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
Film capacitor as power-supply filter
Started by ●October 7, 2019
Reply by ●October 17, 20192019-10-17
Reply by ●October 17, 20192019-10-17
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_capacitorSuperb, 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
Reply by ●October 17, 20192019-10-17
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.> > -- > > John Larkin Highland Technology, Inc > picosecond timing precision measurement > > jlarkin att highlandtechnology dott com > http://www.highlandtechnology.com
Reply by ●October 17, 20192019-10-17
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.
Reply by ●October 17, 20192019-10-17
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
Reply by ●October 17, 20192019-10-17
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
Reply by ●October 17, 20192019-10-17
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
Reply by ●October 17, 20192019-10-17
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
Reply by ●October 17, 20192019-10-17
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
Reply by ●October 19, 20192019-10-19
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
