Film capacitor as power-supply filter

[John Larkin]

On Thu, 17 Oct 2019 17:13:40 -0000 (UTC), Steve Wilson <no@spam.com>
wrote:

jlarkin@highlandsniptechnology.com wrote:

Quite welcome. It's good to have some real numbers on (one) real cap.

Yor data is valid for that capacitor only.

Excellent whining.

It's more data than data on no capacitors. I suspect that all wet
aluminum electros will have similar shaped curves, so will be
self-stabilizing in series strings.

Every cap will be different. There are many different electrolytes with
different characteristics, such as non-solid borax or organic, non-solid
water-based, solid manganese dioxide, solid conducting polymer, non-solid
hybrid electrolyte, etc., and the leakage characteristics will be different
for each type. See Wikipedia, "Aluminum electrolytic capacitor", at

https://en.wikipedia.org/wiki/Aluminum_electrolytic_capacitor

Superb, well-researched whining.

I used a standard Panasonic aluminum electrolytic.

Measure something else and post it here.

--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

 

[John Larkin]

On Thu, 17 Oct 2019 10:17:47 -0700 (PDT), George Herold
<gherold@teachspin.com> wrote:

On Thursday, October 17, 2019 at 12:24:20 PM UTC-4, jla...@highlandsniptechnology.com wrote:
On Thu, 17 Oct 2019 08:53:25 -0700 (PDT), George Herold
gherold@teachspin.com> wrote:

On Thursday, October 17, 2019 at 11:02:13 AM UTC-4, jla...@highlandsniptechnology.com wrote:
On Thu, 17 Oct 2019 05:44:51 -0000 (UTC), Steve Wilson <no@spam.com
wrote:

John Larkin <jlarkin@highland_atwork_technology.com> wrote:

Here's possibly the only curve like this ever posted online:

https://www.dropbox.com/s/i4wwttdgqycz9rv/Alum_Leakage_63u.JPG?raw=1

See Fig. 4(b) on Page 2 in

https://jianghai-europe.com/wp-content/uploads/8-Jianghai-Europe-E-Cap-
Leakage-Current-AAL-2018-09-18.pdf

The curves are exponential.

That fig 4b is an obvious made-up cartoon. It's certainly not
exponential. And it has no numbers.
Ditto on the thanks.
The Tardin article mentions that the caps behave like they have a
zener diode in parallel... So having the current look like noisy
zener current above the 'threshold' makes some sense.

Years ago I charge an Al eletro to ~1/2 the max voltage, left it
on my bench for the weekend and came back to see the voltage had
only dropped by ~10% or so. It would be fun to hook one up
to an electrometer and let it sit there for a week or whatever
and record the voltage.

George H.

Or just check it with a DVM now and then. I did that with a supercap
for a few months.
Right... I think I used the trick of putting a Gig ohm in series
with my DMM and dividing by 100.
I'd bet it can't be exponential* 'all the way down' at some point there'll be some other constant (resistive) leakage path.

Hey are tant's any better than Al-electros. At my ppoe I made this
triangle wave generator, current source into a cap, milli second to
kilo second periods. I used a 100uF tant for the longest times...
seemed to work fine.. but I only 'really' measured the longest times
once. (otherwise just made sure it went up and down.)

George H.
*does exponential imply some thermal mechanism?

A pure RC has a exponential decay, e^(-kt). But the leakage in an
electrolytic isn't ohmic, so the decay slows down as the voltage
drops.

Pretty complex.

--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

 

[Phil Allison]

Steve Wilson = Raving Loony wrote:
------------------------------------

The curves are exponential.

That fig 4b is an obvious made-up cartoon. It's certainly not
exponential. And it has no numbers.

The curve is exponential over the portion that is increasing.

** It was drawn by hand using a round object as a template, you lying IDIOT !!

The curve is CIRCULAR !!

What a fucking retard.

Must be a PIC programmer.



.... Phil

 

[Phil Allison]

Steve Wilson is Clinically Insane wrote:

See Fig. 4(b) on Page 2 in

https://jianghai-europe.com/wp-content/uploads/8-Jianghai-Europe-E-Cap-
Leakage-Current-AAL-2018-09-18.pdf

The curves are exponential.

** Total lunacy.

Wilson is mentally ill or defective or both.



..... Phil

 

[Steve Wilson]

John Larkin <jlarkin@highland_atwork_technology.com> wrote:

On Thu, 17 Oct 2019 17:13:40 -0000 (UTC), Steve Wilson <no@spam.com
wrote:

jlarkin@highlandsniptechnology.com wrote:

Quite welcome. It's good to have some real numbers on (one) real cap.

Yor data is valid for that capacitor only.

Excellent whining.

It's more data than data on no capacitors. I suspect that all wet
aluminum electros will have similar shaped curves, so will be
self-stabilizing in series strings.

Why suspect? Why not read some of the links I provided? For example, see
Page 3 of

https://jianghai-europe.com/wp-content/uploads/8-Jianghai-Europe-E-Cap-
Leakage-Current-AAL-2018-09-18.pdf

Quote:

The operating leakage current [5] as a measure of the forming condition of
anode foil depends on the time, applied voltage, temperature, and history
of the capacitor (fig. 4 (a) ~ (c)). Typical values of the operational
leakage current range between approx. 5 ~ 15% of the data sheet value of
leakage current amount and are usually reached after several ten minutes of
continuous operation.

The leakage current specified in the data sheet shall be valid even after a
long, voltage-free storage period and has therefore a much higher
numerical value than the operating leakage current. The oxide layer
dissolves to a certain extent as a function of temperature and electrolyte
composition, because without any voltage applied, the oxide layer cannot
regenerate ("self-healing") [5].

While low-voltage capacitors (up to 100 V rated voltage) with solvent-based
electrolyte systems are usually very stable, high-voltage capacitors (from
160 V rated voltage) with ethylene glycole-based electrolytes and in
particular so-called "low ESR" types with aqueous electrolytes may exhibit
an increase of leakage currents throughout their lifetime.

15 ~ 30 minutes of operation of the electrolytic capacitors via a resistor
(low-voltage: 100 Ohm, high-voltage: 1 k, see [7], section 4.1
"pretreatment") at a voltage increased gradually to rated voltage may heal
the weak spots in the dielectric and lower the leakage current below the
data sheet value.

Every cap will be different. There are many different electrolytes with
different characteristics, such as non-solid borax or organic, non-solid
water-based, solid manganese dioxide, solid conducting polymer,
non-solid hybrid electrolyte, etc., and the leakage characteristics will
be different for each type. See Wikipedia, "Aluminum electrolytic
capacitor", at

https://en.wikipedia.org/wiki/Aluminum_electrolytic_capacitor

Superb, well-researched whining.

I used a standard Panasonic aluminum electrolytic.

Measure something else and post it here.

You are trying to pretend the measurement you made on one capacitor is the
first time such a measurement has been made. In fact, you said so yourself.

I posted numerous links that show your assumption is not valid. There is a
tremendous amout of knowlege in those links. You would do well to study
them.

 

[John Larkin]

On Thu, 17 Oct 2019 16:44:52 -0000 (UTC), Steve Wilson <no@spam.com>
wrote:

jlarkin@highlandsniptechnology.com wrote:

On Thu, 17 Oct 2019 05:44:51 -0000 (UTC), Steve Wilson <no@spam.com
wrote:

John Larkin <jlarkin@highland_atwork_technology.com> wrote:

Here's possibly the only curve like this ever posted online:

https://www.dropbox.com/s/i4wwttdgqycz9rv/Alum_Leakage_63u.JPG?raw=1

See Fig. 4(b) on Page 2 in

https://jianghai-europe.com/wp-content/uploads/8-Jianghai-Europe-E-Cap-
Leakage-Current-AAL-2018-09-18.pdf

The curves are exponential.

That fig 4b is an obvious made-up cartoon. It's certainly not
exponential. And it has no numbers.

The curve is exponential over the portion that is increasing.

Well, except for the shape of the curve. And the brick wall on the
right.


Every capacitor

will be different, so if you want the curve for your particular capacitor,
you have to measure it.

I did measure one. I suspect that the general trend is common to most
wet aluminum caps.

I know that some polymer alum caps are different.

--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

 

[John Larkin]

On Thu, 17 Oct 2019 20:45:36 -0000 (UTC), Steve Wilson <no@spam.com>
wrote:

John Larkin <jlarkin@highland_atwork_technology.com> wrote:

On Thu, 17 Oct 2019 17:13:40 -0000 (UTC), Steve Wilson <no@spam.com
wrote:

jlarkin@highlandsniptechnology.com wrote:

Quite welcome. It's good to have some real numbers on (one) real cap.

Yor data is valid for that capacitor only.

Excellent whining.

It's more data than data on no capacitors. I suspect that all wet
aluminum electros will have similar shaped curves, so will be
self-stabilizing in series strings.

Why suspect? Why not read some of the links I provided? For example, see
Page 3 of

https://jianghai-europe.com/wp-content/uploads/8-Jianghai-Europe-E-Cap-
Leakage-Current-AAL-2018-09-18.pdf

Quote:

The operating leakage current [5] as a measure of the forming condition of
anode foil depends on the time, applied voltage, temperature, and history
of the capacitor (fig. 4 (a) ~ (c)). Typical values of the operational
leakage current range between approx. 5 ~ 15% of the data sheet value of
leakage current amount and are usually reached after several ten minutes of
continuous operation.

The leakage current specified in the data sheet shall be valid even after a
long, voltage-free storage period and has therefore a much higher
numerical value than the operating leakage current. The oxide layer
dissolves to a certain extent as a function of temperature and electrolyte
composition, because without any voltage applied, the oxide layer cannot
regenerate ("self-healing") [5].

While low-voltage capacitors (up to 100 V rated voltage) with solvent-based
electrolyte systems are usually very stable, high-voltage capacitors (from
160 V rated voltage) with ethylene glycole-based electrolytes and in
particular so-called "low ESR" types with aqueous electrolytes may exhibit
an increase of leakage currents throughout their lifetime.

15 ~ 30 minutes of operation of the electrolytic capacitors via a resistor
(low-voltage: 100 Ohm, high-voltage: 1 k, see [7], section 4.1
"pretreatment") at a voltage increased gradually to rated voltage may heal
the weak spots in the dielectric and lower the leakage current below the
data sheet value.

Every cap will be different. There are many different electrolytes with
different characteristics, such as non-solid borax or organic, non-solid
water-based, solid manganese dioxide, solid conducting polymer,
non-solid hybrid electrolyte, etc., and the leakage characteristics will
be different for each type. See Wikipedia, "Aluminum electrolytic
capacitor", at

https://en.wikipedia.org/wiki/Aluminum_electrolytic_capacitor

Superb, well-researched whining.

I used a standard Panasonic aluminum electrolytic.

Measure something else and post it here.

You are trying to pretend the measurement you made on one capacitor is the
first time such a measurement has been made. In fact, you said so yourself.

I said "possibly" the only one available online, after several minutes
of intense web searching. If you can find an electrolytic cap leakage
measurement, past rated voltage, with real numbers, not fuzzy
cartoons, please post the link for us.

I posted numerous links that show your assumption is not valid.

I didn't assume anything. I measured something.

Try it; it's more fun than cutting and pasting a lot of text.


There is a
>tremendous amout of knowlege in those links.

Lotta words, no numbers. Engineers need numbers.

--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

 

[George Herold]

On Thursday, October 17, 2019 at 2:26:10 PM UTC-4, George Herold wrote:

On Thursday, October 17, 2019 at 2:01:02 PM UTC-4, John Larkin wrote:
On Thu, 17 Oct 2019 10:17:47 -0700 (PDT), George Herold
gherold@teachspin.com> wrote:

On Thursday, October 17, 2019 at 12:24:20 PM UTC-4, jla...@highlandsniptechnology.com wrote:
On Thu, 17 Oct 2019 08:53:25 -0700 (PDT), George Herold
gherold@teachspin.com> wrote:

On Thursday, October 17, 2019 at 11:02:13 AM UTC-4, jla...@highlandsniptechnology.com wrote:
On Thu, 17 Oct 2019 05:44:51 -0000 (UTC), Steve Wilson <no@spam.com
wrote:

John Larkin <jlarkin@highland_atwork_technology.com> wrote:

Here's possibly the only curve like this ever posted online:

https://www.dropbox.com/s/i4wwttdgqycz9rv/Alum_Leakage_63u.JPG?raw=1

See Fig. 4(b) on Page 2 in

https://jianghai-europe.com/wp-content/uploads/8-Jianghai-Europe-E-Cap-
Leakage-Current-AAL-2018-09-18.pdf

The curves are exponential.

That fig 4b is an obvious made-up cartoon. It's certainly not
exponential. And it has no numbers.
Ditto on the thanks.
The Tardin article mentions that the caps behave like they have a
zener diode in parallel... So having the current look like noisy
zener current above the 'threshold' makes some sense.

Years ago I charge an Al eletro to ~1/2 the max voltage, left it
on my bench for the weekend and came back to see the voltage had
only dropped by ~10% or so. It would be fun to hook one up
to an electrometer and let it sit there for a week or whatever
and record the voltage.

George H.

Or just check it with a DVM now and then. I did that with a supercap
for a few months.
Right... I think I used the trick of putting a Gig ohm in series
with my DMM and dividing by 100.
I'd bet it can't be exponential* 'all the way down' at some point there'll be some other constant (resistive) leakage path.

Hey are tant's any better than Al-electros. At my ppoe I made this
triangle wave generator, current source into a cap, milli second to
kilo second periods. I used a 100uF tant for the longest times...
seemed to work fine.. but I only 'really' measured the longest times
once. (otherwise just made sure it went up and down.)

George H.
*does exponential imply some thermal mechanism?

A pure RC has a exponential decay, e^(-kt). But the leakage in an
electrolytic isn't ohmic, so the decay slows down as the voltage
drops.

Pretty complex.
Right, if you monitor the voltage you'd have to integrate it to get the
current.. It's not at all clear to me what that double exponential
would look like.

George H.
something like this?
https://en.wikipedia.org/wiki/Double_exponential_function
That doesn't seem right.

If,
I(t) = Io*exp(V(t)/Vx) = C dV/dt
where Io, Vx and C are constants

Then I get that
V(t) = Vx * ln{(C*Vx)/(Io*t)}.. but I might have made a mistake,
and getting the initial conditions right is a bit.. uncertain.

I need a good graphing program. Time to learn python?

George H.

--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

 

[Bill Sloman]

On Friday, October 18, 2019 at 1:05:18 PM UTC+11, George Herold wrote:

On Thursday, October 17, 2019 at 2:26:10 PM UTC-4, George Herold wrote:
On Thursday, October 17, 2019 at 2:01:02 PM UTC-4, John Larkin wrote:
On Thu, 17 Oct 2019 10:17:47 -0700 (PDT), George Herold
gherold@teachspin.com> wrote:

On Thursday, October 17, 2019 at 12:24:20 PM UTC-4, jla...@highlandsniptechnology.com wrote:
On Thu, 17 Oct 2019 08:53:25 -0700 (PDT), George Herold
gherold@teachspin.com> wrote:

On Thursday, October 17, 2019 at 11:02:13 AM UTC-4, jla...@highlandsniptechnology.com wrote:
On Thu, 17 Oct 2019 05:44:51 -0000 (UTC), Steve Wilson <no@spam.com
wrote:

John Larkin <jlarkin@highland_atwork_technology.com> wrote:

Here's possibly the only curve like this ever posted online:

https://www.dropbox.com/s/i4wwttdgqycz9rv/Alum_Leakage_63u.JPG?raw=1

See Fig. 4(b) on Page 2 in

https://jianghai-europe.com/wp-content/uploads/8-Jianghai-Europe-E-Cap-
Leakage-Current-AAL-2018-09-18.pdf

The curves are exponential.

That fig 4b is an obvious made-up cartoon. It's certainly not
exponential. And it has no numbers.
Ditto on the thanks.
The Tardin article mentions that the caps behave like they have a
zener diode in parallel... So having the current look like noisy
zener current above the 'threshold' makes some sense.

Years ago I charge an Al eletro to ~1/2 the max voltage, left it
on my bench for the weekend and came back to see the voltage had
only dropped by ~10% or so. It would be fun to hook one up
to an electrometer and let it sit there for a week or whatever
and record the voltage.

George H.

Or just check it with a DVM now and then. I did that with a supercap
for a few months.
Right... I think I used the trick of putting a Gig ohm in series
with my DMM and dividing by 100.
I'd bet it can't be exponential* 'all the way down' at some point there'll be some other constant (resistive) leakage path.

Hey are tant's any better than Al-electros. At my ppoe I made this
triangle wave generator, current source into a cap, milli second to
kilo second periods. I used a 100uF tant for the longest times...
seemed to work fine.. but I only 'really' measured the longest times
once. (otherwise just made sure it went up and down.)

George H.
*does exponential imply some thermal mechanism?

A pure RC has a exponential decay, e^(-kt). But the leakage in an
electrolytic isn't ohmic, so the decay slows down as the voltage
drops.

Pretty complex.
Right, if you monitor the voltage you'd have to integrate it to get the
current.. It's not at all clear to me what that double exponential
would look like.

George H.
something like this?
https://en.wikipedia.org/wiki/Double_exponential_function
That doesn't seem right.

If,
I(t) = Io*exp(V(t)/Vx) = C dV/dt
where Io, Vx and C are constants

Then I get that
V(t) = Vx * ln{(C*Vx)/(Io*t)}.. but I might have made a mistake,
and getting the initial conditions right is a bit.. uncertain.

I need a good graphing program. Time to learn python?

Excel isn't a good graphing program, but you can get it to produce graphs.

IIRR Mathcad and Scicad can do it too.

--
Bill Sloman, Sydney

 

[Steve Wilson]

John Larkin <jlarkin@highland_atwork_technology.com> wrote:

On Thu, 17 Oct 2019 20:45:36 -0000 (UTC), Steve Wilson <no@spam.com
wrote:

John Larkin <jlarkin@highland_atwork_technology.com> wrote:

On Thu, 17 Oct 2019 17:13:40 -0000 (UTC), Steve Wilson <no@spam.com
wrote:

jlarkin@highlandsniptechnology.com wrote:

Quite welcome. It's good to have some real numbers on (one) real
cap.

Yor data is valid for that capacitor only.

Excellent whining.

It's more data than data on no capacitors. I suspect that all wet
aluminum electros will have similar shaped curves, so will be
self-stabilizing in series strings.

Why suspect? Why not read some of the links I provided? For example, see
Page 3 of

https://jianghai-europe.com/wp-content/uploads/8-Jianghai-Europe-E-Cap-
Leakage-Current-AAL-2018-09-18.pdf

Quote:

The operating leakage current [5] as a measure of the forming condition
of anode foil depends on the time, applied voltage, temperature, and
history of the capacitor (fig. 4 (a) ~ (c)). Typical values of the
operational leakage current range between approx. 5 ~ 15% of the data
sheet value of leakage current amount and are usually reached after
several ten minutes of continuous operation.

The leakage current specified in the data sheet shall be valid even
after a long, voltage-free storage period and has therefore a much
higher numerical value than the operating leakage current. The oxide
layer dissolves to a certain extent as a function of temperature and
electrolyte composition, because without any voltage applied, the oxide
layer cannot regenerate ("self-healing") [5].

While low-voltage capacitors (up to 100 V rated voltage) with
solvent-based electrolyte systems are usually very stable, high-voltage
capacitors (from 160 V rated voltage) with ethylene glycole-based
electrolytes and in particular so-called "low ESR" types with aqueous
electrolytes may exhibit an increase of leakage currents throughout
their lifetime.

15 ~ 30 minutes of operation of the electrolytic capacitors via a
resistor (low-voltage: 100 Ohm, high-voltage: 1 k, see [7], section 4.1
"pretreatment") at a voltage increased gradually to rated voltage may
heal the weak spots in the dielectric and lower the leakage current
below the data sheet value.

Every cap will be different. There are many different electrolytes
with different characteristics, such as non-solid borax or organic,
non-solid water-based, solid manganese dioxide, solid conducting
polymer, non-solid hybrid electrolyte, etc., and the leakage
characteristics will be different for each type. See Wikipedia,
"Aluminum electrolytic capacitor", at

https://en.wikipedia.org/wiki/Aluminum_electrolytic_capacitor

Superb, well-researched whining.

I used a standard Panasonic aluminum electrolytic.

Measure something else and post it here.

You are trying to pretend the measurement you made on one capacitor is
the first time such a measurement has been made. In fact, you said so
yourself.

I said "possibly" the only one available online, after several minutes
of intense web searching. If you can find an electrolytic cap leakage
measurement, past rated voltage, with real numbers, not fuzzy
cartoons, please post the link for us.

Why measure past the rated voltage? You are never going to operate there.
You simply risk damaging the capacitor for no good reason.

The curve shown in fig. 4 is a generic curve. The actual curves are
different for each capacitor, and depend on variables such as those
described above. So it is impossible to represent all capacitors at once.

I posted numerous links that show your assumption is not valid.

I didn't assume anything. I measured something.

Your data is meaningless. As mentioned elsewhere, capacitor manufacturers
can give actual curves for their capacitors. You can compare your data
against the spec to see if your cap is out of spec.

> Try it; it's more fun than cutting and pasting a lot of text.

Your data is meaningless.

There is a
tremendous amout of knowlege in those links.

Lotta words, no numbers. Engineers need numbers.

Nah. Real engineers need equations. Do an exponential fit to your data. The
Stdev will give an indication of the quality of the measurement. The
equation will allow you to compare other capacitors. The curve can be
compared to actual specs from manufacturers.

You need to also try measuring the capacitor voltage with a constant
current source. That could give valuable new information.

 

[Phil Allison]

Steve Lunatic Wilson wrote:

----------------------------

Why measure past the rated voltage? You are never going to operate there.
You simply risk damaging the capacitor for no good reason.

The curve shown in fig. 4 is a generic curve. The actual curves are
different for each capacitor, and depend on variables such as those
described above. So it is impossible to represent all capacitors at once.

You need to also try measuring the capacitor voltage with a constant
current source. That could give valuable new information.

** This fuckwit troll is a pernicious false arguer and incorrigible context shifter.

He is delusional to the extent he literally believes his own bullshit.

Prefect candidate for the "Church of Scientology" don't you think ?

If he ain't one already that is ...




..... Phil

 

On Sat, 19 Oct 2019 03:37:00 -0700 (PDT), Phil Allison
<pallison49@gmail.com> wrote:

Steve Lunatic Wilson wrote:

----------------------------


Why measure past the rated voltage? You are never going to operate there.
You simply risk damaging the capacitor for no good reason.

The curve shown in fig. 4 is a generic curve. The actual curves are
different for each capacitor, and depend on variables such as those
described above. So it is impossible to represent all capacitors at once.

You need to also try measuring the capacitor voltage with a constant
current source. That could give valuable new information.



** This fuckwit troll is a pernicious false arguer and incorrigible context shifter.

He is delusional to the extent he literally believes his own bullshit.

Prefect candidate for the "Church of Scientology" don't you think ?

If he ain't one already that is ...

He argues out of emotion rather than reason. I have several anti-fans
here who are dying to show me wrong, and will commit any bogus mental
contortion in that cause.

This is amusing, because I'm really interested in how people reason
toward truth, and especially how they don't.



--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

On Sat, 19 Oct 2019 07:48:13 -0000 (UTC), Steve Wilson <no@spam.com>
wrote:

John Larkin <jlarkin@highland_atwork_technology.com> wrote:

On Thu, 17 Oct 2019 20:45:36 -0000 (UTC), Steve Wilson <no@spam.com
wrote:

John Larkin <jlarkin@highland_atwork_technology.com> wrote:

On Thu, 17 Oct 2019 17:13:40 -0000 (UTC), Steve Wilson <no@spam.com
wrote:

jlarkin@highlandsniptechnology.com wrote:

Quite welcome. It's good to have some real numbers on (one) real
cap.

Yor data is valid for that capacitor only.

Excellent whining.

It's more data than data on no capacitors. I suspect that all wet
aluminum electros will have similar shaped curves, so will be
self-stabilizing in series strings.

Why suspect? Why not read some of the links I provided? For example, see
Page 3 of

https://jianghai-europe.com/wp-content/uploads/8-Jianghai-Europe-E-Cap-
Leakage-Current-AAL-2018-09-18.pdf

Quote:

The operating leakage current [5] as a measure of the forming condition
of anode foil depends on the time, applied voltage, temperature, and
history of the capacitor (fig. 4 (a) ~ (c)). Typical values of the
operational leakage current range between approx. 5 ~ 15% of the data
sheet value of leakage current amount and are usually reached after
several ten minutes of continuous operation.

The leakage current specified in the data sheet shall be valid even
after a long, voltage-free storage period and has therefore a much
higher numerical value than the operating leakage current. The oxide
layer dissolves to a certain extent as a function of temperature and
electrolyte composition, because without any voltage applied, the oxide
layer cannot regenerate ("self-healing") [5].

While low-voltage capacitors (up to 100 V rated voltage) with
solvent-based electrolyte systems are usually very stable, high-voltage
capacitors (from 160 V rated voltage) with ethylene glycole-based
electrolytes and in particular so-called "low ESR" types with aqueous
electrolytes may exhibit an increase of leakage currents throughout
their lifetime.

15 ~ 30 minutes of operation of the electrolytic capacitors via a
resistor (low-voltage: 100 Ohm, high-voltage: 1 k, see [7], section 4.1
"pretreatment") at a voltage increased gradually to rated voltage may
heal the weak spots in the dielectric and lower the leakage current
below the data sheet value.

Every cap will be different. There are many different electrolytes
with different characteristics, such as non-solid borax or organic,
non-solid water-based, solid manganese dioxide, solid conducting
polymer, non-solid hybrid electrolyte, etc., and the leakage
characteristics will be different for each type. See Wikipedia,
"Aluminum electrolytic capacitor", at

https://en.wikipedia.org/wiki/Aluminum_electrolytic_capacitor

Superb, well-researched whining.

I used a standard Panasonic aluminum electrolytic.

Measure something else and post it here.

You are trying to pretend the measurement you made on one capacitor is
the first time such a measurement has been made. In fact, you said so
yourself.

I said "possibly" the only one available online, after several minutes
of intense web searching. If you can find an electrolytic cap leakage
measurement, past rated voltage, with real numbers, not fuzzy
cartoons, please post the link for us.

Why measure past the rated voltage? You are never going to operate there.
You simply risk damaging the capacitor for no good reason.

The issue was series strings of electrolytic caps, where the total
supply voltage is more than the rated voltage of the caps. Film caps
can blow up in that situation. What do lytics do?

Answer: their IV curves make them safely self-equalize.

The curve shown in fig. 4 is a generic curve. The actual curves are
different for each capacitor, and depend on variables such as those
described above. So it is impossible to represent all capacitors at once.

I posted numerous links that show your assumption is not valid.

I didn't assume anything. I measured something.

Your data is meaningless. As mentioned elsewhere, capacitor manufacturers
can give actual curves for their capacitors.

Post a link of leakage past rated voltage. Real data, not faked
cartoons.


You can compare your data

against the spec to see if your cap is out of spec.

Try it; it's more fun than cutting and pasting a lot of text.

Your data is meaningless.

Since you probably don't design electronics, it is meaningless to you.

There is a
tremendous amout of knowlege in those links.

Lotta words, no numbers. Engineers need numbers.

Nah. Real engineers need equations. Do an exponential fit to your data. The
Stdev will give an indication of the quality of the measurement. The
equation will allow you to compare other capacitors. The curve can be
compared to actual specs from manufacturers.

You need to also try measuring the capacitor voltage with a constant
current source. That could give valuable new information.

How would that be different? You'd get the same data points, just
slower.





--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

[whit3rd]

On Saturday, October 19, 2019 at 3:48:18 AM UTC-4, Steve Wilson wrote:

Why measure past the rated voltage? You are never going to operate there.
You simply risk damaging the capacitor for no good reason.

Nah. Real engineers need equations. Do an exponential fit to your data.

The 'need equtions' is the reason you want to measure past the rated voltage;
there's not much validity to an equation if there are singularities just outside
the measured range (because, for instance, any polynomial fails to handle a singularity).

When you apply the capacitor, it's sensible to stick to the range the manufacturer
recommends (that's the way the manufacturer and user can coordinate), but NOT for
the purpose of information-gathering.

MOS devices get damaged quickly outside their recommended range, but not usually capacitors.
If in doubt, overvoltage some ceramics and test 'em for changes. I've (carefully) overvoltaged
electrolytics to bring leakage down after storage; it never failed.

 

On Sat, 19 Oct 2019 07:29:50 -0700 (PDT), whit3rd <whit3rd@gmail.com>
wrote:

On Saturday, October 19, 2019 at 3:48:18 AM UTC-4, Steve Wilson wrote:

Why measure past the rated voltage? You are never going to operate there.
You simply risk damaging the capacitor for no good reason.

Nah. Real engineers need equations. Do an exponential fit to your data.

The 'need equtions' is the reason you want to measure past the rated voltage;
there's not much validity to an equation if there are singularities just outside
the measured range (because, for instance, any polynomial fails to handle a singularity).

When you apply the capacitor, it's sensible to stick to the range the manufacturer
recommends (that's the way the manufacturer and user can coordinate), but NOT for
the purpose of information-gathering.

MOS devices get damaged quickly outside their recommended range, but not usually capacitors.

Standard mosfets generally die at gate voltages around 70ish, maybe 5x
rated abs max. The self-protecting ones zener at maybe 44 volts on the
gate.

Most mosfets will avalanche at high drain voltages, maybe 1.5 or so
times abs max, and are then damaged by excess dissipation. Some just
die without avalanching.

The EPC GaN fets die without warning at a bit over 2x max drain
voltage and have more complex gate voltage behavior.

The Cree SiC fets avalanche at around 1.4x rated drain voltage, and
like the mosfets just get hot. You can kill them with a modest gate
over-drive, which is unfortunate because they need close to abs max
gate drive to switch well.

>If in doubt, overvoltage some ceramics and test 'em for changes.

Ceramics are usually happy at several, sometimes ten or twenty, times
rated voltage. But they tend to run out of capacitance.



--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

[Phil Allison]

jla...@highlandsniptechnology.com wrote:

--------------------------------------

Steve Lunatic Wilson wrote:



Why measure past the rated voltage? You are never going to operate there.
You simply risk damaging the capacitor for no good reason.

The curve shown in fig. 4 is a generic curve. The actual curves are
different for each capacitor, and depend on variables such as those
described above. So it is impossible to represent all capacitors at once.

You need to also try measuring the capacitor voltage with a constant
current source. That could give valuable new information.



** This fuckwit troll is a pernicious false arguer and incorrigible
context shifter.

He is delusional to the extent he literally believes his own bullshit.

Prefect candidate for the "Church of Scientology" don't you think ?

If he ain't one already that is ...



He argues out of emotion rather than reason.

** You mean, just like you do ?

I have several anti-fans
here who are dying to show me wrong, and will commit any bogus mental
contortion in that cause.

** I *do* know the feeling ...

Because I go hard against all the fools & trolls on this and other NGs, I get the same malicious treatment.

This is amusing, because I'm really interested in how people reason
toward truth, and especially how they don't.

** Same interest here - the sheer, bloody irrationality of most people is STAGGERING !

The fact was driven home to me forcefully soon as I began posting on usenet, about 20 years ago. People make up their minds about something in a flash, using great gobs of false logic plus "intuition" - then will not back down at any price.

That so many seemingly bright people go right through college and university WITHOUT learning clear thinking or how to spot and avoid logical fallacies is a crime.

I could go on and on ...


..... Phil

 

On Sat, 19 Oct 2019 15:23:03 -0700 (PDT), Phil Allison
<pallison49@gmail.com> wrote:

jla...@highlandsniptechnology.com wrote:

--------------------------------------

Steve Lunatic Wilson wrote:



Why measure past the rated voltage? You are never going to operate there.
You simply risk damaging the capacitor for no good reason.

The curve shown in fig. 4 is a generic curve. The actual curves are
different for each capacitor, and depend on variables such as those
described above. So it is impossible to represent all capacitors at once.

You need to also try measuring the capacitor voltage with a constant
current source. That could give valuable new information.



** This fuckwit troll is a pernicious false arguer and incorrigible
context shifter.

He is delusional to the extent he literally believes his own bullshit.

Prefect candidate for the "Church of Scientology" don't you think ?

If he ain't one already that is ...



He argues out of emotion rather than reason.


** You mean, just like you do ?

Playing with twits doesn't count. That's just sport.

Electronics is pretty check-able, so emotional delusions don't get
very far.

I have several anti-fans
here who are dying to show me wrong, and will commit any bogus mental
contortion in that cause.


** I *do* know the feeling ...

Because I go hard against all the fools & trolls on this and other NGs, I get the same malicious treatment.


This is amusing, because I'm really interested in how people reason
toward truth, and especially how they don't.

** Same interest here - the sheer, bloody irrationality of most people is STAGGERING !

The fact was driven home to me forcefully soon as I began posting on usenet, about 20 years ago. People make up their minds about something in a flash, using great gobs of false logic plus "intuition" - then will not back down at any price.

That so many seemingly bright people go right through college and university WITHOUT learning clear thinking or how to spot and avoid logical fallacies is a crime.

I could go on and on ...


.... Phil

Let's be careful here; we are in dire danger of agreeing on something.



--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

[George Herold]

On Saturday, October 19, 2019 at 2:52:45 AM UTC-4, Bill Sloman wrote:

On Friday, October 18, 2019 at 1:05:18 PM UTC+11, George Herold wrote:
On Thursday, October 17, 2019 at 2:26:10 PM UTC-4, George Herold wrote:
On Thursday, October 17, 2019 at 2:01:02 PM UTC-4, John Larkin wrote:
On Thu, 17 Oct 2019 10:17:47 -0700 (PDT), George Herold
gherold@teachspin.com> wrote:

On Thursday, October 17, 2019 at 12:24:20 PM UTC-4, jla...@highlandsniptechnology.com wrote:
On Thu, 17 Oct 2019 08:53:25 -0700 (PDT), George Herold
gherold@teachspin.com> wrote:

On Thursday, October 17, 2019 at 11:02:13 AM UTC-4, jla...@highlandsniptechnology.com wrote:
On Thu, 17 Oct 2019 05:44:51 -0000 (UTC), Steve Wilson <no@spam.com
wrote:

John Larkin <jlarkin@highland_atwork_technology.com> wrote:

Here's possibly the only curve like this ever posted online:

https://www.dropbox.com/s/i4wwttdgqycz9rv/Alum_Leakage_63u.JPG?raw=1

See Fig. 4(b) on Page 2 in

https://jianghai-europe.com/wp-content/uploads/8-Jianghai-Europe-E-Cap-
Leakage-Current-AAL-2018-09-18.pdf

The curves are exponential.

That fig 4b is an obvious made-up cartoon. It's certainly not
exponential. And it has no numbers.
Ditto on the thanks.
The Tardin article mentions that the caps behave like they have a
zener diode in parallel... So having the current look like noisy
zener current above the 'threshold' makes some sense.

Years ago I charge an Al eletro to ~1/2 the max voltage, left it
on my bench for the weekend and came back to see the voltage had
only dropped by ~10% or so. It would be fun to hook one up
to an electrometer and let it sit there for a week or whatever
and record the voltage.

George H.

Or just check it with a DVM now and then. I did that with a supercap
for a few months.
Right... I think I used the trick of putting a Gig ohm in series
with my DMM and dividing by 100.
I'd bet it can't be exponential* 'all the way down' at some point there'll be some other constant (resistive) leakage path.

Hey are tant's any better than Al-electros. At my ppoe I made this
triangle wave generator, current source into a cap, milli second to
kilo second periods. I used a 100uF tant for the longest times...
seemed to work fine.. but I only 'really' measured the longest times
once. (otherwise just made sure it went up and down.)

George H.
*does exponential imply some thermal mechanism?

A pure RC has a exponential decay, e^(-kt). But the leakage in an
electrolytic isn't ohmic, so the decay slows down as the voltage
drops.

Pretty complex.
Right, if you monitor the voltage you'd have to integrate it to get the
current.. It's not at all clear to me what that double exponential
would look like.

George H.
something like this?
https://en.wikipedia.org/wiki/Double_exponential_function
That doesn't seem right.

If,
I(t) = Io*exp(V(t)/Vx) = C dV/dt
where Io, Vx and C are constants

Then I get that
V(t) = Vx * ln{(C*Vx)/(Io*t)}.. but I might have made a mistake,
and getting the initial conditions right is a bit.. uncertain.

I need a good graphing program. Time to learn python?

Excel isn't a good graphing program, but you can get it to produce graphs.

Excel is my least favorite program ever... the graphs are particularly
bad.. but the rest too.
> IIRR Mathcad and Scicad can do it too.
Sure but I liked python.. it's interpreted like basic, I really like that
when for looking for my mistakes.

George H.

--
Bill Sloman, Sydney

 

[Phil Allison]

George Herold wrote:
--------------------

Some retard posted:

Why measure past the rated voltage? You are never going to operate there.
You simply risk damaging the capacitor for no good reason.


I just want to say, that when people tell me *not* to measure
parts above and beyond the specs.. The more I want too. :^)

** Test 'em to destruction I say ...

Just kidding, but current limited breakdown testing is simply the only way to do find out the actual limit of many parts. Carried out sensibly, it does no damage.

Anecdote:

I once purchased a quantity of MJ15030/31s from a popular components retailer in Sydney. These are medium power TO220 pak devices rated at 160V for use as output drivers in power amplifiers.

Nearly all of them were *dead short* as purchased !!

I got a very grumpy reaction when I returned them and refused to take more from the same bin. WTF - Motorola do not supply dead BJTs.

I smelt a rat, someone had been at them before me.

Turned out a local amplifier maker ( Chris from PTM Electronics ) "borrowed" hundreds of them from the same store to put through his quality checking process then returned any he did not like.

His "process" involved the use of an old HP Curve Tracer, which is well capable of destroying such devices and had done so to a great many.

Wot an asshole.


...... Phil

 

[George Herold]

On Saturday, October 19, 2019 at 10:38:44 AM UTC-4, jla...@highlandsniptechnology.com wrote:

On Sat, 19 Oct 2019 07:48:13 -0000 (UTC), Steve Wilson <no@spam.com
wrote:

John Larkin <jlarkin@highland_atwork_technology.com> wrote:

On Thu, 17 Oct 2019 20:45:36 -0000 (UTC), Steve Wilson <no@spam.com
wrote:

John Larkin <jlarkin@highland_atwork_technology.com> wrote:

On Thu, 17 Oct 2019 17:13:40 -0000 (UTC), Steve Wilson <no@spam.com
wrote:

jlarkin@highlandsniptechnology.com wrote:

Quite welcome. It's good to have some real numbers on (one) real
cap.

Yor data is valid for that capacitor only.

Excellent whining.

It's more data than data on no capacitors. I suspect that all wet
aluminum electros will have similar shaped curves, so will be
self-stabilizing in series strings.

Why suspect? Why not read some of the links I provided? For example, see
Page 3 of

https://jianghai-europe.com/wp-content/uploads/8-Jianghai-Europe-E-Cap-
Leakage-Current-AAL-2018-09-18.pdf

Quote:

The operating leakage current [5] as a measure of the forming condition
of anode foil depends on the time, applied voltage, temperature, and
history of the capacitor (fig. 4 (a) ~ (c)). Typical values of the
operational leakage current range between approx. 5 ~ 15% of the data
sheet value of leakage current amount and are usually reached after
several ten minutes of continuous operation.

The leakage current specified in the data sheet shall be valid even
after a long, voltage-free storage period and has therefore a much
higher numerical value than the operating leakage current. The oxide
layer dissolves to a certain extent as a function of temperature and
electrolyte composition, because without any voltage applied, the oxide
layer cannot regenerate ("self-healing") [5].

While low-voltage capacitors (up to 100 V rated voltage) with
solvent-based electrolyte systems are usually very stable, high-voltage
capacitors (from 160 V rated voltage) with ethylene glycole-based
electrolytes and in particular so-called "low ESR" types with aqueous
electrolytes may exhibit an increase of leakage currents throughout
their lifetime.

15 ~ 30 minutes of operation of the electrolytic capacitors via a
resistor (low-voltage: 100 Ohm, high-voltage: 1 k, see [7], section 4.1
"pretreatment") at a voltage increased gradually to rated voltage may
heal the weak spots in the dielectric and lower the leakage current
below the data sheet value.

Every cap will be different. There are many different electrolytes
with different characteristics, such as non-solid borax or organic,
non-solid water-based, solid manganese dioxide, solid conducting
polymer, non-solid hybrid electrolyte, etc., and the leakage
characteristics will be different for each type. See Wikipedia,
"Aluminum electrolytic capacitor", at

https://en.wikipedia.org/wiki/Aluminum_electrolytic_capacitor

Superb, well-researched whining.

I used a standard Panasonic aluminum electrolytic.

Measure something else and post it here.

You are trying to pretend the measurement you made on one capacitor is
the first time such a measurement has been made. In fact, you said so
yourself.

I said "possibly" the only one available online, after several minutes
of intense web searching. If you can find an electrolytic cap leakage
measurement, past rated voltage, with real numbers, not fuzzy
cartoons, please post the link for us.

Why measure past the rated voltage? You are never going to operate there.
You simply risk damaging the capacitor for no good reason.

The issue was series strings of electrolytic caps, where the total
supply voltage is more than the rated voltage of the caps. Film caps
can blow up in that situation. What do lytics do?

Answer: their IV curves make them safely self-equalize.


The curve shown in fig. 4 is a generic curve. The actual curves are
different for each capacitor, and depend on variables such as those
described above. So it is impossible to represent all capacitors at once.

I posted numerous links that show your assumption is not valid.

I didn't assume anything. I measured something.

Your data is meaningless. As mentioned elsewhere, capacitor manufacturers
can give actual curves for their capacitors.

Post a link of leakage past rated voltage. Real data, not faked
cartoons.


You can compare your data
against the spec to see if your cap is out of spec.

Try it; it's more fun than cutting and pasting a lot of text.

Your data is meaningless.

Since you probably don't design electronics, it is meaningless to you.


There is a
tremendous amout of knowlege in those links.

Lotta words, no numbers. Engineers need numbers.

Nah. Real engineers need equations. Do an exponential fit to your data. The
Stdev will give an indication of the quality of the measurement. The
equation will allow you to compare other capacitors. The curve can be
compared to actual specs from manufacturers.

You need to also try measuring the capacitor voltage with a constant
current source. That could give valuable new information.

How would that be different? You'd get the same data points, just
slower.

I just want to say, that when people tell me *not* to measure
parts above and beyond the specs.. The more I want too. :^)

I've had 36V opamps running up around 48V for a while...
many minutes.

How do you test some power supply but to load it and see how it fails*

George H.

*I'm saying a little thank you to all the parts gave up theirs lives
so I might know their limits.

--

John Larkin Highland Technology, Inc

lunatic fringe electronics