3 ms·

I corrected my text above to read "unreasonably short lifetime" now. In my experience, plenty of products from the 90s and older still seem to work absolutely f

by anyfoo 4y ago

I corrected my text above to read "unreasonably short lifetime" now. In my experience, plenty of products from the 90s and older still seem to work absolutely fine despite their use of electrolytic caps. Yes, some of their parameters may have degraded, but it still seems to be within tolerance for their particular use in the design. It also depends on how exactly the caps are used. Caps close to a massive heat source, like a power resistor, are likely to dry out relatively quickly, while others, like those used as part of small signal filters, may last literal decades, with not much change in e.g. ESR or capacitance (and hence still conform to factory calibration pretty okay). Admittedly I don't have any hard data for that, only anecdotical experience with measuring ESR and capacitance and saying "this looks fine". The crucial point is that the "capacitor plague" affected much more than products which were on 24/7 or which had tight tolerances, to the point where it was very well visible to the "casual" consumer. Yes, we may not expect a server mainboard that was on for the last 20 years to still have its caps within spec, but wrt the capacitor plague, the gaming PC you mentioned would have been quickly affected, in an obvious manner, as well.

coryrc 4y ago
> while others, like those used as part of small signal filter I wouldn't expect those to be electrolytic, though. Electrolytic capacitors are mostly used when the exact characteristics are not important, like on a supply bus, where your qualifications are typically either "at least" or "no more" than some value. Tripling capacitance usually has no negative effect on a supply bus but huge change of doing signal conditioning, so something like that is more often going to be a capacitor that is intrinsically more stable.
- anyfoo 4y ago
  Good point, but in audio applications for example, for cross-over filters, bipolar electrolytic caps are common. The “calibration”, if any, may be very simple, though.

by anyfoo 4y ago

coryrc 4y ago

> while others, like those used as part of small signal filter I wouldn't expect those to be electrolytic, though. Electrolytic capacitors are mostly used when the exact characteristics are not important, like on a supply bus, where your qualifications are typically either "at least" or "no more" than some value. Tripling capacitance usually has no negative effect on a supply bus but huge change of doing signal conditioning, so something like that is more often going to be a capacitor that is intrinsically more stable.

anyfoo 4y ago
Good point, but in audio applications for example, for cross-over filters, bipolar electrolytic caps are common. The “calibration”, if any, may be very simple, though.