janneman said:
What, you mean Christer's out and I'm in?
Thanks a lot, Christer! TATTLETALE! 😀
se
Jan,
your apology is accepted.
I also agree that the tread is losing more and more focus
and becoming more and more confused. It reminds me a
bit if that Bach kantata with soparano and tenor singing
"Ach ja, ach nein, ach ja, ach nein ..." ad infinitum. My only
reason, except for a general curiosity to learn a bit more
about things, has been to try steer up the discussion by
pointing to things that need to be cleared up and that needs
to be backed up by better arguments etc. if the thread is
to progress at all. I am sure not everybody sees it that
way and I may have failed in my "mission" and just caused
more confusion.
your apology is accepted.
I also agree that the tread is losing more and more focus
and becoming more and more confused. It reminds me a
bit if that Bach kantata with soparano and tenor singing
"Ach ja, ach nein, ach ja, ach nein ..." ad infinitum. My only
reason, except for a general curiosity to learn a bit more
about things, has been to try steer up the discussion by
pointing to things that need to be cleared up and that needs
to be backed up by better arguments etc. if the thread is
to progress at all. I am sure not everybody sees it that
way and I may have failed in my "mission" and just caused
more confusion.
fdegrove said:
Aha, are we finally getting somewhere? So perhaps DH is then
a phenomenon only in ceramics, electrolytics and other "strange"
caps, which we already know are more complex to model than
film caps?
Couldn't you have said so some three or four hundred pages
ago??? 😉
Linear distortion?
Forgive me, but the phrase "linear distortion" seems even more of a contradiction in terms than "military intelligence".
"Linear distortion", or whatever it is you want to call it, only has effects which are measurable using continuous sinewaves.
I hereby sneer publicly at anybody who claims "linear distortion" in cables is worth worrying about, until they publish a genuine measured frequency response plot of their loudspeakers in their listening room. That's the sort of "linear distortion" you're up against.
If you've not done this - buy a good soundcard, buy AudioTester, buy a good reference microphone, and just do it. If you're not ashamed and embarrassed to publish the results, I look forward to seeing them....
Cheers
IH
Forgive me, but the phrase "linear distortion" seems even more of a contradiction in terms than "military intelligence".
"Linear distortion", or whatever it is you want to call it, only has effects which are measurable using continuous sinewaves.
I hereby sneer publicly at anybody who claims "linear distortion" in cables is worth worrying about, until they publish a genuine measured frequency response plot of their loudspeakers in their listening room. That's the sort of "linear distortion" you're up against.
If you've not done this - buy a good soundcard, buy AudioTester, buy a good reference microphone, and just do it. If you're not ashamed and embarrassed to publish the results, I look forward to seeing them....
Cheers
IH
Christer said:
Hmmmm. Why wouldn't it occur in film caps? DA is hysteretic, yes? From what I've seen so far, it seems that dielectric hysteresis currently the preferred terminology when it comes to ferroelectric materials. The only difference I seem to have found is that the mechanisms are different. In typical plastic dielectrics, it's due to polar molecules while in ferroelectric ceramics it's due to electric domains.
se
Re: Linear distortion?
At first glance it would seem so. But seeing as "linear distortion" is an alteration of the waveform, I don't see that it's any less a distortion than nonlinear distortion.
How do you figure?
Not to mention a considerable amount of non-linear distortion as well, particularly IM.
se
IanHarvey said:
At first glance it would seem so. But seeing as "linear distortion" is an alteration of the waveform, I don't see that it's any less a distortion than nonlinear distortion.
How do you figure?
Not to mention a considerable amount of non-linear distortion as well, particularly IM.
se
Again, in plastic film caps, the DA is generally not due to the dipole moment of the molecules; it's a function of charge storage in polarizable regions. A smaller effect than dipole alignment to be sure, but that's why plastic film caps have orders of magnitude lower DA than electrolytics and some types of ceramics. The dipole moments are essentially tied down because they're part of long chains which can't wiggle around much below the plastic's Tg.
SY said:
Ok, so the Kundert paper's erroneous on that count? Do you have a source for what you say is the actual cause?
se
Kundert's paper is a way to model DA for materials in general. Trying to extrapolate it to understand specific physical mechanisms in specific families of materials is stretching it farther than the author intended. Note that the author doesn't show any diagrammatic representation of a polymer containing a dipole moment, doesn't deal with specific mechanisms of induced polarizability or charge stabilization, nor define what he means by "dipole" or "charge particle" in a molecular sense. That's not a defect of the paper, it's just something beyond its scope.
There are a few hundred books out there on the electrical properties of polymers. I may have even contributed to a few of them. I'm not at my office today, but my next time there (probably Monday), I'll suggest a title or two.
There are a few hundred books out there on the electrical properties of polymers. I may have even contributed to a few of them. I'm not at my office today, but my next time there (probably Monday), I'll suggest a title or two.
Steve Eddy said:
Maybe I was unclear. The comment was made under
the assumption that Frank is right that DA and DH are
different phenomenae. My earlier impression of his claims was
that both always exst in parallel (jumping to conclusions
perhaps, but a reasonable one given how little he told us,
I think). Since for instance ceramic caps have a non-linear
behaviour not present in film caps and certain other strange
behaviours, it now seemed more plausible to me that there might,
perhaps, be some further hysetersis phenomenen besides
DA in them. If it is so, I have no idea. Maybe SY has something
to say, he seems to know this stuff on detailed level, but
maybe it is only polymers he knows about?
SY said:
Ok.
Ok, if you so smart, who wunnuh secon whurl whoa? 😀
Thanks. In the meantime, how 'bout some keywords that might be searched on the net?
se
"Not responsible!"
I'd search "polymer charge storage" to start.
I'm still waiting for someone to define their terms. I understand what DA is about, and it exhibits the properties of a hysteretic phenomenon. But I have no idea what the people who are claiming that DH is something distinct mean by the terms they're using. I'm just an ignorant materials scientist.
Christer said:
Well, I'm wondering if the nonlinearities in ferroelectrics, which seem to behave anaogously to ferromagnetics may be due to an equivalent "saturation" that you find in ferromagnetics.
Perhaps. I'm willing to listen to all parties as long as they have something to say other than "they're different." 🙂
se
SY said:
Thanks.
Dunno about you, but I ain't holdin' my breath on that one. 🙂
So would that make you a *ahem* mat' scientist? 🙂
se
Be verwy quiet... I'm hunting rabids......
" Thanks. In the meantime, how 'bout some keywords that might be searched on the net?"
Try:
LUNATIC
MONOMANIA
ACOETHES
LOGOMANIA
PREPOSSESSION
You guys keep him distracted with Dielectric Hysteresis
while I sneak up behind him
and throw the net over him, and knock him out.... 
Fred
PS
"Although stalking victims may desperately want to know why they were chosen as the victim, what they might have done to trigger a stalker's obsession with them, often, they find the answer is NOTHING. They are just one of a serial stalker's many victims. These stalkers are simply following a pattern of behaviour they have practised for years. No matter what the reason or cause for the stalking, victims should be cautioned that serial stalkers in particular are very disturbed individuals."
" Thanks. In the meantime, how 'bout some keywords that might be searched on the net?"
Try:
LUNATIC
MONOMANIA
ACOETHES
LOGOMANIA
PREPOSSESSION
You guys keep him distracted with Dielectric Hysteresis
while I sneak up behind him and throw the net over him, and knock him out.... Fred
PS
"Although stalking victims may desperately want to know why they were chosen as the victim, what they might have done to trigger a stalker's obsession with them, often, they find the answer is NOTHING. They are just one of a serial stalker's many victims. These stalkers are simply following a pattern of behaviour they have practised for years. No matter what the reason or cause for the stalking, victims should be cautioned that serial stalkers in particular are very disturbed individuals."
Hi,
As a matter of fact, I have explained it already but it turned out the explanation was either not convenient or just too damn simple to be accepted.
So, what about who's wasting space where? And who's baiting who?
If you don't care to read through the entire thread than that's your choice, just don't blame me for your choices.
For your convenience I'll repeat it once more:
DH is a consequence of DA under some circumstances, DA and DH are not the same. No matter how many publications confuse both.
If you want proof of it do some research on integrator techniques.
In the meantime just be nice to animals like myself, please.
Cheers,😉
As a matter of fact, I have explained it already but it turned out the explanation was either not convenient or just too damn simple to be accepted.
So, what about who's wasting space where? And who's baiting who?
If you don't care to read through the entire thread than that's your choice, just don't blame me for your choices.
For your convenience I'll repeat it once more:
DH is a consequence of DA under some circumstances, DA and DH are not the same. No matter how many publications confuse both.
If you want proof of it do some research on integrator techniques.
In the meantime just be nice to animals like myself, please.
Cheers,😉
fdegrove said:
I must've missed it. Did you write it in disappearing ink?
That's an explanation? Gee, could you make it just a little more vague?
explain 1 a L to make known b : to make plain or understandable 2 : to give the reason for or cause of 3 : to show the logical development or relationships of : to make something plain or understandable.
But as far as your "explanation" goes, what circumstances is DH a consequence of DA and what circumstances is it not? If DA is inherently hysteretic, when can DH not be a consequence of DA?
If I Google "dielectric hysteresis" and "integrator" I come up with just 5 hits. Only one is of any relevance.
http://dsp.hit.edu.cn/graduates/doctors/meixiaodan/ADC.pdf
This paper presents a new method of A/D conversion based on width modulating circuit. Its state of working is so steady that it hasn't nonlinear error in theory and can omit the dielectric hysteresis effect of integral capacitor.
Now if I Google "dielectric absorption" and "integrator" I get 183 hits, the first of which is Pease's piece on "soakage." As well as a bunch of others along similar lines.
And if I do a search on "dielectric absorption" and "integrator" and "hysteresis" I get some interesting results. Such as this datasheet for some National monolithic sample and hold circuits:
http://www.ee.washington.edu/stores/DataSheets/linear/lf398.pdf
A significant source of error in an accurate sample and hold circuit is dielectric absorption in the hold capacitor. A mylar cap, for instance, may "sag back" up to 0.2% after a quick change in voltage. A long sample time is required before the circuit can be put back into the hold mode with this type of capacitor. Dielectrics with very low hysteresis are polystyrene, polypropylene, and Teflon. Other types such as mica and polycarbonate are not nearly as good. The advantage of polypropylene over polystyrene is that it extends the maximum ambient temperature from 85C to 100C. Most ceramic capacitors are unusable with > 1% hysteresis. Ceramic "NPO" and "COG" capacitors are now available for 125C operation and also have low dielectric absorption. For more exact data, see the curve Dielectric Absorption Error. The hysteresis numbers are final values, taken after full relaxation. The hysteresis error can be significantly reduced if the output of the LF198 is digitized quickly after the hold mode is initiated. The hysteresis relaxation time constant in polypropylene, for instance, is 10-50 ms. If A-to-D conversion can be made within 1 ms, hysteresis error will be reduced by a factor of 10.
So, is National confusing both here?
se
Hi,
It is and I couldn't make it anymore clearer than it already is....
Lest you want to look up what hysteresis is and what DA means there's very little to say about it...
Unless you want to go way beyond audio use that is perhaps.
Once again, DH is and can be an artefact of DA.
DH and DA are NOT the same, no matter how much nonsense you may dig up on the net.
To understand it you need to know the difference between the two.
So, here we go again, ad nauseam et ad bored to death dom....
Cheers,
It is and I couldn't make it anymore clearer than it already is....
Lest you want to look up what hysteresis is and what DA means there's very little to say about it...
Unless you want to go way beyond audio use that is perhaps.
Once again, DH is and can be an artefact of DA.
DH and DA are NOT the same, no matter how much nonsense you may dig up on the net.
To understand it you need to know the difference between the two.
So, here we go again, ad nauseam et ad bored to death dom....
Cheers,
fdegrove said:
Ok, let's start with hysteresis:
The magnetization of ferromagnetic substances due to a varying magnetic field lags behind the field. This effect is called hysteresis, and the term is used to describe any system in whose response depends not only on its current state, but also upon its past history.
hys-ter-e-sis:
n [NL, fr. Gk hysteresis shortcoming, fr. hysterein to be late, fall short, fr. hysteros later]
a retardation of the effect when the forces acting upon a body are changed (as if from viscosity or internal friction); esp: a lagging in the values of resulting magnetization in a magnetic material (as iron) due to a changing magnetizing force. -hys-ter-et-ic adj
The lagging of an effect behind its cause, as when the change in magnetism of a body lags behind changes in the magnetic field.
HYSTERESIS (Gr. iIaT~p~OTI, from ior~piv, to lag behind), a term added to the vocabulary of physical science by J. A. Ewing, who defines it as follows: When there are two qualities M and N such that cyclic variations of N cause cyclic variations of M, then if the changes of M lag behind those of N, we may say that there is hysteresis in the relation of M to N (Phil. Trans., 1885, 176, p. 524).
Now dielectric absorption:
A capacitor which has been charged for a long time and then been completely discharged, has a small voltage on its terminal wires again, within seconds or minutes.
This effect is known as dielectric absorption.
This is the phenomenon where after a capacitor has been charged for some time, and then discharged, some stored charge will migrate out of the dielectric over time, thus changing the voltage value of the capacitor.
A characteristic of dielectrics which determines the length of time a capacitor takes to deliver the total amount of its stored energy. It manifests itself as the reappearance of a potential on the electrodes after the capacitor has been discharged. Its magnitude depends on the charge and discharge time of the capacitor.
Ok. Now what?
Ok, again, when is it that DH isn't an artefact of DA?
se
- Status
- Not open for further replies.