15% or 20% is appropriate. Since > operating life continues to increase for further derating, military > and space applications use 50% voltage derating." > ======================================== > > I've herd stories one should not operating caps well below their rated > voltage, but that would tend to suggest that is not so. > > -- > A: Because it messes up the order in which people normally read text. > Q: Why is top-posting such a bad thing? > A: Top-posting. > Q: What is the most annoying thing in e-mail? > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
