Capacitors leaking on LG 50PC3D
benitos
supply board , cannot turn on the television.
Power LED is blinking.
Can these 2200uF capacitors damaged something else on the board ?
Tks...
Jeff Liebermann
wrote:
Just barely, and only over a fairly long time period (months). There
are many different types of electrolyte. Some are mild acids, but
most are water or alcohol based.
<http://en.wikipedia.org/wiki/Electrolytic_capacitor#Electrolyte>
Just clean up the mess, replace the big caps (even if they haven't
blown up yet), and be done with it. If you have an ESR tester, it
might help identify which caps are the likely culprits.
More:
<http://www.badcaps.net/forum/showthread.php?s=f467f8a95fa3c34842bd4bbc39d50a2e&t=13045>
--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
Kripton
> On Mon, 24 Jan 2011 10:57:29 -0800 (PST), benitos <pot...@cae.ca>
> wrote:
>
>> Hi , after changing many capacitors that were leaking on the power
>> supply board , cannot turn on the television.
>>
>> Power LED is blinking.
>>
>> Can these 2200uF capacitors damaged something else on the board ?
>
> Just barely, and only over a fairly long time period (months). There
> are many different types of electrolyte. Some are mild acids, but
> most are water or alcohol based.
> <http://en.wikipedia.org/wiki/Electrolytic_capacitor#Electrolyte>
> Just clean up the mess, replace the big caps (even if they haven't
> blown up yet), and be done with it. If you have an ESR tester, it
> might help identify which caps are the likely culprits.
>
> More:
> <http://www.badcaps.net/forum/showthread.php?s=f467f8a95fa3c34842bd4bbc39d50a2e&t=13045>
here
>
is an esr meter repository to choose from a schematic to build your own
esr meter !
http://kripton2035.free.fr/esr-repository.html
have a look.
regards,
--
---
Kripton
Phil Allison
<Kripton>
>
> is an esr meter repository to choose from a schematic to build your own
> esr meter !
>
> http://kripton2035.free.fr/esr-repository.html
** Anyone who needs to check the ESR of a few electros can lash up a test
rig in seconds - all you need is a bench audio generator and a basic scope
or CRO as poms and Aussies like to call them.
Set the audio gen to about 100kHz and connect the output across the electro
under test - then connect the scope probes direct to the same cap ( not the
generator). You should see a small voltage at 100kHz on the scope.
By comparison with known good electros of similar ratings, one can note the
residual voltages and determine if a given electro is OK.
Tests can be done while the electro caps are still in circuit - but be
careful to make sure they are fully discharged first !!!
..... Phil
William Sommerwerck
> directly to the same cap (not the generator). You should see a
> small voltage at 100kHz on the scope.
If one takes that literally, the scope probes /will/ be connected directly
to the generator.
Did you leave something out?
Jeffrey Angus
Nope, it IS connected directly to the generator.
And the capacitor across both.
You see a reduced value of signal due to the ESR of the capacitor
vs the source impedance of the signal generator.
Pretty simple.
Not direct reading, but accurate comparison.
Jeff
Phil Allison
"Jeffrey Angus"
William Sommerwanker
>>
>>> Set the audio gen to about 100kHz and connect the output
>>> across the electro under test -- then connect the scope probes
>>> directly to the same cap (not the generator). You should see a
>>> small voltage at 100kHz on the scope.
>>
>> If one takes that literally, the scope probes /will/ be connected
>> directly
>> to the generator.
>>
>> Did you leave something out?
>>
>
> Nope, it IS connected directly to the generator.
> And the capacitor across both.
** Connection of the scope direct to the electro cap is important.
Otherwise, the inductive reactance of the cable from the generator ( at
100kHz ) to the cap becomes included in the scope display of ESR - and is
often more than the ESR of a good cap.
..... Phil
David Nebenzahl
Skimming through a bunch of ESR meter schematics, this seems to be the
game plan for most of them:
Oscillator --> attenuator --> cap under test -->
op amp/comparator --> rectifier --> meter
(osc. is usually around 50-100 kHz)
Gots to build me one someday ...
(the attenuator delivers only millivolts to the cap being tested,
avoiding electrolytic polarity issues and any semiconductor junction
resistances)
--
Comment on quaint Usenet customs, from Usenet:
To me, the *plonk...* reminds me of the old man at the public hearing
who stands to make his point, then removes his hearing aid as a sign
that he is not going to hear any rebuttals.
Meat Plow
So the cap goes before the scope leads?
--
Live Fast, Die Young and Leave a Pretty Corpse
Jeff Liebermann
<jan...@suddenlink.net> wrote:
>On 1/24/2011 6:40 PM, William Sommerwerck wrote:
>>> Set the audio gen to about 100kHz and connect the output
>>> across the electro under test -- then connect the scope probes
>>> directly to the same cap (not the generator). You should see a
>>> small voltage at 100kHz on the scope.
>>
>> If one takes that literally, the scope probes /will/ be connected directly
>> to the generator.
>>
>> Did you leave something out?
>Nope, it IS connected directly to the generator.
>And the capacitor across both.
Retch.
>You see a reduced value of signal due to the ESR of the capacitor
>vs the source impedance of the signal generator.
That would work if you knew the exact source resistance of the
generator and that the generator is not going to try and protect
itself from what it considers to be an AC short circuit load.
If you have 1 volt of output swing, and an assumed function generator
output impedance of 50 ohms, the short circuit current will be about
20ma. Shove that into a 0.5 ohm electrolytic cazapitor, and you'll
measure maybe 10mv across the cazapitor. That's kinda hard to see. Of
course you could supply more than 1 volt but then you will have some
problems trying to use this technique without removing the cazapitor
from the PCB.
For what it's worth, I did it this way until I bought an ESR meter.
Later, I decided to actually measure the output impedance of my
function generator. The data sheet said 50/75 ohms, but it was
anywhere between 30 and 100 ohms depending on the position of the dial
and output step attenuator. So much for accuracy.
If you look carefully at the schematics supplied below, most of them
put a known series resistance at the output of the generator section
to the cazapitor. You could do the same thing with the function
generator. 100 ohms in series with an alleged 50 ohms will not
magically make the method more accurate, but it will reduce the error
to a tolerable level.
>Pretty simple.
>Not direct reading, but accurate comparison.
>Jeff
Nothing is simple, but these examples might help:
Measuring Capacitor Self-inductance and ESR
<http://www.emcesd.com/tt020100.htm>
Oscilloscope ESR Tester
<http://electronics-diy.com/electronic_schematic.php?id=948>
99 Cent ESR Test Adapter
<http://octopus.freeyellow.com/99.html>
More links at the bottom of this page:
<http://en.wikipedia.org/wiki/ESR_meter>
Phil Allison
"David Nebenzahl"
> Skimming through a bunch of ESR meter schematics, this seems to be the
> game plan for most of them:
>
> Oscillator --> attenuator --> cap under test -->
> op amp/comparator --> rectifier --> meter
>
> (osc. is usually around 50-100 kHz)
>
>
> (the attenuator delivers only millivolts to the cap being tested, avoiding
> electrolytic polarity issues and any semiconductor junction resistances)
** The idea of including an "attenuator " is misleading.
The electro under test needs to be driven with a known *current* at
00kHz - 20 to 50 mA is good.
Simply shorting my bench audio generator with the output level set to max
produces 29.7 mV into a 1 ohm resistor at 100kHz or 30mA, near enough.
If the electro under test has an ESR of 100 milliohms - the above set up
produces 3 mV rms across the cap which is easily enough viewed on most
scopes.
Long as you connect the scope direct to the leads of the electro and know
the current level from the generator - actual ESR values can be found.
.... Phil
stra...@yahoo.com
Not likely to do much better than the MUL3333 ESR meter from Mat
Electronics for $50. The main 'quirk' on the unit is the battery case
holds 6 AA cells but it's wired as 3 parallel groups of 2 cells
meaning just use 2 AA cells and skip the other 4. Very good value for
the money. With any ESR meter there are 'gotchas' to beware of. Any
ceramic caps in parallel with a 'lytic will mask the true condition of
the 'lytic. If it reads bad, it IS but if it reads good it might not
be. May times I've run into boards with many caps of the same value.
If one of those is bad I change all of that value figuring if one is
bad the others aren't far behind. Also, the output caps in SMPS need
to be nearly perfect. 'Good enough' rarely is. When in doubt toss em
out.
http://www.matelectronics.com/
G²
Phil Allison
"Jeff Liebermann"
>
> If you have 1 volt of output swing, and an assumed function generator
> output impedance of 50 ohms, the short circuit current will be about
> 20ma. Shove that into a 0.5 ohm electrolytic cazapitor, and you'll
> measure maybe 10mv across the cazapitor. That's kinda hard to see.
** What kind of POS scope do you have ???
10mV rms = 28.3 mV p-p.
My scope goes down to 5mV per division - then has a 5X mag switch if
needed.
> Of
> course you could supply more than 1 volt but then you will have some
> problems trying to use this technique without removing the cazapitor
> from the PCB.
** Utter bollocks !!!
As your own example proves.
> For what it's worth, I did it this way until I bought an ESR meter.
> Later, I decided to actually measure the output impedance of my
> function generator. The data sheet said 50/75 ohms, but it was
> anywhere between 30 and 100 ohms depending on the position of the dial
> and output step attenuator.
** Just set it to max and that's it for ESR testing.
> If you look carefully at the schematics supplied below, most of them
> put a known series resistance at the output of the generator section
> to the cazapitor. You could do the same thing with the function
> generator. 100 ohms in series with an alleged 50 ohms will not
> magically make the method more accurate, but it will reduce the error
> to a tolerable level.
** More bollocks.
The vast majority of electros have less than 1 ohm ESR values - so any
error in the calculated drive current is TINY in comparison to a 50 ohm
source.
The variation in ESR values between new electros of the same type is far
more.
.... Phil
Phil Allison
<stra...@yahoo.com>
With any ESR meter there are 'gotchas' to beware of. Any
ceramic caps in parallel with a 'lytic will mask the true condition of
the 'lytic.
** Totally insane BOLLOCKS !!!!!
A 0.1uF ceramic has an impedance of 16 ohms at 100KHz - while a typical
100uF electro has an impedance of 0.16 ohms at 100kHz. That is 100 times
less !!!
Imbecile.
If it reads bad, it IS but if it reads good it might not be.
** Only time that is ever true is if the electro is shorted - internally or
externally.
May times I've run into boards with many caps of the same value.
If one of those is bad I change all of that value figuring if one is
bad the others aren't far behind.
** Not a bad idea - if all the electros have been subjected to the same
temps for the same times.
Also, the output caps in SMPS need to be nearly perfect.
** Well, that may be so in some cases.
But designers usually leave a margin for component variations and some
deterioration in electros.
Once the ESR of an electro rises by more than 50%, it may be time for
replacement - cos it is now gonna keep rising.
..... Phil
stra...@yahoo.com
> <stratu...@yahoo.com>
Who said anything about 0.1uF? The Sony EQ-45 board in the DVW-500
Digital Betacam has a lot of 100uF surface mount 'lytics, many of
which read 'OK' but when removing the 'lytic, IT reads very bad and
the pads on the board read 'OK' without the 'lytic.
Can't argue with facts.
G²
stra...@yahoo.com
Also, your math is wrong hotshot.
G²
Jeff Liebermann
wrote:
>"Jeff Liebermann"
>> If you have 1 volt of output swing, and an assumed function generator
>> output impedance of 50 ohms, the short circuit current will be about
>> 20ma. Shove that into a 0.5 ohm electrolytic cazapitor, and you'll
>> measure maybe 10mv across the cazapitor. That's kinda hard to see.
>
>** What kind of POS scope do you have ???
Tek 2247A. I have several others, but that's the one I like to use.
<http://802.11junk.com/jeffl/pics/home/slides/BL-shop6.html>
>10mV rms = 28.3 mV p-p.
Read what I wrote again. I said "1 volt of output swing" which means
1 volt peak to peak. Sorry for not being absolutely clear. Also, all
the ESR test circuits I've seen use a square wave, which is normally
not measured in RMS units.
>My scope goes down to 5mV per division - then has a 5X mag switch if
>needed.
Mine goes down to 2mv/div. About 1/3 of that is noise. My guess(tm)
is that anything I measure has a built in 1mv error due to this noise.
I think the X5 or whatever magnification on your unspecified model
scope usually refers to the horizontal sweep, not the vertical gain.
>> Of
>> course you could supply more than 1 volt but then you will have some
>> problems trying to use this technique without removing the cazapitor
>> from the PCB.
>
>** Utter bollocks !!!
> As your own example proves.
How so? If the cazapitor happens to appear across a semiconductor
junction, as will happen with the output of an integrated switching
regulator with a reverse protection diode on its output, the
protection diode is going to conduct if fed more than about 0.6V peak
to peak. I think (not sure) that the original Bob Parker meter ran at
about 80mv peak to peak to avoid this manner of problem.
>> For what it's worth, I did it this way until I bought an ESR meter.
>> Later, I decided to actually measure the output impedance of my
>> function generator. The data sheet said 50/75 ohms, but it was
>> anywhere between 30 and 100 ohms depending on the position of the dial
>> and output step attenuator.
>
>** Just set it to max and that's it for ESR testing.
Lets just say I don't like running my test equipment flat out into an
AC short circuit (the cap under test). My cheapo Leader LFG-1300S
function generator has some kind of overcurrent protection circuit on
the output, that limits the square wave output swing, but also mangles
the waveform.
>> If you look carefully at the schematics supplied below, most of them
>> put a known series resistance at the output of the generator section
>> to the cazapitor. You could do the same thing with the function
>> generator. 100 ohms in series with an alleged 50 ohms will not
>> magically make the method more accurate, but it will reduce the error
>> to a tolerable level.
>
>** More bollocks.
>
>The vast majority of electros have less than 1 ohm ESR values - so any
>error in the calculated drive current is TINY in comparison to a 50 ohm
>source.
True, except that the variation between what's considered a good and a
bad electrolytic is sufficiently small that source impedance makes a
difference.
<http://members.ozemail.com.au/~bobpar/2003esrchart.txt>
(Notice the odd variations across the voltage ranges).
I find myself working at the bitter edge of some of the recommended
maximum ESR values all too often. I sometimes have to flip a coin to
decide if the cap is good or bad. The last thing I need is a blurry
oscilloscope trace or an undefined generator source resistance.
>The variation in ESR values between new electros of the same type is far
>more.
Huh? I've taken bags of brand new electrolytic caps and tested them
to see if there was any way to predict which ones would fail and which
ones would survive. For a given value, voltage, and temperature,
they're all about the same. I see wide variations in value (i.e. +80%
to -20%), but the initial ESR just follows the value. However, after
running a crude accelerated lifetime test on the caps (high ripple
current and high temperatures), I find the good and the bad caps
diverging in ESR.
Phil Allison
<stra...@yahoo.com>
"Phil Allison"
>
>
> With any ESR meter there are 'gotchas' to beware of. Any
> ceramic caps in parallel with a 'lytic will mask the true condition of
> the 'lytic.
>
> ** Totally insane BOLLOCKS !!!!!
>
> A 0.1uF ceramic has an impedance of 16 ohms at 100KHz - while a typical
> 100uF electro has an impedance of 0.16 ohms at 100kHz. That is 100 times
> less !!!
>
> Imbecile.
>
> If it reads bad, it IS but if it reads good it might not be.
>
> ** Only time that is ever true is if the electro is shorted - internally
> or
> externally.
>
> May times I've run into boards with many caps of the same value.
> If one of those is bad I change all of that value figuring if one is
> bad the others aren't far behind.
>
> ** Not a bad idea - if all the electros have been subjected to the same
> temps for the same times.
>
> Also, the output caps in SMPS need to be nearly perfect.
>
> ** Well, that may be so in some cases.
>
> But designers usually leave a margin for component variations and some
> deterioration in electros.
>
> Once the ESR of an electro rises by more than 50%, it may be time for
> replacement - cos it is now gonna keep rising.
>
Who said anything about 0.1uF?
** Read you own post - fuckhead.
" Any ceramic caps in parallel with a 'lytic will mask the true condition of
the 'lytic. "
The Sony EQ-45 board in the DVW-500
Digital Betacam has a lot of 100uF surface mount 'lytics, many of
which read 'OK' but when removing the 'lytic, IT reads very bad and
the pads on the board read 'OK' without the 'lytic.
** Really ??
Can't argue with facts.
** Let me know when you have one - fuckhead.
BTW
The Matelectronics ESR meter is an total pile of shit.
.... Phil
Phil Allison
Phil Allison
"Jeff Liebermann is a total IMBECILE "
>
>>> If you have 1 volt of output swing, and an assumed function generator
>>> output impedance of 50 ohms, the short circuit current will be about
>>> 20ma. Shove that into a 0.5 ohm electrolytic cazapitor, and you'll
>>> measure maybe 10mv across the cazapitor. That's kinda hard to see.
>>
>>** What kind of POS scope do you have ???
>
>
> Read what I wrote again. I said "1 volt of output swing" which means
> 1 volt peak to peak.
** I see: "10mv across ...."
Which is what my comments are obviously about.
So you lose this one.
> Also, all the ESR test circuits I've seen use a square wave,
** My ESR test idea uses a sine wave.
So you lose this one too.
>>My scope goes down to 5mV per division - then has a 5X mag switch if
>>needed.
>
> Mine goes down to 2mv/div.
** Then 10mV rms is easy to see and measure.
So you lose this one also.
> I think the X5 or whatever magnification on your unspecified model
> scope usually refers to the horizontal sweep, not the vertical gain.
** Think again - Mr bullshitartist.
>>> Of
>>> course you could supply more than 1 volt but then you will have some
>>> problems trying to use this technique without removing the cazapitor
>>> from the PCB.
>>
>>** Utter bollocks !!!
>>
>> As your own example proves.
>
> How so?
** Cos the residual voltage on the cap under test is only 10 mV !!!!!!!!!!!
So you lose another one.
Are you DRUNK ????
>>** Just set it to max and that's it for ESR testing.
>
> Lets just say I don't like running my test equipment flat out into an
> AC short circuit (the cap under test).
** Yawnnnnnnnn........
Let me just say that you are clearly a total fuckwit.
>>> If you look carefully at the schematics supplied below, most of them
>>> put a known series resistance at the output of the generator section
>>> to the cazapitor. You could do the same thing with the function
>>> generator. 100 ohms in series with an alleged 50 ohms will not
>>> magically make the method more accurate, but it will reduce the error
>>> to a tolerable level.
>>
>>** More bollocks.
>>
>>The vast majority of electros have less than 1 ohm ESR values - so any
>>error in the calculated drive current is TINY in comparison to a 50 ohm
>>source.
>
> True, except that the variation between what's considered a good and a
> bad electrolytic is sufficiently small that source impedance makes a
> difference.
** Absolute NONSENSE !!
Another lose for you.
Are you DRUNK ???
>>The variation in ESR values between new electros of the same type is far
>>more.
>
> Huh?
** Yes.
Maker's specs say the sample to sample variation is way more than 2%.
You ridiculous, bullshitting fuckhead.
..... Phil
stra...@yahoo.com
>
> ** No it ain't.
>
> Go get fucked you stupid cunt.
Yeah, it is. 0.1uF to 100uF is 1000 times, not 100 as you wrote.
Quote from you
"** Totally insane BOLLOCKS !!!!!
A 0.1uF ceramic has an impedance of 16 ohms at 100KHz - while a
typical
100uF electro has an impedance of 0.16 ohms at 100kHz. That is 100
times
less !!!
Imbecile"
I said nothing of parallel cap values. You assumed it - incorrectly.
G²
Phil Allison
** Anyone who needs to check the ESR of a few electros can lash up a test
rig in seconds - all you need is a bench audio generator and a basic scope
Set the audio gen to about 100kHz (sine wave) use full level and connect
the output across the electro under test - then connect the scope probes
direct to the same cap, not the generator - this is important.
You should see a small voltage at 100kHz on the scope - say 2 to 100mV rms.
By comparison with known good electros of similar ratings, one can note the
residual voltages and determine if a given electro is OK.
If you put a 1 ohm test load on the audio gen - you can easily find the
output current and then use the voltage readings on the scope to get actual
ESR values for electros.
Tests can be done while caps are still in circuit - but be careful to make
sure they are fully discharged first !!!
.... Phil
Meat Plow
> ** Anyone who needs to check the ESR of a few electros can lash up a
> test
> rig in seconds - all you need is a bench audio generator and a basic
> scope or CRO as poms and Aussies call them.
>
> Set the audio gen to about 100kHz
My Leader audio generator doesn't do 100kHz. What 'audio generator' does?
Phil Allison
<stra...@yahoo.com
> Also, your math is wrong hotshot.
>
> ** No it ain't.
>
> Go get fucked you stupid cunt.
> Yeah, it is. 0.1uF to 100uF is 1000 times, not 100 as you wrote.
** ROTFLMAO !!
I wrote NOTHING OF THE SORT
YOU STUPID FUCKING CUNTHEAD !!
---------------------------------------------------
> Quote from you
"** Totally insane BOLLOCKS !!!!!
A 0.1uF ceramic has an impedance of 16 ohms at 100KHz - while a
typical 100uF electro has an impedance of 0.16 ohms at 100kHz. That is 100
times less !!! Imbecile"
** 100 times less is just what it is !!!
YOU STUPID FUCKING CUNTHEAD !!
---------------------------------------------------
> I said nothing of parallel cap values.
** You stinking bloody LIAR !!!!!!!!!!!!!!!!!!!!!!!!!!!!
" With any ESR meter there are 'gotchas' to beware of.
Any ceramic caps in parallel with a 'lytic will mask the
true condition of the 'lytic. "
Go straight into hell you vile, waste of space.
..... Phil
Phil Allison
"Meat Plow"
> My Leader audio generator doesn't do 100kHz.
** Wot a piece of shit.
50kHz will do, at a pinch.
> What 'audio generator' does?
** Nearly all go to at least 100 kHz.
Many go out to 1MHz.
Function generators often go out to way more.
.... Phil
Meat Plow
> "Meat Plow"
>
>> My Leader audio generator doesn't do 100kHz.
>
> ** Wot a piece of shit.
>
> 50kHz will do, at a pinch.
It was certified by all my warranty work requirements.
Teac/Tascam, Panasonic, Sansui, Yamaha, Sony etc...
>
>> What 'audio generator' does?
>
>
> ** Nearly all go to at least 100 kHz.
>
> Many go out to 1MHz.
Why would an 'audio generator' need to have a resolution
up to 1 Mhz?
> Function generators often go out to way more.
That's nice but I use a signal/function generator to
generate signals out of the audio realm.
Phil Allison
"Meat Plow is a Stupid Cunt "
>
>>> My Leader audio generator doesn't do 100kHz.
>>
>> ** Wot a piece of shit.
>>
>> 50kHz will do, at a pinch.
>
> It was certified by all my warranty work requirements.
> Teac/Tascam, Panasonic, Sansui, Yamaha, Sony etc...
** It's still a piece of shit.
>>> What 'audio generator' does?
>>
>>
>> ** Nearly all go to at least 100 kHz.
>>
>> Many go out to 1MHz.
>
>> Function generators often go out to way more.
>
> That's nice but I use a signal/function generator to
> generate signals out of the audio realm.
** Then use it for this.
FUCKWIT !!!!
..... Phil
stra...@yahoo.com
Assuming you're perfect and found wanting seems to set you off. Have a
nice day.
G²
Meat Plow
> "Meat Plow is a Stupid Cunt "
>>
>>>> My Leader audio generator doesn't do 100kHz.
>>>
>>> ** Wot a piece of shit.
>>>
>>> 50kHz will do, at a pinch.
>>
>> It was certified by all my warranty work requirements. Teac/Tascam,
>> Panasonic, Sansui, Yamaha, Sony etc...
>
>
> ** It's still a piece of shit.
Only in your mind. It does exactly what it was designed
to do.
>
>
>>>> What 'audio generator' does?
>>>
>>>
>>> ** Nearly all go to at least 100 kHz.
>>>
>>> Many go out to 1MHz.
>>
>>> Function generators often go out to way more.
>>
>> That's nice but I use a signal/function generator to generate signals
>> out of the audio realm.
>
>
> ** Then use it for this.
>
> FUCKWIT !!!!
>
>
>
> ..... Phil
But your point was use an 'audio generator.'
I guess in your own way you admit your advice was shite.
Phil Allison
Phil Allison
>
>>>
>>>>> My Leader audio generator doesn't do 100kHz.
** Which model is it??
Post a link to it.
I found 6 different "Leader" audio gens on the net and all go out to at
least 100kHz.
..... Phil
stra...@yahoo.com
0.1 into 100 is 100? Is that Aussie math? Answers a LOT of questions
though.
G²
Phil Allison
> > Also, your math is wrong hotshot.
>
> > ** No it ain't.
>
> > Go get fucked you stupid cunt.
> > Yeah, it is. 0.1uF to 100uF is 1000 times, not 100 as you wrote.
>
> ** ROTFLMAO !!
>
> I wrote NOTHING OF THE SORT
>
> YOU STUPID FUCKING CUNTHEAD !!
> ---------------------------------------------------
>
> > Quote from you
>
> "** Totally insane BOLLOCKS !!!!!
>
> A 0.1uF ceramic has an impedance of 16 ohms at 100KHz - while a
> typical 100uF electro has an impedance of 0.16 ohms at 100kHz. That is 100
> times less !!! Imbecile"
>
> ** 100 times less is just what it is !!!
0.1 into 100 is 100? Is that Aussie math?
** My god - you are one
FUCKING RETARDED CUNT !!!
16 divided by 0.16 = 100 !!!!!!!!!!!!!!!!
---------------------------------------------
Get CANCER and DIE you vile scumbag.
..... Phil
stra...@yahoo.com
You're just too dense to deal with. G'Day mate.
G²
Meat Plow
It's a LAG 120B and your right it's highest resolution is 1 Mhz.
Sorry. Never used it that high with amplifiers.
Phil Allison
<stra...@yahoo.com>
** This bullshit artist is the PRINCE of FUCKWITS
Other fuckwits round the world regard him with complete awe.
He shows them the way ........
Phil Allison
"Meat Plow"
Phil Allison wrote:
>
>>>>>>> My Leader audio generator doesn't do 100kHz.
>>
>> ** Which model is it??
>>
>> Post a link to it.
>>
>> I found 6 different "Leader" audio gens on the net and all go out to at
>> least 100kHz.
>>
>>
>
> Sorry. Never used it that high with amplifiers.
** Apology accepted.
( I can hardly believe I am posting that .... )
One reason for having 100kHz or more available on an "Audio Generator" is to
enable the testing of audio filters that may have turn over frequencies at
say 22 kHz. To find the roll of slope, one needs to check the response for
several octaves above that frequency.
Another use is in testing the response of audio transformers - ie line,
mic or valve output. These often exhibit severe ringing at frequencies
between 25 kHz and 150kHz. This can often be eliminated with a suitable RC
damping network.
Audio gens also need to go down to 1 or 2 Hz as well - so one can check any
sub sonic filters included in amplifiers and other devices OR to force DC
and anti-thump protection relays in power amps to cycle to verify their
operation.
Many other good reasons exist too.
.... Phil
Meat Plow
Thanks and ESR solution archived. And I can't believe I didn't remember
the LAG 120 did 1 MHz seeing I've owned it now for 35 years. However I
ALWAYS used/use it for 400 -1000 MHz depending on calibration
instructions for various audio devices. I doubt it would even work on
higher resolutions without cleaning the push buttons. So once again
sorry.
David Nebenzahl
[snip now-meaningless stuff]
Um, sir, you're going to need another ticket if you want to get on this
ride* again.
[The Phil Allison's Off His Meds Again Cyclo-Rama]
--
Comment on quaint Usenet customs, from Usenet:
To me, the *plonk...* reminds me of the old man at the public hearing
who stands to make his point, then removes his hearing aid as a sign
that he is not going to hear any rebuttals.
Jeff Liebermann
<mhy...@yahoo.com> wrote:
>On Tue, 25 Jan 2011 14:58:37 +1100, Phil Allison wrote:
>> Set the audio gen to about 100kHz
>
>My Leader audio generator doesn't do 100kHz. What 'audio generator' does?
My Leader LFG-1300S goes to 2MHz. My broken Wavetek Model 120 also
goes to 2Mhz. My broken HP 3312A function generator would go to 13Mhz
if it would kindly allow itself to be fixed. The square waves start
to have rounded corners near the higher frequencies, but at 100Khz,
it's a real nice square wave.
Michael A. Terrell
Meat Plow wrote:
>
> On Tue, 25 Jan 2011 14:58:37 +1100, Phil Allison wrote:
>
> > ** Anyone who needs to check the ESR of a few electros can lash up a
> > test
> > rig in seconds - all you need is a bench audio generator and a basic
> > scope or CRO as poms and Aussies call them.
> >
> > Set the audio gen to about 100kHz
>
> My Leader audio generator doesn't do 100kHz. What 'audio generator' does?
EICO Model 377
--
You can't fix stupid. You can't even put a band-aid on it, because it's
Teflon coated.
William Sommerwerck
> Otherwise, the inductive reactance of the cable from the generator
> ( at 100kHz ) to the cap becomes included in the scope display of
> ESR - and is often more than the ESR of a good cap.
Thanks for the clarification. I suspected something like that, but didn't
consider the cable's self-inductance would be significant at 100kHz.
William Sommerwerck
> electro and know the current level from the generator --
> actual ESR values can be found.
In other words... If the driving frequency is high enough that the
capacitive reactance is essentially zero, then the net impedance is
essentially the ESR. Right?
Phil Allison
"William Sommerwerck"
> In other words... If the driving frequency is high enough that the
> capacitive reactance is essentially zero, then the net impedance is
> essentially the ESR. Right?
** Errr - yep.
But it ain't that simple.
One has to examine the actual impedance curves for typical electros to see
what the game is - the curve is like no other kind of cap.
Think of Q factors of circa 0.05 and ESRs that way exceed the calculated
impedance at 100kHz.
..... Phil
George Herold
Nice tip thanks Phil. The 100uF electro's I have came out with ~0.15
ohms of ESR, using your method.
I've never seen an impedance curve for an electro cap. Do you have a
link or know which manufacturer's website I might check?
As a 'silly' rule of thumb it seems that most caps I run across have a
minimum impedance of ~0.1 ohms. (Ignoring the 'resonant' dips that
you sometimes see in the impedance plot.)
George H.
baron
>> A 0.1uF ceramic has an impedance of 16 ohms at 100KHz - while a
>> typical 100uF electro has an impedance of 0.16 ohms at 100kHz. That
>> is 100 times less !!!
> Can't argue with facts.
Since Phil is comparing impedance values and not component values,
I guess Phil is right !
--
Best Regards:
Baron.
Phil Allison
"George Herold is a real Pain "
>>
> > In other words... If the driving frequency is high enough that the
> > capacitive reactance is essentially zero, then the net impedance is
> > essentially the ESR. Right?
>
> ** Errr - yep.
>
> But it ain't that simple.
>
> One has to examine the actual impedance curves for typical electros to see
> what the game is - the curve is like no other kind of cap.
>
> Think of Q factors of circa 0.05 and ESRs that way exceed the calculated
> impedance at 100kHz.
>
Nice tip thanks Phil. The 100uF electro's I have came out with ~0.15
ohms of ESR, using your method.
I've never seen an impedance curve for an electro cap. Do you have a
link or know which manufacturer's website I might check?
** Found this PDF on the net - seems to have lots good info on the humble
electro.
See page 15, figs 13 and 14.
One can easily see the dramatic effect temperature has on the impedance
minima or ESR - electros work better when they are HOT !!
Also, the minimum impedance value ( same as the ESR ) occurs around 50 -
100kHz and is quite broad - the higher the ESR and the lower the temp the
broader.
At 20C the 47uF, 350 volt electro in fig 14 exhibits a deep impedance minima
( essentially 0.4 ohms resistive ) from 10kHz to 2 MHz.
.... Phil
George Herold
> "George Herold is a real Pain "
>
>
>
> > > In other words... If the driving frequency is high enough that the
> > > capacitive reactance is essentially zero, then the net impedance is
> > > essentially the ESR. Right?
>
> > ** Errr - yep.
>
> > But it ain't that simple.
>
> > One has to examine the actual impedance curves for typical electros to see
> > what the game is - the curve is like no other kind of cap.
>
> > Think of Q factors of circa 0.05 and ESRs that way exceed the calculated
> > impedance at 100kHz.
>
> Nice tip thanks Phil. The 100uF electro's I have came out with ~0.15
> ohms of ESR, using your method.
> I've never seen an impedance curve for an electro cap. Do you have a
> link or know which manufacturer's website I might check?
>
> ** Found this PDF on the net - seems to have lots good info on the humble
> electro.
>
>
> See page 15, figs 13 and 14.
>
> One can easily see the dramatic effect temperature has on the impedance
> minima or ESR - electros work better when they are HOT !!
>
> Also, the minimum impedance value ( same as the ESR ) occurs around 50 -
> 100kHz and is quite broad - the higher the ESR and the lower the temp the
> broader.
>
> At 20C the 47uF, 350 volt electro in fig 14 exhibits a deep impedance minima
> ( essentially 0.4 ohms resistive ) from 10kHz to 2 MHz.
>
> .... Phil
That's great! Thanks Phil, I found some graphs by Vishay, but they
weren't nearly as nice. (No temperature dependence and frequencies
only to 100kHz) Of course at high temperatures the electro's leak
more.
I used your techinque to look at a 1000uF cap. I used a DSO with a
bit of signal averaging. ('scope triggered from a sync output from the
generator) I got something like 0.016 ohms at 100kHz. Our SRS RCL
meter measured 0.014 ohms at 10kHz for the same cap. and then 'lost
it's mind' at 100kHz. (reported a negative capacitance.)
George H.
David Nebenzahl
> I used your techinque to look at a 1000uF cap. I used a DSO with a
> bit of signal averaging. ('scope triggered from a sync output from the
> generator) I got something like 0.016 ohms at 100kHz. Our SRS RCL
> meter measured 0.014 ohms at 10kHz for the same cap. and then 'lost
> it's mind' at 100kHz. (reported a negative capacitance.)
Perhaps you've stumbled onto the "anti-capacitor". Maybe you could
patent it ...
George Herold
Hmm, Well I was thinking about this. Perhaps the RCL meter looks at
the phase shift to get the sign. The minus sign would indicate that
at 100kHz the 1000uF cap has passed through it's minimum impedance
point and is now rising up the other side and looking more inductive
to the driver.
(Just a guess.)
George H.