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In Reply to: Vote here: Low or High ESR capacitors? posted by dread on March 04, 2001 at 02:58:36:
dimwit wrote:Vote: Interesting debate... LOL..
For your next high powered audio amplfier that will
drive 8, 4, and 2 ohm loads, are you going to
use high ESR or low ESR capacitors in the power supply ?
I'm not asking for advice or reasons why, just
say "low ESR" or "high ESR" in the reply.There is no debate. NOWHERE did I say that one shouldn't use low ESR capacitors. I only stated that the claim you made as to why they should be used is misinformed due to your lack of understanding. You mistakenly think that the time it takes for a capacitor to discharge into a particular load relates to how fast it can deliver current to a particular load.
I tried to explain to you why it's misinformed but you simply resorted to weaseling by saying you didn't say something you quite clearly said and implying that I said something I quite clearly did NOT say, culminating in this pathetic post.
So again, I have NOT said that there are no reasons to use low ESR capacitors. Only that the reason you gave as primary reason they should be used isn't one of those reasons.
Your words once again:
You main capacitor has to be low ESR so it can dump
the current quickly into the load. IF a capacitor
has zero ESR, then it will dump all the charge into
a short immediately, but in reality this is not
the case. The internal resistance cause the capacitor
to discharge slower so if you were to short out the
capacitor briefly, then re-short it again, there is
still charge in it.se
Follow Ups:
What are you voting for? Stay on topic.. lol ..On a sidenote, I try to explain things in a simple
manner to help people understand, if you want
to analyze every word and reverse engineer my
grammer, you are wasting your time. The statement
I made I loose as all my explainations. The purpose
of DIY is to help non technical (and technical) people understand
what they are doing.I was thinking about discharging alot of current into
the load and high ESR will limit the current discharged into
the load, perhaps that would be a better choice
of words... LOL ... who cares.. At the time, I just
the babble quickly, you are the only one who is analzying
it when it essentially says the same thing... LOL ..
the bottom line was to use low ESR and since the first post you
are talking about issues that are not related to what I was talking about because you didn't understand what I was trying to say,
it's not your fault, don't worry about it.The other post you said that low ESR capacitors are used
by lack of misinformed industry and that doesn't make
it right for using them... LOL ... make up your mind,
now you say low ESR is what you should use, that is
what I said in my first post so why do you persist
with the discussion when there is no discussion. LOL ....This thread is to see what others are using/prefer, it
has nothing to do with anything more, don't look too
deep on this thread. It's just a poll.
> I was thinking about discharging alot of current into
> the load and high ESR will limit the current discharged into
> the load, perhaps that would be a better choiceHm, I may only be an ex engineering physics student here but that doesn't sound like the correct use of ESR. It is effective SERIES resistance to an AC signal at a given frequency. Lead and plate resistance is a factor but the major contribution is mollecular friction caused my the electrostatic attraction/repulsion of polar molecules in the dielectric (aka power loss due to heating). Pure internal resistance and self-inductance would be the major factors in discharging a cap into a short. Try a flat plate vacuum or air-variable cap, they'll behave a bit differently than an electro or film cap.
The memory effect you spoke of earlier (when talking about how a cap can seem to charge itself back up a bit after discharging it) is due to these polar molecules, which were discpaced by the initial charge on the plates, slowly relaxing to their former positions in the dielectric and inducing an electrostatic charge on the plates. Try this... take two sheets of metal foil and put a sheet of plastic between them. Now, melt the plastic and apply a real high voltage charge to the foil plates and let the plastic harden before you remove the charge. You now have an electret. It won't have the same voltage as the initial charge because of mollecular relaxation, but you will still have a permanent charge because in solid form, the polar molecules are unable to return to their former "uncharged" positions.
The main use of high ESR caps that I've seen (mostly in RF circutry) is to bypass a storage cap in order to reduce ripple by converting it to heat (ie small metal-ceramic cap bypassing a much larger film type)
Pam wrote:The memory effect you spoke of earlier (when talking about how a cap can seem to charge itself back up a bit after discharging it) is due to these polar molecules, which were discpaced by the initial charge on the plates, slowly relaxing to their former positions in the dielectric and inducing an electrostatic charge on the plates.
He wasn't talking about dielectric absorption. He was simply referring to the RC time, saying that if you remove the load before the capacitor has discharged, some charge will remain on the plates. In other words, if RC = 1 second, and you only close the circuit for 0.5 seconds and then open the circuit, the capacitor will not have completely discharged. A whole other ballgame from dipoles and electron migration.
se
Ah... still seems like ESR is the wrong term to use in that discussion. What frequency do you plug in to get the ESR in that situation? You'd want the lead resistance (and maybe self inductance) in that situation.
Pam wrote:Ah... still seems like ESR is the wrong term to use in that discussion. What frequency do you plug in to get the ESR in that situation? You'd want the lead resistance (and maybe self inductance) in that situation.
Hehehe. Good question. Dunno. Hmmmm. I guess you could get a resistanceless, inductanceless material and somehow manage to instantaneously short across the leads, measure the current over time which would give you the di/dt, and then...
Hell, I don't know. The whole thing's best forgotten I think. :)
se
Although I am no EE, I do appreciate the fact that electronic designs offer various trade-offs and are optimized for different sorts of applications. Why don't you collect a list of various high profile amplifier manufacturers and their preferences? That might add insight to why the professionals do what they do.Did you ever decide whether or not you believe ESR limits the speed at which the capacitor can deliver current? In over ten replies to se on the topic, I can't seem to find your answer.
At the expense of appearing picky, it does not advance your position in a technical forum when you misspell so many words in a short post. Use a spell checker.
==Why don't you collect a list of various high
==profile amplifier manufacturers and their preferences? That might
==add insight to why the professionals do what they do.My point is that the average DIY'er doesn't have to
be an expert to build quality gear.I will do one better than that. Lets go to a good capacitor manufacturer like Cornell Dubilier and
lets go buy some capacitors with high ESR rating for
your power supply design (for your power amplifier).Our goal in this example is to find a capacitor with rating of 50 -
100 volts with 10,000uf capacitance with high ESR, this is a good reference.Here is the link;
http://www.cornell-dubilier.com/alum.htmFor high capacitance we are limited to the "computer-grade"
or "snap-in" types. If you search thru the various CDE types
with our specifications above, they will give you a list
of capacitors and their specifications.Notice how all the capacitors that meet our voltage
and capactitance specification have LOW ESR, less than 50mohms of
ESR, some are 20mohm typical, some are 0.02mohm.What does this mean? Cornell Dubilier, the manufacturer, doesn't
even offer high ESR capacitors even if you wanted to buy them...
If there was a market for them, I'm sure they would offer them....
.. LOL ...
dread wrote:My point is that the average DIY'er doesn't have to
be an expert to build quality gear.Not being an expert is one thing. Being misinformed is another.
I will do one better than that. Lets go to a good capacitor manufacturer like Cornell Dubilier and
lets go buy some capacitors with high ESR rating for
your power supply design (for your power amplifier).Let's...
Our goal in this example is to find a capacitor with rating of 50 -
100 volts with 10,000uf capacitance with high ESR, this is a good reference.Define "high ESR." Or are you too busy putting together your straw man kit?
Here is the link;
http://www.cornell-dubilier.com/alum.htmOk...
For high capacitance we are limited to the "computer-grade"
or "snap-in" types. If you search thru the various CDE types
with our specifications above, they will give you a list
of capacitors and their specifications.Uh huh...
Notice how all the capacitors that meet our voltage
and capactitance specification have LOW ESR, less than 50mohms of
ESR, some are 20mohm typical, some are 0.02mohm.Uh, compared to 0.02mohm, 20mohm is VERY HIGH. You're talking three orders of magnitude. So how can you call them both "low ESR"? Compared to WHAT? Those 1,000 ohm ESR capacitors they have on your planet?
What does this mean?
It means your straw man isn't going to work like you hoped it would.
Cornell Dubilier, the manufacturer, doesn't
even offer high ESR capacitors even if you wanted to buy them...
If there was a market for them, I'm sure they would offer them....Sure they offer high ESR caps. Those 20mohm caps are high ESR compared to the low ESR 0.02mohm caps. Unless you believe that three orders of magnitude isn't a big difference.
But of course this is all just a smoke screen. If you'd simply recommended low ESR caps I wouldn't have said a word. And although you claimed that's all you said, that's simply not true. You gave a very specific reason why low ESR caps should be used. To remind you one more time:
You main capacitor has to be low ESR so it can dump
the current quickly into the load. IF a capacitor
has zero ESR, then it will dump all the charge into
a short immediately, but in reality this is not
the case. The internal resistance cause the capacitor
to discharge slower so if you were to short out the
capacitor briefly, then re-short it again, there is
still charge in it.This reason is based on your mistaken notion that resistance somehow relates to the "speed" with which current can be delivered to the load.
Since you're using capacitor manufacturers to make your straw man argument, let's use them to make a real argument with regard to ESR.
Let's try Chemi-Con:
Understanding Aluminum Electrolytic Capacitors
Let's see why they strive for low ESR.
A critical component in the manufacturing of a capacitor that must always be considered is the equivalent series resistance.
Well they certainly seem to think it's important. And I never said otherwise. But why do they think it's important?
It is this resistance that leads to heat generation in the capacitor when AC current is applied.
Mmmm. Doesn't have anything to do with the reason you offered.
What else to they have to say?
The amount of heat generated by ripple current depends upon the ESR of the capacitor
Still doesn't have anything to do with the reason you offered.
.. LOL ...
Indeed.
se
==20mohm is VERY HIGH0.02 ohms is very high huh ? You keep making me laugh... LOL ...
==The amount of heat generated by ripple current depends upon the ESR ==of the capacitor
That's what I have been trying to tell you since day one,
but your lack of interpretation is your failing. You don't want to current limit your capacitors, but instead you are saying
that high ESR is best. If you want to use high ESR capacitors,
be my guest.If you think 20mohm is high ESR, then you should tell those
engineers and Cornell that they have been designing capacitors
all wrong from day one. HA HA HA HA..Call CNN news and tell them of your major discovery... LOL ..
Answer this? When is the last time you built a Mosfet
power amplifier? You said you never had any experience
with Mosfet in your previous post ?Why am I wasting my time debating with someone who
have never built an amplifer or power supply?I'm trying to be nice but you keep preaching..... LOL
dimwit wrote:0.02 ohms is very high huh ? You keep making me laugh... LOL ...
Yes, 0.02 ohms compared to 0.00002 ohms is very high. "High ESR" is relative. It doesn't tell you anything unless you have something to compare it to. Since you stated that the ESR of the capacitors from Cornell-Dublier ranged from 0.00002 ohms to 0.02 ohms, that gives a frame of reference.
==The amount of heat generated by ripple current depends upon the ESR ==of the capacitor
That's what I have been trying to tell you since day one,
but your lack of interpretation is your failing.It has absolutely nothing to do with interpretation. Nothing you said had anything remotely related to heat generated by ripple current. You're simply lying now. Get lost.
You pulled this same nonsense the last time you showed up here and the moderator ended up deleting your posts.
se
So you are saying that we should NOT use low ESR capacitors
with 0.02 ohms ESR because that is very high ?...LOL...
Show me a capacitor with these specs: 100VDC, 20,000uf, .000001 ohm
esr.. I need one really.==You pulled this same nonsense the last time you showed up here and ==the moderator ended up deleting your posts.
Couldn't have been me, I'm new here. LOL....
P.S. Just like playing chess, your turn.
Dread must be crazy (or completely uneducated) if he can say under all circumstances that a certain resistance is high or low. Steve, save your breath (or your energy typing I guess in this case).And dread, if you laugh out loud one more time, I'm going to muzzle you.
Andy
See the original thread, not this one, to know what
we are talking about. This thread is too confusing
for newbies to understand the debate we started a while
back... LOLNow you are making accusations like this;
"circumstances that a certain resistance is high or low".
Sound like you are making up more nonsense to throw in this
soup... LOL...... this thread and the other thread is major comedy.....
Being new to this board, are all you guys this way ? LOL..
dread wrote:
Being new to this board, are all you guys this way ? LOL..Yes, we are level-headed, intelligent people. So, please go away.
Andy
Leave now ? We have the hottest topic on the internet,
this thread is alive... LOL ..
Andy B wrote:Dread must be crazy (or completely uneducated) if he can say under all circumstances that a certain resistance is high or low. Steve, save your breath (or your energy typing I guess in this case).
Yes, it is ridiculous. And he is nuts. He says something and then says he didn't say it. Then he says he said it but he meant something else. Then he says he's been saying something all along that he's never said at all. And if that's not bad enough he has to end everything with a "lol!" The boy's disturbed. He wandered in here once before and was the same nut case then.
And yes, I'll be saving my breath. Thanks. :)
se
It's not my fault that you don't understand what I'm saying.
People with electronics backround have an easier time
understanding the subject.I'm trying to help the lamen like yourself and others and all you
do is comeback with ridiculous nonsense that is not
applicable to the conversation at hand. If you want me to teach
you electronics, I would be happy to do so but frankly,
I don't have the time --> teaching doesn't pay well ... LOL..
nt
A friend of mine is a BioMed Tech who has worked on power supplies up to about 34000VA. I've asked him about capacitors on a couple occasions and what he's said pretty much supports Steve.My Electronics Background is one and a half years of electrical engineering so far. I've personally built power supplies for MOSTFET amplifiers (although not audio amplifiers, but it is similar) up to 3000VA. 60% of what you are saying doesn't make any sense. (The other 40% consists of the letters: "LOL")
Having said that, I'm also going to stop wasting my breath.
Charlie
If you want to use high ESR capacitors (like Steve) in your design,
you can do so.. LOL ...
==Did you ever decide whether or not you believe ESR limits the speed ==at which the capacitor can deliver current?I wasn't talking about the speed, I was trying to say
you don't want to current limit your design but
that's how it got interpreted by an individual.. LOL ..Of course there is misspleellled words, that is what happens
when you type fast, I'm not writing a story for an english
class .... ha ha ha ha...You can aurgue that Bill Gates should comb his hair during
press conferences... LOL....
... LOL ...
dread wrote:I wasn't talking about the speed, I was trying to say
you don't want to current limit your design but
that's how it got interpreted by an individual.. LOL ..Yes, you were talking about speed. You were talking about how FAST a capacitor discharges. One more reminder:
You main capacitor has to be low ESR so it can dump
the current quickly into the load. IF a capacitor
has zero ESR, then it will dump all the charge into
a short immediately, but in reality this is not
the case. The internal resistance cause the capacitor
to discharge slower so if you were to short out the
capacitor briefly, then re-short it again, there is
still charge in it.How can you use the words "quickly," "immediately," and "slower" and then turn around and say you weren't talking about speed?
And as for not wanting to current limit your design, you contradict yourself there as well. You said it didn't matter if your transformer loads down:
Loading down your transformer is irrelivant, the purpose to
make a power amplifier is to drive the speakers and some
speakers are 1 - 3 ohm nominal, not all are just 8 ohms.But the transformer loads down because it's CURRENT LIMITING!
You apparently have no real clue what you're talking about and are just trying to bluff and weasel your way through this.
se
Why did John Curl try to discredit your knowledge of engineering in a
previous post ? Why did he feel that you had no idea on what you were
talking about? You responded and said that he had no clue
on what he was talking about.You must love attention, we are playing the same game
as you did with him.. LOL ..I've seen some good responses from you on other topics,
but when it comes to this topic, you just don't
understand what I'm talking about when it comes
to transformers and capacitors ...LOL...I'm not asking you to understand, you are the
one who came to me for more answers. I can
teach you these concepts but you make a difficult
student.. LOL...Like I said, I'm not trying to attack you, you
keep coming back for more punishment, the more
I try to put this issue to rest, the more you
come back with additional off topic information.If you want to convince the electronics industry and the audio
industry that their power supply designs have been
all wrong since the invention of electricity, be my guest.
It's a free country, you can have your own beliefs, I have
mine, that is what seperates good engineering from bad
engineering. LOL ..I've seen the results of bad engineering over the course
of my career, the vast majority of engineers do it
for the money, they have no idea how to put all the components
together to form a product, they may know how each component
works, but building real product eludes them.The facts are this;
1. Capacitor manufacturers design their capacitors
for power supply applications with low ESR. You
can't even find a high ESR capacitor unless you found
a janky vendor that makes one in southeast asian.. LOL2. Audiophile amplifiers use these low ESR capactors
in their power supply designs, they have no choice...
(unless they bought some crappy ones from example #1.. LOL..)
In summary, if McDonalds advertises a "BIG MAC", then
changed their marketing strategy and now markets the "BIG MAC with beef" some people will ask "do the other hamburgers have beef ?".
Of course the hamburber has beef, it's a given.. Just like power
supply capacitors, low ESR is a given.. Other will ask
about the veggie burger now... LOL
The point is, LOL, that people tend to use low ESR capacitors for the wrong reasons, and that perpetuating those reasons isn't helping anybody, LOL. That DOESN'T MEAN he doesn't think low ESR caps are a good idea, LOL!
For instance, I could say that it's a good idea for high power amps which need +/- 140v supplies (or so) to use a power transformer instead of running the AC line straight into a bridge because power transfomers make the amp heavier and people will think it's better built, LOL! While it's TRUE that you should use a transformer, my reason is complete bunk, and spreading it around isn't helping anybody, LOL!Charlie
PS. LOL!
=The point is, LOL, that people tend to use low ESR capacitors for the =wrong reasonsWe were talking about a SPECIFIC application on another thread, not this thread, if you look at the other thread, it's comedy...
In that application, low ESR is best. LOL
low esr may be better in that previous thread where you brought it up, but not for the reasons you advanced.jim
I'll Admit I'm ignorant, But these three letters are starting to
bug me.
What's does it stand for?And I ain't askin' for insults.
Laughing Out Loudor
Lick Only Lengthwise
depending upon the conversation.
The little voices told me that soap is the hallmark of civilization.
It's "netlingo"http://www.netlingo.com/
LOL = laughing out loud
There is more lingo, check the link above.
This is common language on email, message boards,
chat, etc..fun stuff
Complete with a website.Boy, I am spending way too much time online.
I think I'll go enjoy the fresh air and reality.
But I'll check the website out of dumb curiousity though.
THANX!
I guess these three letters are only limited to ones
Imagination.
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