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 ?

Tks...

On Mon, 24 Jan 2011 10:57:29 -0800 (PST), benitos
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.

Mo
http://www.badcaps.net/forum/showthread.php?s=f467f8a95fa3c34842bd4bbc39d50a2e& t=13045


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On 2011-01-24 20:40:46 +0100, Jeff Liebermann said:

On Mon, 24 Jan 2011 10:57:29 -0800 (PST), benitos
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.

Mo
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

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

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?

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.

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

"Jeffrey Angus"
William Sommer******

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

On 1/24/2011 5:20 PM Jeffrey Angus spake thus:

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.

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.

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.

On Tue, 25 Jan 2011 12:29:44 +1100, Phil Allison wrote:

"Jeffrey Angus"
William Sommer******

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

So the cap goes before the scope leads?



--
Live Fast, Die Young and Leave a Pretty Corpse

On Mon, 24 Jan 2011 19:20:58 -0600, Jeffrey Angus
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

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

"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

On Jan 24, 5:55*pm, David Nebenzahl wrote:
On 1/24/2011 5:20 PM Jeffrey Angus spake thus:





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.

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.

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.

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

"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 ******** !!!

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 ********.

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

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 ******** !!!!!

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

On Jan 24, 6:52*pm, "Phil Allison" wrote:


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 ******** *!!!!!

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

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

On Jan 24, 6:52*pm, "Phil Allison" wrote:


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 ******** *!!!!!

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

Also, your math is wrong hotshot.

G²

On Tue, 25 Jan 2011 13:40:21 +1100, "Phil Allison"
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 ******** !!!
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 ********.

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.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

"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 ******** !!!!!

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 - ****head.

" 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 - ****head.

BTW

The Matelectronics ESR meter is an total pile of ****.


..... Phil

Also, your math is wrong hotshot.


** No it ain't.

Go get ****ed you stupid ****.

"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 ???

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.


** 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 bull****artist.



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 ******** !!!

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 ****wit.


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 ********.

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, bull****ting ****head.



...... Phil

On Jan 24, 7:30*pm, "Phil Allison" wrote:


Also, your math is wrong hotshot.

** *No it ain't.

* Go get ****ed you stupid ****.

Yeah, it is. 0.1uF to 100uF is 1000 times, not 100 as you wrote.

Quote from you
"** Totally insane ******** !!!!!

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

** 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 (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

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?



--
Live Fast, Die Young and Leave a Pretty Corpse

"Meat Plow"

My Leader audio generator doesn't do 100kHz.

** Wot a piece of ****.

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

On Tue, 25 Jan 2011 15:11:31 +1100, Phil Allison wrote:

"Meat Plow"

My Leader audio generator doesn't do 100kHz.

** Wot a piece of ****.

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.





--
Live Fast, Die Young and Leave a Pretty Corpse

"Meat Plow is a Stupid **** "

My Leader audio generator doesn't do 100kHz.

** Wot a piece of ****.

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 ****.



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.

****WIT !!!!



...... Phil

On Tue, 25 Jan 2011 15:24:01 +1100, Phil Allison wrote:

"Meat Plow is a Stupid **** "

My Leader audio generator doesn't do 100kHz.

** Wot a piece of ****.

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 ****.

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.

****WIT !!!!



..... Phil

But your point was use an 'audio generator.'

I guess in your own way you admit your advice was ****e.



--
Live Fast, Die Young and Leave a Pretty Corpse

"Meat Plow is a Lying Stupid **** "



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

On Tue, 25 Jan 2011 15:44:20 +1100, Phil Allison wrote:

"Meat Plow is a Lying Stupid **** "



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

It's a LAG 120B and your right it's highest resolution is 1 Mhz.

Sorry. Never used it that high with amplifiers.



--
Live Fast, Die Young and Leave a Pretty Corpse

"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.


It's a LAG 120B and your right it's highest resolution is 1 Mhz.

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

On Tue, 25 Jan 2011 16:14:58 +1100, Phil Allison wrote:

"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.


It's a LAG 120B and your right it's highest resolution is 1 Mhz.

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

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.



--
Live Fast, Die Young and Leave a Pretty Corpse

On 1/24/2011 8:57 PM spake thus:

[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.

On Tue, 25 Jan 2011 04:01:10 +0000 (UTC), Meat Plow
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.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

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.

** 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.

Thanks for the clarification. I suspected something like that, but didn't
consider the cable's self-inductance would be significant at 100kHz.

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.

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?

"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

On Jan 25, 7:31*am, "Phil Allison" wrote:
"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

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.

Inscribed thus:

A 0.1uF ceramic has an impedance of 16 ohms at 100KHz Â* - Â* 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.

"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.

http://www.epcos.com/web/generator/W...nformation.pdf

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