"DaveC" wrote in message
obal.net...
Today I ordered electrolytic caps. It was frustrating. I had planned to
get
the best low-ESR replacements for all the caps in some switching power
supplies. I discovered how limited any one manufacturer's low-ESR catalog
is.
Many of what I needed (none of which seem to me to be esoteric values)
were
not available. A couple of times I had to leave a particular
manufacturer's
catalog altogether to find a value.

Which brings me to my question. I was trying to get all Panasonic
FM-series
(hi-temp, low-ESR) caps. I've heard good things about Panasonic's caps,
but
being forced to another brand I has no idea of comparable quality. (This,
at
Digi-Key and Mouser.)

Also, How important is the type of electrolyte? I've read that low-ESR
caps
are frequently made with water-based electrolyte whereas non-water-based
formulae cannot give low ESR value.

The qualities of caps (ie, hi-ripple, hi-temp, low-ESR, etc.) are
frequently
discussed on electronics forum, but I haven't seen the different
manufacturers compared.

How do the quality of caps compare by

Nichicon
Panasonic
Vishay / Sprague
Mallory
Rubycon
United Chemi-Con
Cornell Dublier
Xicon

Feel free to add to the list, praise, trash, and/or list in order of your
preference. Extra credit for essays on why you like / hate / prefer a
brand
or series of caps.

Thanks,
--
DaveC

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Stretch my old ring out.

I Am Kirk Johnson.
"Anal Stretching, Wrenching & Expanding Specialist"
http://www.imagefap.com/image.php?id=1988478267

William Sommerwerck wrote:

Point 2: Leave the side panels off like I tend to do!

I do, but that's mostly to make it easy to perform full backups. The machine
run coolers, though it spews more RF, which keeps atomic clocks in the same
room from synching.

Thankfully I have no atomic clocks to worry about.


By the way, check the CPU cooler occasionally. Mine hadn't been cleaned
since I bought the computer over eight years ago, and you cannot believe how
clogged with shmutz the heat sink was.

Yes, I keep an eye on that kind of thing.

Graham

On Sun, 10 May 2009 13:54:33 +0100, Eeyore
wrote:



William Sommerwerck wrote:

Point 2: Leave the side panels off like I tend to do!

I do, but that's mostly to make it easy to perform full backups. The machine
run coolers, though it spews more RF, which keeps atomic clocks in the same
room from synching.

Thankfully I have no atomic clocks to worry about.


By the way, check the CPU cooler occasionally. Mine hadn't been cleaned
since I bought the computer over eight years ago, and you cannot believe how
clogged with shmutz the heat sink was.

Yes, I keep an eye on that kind of thing.

Graham


Dust sucks, because we *cannot* see it, so you must have a pretty good
eye. ;-)

I *can* see my accumulations of dust though. So I keep my system's
sinks clean pretty often as well. On the order of once every other month
even.

On Fri, 08 May 2009 14:55:18 +0100, Eeyore
wrote:



Spehro Pefhany wrote:

Sylvia Else wrote:
Mike Tomlinson wrote:
Dave Platt writes

One manufacturer was citing a "50,000
hour" lifetime figure on the motherboard carton

Are you sure there isn't a microdot in the small print with the words
"electrolytic capacitors excepted" printed on it?


"lifetime" is a word of dubious interpretation. Does it mean that it
won't break in that time, that it can be repaired in that time if it
does break, or something else?

If they claimed an MTBF of 50,000 hours, that would be different.


AFAIUI, MTBF typically applies only to the flat part at the bottom of
teh bathtub curve. They conveniently hack off the infantile failures
at the left and the increasing failures as the useful life expires on
the right. IOW, a product can have a much higher MTFB than the time it
takes to wear out.

Also, 50,000 hours 24/7 is only 5.7 years, which is more-or-less what
you'd expect out of a motherboard.

And if you run a 105C cap at 40C you'll get ~ 85 times the datasheet
lifetime. So a 2,000 hr 105C cap would last over 19 years. Watch the ripple
current of course !

Interesting point there. One decoupling cap on a mobo of mine near the
graphics card slot was visibly bulged whereas others weren't. I imagine it
was hot air being blown onto it by the GPU fan.

Graham

I would imagine that it was a crappy capacitor, perhaps one of those
knock-off Taiwan caps. Sceptre LCD monitors had a rash of crappy
electrolytics which they used on the outputs of their switchers a few
years ago. Many computer motherboards also used icky caps. The two
Sceptre monitors that a friend had crapped out around the same time. I
replaced the high stress caps with United Chemicon caps.

For my pulse power amplifier applications, I stick to United Chemicon.

--
Mark

For my pulse power amplifier applications, I stick to United Chemicon./

Which series do you use? U-C make several qualities in radial lead cans.
--
DaveC

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Eeyore wrote:
William Sommerwerck wrote:
[...]
By the way, check the CPU cooler occasionally. Mine hadn't been cleaned
since I bought the computer over eight years ago, and you cannot believe how
clogged with shmutz the heat sink was.

Yes, I keep an eye on that kind of thing.

This box is a dual Xeon, with huge CPU heatsinks that get very filthy. I
take the fans off & brush out the heatsinks once or twice a year.


--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------

On Mon, 11 May 2009 13:54:10 -0700, DaveC wrote:

For my pulse power amplifier applications, I stick to United Chemicon./

Which series do you use? U-C make several qualities in radial lead cans.

KZE

Eeyore wrote:


By the way, check the CPU cooler occasionally. Mine hadn't been cleaned
since I bought the computer over eight years ago, and you cannot believe how
clogged with shmutz the heat sink was.

Yes, I keep an eye on that kind of thing.

Graham



The ethernet tokens should also be polished every three weeks.

--
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