DIYbanter - View Single Post - Why doesn't everything use solid aluminium capacitors?

Ralph Mowery

In article ,
says...

There is also a problem with life expectancy from self heating due to
the Equivalent Series Resistance (ESR). For a switched mode supply a
capacitor with a low ESR is required. A decade or so ago I read a
technical report from one of the more respected capacitor manufacturers
(Rubicon I think) where they claimed that they used physically larger
cans/packaging than some of their Korean competitors to ensure lower ESR
figures. I always found that when changing duff electrolytic with Korean
brand names such as SamYoung etc. that the replacements from a variety
of reputable brands were physically larger - usually the same diameter
can but the height of the can was maybe 5mm more.

It is not only the cheep or China parts that fail. I have a couple of
pieces of HP test gear that I bought surplus that the capacitors have
failed in the power supplies. They origionally sold for about $ 50,000
each back in the mid 1990's. I guess that about 20 years is not too bad
for them. Not sure how many hours they may have had on them.