To second the older electronics: I maintain nearly 100 analytical instruments. The old designs(1970-late 80's) are almost all electrolytic caps and none of the caps have ever failed. When I do find a bad cap it's always in a modern design. A high frequency switcher with under rated caps. When i say under rated i mean take the peak figure and multiple it by two, that's the real part value.
My opinion, bad designs. Steve On Sat, Nov 26, 2011 at 1:25 AM, Chris Albertson <albertson.ch...@gmail.com>wrote: > Many of us have seen electronic equipment last longer then one year. > Some of use even have still working antiques with old eletro caps. > Those short lifetimes assume a worse case, usually with a very high > ripple current. IOf you can reduce the ripple the MTBF goes up. > > One question: How does one avoid using electrolytic caps if you need > (say) 1,000uF or even 100uF. Those would be some mighty big film > caps. > > > > > On Fri, Nov 25, 2011 at 10:06 PM, <saidj...@aol.com> wrote: > > Electrolytic caps have an extremely poor lifetime (MTBF). Sanyo on their > > website state "50K Hrs at 50C". > > > > This means only 6250 MTBF hours at 80C for one single cap. MTBF gets > worse > > the more caps are being used of course. I have seen some Panasonic > > electrolytics state only 2000 hours MTBF at temperature in their > datasheets. > > > > That's not even one year before a mean failure occurs making these > useless > > in high-reliability applications. > > > > Note also that caps in high AC current situations (Buck DC-DC switcher > > input cap for example) will self heat due to internal resistance, making > things > > even worse. This is probably one of the main failure reasons for PC > > motherboards. > > > > And that's with name brand parts, it's even worse if one ends up buying > > counter-fit or non-name-brand Electrolytics. > > > > Some of our competitors use Electrolytics all over the place (we don't > use > > any electrolytics) - that's been good for our business. > > > > bye, > > Said > > > > > > In a message dated 11/24/2011 17:08:42 Pacific Standard Time, > > li...@lazygranch.com writes: > > > > I'm not familiar with rubycon caps. The low ESR large value caps are > > "organic semiconductor." OSCON is a common brand from Sanyo. Finding the > > ultimate cap is nearly as much fun as finding the ultimate LDO. Check > > out Nichicon. Or you can stick with the Rubycon. Glancing at their > > website, they seem to copy the Nichicon product line. > > > > > > _______________________________________________ > > time-nuts mailing list -- time-nuts@febo.com > > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > > > > > -- > > Chris Albertson > Redondo Beach, California > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.