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

This is an invalid return address
Please reply in the news group

DaveC wrote:

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.

Toss a coin ?

I'd tend to trust Panasonic btw. They tend to have good specs but even they have
various options. When purchasing for a new project, they are my first choice for
prototyping. At the economy level I'd go for Samwha ( had excellent results ).

Graham

Eeyore wrote in
:

I'd tend to trust Panasonic btw.

Me too. I used them to replace the low ESR caps on an ITX mainboard that runs
in fairly hot and enclosed conditions. The board failed previously because
caps with dodgy electrolyte were used, it leaked, dried, causing poor power
conditioning and early video failure. The problem has not reappeared with the
Panasonic FM electrolytics I used.

Panasonic and Nichicon make about 20 different grades and "types" of
electrolytics. Does one just look for high operating temp and low ESR, or
are there other factors (or combinations thereof) to consider?

William Sommerwerck wrote:

Panasonic and Nichicon make about 20 different grades and "types" of
electrolytics. Does one just look for high operating temp and low ESR, or
are there other factors (or combinations thereof) to consider?

If you get their full catalogues, there should be a selection table.

Graham

On Thu, 7 May 2009 10:34:08 -0700, "William Sommerwerck"
wrote:

Panasonic and Nichicon make about 20 different grades and "types" of
electrolytics. Does one just look for high operating temp and low ESR, or
are there other factors (or combinations thereof) to consider?

Dimensions (which affects life reduction due to self heating as well
as simply fitting the available space), lifetime (at temperature),
cost, availability, low operating temperature, maximum ripple current,
leakage current, tolerance, working voltage, surge voltage, etc.

Spehro Pefhany wrote in
:

Panasonic and Nichicon make about 20 different grades and "types" of
electrolytics. Does one just look for high operating temp and low ESR, or
are there other factors (or combinations thereof) to consider?

Dimensions (which affects life reduction due to self heating as well
as simply fitting the available space), lifetime (at temperature),
cost, availability, low operating temperature, maximum ripple current,
leakage current, tolerance, working voltage, surge voltage, etc.


Those are interesting, but I found that it's often easier to focus on a
subset. Dimensions are often dictated by the space, so I just go for higher
voltage caps which will be bigger anyway, that solves the self-heating and
the voltage overhead for safety.

Availaibility is interesting, but often the best parts get neglected till
people cry over spilt unobtainium. Although they cost a bit more, it might be
best to go for them anyway, that way suppliers will take care of
availability. The best way to make unobtainium is the slow fission of
amnesium...

One thing I never remember well is the correlation between ripple current and
ESR, though I imagine low ESR types tolerate ripple currents better because
they will dissipate less power per amp of ripple.

"William Sommerwerck" wrote in
:

Does one just look for high operating temp and low ESR

Worked for me. I bet there is a more proper way to go, but I just assumed
that those two considerations would give me the best lifetime, though I also
add in a choice for a higher voltage cap because voltage headroom also
certifies an easy ride and long life.

On May 7, 9:53*am, DaveC wrote:
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.

"low ESR" is not good enough for a purchasing spec. By the standards
of just a few decades ago, all of today's electrolytics are low ESR.
But whether anything meets your requirement is driven by the
requirement, not bullet points in the capacitor maker's glossies.

It's easy to find electrolytics of same voltage and capacitance which
have ESR specs different by a factor of 10 or more. It shouldn't be
too surprising that package and size have a lot to do with ESR. If
your requirements are not met by any commercially available
capacitors, you might think about making your design more
realistic :-).

Digikey etc. let you sort by ESR.

It is also possible to choose capacitors which are too low in ESR and
lead to instability with low-dropout regulators or other circuits.

Tim.

On Thu, 7 May 2009 09:42:16 -0700 (PDT), Tim Shoppa
wrote:

On May 7, 9:53*am, DaveC wrote:
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.

"low ESR" is not good enough for a purchasing spec. By the standards
of just a few decades ago, all of today's electrolytics are low ESR.
But whether anything meets your requirement is driven by the
requirement, not bullet points in the capacitor maker's glossies.

It's easy to find electrolytics of same voltage and capacitance which
have ESR specs different by a factor of 10 or more. It shouldn't be
too surprising that package and size have a lot to do with ESR. If
your requirements are not met by any commercially available
capacitors, you might think about making your design more
realistic :-).

Digikey etc. let you sort by ESR.

It is also possible to choose capacitors which are too low in ESR and
lead to instability with low-dropout regulators or other circuits.

Tim.

And a lot of, maybe most, switchers are stabilized by the filter cap
esr.

John

Tim Shoppa wrote:

Digikey etc. let you sort by ESR.

Manufacturer's data sheets are more comprehensive. And don't forget ripple current.

Graham

In article .net,
DaveC wrote:

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.

How critically are you trying to match the values?

Please remember that 'lytics are manufactured and sold with a rather
wide tolerance range. For example, the Panasonic FM and FC series
have a +/- 20% tolerance specification, and the nominal values they
list (in the Digi-Key catalog at least) are around 20-30% apart... so
there's some amount of overlap between the values you'd expect to get.

Older caps were often sold with -20% +80% tolerance, which meant that
you could end up getting quite a lot more capacitance than you had
"paid for".

In most cases, these days, I'd just look at the space I have available
to fit the cap, and then pick the "equal or next largest capacitance,
equal or higher working voltage" to what the BOM calls for. Unless
there was a particular need for a specific value (e.g. for timing
purpose) I wouldn't sweat about things like "the BOM calls for a 220
uF, and all they have in that size is a 330 uF."

And, if there were timing issues involved, I don't think I'd be using
a 'lytic at all in that application!

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.)

I've heard good things about Nichicon, and have used them in some
repair/retrofit projects. Don't have anywhere near enough information
about long-term performance to be of help with your question, though.

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.

For what it's worth, I've seen several of the PC-motherboard
manufacturers touting their use of solid-electrolyte capacitors for
the CPU VRM... and this is a high-current, high-ripple, low-ESR-
is-very-important application. One manufacturer was citing a "50,000
hour" lifetime figure on the motherboard carton (although I think this
assumes very good cooling of the board).

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

In article , 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?

--
(\__/)
(='.'=) Bunny says Windows 7 is Vi$ta reloaded.
(")_(") http://imgs.xkcd.com/comics/windows_7.png

Mike Tomlinson wrote:
In article , 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.

Sylvia.

On Fri, 08 May 2009 22:04:27 +1000, Sylvia Else
wrote:

Mike Tomlinson wrote:
In article , 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.

Sylvia.

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.

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

In article , Spehro Pefhany
writes

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

Not from electrolytic caps, which was kind of the point. Even Panasonic
specify only 10k hours for their top of the range electros.

--
(\__/)
(='.'=) Bunny says Windows 7 is Vi$ta reloaded.
(")_(") http://imgs.xkcd.com/comics/windows_7.png

Sylvia Else wrote:
Mike Tomlinson wrote:
In article , 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.

****, I'd generally be happy with 2000 hours MTBF.

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

On Sat, 09 May 2009 02:16:42 +1000, Bob Larter
wrote:

Sylvia Else wrote:
Mike Tomlinson wrote:
In article , 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.

****, I'd generally be happy with 2000 hours MTBF.

Less than 12 weeks? You have a bright potential future with Samsung,
HP etc.

Mike Tomlinson wrote:

In article , 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?

After the bad caps debacle one manufacturer, it might be Gigabyte, moved
to the OSCON type in which case it may very well be true.

Graham

Eeyore wrote:



Mike Tomlinson wrote:

In article , 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?

After the bad caps debacle one manufacturer, it might be Gigabyte,
moved to the OSCON type in which case it may very well be true.

Graham

Yes ! Gigabyte got bitten hard by that and the fake motherboard scam.

--
Best Regards:
Baron.

On May 7, 6:53*am, DaveC wrote:
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

I buy the replacement parts at a Hollywood dub house. Last year I
bought 14.000 'lytics , 10,000 installed by 3 of us. My first choice
in Panasonic FM but the selection isn't as wide as the second choice
of FC caps. If I run into a physical size problem Nichicon PW series
often helps. For surface mount first choice is Panasonic FK and
sometimes HC series. If you're doing this a lot like we are, Metcal
soldering irons are HIGHLY recommended. The STTC-126 tip (700 F 30
degree bent tip) is really good for clearing stubborn holes - usually
ground planes with lousy thermal reliefs. A lifted pad is a very rare
event with a good soldering iron.

100uf 25V (most common value for us) cost 20 cents in 1's 10.28 / 100
but are only $57.54 / 1000. I try for 1000s whenever possible.

G²

"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

This is an invalid return address
Please reply in the news group



Stretch my old ring out.

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