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Comment by mey | Hacker News Reader

So basically, this, plus looking at the pics he links from the over clockers forums leads me to this conclusion.

You should buy

     A whole house surge protector
     A really nice UPS supply with a lead acid battery that does line cleaning for your computer equipment.

Doesn't solve the real problem, but at least saves a significant amount of hassle... Why systems survive so well in a proper colo environment over most homes. (Aside from air particles and temperature).

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That is a different sort of ripple. Your big electrolytic capacitors are used in the AC/DC conversion where the rectified sine wave is smoothed into a constant voltage.

  |                           |
  |  _   _   _         ===>>  |
  | / \ / \ / \ /             |--------------
  +V---V---V---V-             +---------------

The capacitors store energy during the peaks and return it during the troughs. The ripple is the current in and out of the capacitor which heats them and does "stuff-I-don't-understand" to their chemistry.

The article complains that some capacitors don't last their 4000 rated hours. But even if they do, 4000/24 is 167. All of your electrolytic capacitors are tiny time bombs.

That is some impressive variable-width ASCII art, I must say.

I was going to chastise you for breaking the entire internet by failing to render <PRE> with fixed width fonts, but it looks like the W3C did that in HTML 4.0 when they reduced the fixed width requirement to a "may render in fixed width font".

If you ever see two members of W3C next to each other, please knock their heads together for me.

It looks like lifetime is specified in hours of life at a high temperature - e.g.:

http://www.rubycon.co.jp/en/catalog/e_pdfs/aluminum/e_BXF.pd...

Lifetime is specified at 10000hrs at 105deg C.

As temperature decreases, lifetime appx doubles per 10deg C:

http://www.low-esr.com/endurance.asp

It looks like a cap rated at 4000h @ 105deg C should last around 60 years at 100deg F or so. Anecdotally I have a guitar amp made in the 60s with the original electrolytics still working. Sounds great.

As per my other comment on this thread, you can intentionally decrease the lifetime (aka MTBF) by running the part at 10 or 20% overvoltage, in addition to extreme temp, to create a corner case and stimulate premature failure in reasonable amount of time. 20% overvoltage won't kill the cap, as any part has absolute maximum ratings well beyond what the spec sheet says. Even bad caps have some degree of guard band, else they would never leave the factory.

Interestingly enough I have heard in a few places that there is a 'sweet spot' in terms of duty-cycle that extends the life of electrolytic caps... I would that that high-use electronics (or 'always-on' devices) probably miss that spot.

I have wanted one of these for a really long time: http://www.brickwall.com/

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