Capacitor Mystery

[Watson A.Name - \"Watt Su]

Pic posted in alt.binaries.schematics.electronic.

I have several of these that measure considerably less than their marked
value. I'm thinking that they might be the type of capacitor that uses
metallized film, which burns off when it has a dielectric failure. The
many burnoffs may cause the capacitance to decrease substantially over
time. Could this be the reason for the low measured capacitance?

I've googled and I came up with info on Siemens capacitors at EPCOS,
which seems to be the Siemens and Matsushita capacitors, which is how
the documents are labeled. But I can't find any info on this model. I
would guess that these capacitors are teenagers at least, agewise. I've
also looked on Faradnet. Any ideas?

Thanks.

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@

 

[Jerry G.]

Why don't you simply replace them for new ones of their marked value??? This
should not be too complicated...

--

Jerry G.
=====


"Watson A.Name - "Watt Sun, the Dark Remover"" <NOSPAM@dslextreme.com> wrote
in message news:10d91ic3aj1khf2@corp.supernews.com...
Pic posted in alt.binaries.schematics.electronic.

I have several of these that measure considerably less than their marked
value. I'm thinking that they might be the type of capacitor that uses
metallized film, which burns off when it has a dielectric failure. The
many burnoffs may cause the capacitance to decrease substantially over
time. Could this be the reason for the low measured capacitance?

I've googled and I came up with info on Siemens capacitors at EPCOS,
which seems to be the Siemens and Matsushita capacitors, which is how
the documents are labeled. But I can't find any info on this model. I
would guess that these capacitors are teenagers at least, agewise. I've
also looked on Faradnet. Any ideas?

Thanks.

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@

 

[Sir Charles W. Shults III]

"Jerry G." <jerryg50@hotmail.com> wrote in message
news:cb3tfv$c40$1@news.eusc.inter.net...

Why don't you simply replace them for new ones of their marked value???
This
should not be too complicated...

You have missed his point entirely. He is not saying that he has
problems with failures in a circuit; he is interested in known *why* these
devices are failing as they are.

Cheers!

Sir Charles W. Shults III, K. B. B.
Xenotech Research
321-206-1840
http://www.xenotechresearch.com

 

[Watson A.Name - \"Watt Su]

"Jerry G." <jerryg50@hotmail.com> wrote in message
news:cb3tfv$c40$1@news.eusc.inter.net...

Why don't you simply replace them for new ones of their marked
value??? This
should not be too complicated...

--

Jerry G.
=====

I just go Click, Click! And the whole board pops out of the card cage,
I drop it in the trash, and I just insert another card, of which I
literally have tons more.

And i'm just interested in the failure mode, why and how this is
happening. Many of the others measure something like .872 uF, which is
well below the 5% tolerance but still allows the circuit to function.
But I'm thinking that the marginal capacitance is causing the audio
quality to suffer.

"Watson A.Name - "Watt Sun, the Dark Remover"" <NOSPAM@dslextreme.com
wrote
in message news:10d91ic3aj1khf2@corp.supernews.com...
Pic posted in alt.binaries.schematics.electronic.

I have several of these that measure considerably less than their
marked
value. I'm thinking that they might be the type of capacitor that
uses
metallized film, which burns off when it has a dielectric failure.
The
many burnoffs may cause the capacitance to decrease substantially over
time. Could this be the reason for the low measured capacitance?

I've googled and I came up with info on Siemens capacitors at EPCOS,
which seems to be the Siemens and Matsushita capacitors, which is how
the documents are labeled. But I can't find any info on this model.
I
would guess that these capacitors are teenagers at least, agewise.
I've
also looked on Faradnet. Any ideas?

Thanks.

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@

 

[John Fields]

On Tue, 22 Jun 2004 05:17:58 -0700, "Watson A.Name - \"Watt Sun, the
Dark Remover\"" <NOSPAM@dslextreme.com> wrote:

"Jerry G." <jerryg50@hotmail.com> wrote in message
news:cb3tfv$c40$1@news.eusc.inter.net...
Why don't you simply replace them for new ones of their marked
value??? This
should not be too complicated...

--

Jerry G.
=====

I just go Click, Click! And the whole board pops out of the card cage,
I drop it in the trash, and I just insert another card, of which I
literally have tons more.

And i'm just interested in the failure mode, why and how this is
happening. Many of the others measure something like .872 uF, which is
well below the 5% tolerance but still allows the circuit to function.
But I'm thinking that the marginal capacitance is causing the audio
quality to suffer.

---
If you want to investigate the failure mode you might want to build
yourself a zapper, then do a "before and after" test on one (or
several) of the caps; measure the capacitance, zap the cap to burn
off some of the metalization and then remeasure the capacitance.
Depending on how much metal you remove/displace (or whatever that
self-healing mechanism is) per hit, you may have to zap it a bunch of
times before you get a measureble change in capacitance.

--
John Fields

 

[Watson A.Name - \"Watt Su]

"John Fields" <jfields@austininstruments.com> wrote in message
news:ucpgd0tph7cer99uqhjek12bhpmpo2is30@4ax.com...

On Tue, 22 Jun 2004 05:17:58 -0700, "Watson A.Name - \"Watt Sun, the
Dark Remover\"" <NOSPAM@dslextreme.com> wrote:


"Jerry G." <jerryg50@hotmail.com> wrote in message
news:cb3tfv$c40$1@news.eusc.inter.net...
Why don't you simply replace them for new ones of their marked
value??? This
should not be too complicated...

--

Jerry G.
=====

I just go Click, Click! And the whole board pops out of the card
cage,
I drop it in the trash, and I just insert another card, of which I
literally have tons more.

And i'm just interested in the failure mode, why and how this is
happening. Many of the others measure something like .872 uF, which
is
well below the 5% tolerance but still allows the circuit to function.
But I'm thinking that the marginal capacitance is causing the audio
quality to suffer.

---
If you want to investigate the failure mode you might want to build
yourself a zapper, then do a "before and after" test on one (or
several) of the caps; measure the capacitance, zap the cap to burn
off some of the metalization and then remeasure the capacitance.
Depending on how much metal you remove/displace (or whatever that
self-healing mechanism is) per hit, you may have to zap it a bunch of
times before you get a measureble change in capacitance.

But not only how many times, but how much voltage? It's a 1 uF cap, so
it will hold qquite a bit of charge. How do I zap it? Jacob's Ladder?
Tesla Coil? Connect it to the primary of a 120VAC to 6VAC at a couple
amps transformer, and then arc the 6V winding to a nice, high current
power suource?

If the zapping isn't strong enough, the change after many zaps might be
nearly zero. if it's too strong, the smoke might come out. Or
something else might come out. Scary thought.

--
John Fields

 

[Glenn Waller]

Electrolytic capacitors have a life span, under good conditions, of 5 years.

You're lucky to have a few teenagers amongst those you have.

The fact is that this is the basis of consumer electronics life-period. (life-span)

Any devices life span is dictated by the life expectancy of it's components. Caps are usually the culprit of this in power supplies for tv's and video/entertainment equipment. (always powered on, in stand-by)

Watson A.Name - "Watt Sun, the Dark Remover" wrote:

"John Fields" <jfields@austininstruments.com> wrote in message
news:ucpgd0tph7cer99uqhjek12bhpmpo2is30@4ax.com...

On Tue, 22 Jun 2004 05:17:58 -0700, "Watson A.Name - \"Watt Sun, the
Dark Remover\"" <NOSPAM@dslextreme.com> wrote:


"Jerry G." <jerryg50@hotmail.com> wrote in message
news:cb3tfv$c40$1@news.eusc.inter.net...

Why don't you simply replace them for new ones of their marked

value??? This

should not be too complicated...

--

Jerry G.
=====

I just go Click, Click! And the whole board pops out of the card

cage,

I drop it in the trash, and I just insert another card, of which I
literally have tons more.

And i'm just interested in the failure mode, why and how this is
happening. Many of the others measure something like .872 uF, which

is

well below the 5% tolerance but still allows the circuit to function.
But I'm thinking that the marginal capacitance is causing the audio
quality to suffer.

---
If you want to investigate the failure mode you might want to build
yourself a zapper, then do a "before and after" test on one (or
several) of the caps; measure the capacitance, zap the cap to burn
off some of the metalization and then remeasure the capacitance.
Depending on how much metal you remove/displace (or whatever that
self-healing mechanism is) per hit, you may have to zap it a bunch of
times before you get a measureble change in capacitance.


But not only how many times, but how much voltage? It's a 1 uF cap, so
it will hold qquite a bit of charge. How do I zap it? Jacob's Ladder?
Tesla Coil? Connect it to the primary of a 120VAC to 6VAC at a couple
amps transformer, and then arc the 6V winding to a nice, high current
power suource?

If the zapping isn't strong enough, the change after many zaps might be
nearly zero. if it's too strong, the smoke might come out. Or
something else might come out. Scary thought.


--
John Fields

 

[Al]

In article <K0yCc.62075$sj4.56237@news-server.bigpond.net.au>,
Glenn Waller <gwal9061@bigpond.net.au> wrote:

Electrolytic capacitors have a life span, under good conditions, of 5 years.

You're lucky to have a few teenagers amongst those you have.

The fact is that this is the basis of consumer electronics life-period.
(life-span)

Dunno about that! I have a Roberts Tape Recorder from the 60's that
still works fine. Never replaced a component in it. Were the old
components more robust than the current crop?

Al

--
There's never enough time to do it right the first time.......

 

[Kevin Carney]

Capacitors take a beating in modern equipment ( mid 1980's and now). I
would say when they started using cap's in switching supplies and in pulse
formation (Vertical and Horizontal sweep) and flyback derived DC voltages.
Reducing size of equipment and improper cooling (cheap fans) doesn't help
either. Will the short product cycles eventually burn the Manufacturers ?
Products today are not as reliable as they once were, they don't have to be.
People accept the junk products of today, they accept having to install
continuous software upgrades as a way of life. Years ago if you had to
constantly upgrade to keep going, people would find another way. My opinion
only...

--
change .combo to .com for correct email

***************************************************
"We ought always to know precisely why a given job
is done in a particular way, and why it is done at
all, and why it can't be done more efficiently,
if it must be done at all."-- T.J.Watson

***************************************************

"Al" <no.spam@here.com> wrote in message
news:no.spam-C97464.08585924062004@news.verizon.net...

In article <K0yCc.62075$sj4.56237@news-server.bigpond.net.au>,
Glenn Waller <gwal9061@bigpond.net.au> wrote:

Electrolytic capacitors have a life span, under good conditions, of 5
years.

You're lucky to have a few teenagers amongst those you have.

The fact is that this is the basis of consumer electronics life-period.
(life-span)



Dunno about that! I have a Roberts Tape Recorder from the 60's that
still works fine. Never replaced a component in it. Were the old
components more robust than the current crop?

Al

--
There's never enough time to do it right the first time.......

 

[Watson A.Name \"Watt Sun]

Glenn Waller wrote:

Electrolytic capacitors have a life span, under good conditions, of 5
years.

You're lucky to have a few teenagers amongst those you have.

The fact is that this is the basis of consumer electronics life-period.
(life-span)

Any devices life span is dictated by the life expectancy of it's
components. Caps are usually the culprit of this in power supplies for
tv's and video/entertainment equipment. (always powered on, in stand-by)

It's supposed to last a lot longer than 5 years because it's not an
electrolytic.

My own experience says that electrolytics last a lot longer than 5 years
as long as t hey don't get hot. The hotter they get, t he shorter thay
last. So if you have an old toob amp with the 'lytics next to a toob,
then good luck. That commonly happened with the rectifier. But
nowadays you get get a solid state substitute for the 6X4, 5U4 or whatever.

[snip]

And i'm just interested in the failure mode, why and how this is
happening. Many of the others measure something like .872 uF, which is

well below the 5% tolerance but still allows the circuit to function.
But I'm thinking that the marginal capacitance is causing the audio
quality to suffer.

---
If you want to investigate the failure mode you might want to build
yourself a zapper, then do a "before and after" test on one (or
several) of the caps; measure the capacitance, zap the cap to burn
off some of the metalization and then remeasure the capacitance.
Depending on how much metal you remove/displace (or whatever that
self-healing mechanism is) per hit, you may have to zap it a bunch of
times before you get a measureble change in capacitance.

But not only how many times, but how much voltage? It's a 1 uF cap, so
it will hold qquite a bit of charge. How do I zap it? Jacob's Ladder?
Tesla Coil? Connect it to the primary of a 120VAC to 6VAC at a couple
amps transformer, and then arc the 6V winding to a nice, high current
power suource?

If the zapping isn't strong enough, the change after many zaps might be
nearly zero. if it's too strong, the smoke might come out. Or
something else might come out. Scary thought.

--
John Fields

 

[Michael Hofmann]

Glenn Waller wrote:

Electrolytic capacitors have a life span, under good conditions, of 5
years.

Yeah right. Don't tell my vintage audio equipment. 30+ years and counting.
And btw, sensible manufacturers give you a formula to calculate expected
lifetime. I have never seen one state an explicit number of years.

Michael

 

[Bob Myers]

"Michael Hofmann" <westbound@gmx.net> wrote in message
news:2k06nuF161o4tU1@uni-berlin.de...

Glenn Waller wrote:
Electrolytic capacitors have a life span, under good conditions, of 5
years.

Yeah right. Don't tell my vintage audio equipment. 30+ years and counting.
And btw, sensible manufacturers give you a formula to calculate expected
lifetime. I have never seen one state an explicit number of years.

Keep in mind, though, that there's a difference between the
expected IN-SERVICE lifetime for electrolytics, vs. their
shelf life. If stored for long periods with no voltage applied,
the dielectric layer (the really, really thin layer of aluminum
oxide formed on the foil) may degrade, often to the point of
making the cap very likely to fail soon after being placed in
service. If the cap is actually IN service, though, the regular
application of voltage across the thing keeps it healthy.
(Remember that the dielectric layer is produced by the
application of a "forming" voltage as part of the manufacturing
process in the first place.)

This, of course, is a completely separate concern than the
possibility of the electrolyte drying up due to a less-than-perfect
seal...

Bob M.

Michael

 

[Al]

In article <WvHCc.4688$d43.391@news.cpqcorp.net>,
"Bob Myers" <nospamplease@address.invalid> wrote:

"Michael Hofmann" <westbound@gmx.net> wrote in message
news:2k06nuF161o4tU1@uni-berlin.de...
Glenn Waller wrote:
Electrolytic capacitors have a life span, under good conditions, of 5
years.

Yeah right. Don't tell my vintage audio equipment. 30+ years and counting.
And btw, sensible manufacturers give you a formula to calculate expected
lifetime. I have never seen one state an explicit number of years.

Keep in mind, though, that there's a difference between the
expected IN-SERVICE lifetime for electrolytics, vs. their
shelf life. If stored for long periods with no voltage applied,
the dielectric layer (the really, really thin layer of aluminum
oxide formed on the foil) may degrade, often to the point of
making the cap very likely to fail soon after being placed in
service. If the cap is actually IN service, though, the regular
application of voltage across the thing keeps it healthy.
(Remember that the dielectric layer is produced by the
application of a "forming" voltage as part of the manufacturing
process in the first place.)

This, of course, is a completely separate concern than the
possibility of the electrolyte drying up due to a less-than-perfect
seal...

Bob M.


Michael

The statements above illustrate why it is so important to state the
conditions under which the items under discussion are used. Both answers
are correct, if the conditions warrent them.

BTW, I think I once read that the Spitfire engines used during the
Battle of Britain had to be overhauled after 10 hours of flight. And
that was because they were being operated in an overrated condition so
they could produce the extra horsepower needed for the air battles. The
NAZI planes could not be overrated as they had much further to fly.

Al

--
There's never enough time to do it right the first time.......

 

[Watson A.Name - \"Watt Su]

"Michael Hofmann" <westbound@gmx.net> wrote in message
news:2k06nuF161o4tU1@uni-berlin.de...

Glenn Waller wrote:
Electrolytic capacitors have a life span, under good conditions, of
5
years.

Yeah right. Don't tell my vintage audio equipment. 30+ years and
counting.
And btw, sensible manufacturers give you a formula to calculate
expected
lifetime. I have never seen one state an explicit number of years.

Michael

It used to be that serious audiophile gear used good quality 'lytics
such as Western Electric caps. Those were the gray colored ones that
were made for communications equipment that was designed to last for 30
years. I think McIntosh used those, and maybe some other makers as
well.

I have a few HP power supplies that are over 30 years old, and still
going strong with the original caps in them. So never say never.