http://alytus.auksa.lt/esr/

On Tue, 03 Jul 2007 07:37:11 -0500, J.P. wrote:

http://alytus.auksa.lt/esr/

Bizarre, complex, and doesn't actually measure ESR.

John

On Tue, 03 Jul 2007 11:22:41 -0700, John Larkin
wrote:

On Tue, 03 Jul 2007 07:37:11 -0500, J.P. wrote:

http://alytus.auksa.lt/esr/

Bizarre, complex, and doesn't actually measure ESR.

John
Take that up with the inventor

"J.P." wrote:

http://alytus.auksa.lt/esr/

You posted this crap here too ?

Maybe some kind person will provide a circuit that works.

Graham

John Larkin wrote:

J.P. wrote:

http://alytus.auksa.lt/esr/

Bizarre, complex, and doesn't actually measure ESR.

I couldn't agree more.

Graham

"J.P." wrote:

On Tue, 03 Jul 2007 11:22:41 -0700, John Larkin
wrote:

On Tue, 03 Jul 2007 07:37:11 -0500, J.P. wrote:

http://alytus.auksa.lt/esr/

Bizarre, complex, and doesn't actually measure ESR.

John
Take that up with the inventor


Inventor? Too bad he wasn't a designer.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

On Tue, 03 Jul 2007 19:34:52 GMT, J.P. wrote:

On Tue, 03 Jul 2007 11:22:41 -0700, John Larkin
wrote:

On Tue, 03 Jul 2007 07:37:11 -0500, J.P. wrote:

http://alytus.auksa.lt/esr/

Bizarre, complex, and doesn't actually measure ESR.

John
Take that up with the inventor

---
Why?

You're the one who posted it for no good reason.


--
JF

On Wed, 04 Jul 2007 05:24:53 GMT, "Michael A. Terrell"
wrote:

"J.P." wrote:

On Tue, 03 Jul 2007 11:22:41 -0700, John Larkin
wrote:

On Tue, 03 Jul 2007 07:37:11 -0500, J.P. wrote:

http://alytus.auksa.lt/esr/

Bizarre, complex, and doesn't actually measure ESR.

John
Take that up with the inventor


Inventor? Too bad he wasn't a designer.
It does measure ESR and is a viable citcuit. Best look again.Just
because you read some from Eyesore on the RAT group doen't mean it is
true...and disrespecting a well meaning vet doesn't do so much for
your position either...these USENET trolls can kiss amy ass...although
I am not gay like they are...

On Wed, 04 Jul 2007 08:00:14 -0500, John Fields
wrote:

On Tue, 03 Jul 2007 19:34:52 GMT, J.P. wrote:

On Tue, 03 Jul 2007 11:22:41 -0700, John Larkin
wrote:

On Tue, 03 Jul 2007 07:37:11 -0500, J.P. wrote:

http://alytus.auksa.lt/esr/

Bizarre, complex, and doesn't actually measure ESR.

John
Take that up with the inventor

---
Why?

You're the one who posted it for no good reason.
You are full of ****...**** off asshole...

"J.P." wrote:

On Wed, 04 Jul 2007 05:24:53 GMT, "Michael A. Terrell"
wrote:

"J.P." wrote:

On Tue, 03 Jul 2007 11:22:41 -0700, John Larkin
wrote:

On Tue, 03 Jul 2007 07:37:11 -0500, J.P. wrote:

http://alytus.auksa.lt/esr/

Bizarre, complex, and doesn't actually measure ESR.

John
Take that up with the inventor


Inventor? Too bad he wasn't a designer.
It does measure ESR and is a viable citcuit. Best look again.Just
because you read some from Eyesore on the RAT group doen't mean it is
true...and disrespecting a well meaning vet doesn't do so much for
your position either...these USENET trolls can kiss amy ass...although
I am not gay like they are...


You sure seem to like men's asses, not to be gay. In fact, it really
interferes with your reading comprehension. IDIDN'T SAY THAT IT DIDN'T
WORK. THE ESR METER WAS "INVENTED" AND PATENTED DECADES AGO. YOUR TOY
ISN'T THAT PIECE OF EQUIPMENT, SO HE DIDN'T "INVENT" THE ESR METER.
HTHY, ass lover.

--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

"J.P." wrote:

On Wed, 04 Jul 2007 08:00:14 -0500, John Fields
wrote:

On Tue, 03 Jul 2007 19:34:52 GMT, J.P. wrote:

On Tue, 03 Jul 2007 11:22:41 -0700, John Larkin
wrote:

On Tue, 03 Jul 2007 07:37:11 -0500, J.P. wrote:

http://alytus.auksa.lt/esr/

Bizarre, complex, and doesn't actually measure ESR.

John
Take that up with the inventor

---
Why?

You're the one who posted it for no good reason.
You are full of ****...**** off asshole...


That's not nice! I hope you have your asbestos panties on, sweetie!
John LOVES flaming little idiots like you.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

On Wed, 04 Jul 2007 19:23:23 GMT, J.P. wrote:

On Wed, 04 Jul 2007 08:00:14 -0500, John Fields
wrote:

On Tue, 03 Jul 2007 19:34:52 GMT, J.P. wrote:

On Tue, 03 Jul 2007 11:22:41 -0700, John Larkin
wrote:

On Tue, 03 Jul 2007 07:37:11 -0500, J.P. wrote:

http://alytus.auksa.lt/esr/

Bizarre, complex, and doesn't actually measure ESR.

John
Take that up with the inventor

---
Why?

You're the one who posted it for no good reason.
You are full of ****...

---
Really?

Why did you post it then?

No one asked you to and you provided no explanation with the post,
just a link to the graphic, so it's not like anyone cared about it
or even knew it was on the way.
---

**** off asshole...

---
Blow me.


--
JF

On Wed, 04 Jul 2007 19:40:29 GMT, "Michael A. Terrell"
wrote:

"J.P." wrote:

On Wed, 04 Jul 2007 08:00:14 -0500, John Fields
wrote:

On Tue, 03 Jul 2007 19:34:52 GMT, J.P. wrote:

On Tue, 03 Jul 2007 11:22:41 -0700, John Larkin
wrote:

On Tue, 03 Jul 2007 07:37:11 -0500, J.P. wrote:

http://alytus.auksa.lt/esr/

Bizarre, complex, and doesn't actually measure ESR.

John
Take that up with the inventor

---
Why?

You're the one who posted it for no good reason.
You are full of ****...**** off asshole...


That's not nice! I hope you have your asbestos panties on, sweetie!
John LOVES flaming little idiots like you.
Your suck buddy?

On Wed, 04 Jul 2007 15:38:39 -0500, John Fields
wrote:

On Wed, 04 Jul 2007 19:23:23 GMT, J.P. wrote:

On Wed, 04 Jul 2007 08:00:14 -0500, John Fields
wrote:

On Tue, 03 Jul 2007 19:34:52 GMT, J.P. wrote:

On Tue, 03 Jul 2007 11:22:41 -0700, John Larkin
wrote:

On Tue, 03 Jul 2007 07:37:11 -0500, J.P. wrote:

http://alytus.auksa.lt/esr/

Bizarre, complex, and doesn't actually measure ESR.

John
Take that up with the inventor

---
Why?

You're the one who posted it for no good reason.
You are full of ****...

---
Really?

Why did you post it then?

No one asked you to and you provided no explanation with the post,
just a link to the graphic, so it's not like anyone cared about it
or even knew it was on the way.
---

**** off asshole...

---
Blow me.
Impossible..youre a bitch

On Wed, 04 Jul 2007 22:37:47 GMT, J.P. wrote:

On Wed, 04 Jul 2007 19:40:29 GMT, "Michael A. Terrell"
wrote:

"J.P." wrote:

On Wed, 04 Jul 2007 08:00:14 -0500, John Fields
wrote:

On Tue, 03 Jul 2007 19:34:52 GMT, J.P. wrote:

On Tue, 03 Jul 2007 11:22:41 -0700, John Larkin
wrote:

On Tue, 03 Jul 2007 07:37:11 -0500, J.P. wrote:

http://alytus.auksa.lt/esr/

Bizarre, complex, and doesn't actually measure ESR.

John
Take that up with the inventor

---
Why?

You're the one who posted it for no good reason.
You are full of ****...**** off asshole...


That's not nice! I hope you have your asbestos panties on, sweetie!
John LOVES flaming little idiots like you.
Your suck buddy?

---
Nope, but if you'd been around for a while you might have found that
Michael (even with his physical deformities) fixes broken PCs and
gives them to senior citizens, for free, in an effort to get them
computer literate.

And you?


--
JF

J.P. wrote:

On Wed, 04 Jul 2007 05:24:53 GMT, "Michael A. Terrell"
wrote:

"J.P." wrote:

On Tue, 03 Jul 2007 11:22:41 -0700, John Larkin
wrote:

On Tue, 03 Jul 2007 07:37:11 -0500, J.P.
wrote:
http://alytus.auksa.lt/esr/

Bizarre, complex, and doesn't actually measure ESR.

John
Take that up with the inventor


Inventor? Too bad he wasn't a designer.
It does measure ESR and is a viable citcuit. Best look again.Just
because you read some from Eyesore on the RAT group doen't mean it is
true...and disrespecting a well meaning vet doesn't do so much for
your position either...these USENET trolls can kiss amy ass...although
I am not gay like they are...

Actually that bridge is completely misconfigured. It won't measure
anything sensible *ever*. Now go ahead and tell us what you think it
does, and why.

- YD.


--

On Wed, 04 Jul 2007 22:38:13 GMT, J.P. wrote:

On Wed, 04 Jul 2007 15:38:39 -0500, John Fields
wrote:

On Wed, 04 Jul 2007 19:23:23 GMT, J.P. wrote:

On Wed, 04 Jul 2007 08:00:14 -0500, John Fields
wrote:

On Tue, 03 Jul 2007 19:34:52 GMT, J.P. wrote:

On Tue, 03 Jul 2007 11:22:41 -0700, John Larkin
wrote:

On Tue, 03 Jul 2007 07:37:11 -0500, J.P. wrote:

http://alytus.auksa.lt/esr/

Bizarre, complex, and doesn't actually measure ESR.

John
Take that up with the inventor

---
Why?

You're the one who posted it for no good reason.
You are full of ****...

---
Really?

Why did you post it then?

No one asked you to and you provided no explanation with the post,
just a link to the graphic, so it's not like anyone cared about it
or even knew it was on the way.
---

**** off asshole...

---
Blow me.
Impossible..youre a bitch

---
So you approve of the act, but not the gender?

That is, if I had a dick you'd be all over it, yes?


--
JF

"J.P." wrote:

On Wed, 04 Jul 2007 19:40:29 GMT, "Michael A. Terrell"
wrote:

"J.P." wrote:

On Wed, 04 Jul 2007 08:00:14 -0500, John Fields
wrote:

On Tue, 03 Jul 2007 19:34:52 GMT, J.P. wrote:

On Tue, 03 Jul 2007 11:22:41 -0700, John Larkin
wrote:

On Tue, 03 Jul 2007 07:37:11 -0500, J.P. wrote:

http://alytus.auksa.lt/esr/

Bizarre, complex, and doesn't actually measure ESR.

John
Take that up with the inventor

---
Why?

You're the one who posted it for no good reason.
You are full of ****...**** off asshole...


That's not nice! I hope you have your asbestos panties on, sweetie!
John LOVES flaming little idiots like you.
Your suck buddy?


See? You ARE GAY, and trolling for partners. What a pathetic liar
you are.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

"YD" wrote in message
...
J.P. wrote:

On Wed, 04 Jul 2007 05:24:53 GMT, "Michael A. Terrell"
wrote:

"J.P." wrote:

On Tue, 03 Jul 2007 11:22:41 -0700, John Larkin
wrote:

On Tue, 03 Jul 2007 07:37:11 -0500, J.P.
wrote:
http://alytus.auksa.lt/esr/

Bizarre, complex, and doesn't actually measure ESR.

John
Take that up with the inventor


Inventor? Too bad he wasn't a designer.
It does measure ESR and is a viable citcuit. Best look again.Just
because you read some from Eyesore on the RAT group doen't mean it is
true...and disrespecting a well meaning vet doesn't do so much for
your position either...these USENET trolls can kiss amy ass...although
I am not gay like they are...

Actually that bridge is completely misconfigured. It won't measure
anything sensible *ever*. Now go ahead and tell us what you think it
does, and why.

- YD.



Actually, the bridge is *not* misconfigured. If you think it is, please tell us
how it is misconfigured, and how it *should* be configured.

The capacitor under test is effectively in parallel with R16, the lower left
part of the bridge. The ESR of the capacitor will unbalance the bridge. The
unbalance is amplified by U1C, fed to U1D where it is rectified and filtered,
then measured by the meter.

That's my take on the operation.. now, please tell us why it doesn't measure
anything sensible, *ever*.

--
Dave M
MasonDG44 at comcast dot net (Just substitute the appropriate characters in the
address)

"In theory, there isn't any difference between theory and practice. In
practice, there is." - Yogi Berra

On Tue, 03 Jul 2007 19:44:04 GMT, Eeyore
wrote:



"J.P." wrote:

http://alytus.auksa.lt/esr/

You posted this crap here too ?

Maybe some kind person will provide a circuit that works.

Graham

Yikes, that circuit might measure impedance, but surely not ESR. That
would be a good design for students to nit-pick for a homework
assignment.

HP4194 or HP4195 work great for ESR measurements. Got those two
instruments sitting next to me. Still need to build up the interface
boxes to the 4195! I think we have the schematics of both boxes too.

---
Mark

On Thu, 05 Jul 2007 23:06:47 GMT, qrk wrote:

On Tue, 03 Jul 2007 19:44:04 GMT, Eeyore
wrote:



"J.P." wrote:

http://alytus.auksa.lt/esr/

You posted this crap here too ?

Maybe some kind person will provide a circuit that works.

Graham

Yikes, that circuit might measure impedance, but surely not ESR. That
would be a good design for students to nit-pick for a homework
assignment.

HP4194 or HP4195 work great for ESR measurements. Got those two
instruments sitting next to me. Still need to build up the interface
boxes to the 4195! I think we have the schematics of both boxes too.

---
Mark
The guy that designed it repairs Tek scopes for a hobby and many have
been built and used successfully already...those hillbillies don't
have a clue...go to thr Yahoo Tek scope repair group and ask them if
you have any doubts...

DaveM wrote:

"YD" wrote in message
...
J.P. wrote:

On Wed, 04 Jul 2007 05:24:53 GMT, "Michael A. Terrell"
wrote:

"J.P." wrote:

On Tue, 03 Jul 2007 11:22:41 -0700, John Larkin
wrote:

On Tue, 03 Jul 2007 07:37:11 -0500, J.P.
wrote:
http://alytus.auksa.lt/esr/

Bizarre, complex, and doesn't actually measure ESR.

John
Take that up with the inventor


Inventor? Too bad he wasn't a designer.
It does measure ESR and is a viable citcuit. Best look again.Just
because you read some from Eyesore on the RAT group doen't mean
it is true...and disrespecting a well meaning vet doesn't do so
much for your position either...these USENET trolls can kiss amy
ass...although I am not gay like they are...

Actually that bridge is completely misconfigured. It won't measure
anything sensible ever. Now go ahead and tell us what you think it
does, and why.

- YD.



Actually, the bridge is not misconfigured. If you think it is,
please tell us how it is misconfigured, and how it should be
configured.

The capacitor under test is effectively in parallel with R16, the
lower left part of the bridge. The ESR of the capacitor will
unbalance the bridge. The unbalance is amplified by U1C, fed to U1D
where it is rectified and filtered, then measured by the meter.

That's my take on the operation.. now, please tell us why it doesn't
measure anything sensible, ever.

Yes, my bad. At first glance it seemed the DUT was connected across the
bridge.

- YD.

--

On Fri, 06 Jul 2007 01:13:34 GMT, J.P. wrote:

On Thu, 05 Jul 2007 23:06:47 GMT, qrk wrote:

On Tue, 03 Jul 2007 19:44:04 GMT, Eeyore
wrote:



"J.P." wrote:

http://alytus.auksa.lt/esr/

You posted this crap here too ?

Maybe some kind person will provide a circuit that works.

Graham

Yikes, that circuit might measure impedance, but surely not ESR. That
would be a good design for students to nit-pick for a homework
assignment.

HP4194 or HP4195 work great for ESR measurements. Got those two
instruments sitting next to me. Still need to build up the interface
boxes to the 4195! I think we have the schematics of both boxes too.

---
Mark
The guy that designed it repairs Tek scopes for a hobby and many have
been built and used successfully already...those hillbillies don't
have a clue...go to thr Yahoo Tek scope repair group and ask them if
you have any doubts...

It doesn't measure ESR, it measures a sort of twisted/nonlinear/offset
version of total impedance. It probably will tell open electrolytic
caps from good ones, but the thing the needle indicates isn't ESR. For
very big C's with low ESL (ie, when Z is mostly ESR, and low ESR at
that) then it mostly measures ESR.

For a similar level of complexity, one could measure true ESR. Or for
a lot less complexity, one could measure what this thing measures.

John

"John Larkin" wrote in message
...


It doesn't measure ESR, it measures a sort of twisted/nonlinear/offset
version of total impedance. It probably will tell open electrolytic
caps from good ones, but the thing the needle indicates isn't ESR. For
very big C's with low ESL (ie, when Z is mostly ESR, and low ESR at
that) then it mostly measures ESR.

For a similar level of complexity, one could measure true ESR. Or for
a lot less complexity, one could measure what this thing measures.

John


Circuit please...

On Fri, 06 Jul 2007 02:54:06 GMT, "Lord Garth"
wrote:


"John Larkin" wrote in message
.. .


It doesn't measure ESR, it measures a sort of twisted/nonlinear/offset
version of total impedance. It probably will tell open electrolytic
caps from good ones, but the thing the needle indicates isn't ESR. For
very big C's with low ESL (ie, when Z is mostly ESR, and low ESR at
that) then it mostly measures ESR.

For a similar level of complexity, one could measure true ESR. Or for
a lot less complexity, one could measure what this thing measures.

John


Circuit please...


Something roughly like this, maybe. This is a 2-minute hack, so don't
jump all over it right away; a real design would take more time.
Basically, it's an oscillator that dumps current into the cap, and a
synchronous detector to remove most of the orthogonal component. It
ain't perfect, but should be a lot better than a scalar measurement.

John

"John Larkin" wrote in message
...
On Fri, 06 Jul 2007 02:54:06 GMT, "Lord Garth"
wrote:


"John Larkin" wrote in
message
.. .


It doesn't measure ESR, it measures a sort of twisted/nonlinear/offset
version of total impedance. It probably will tell open electrolytic
caps from good ones, but the thing the needle indicates isn't ESR. For
very big C's with low ESL (ie, when Z is mostly ESR, and low ESR at
that) then it mostly measures ESR.

For a similar level of complexity, one could measure true ESR. Or for
a lot less complexity, one could measure what this thing measures.

John


Circuit please...


Something roughly like this, maybe. This is a 2-minute hack, so don't
jump all over it right away; a real design would take more time.
Basically, it's an oscillator that dumps current into the cap, and a
synchronous detector to remove most of the orthogonal component. It
ain't perfect, but should be a lot better than a scalar measurement.

John



Thank You...

On Fri, 06 Jul 2007 02:54:06 GMT, "Lord Garth" wrote:


"John Larkin" wrote in message
.. .


It doesn't measure ESR, it measures a sort of twisted/nonlinear/offset
version of total impedance. It probably will tell open electrolytic
caps from good ones, but the thing the needle indicates isn't ESR. For
very big C's with low ESL (ie, when Z is mostly ESR, and low ESR at
that) then it mostly measures ESR.

For a similar level of complexity, one could measure true ESR. Or for
a lot less complexity, one could measure what this thing measures.

John


Circuit please...

This is the same circuit:

http://www.qsl.net/iz7ath/web/02_bre..._esr/index.htm

and here's the schematic:

http://www.qsl.net/iz7ath/web/02_bre..._esr/fig03.gif

The key to understanding how this operates is to note that a square wave is
applied to the bridge. If a capacitor with zero ESR is connected to the
DUT terminals, the output from the bridge will be only some tiny (area)
spikes occurring at the edges of the input square wave. If the DUT has a
non-zero ESR, then the bridge output will have a square wave component
proportional to the ESR value, and this will deflect the meter.

"The Phantom" wrote in message


This is the same circuit:

http://www.qsl.net/iz7ath/web/02_bre..._esr/index.htm

and here's the schematic:

http://www.qsl.net/iz7ath/web/02_bre..._esr/fig03.gif

The key to understanding how this operates is to note that a square
wave is applied to the bridge.

The wave is on the positive side, so why have a split supply? In fact the
negative side doesn't seem to be used anywhere.


If a capacitor with zero ESR is
connected to the DUT terminals, the output from the bridge will be
only some tiny (area) spikes occurring at the edges of the input
square wave.

The tinyness of the spikes depends on C. I think an ESR meter should ignore
C.


If the DUT has a non-zero ESR, then the bridge output
will have a square wave component proportional to the ESR value, and
this will deflect the meter.

--

Reply in group, but if emailing add another
zero, and remove the last word.

On Thu, 05 Jul 2007 21:25:46 -0700, The Phantom
wrote:

On Fri, 06 Jul 2007 02:54:06 GMT, "Lord Garth" wrote:


"John Larkin" wrote in message
. ..


It doesn't measure ESR, it measures a sort of twisted/nonlinear/offset
version of total impedance. It probably will tell open electrolytic
caps from good ones, but the thing the needle indicates isn't ESR. For
very big C's with low ESL (ie, when Z is mostly ESR, and low ESR at
that) then it mostly measures ESR.

For a similar level of complexity, one could measure true ESR. Or for
a lot less complexity, one could measure what this thing measures.

John


Circuit please...

This is the same circuit:

http://www.qsl.net/iz7ath/web/02_bre..._esr/index.htm

and here's the schematic:

http://www.qsl.net/iz7ath/web/02_bre..._esr/fig03.gif

The key to understanding how this operates is to note that a square wave is
applied to the bridge. If a capacitor with zero ESR is connected to the
DUT terminals, the output from the bridge will be only some tiny (area)
spikes occurring at the edges of the input square wave. If the DUT has a
non-zero ESR, then the bridge output will have a square wave component
proportional to the ESR value, and this will deflect the meter.

Technically true, except that it measures impedance, not ESR. And it's
a lot more complex than it needs to be. It will tell the difference
between open electrolytics and good ones, at least for large C values.

And it's not "proportional to the ESR value" except under a narrow set
of conditions.

John

On Wed, 04 Jul 2007 08:49:16 -0500, J.P. wrote:

On Wed, 04 Jul 2007 05:24:53 GMT, "Michael A. Terrell"
wrote:

"J.P." wrote:

On Tue, 03 Jul 2007 11:22:41 -0700, John Larkin
wrote:

On Tue, 03 Jul 2007 07:37:11 -0500, J.P. wrote:

http://alytus.auksa.lt/esr/

Bizarre, complex, and doesn't actually measure ESR.

John
Take that up with the inventor


Inventor? Too bad he wasn't a designer.
It does measure ESR and is a viable citcuit. Best look again.Just
because you read some from Eyesore on the RAT group doen't mean it is
true...and disrespecting a well meaning vet doesn't do so much for
your position either...


An Italian veteran?

It's surprising how common schematic plagiarism is.

John

"J.P." wrote:

On Wed, 04 Jul 2007 05:24:53 GMT, "Michael A. Terrell"
wrote:

"J.P." wrote:

On Tue, 03 Jul 2007 11:22:41 -0700, John Larkin
wrote:

On Tue, 03 Jul 2007 07:37:11 -0500, J.P. wrote:

http://alytus.auksa.lt/esr/

Bizarre, complex, and doesn't actually measure ESR.

John
Take that up with the inventor


Inventor? Too bad he wasn't a designer.
It does measure ESR and is a viable citcuit. Best look again.Just
because you read some from Eyesore on the RAT group


Me subscribe to RetentiveAssholes(with a hardon for)Tubes? You're
out of your ever loving mind, Jane.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

On Fri, 06 Jul 2007 07:04:58 -0700, John Larkin
wrote:

On Thu, 05 Jul 2007 21:25:46 -0700, The Phantom
wrote:

On Fri, 06 Jul 2007 02:54:06 GMT, "Lord Garth" wrote:


"John Larkin" wrote in message
...


It doesn't measure ESR, it measures a sort of twisted/nonlinear/offset
version of total impedance. It probably will tell open electrolytic
caps from good ones, but the thing the needle indicates isn't ESR. For
very big C's with low ESL (ie, when Z is mostly ESR, and low ESR at
that) then it mostly measures ESR.

For a similar level of complexity, one could measure true ESR. Or for
a lot less complexity, one could measure what this thing measures.

John


Circuit please...

This is the same circuit:

http://www.qsl.net/iz7ath/web/02_bre..._esr/index.htm

and here's the schematic:

http://www.qsl.net/iz7ath/web/02_bre..._esr/fig03.gif

The key to understanding how this operates is to note that a square wave is
applied to the bridge. If a capacitor with zero ESR is connected to the
DUT terminals, the output from the bridge will be only some tiny (area)
spikes occurring at the edges of the input square wave. If the DUT has a
non-zero ESR, then the bridge output will have a square wave component
proportional to the ESR value, and this will deflect the meter.

Technically true, except that it measures impedance, not ESR. And it's
a lot more complex than it needs to be. It will tell the difference
between open electrolytics and good ones, at least for large C values.

And it's not "proportional to the ESR value" except under a narrow set
of conditions.

John

I agree. It's rude, it's crude and it "sorta" works. I think this other
one: http://www.ludens.cl/Electron/esr/esr.html might work somewhat better.

It occurred to me that if one were to connect a "known good" capacitor
(low ESR, in other words) of about the same value across the other bottom
leg of the bridge (and maybe drive the bridge with a sine wave), then you
would get a fairly good indication of ESR. This could be a cheap fixture
when testing a bunch of caps for ESR, say on incoming inspection.

It also occurred to me that if one's purpose were to test electrolytics to
be used in 60 Hz power supplies, perhaps another technique might be
workable.

Use a sine wave source of, say, 1kHz to 10kHz. Wire up an opamp based
impedance converter to synthesize a negative resistance. Let an ordinary
potientiometer be the resistance that is converted (one-to-one) to a
negative resistance. Place the capacitor under test in series with the
negative resistor and drive the combination with a low impedance sine wave
source. Measure the current through the combination and dial the
potentiometer around until the current is maximized. The resistance of the
potentiometer is then equal to the ESR of the cap.

A negative resistance could be synthesized in the kilohertz range easily.
This could even work at higher frequencies if the impedance converter is
made to work ok.

John Larkin wrote:

The key to understanding how this operates is to note that a
square wave is applied to the bridge. If a capacitor with zero
ESR is connected to the DUT terminals, the output from the bridge
will be only some tiny (area) spikes occurring at the edges of
the input square wave. If the DUT has a non-zero ESR, then the
bridge output will have a square wave component proportional to
the ESR value, and this will deflect the meter.

Technically true, except that it measures impedance, not ESR. And
it's a lot more complex than it needs to be. It will tell the
difference between open electrolytics and good ones, at least for
large C values.

And it's not "proportional to the ESR value" except under a narrow
set of conditions.

John

Poor terminology - impedance is measured with a sine wave, not a
square wave. A square wave gives a triangular ripple voltage across
a capacitor:

dv = I * dt / C

If the test frequency is high enough (100KHz), the ripple voltage is
negligible compared to the ESR for most electrolytic capacitors of
interest.

Your circuit applies a high frequency square wave to the capacitor
under test, removes the DC component, and rectifies the result. The
output is the current times the Equivalent Series Resistance (ESR)
times the gain.

The circuits shown at

http://www.qsl.net/iz7ath/web/02_bre..._esr/index.htm

and

http://alytus.auksa.lt/esr/esr_meter_schematic.pdf

apply a 100KHz square wave to the capacitor under test, remove the
dc component, and rectify the result. The output is the current
times the ESR times the gain.

All three circuits do the same thing. Your disparaging comments and
criticisms are inaccurate, unwarranted, and apply to your circuit
also.

Part of the complexity of the original is due to accomplishing all
the functions in a single IC, a TL084. The circuit could be
simplified somewhat by using a more modern rail-to-rail op amp and
by removing a few superfluous components.

Your circuit requires three different ic's: a Schmidt inverter for
the oscillator, an op amp, and a cmos switch.

Your circuit omits the input protection diodes in the event a fully
charged capacitor is inadvertently applied to the tester. This is
not the best solution, since the current from a large capacitor may
destroy the diodes, or it may damage the capacitor itself. But the
input protection is definitely needed, and a slightly more complex
circuit would provide much better protection without risk of damage.

Perhaps the most important flaw is your circuit would give a low ESR
reading with a shorted capacitor, indicating the capacitor is good
and can be used in a circuit. This would cause the circuit to fail
to operate properly, and may damage the circuit.

The original circuit provides a warning LED to show the capacitor is
shorted. Here is the text. See item #3:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~
The project came from an italian magazine (Nuova Elettronica N212);

It's very simple but interesting; I've built it and tested some
capacitors, so I think it's very useful: build it; It measures the
ESR (Equivalent Serie Resistance) of capacitor (electrolytic and
not); pratically you can see if a capacitor is good or not.

It's a bridge circuit that work at 100Khz; there're the following
possibilities:

1) The electrolytic capacitor is good: (low ESR) the bridge will
stay balanced and the meter will indicate the maximun current.

2) The electrolytic capacitor is not good: (high ESR) the bridge
will be unbalanced and that will cause the meter to indicate less
current; as less the meter will indicate as higher will be the ESR;
After few measure you'll be able to decide if a capacitor is good or
not.

3) There is a short circuit in the electrolytic capacitor: the meter
will indicate the maximum current and the red LED will lamp;
capacitor is not good.

4) The electrolytic capacitor is broken: the meter will not move.
Capacitor is not good.

http://www.qsl.net/iz7ath/web/02_bre..._esr/index.htm

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~
The original circuit is functional and provides very important
features that your circuit lacks. It needs a little better input
protection which could be easily added.

Of course, that would make the circuit a bit more complicated

Regards,

Mike Monett

Mike Monett wrote:

The original circuit is functional and provides very important
features that your circuit lacks.

I almost forgot. The original circuit applies a maximum of 0.1V peak
to the capacitor under test. This is low enough so the polarity is
not important. It will not turn on semiconductor junctions, so most
capacitors may be tested in-circuit.

Your version applies 2.5VDC to the capacitor. This means the cap
must be unsoldered from the circuit, tested, then re-soldered back
in the circuit. This takes time and risks damage to the cap and pcb.

Also, the 2.5VDC means the user must observe polarity on low-voltage
caps. This adds complexity and increases the difficulty of use.

These are significant design flaws.

Regards,

Mike Monett

"John Larkin" wrote in message
...
On Fri, 06 Jul 2007 02:54:06 GMT, "Lord Garth"
wrote:


"John Larkin" wrote in
message
.. .


It doesn't measure ESR, it measures a sort of twisted/nonlinear/offset
version of total impedance. It probably will tell open electrolytic
caps from good ones, but the thing the needle indicates isn't ESR. For
very big C's with low ESL (ie, when Z is mostly ESR, and low ESR at
that) then it mostly measures ESR.

For a similar level of complexity, one could measure true ESR. Or for
a lot less complexity, one could measure what this thing measures.

John


Circuit please...


Something roughly like this, maybe. This is a 2-minute hack, so don't
jump all over it right away; a real design would take more time.
Basically, it's an oscillator that dumps current into the cap, and a
synchronous detector to remove most of the orthogonal component. It
ain't perfect, but should be a lot better than a scalar measurement.

John


This was built along similar lines. The synchronous rectification is not
perfect due to phase shift in the forward signal path but the arrangement is
useful for reducing the annoying capacitive quadrature component from Q's up
to about 3 (at the 100kHz). It's usable down to the milliohm area and proved
the (cheap) 1000 off 10uF cap's I bought, had an ESR of between 1 and 3
ohms!.
OTOH, the very expensive "BC" 10,000uF 63V caps I used on a job had an ESR
of 5m ohm. 'Spose you get what you pay for.





--
Posted via a free Usenet account from http://www.teranews.com

On Fri, 06 Jul 2007 08:26:13 -0700, John Larkin
wrote:

On Wed, 04 Jul 2007 08:49:16 -0500, J.P. wrote:

On Wed, 04 Jul 2007 05:24:53 GMT, "Michael A. Terrell"
wrote:

"J.P." wrote:

On Tue, 03 Jul 2007 11:22:41 -0700, John Larkin
wrote:

On Tue, 03 Jul 2007 07:37:11 -0500, J.P. wrote:

http://alytus.auksa.lt/esr/

Bizarre, complex, and doesn't actually measure ESR.

John
Take that up with the inventor


Inventor? Too bad he wasn't a designer.
It does measure ESR and is a viable citcuit. Best look again.Just
because you read some from Eyesore on the RAT group doen't mean it is
true...and disrespecting a well meaning vet doesn't do so much for
your position either...


An Italian veteran?

It's surprising how common schematic plagiarism is.

John
It's surprising how many total assholes stand on quicksand and defend
their position even when proven wrong because they are not man enough
to admit they went off half cocked or in your lover's case - Hanoy
Terril - half pussed...C'ya losers...

"john jardine" wrote:

John Larkin wrote:

Something roughly like this, maybe. This is a 2-minute hack, so
don't jump all over it right away; a real design would take more
time.

Basically, it's an oscillator that dumps current into the cap,
and a synchronous detector to remove most of the orthogonal
component. It ain't perfect, but should be a lot better than a
scalar measurement.

John

This was built along similar lines. The synchronous rectification
is not perfect due to phase shift in the forward signal path but
the arrangement is useful for reducing the annoying capacitive
quadrature component from Q's up to about 3 (at the 100kHz). It's
usable down to the milliohm area and proved the (cheap) 1000 off
10uF cap's I bought, had an ESR of between 1 and 3 ohms!.

Hi John,

Do you mind if I make some comments? The 1 ohm resistor, R5, can be
removed from the circuit. It is at a virtual ground node and has
little or no voltage across it. So removing it has little effect on
the circuit.

With R5 gone, and the ESR range switch in the 1 ohm position, the
180 ohm resistor, R4, is effectively in series with the capacitor
under test. The op amp merely changes the location of the ground
node, and inverts the output signal polarity.

Since R4 (180 ohms) is now in series with the capacitor, it
completely swamps out the internal ESR (0.05 ohms.) This means the
series combination of C, L, and R has negligible "Q", and there is
no quadrature or orthogonal component in the circuit.

However, as the ESR decreases, the corresponding voltage drop that
we are trying to measure also decreases. We no are faced with the
problem that the di/dt from the inductor is much larger than the I*R
drop from the ESR. This means the leading and trailing edge of the
square wave have large spikes.

If you used a diode peak detector to measure the amplitude, it would
respond as best it could to the leading edge spike, which would make
it impossible to measure the drop across the ESR. Your circuit and
Larkin's share this problem.

Using a synchronous rectifier helps a bit, but you are now faced
with trying to turn it on after the leading edge spike, and to turn
it off before the trailing edge spike. That could be tricky.

I spent this afternoon looking at these problems in SPICE, and have
come to an amazing observation. There is a hidden but very
significant feature in the bridge ESR circuit referred to at the
beginning of this thread. The links a

1. Talino Tribuzio's page, showing the circuit from Nuova
Elettronica:

http://www.qsl.net/iz7ath/web/02_bre..._esr/index.htm

2. Gintaras' web page, who refers to Tribuzio's page in his readme

http://alytus.auksa.lt/esr/

The schematic is at

http://alytus.auksa.lt/esr/esr_meter_schematic.pdf

The valuable hidden feature is the bridge configuration completely
eliminates the leading and trailing edge spikes due to the capacitor
internal inductance. Since the spikes are in phase with the square
wave signal on the other side of the bridge, they simply disappear
at the output of the op amp!

This means the peak detector has a very clean square wave to work
with, and it can give a much more accurate measurement of the
signal. There is no tricky timing to fiddle with that can go out of
whack just when you need to use the tester.

If you like, I can post the analysis of your circuit and Larkin's
version showing the huge spikes that appear as the ESR becomes
smaller, and the triangular wave from the capacitance charging and
discharging. I don't really see a good way of overcoming these
problems.

As I mentioned in previous posts, the bridge circuit has significant
advantages, including low test voltage, in-circuit test, shorted
capacitor detect, etc. With the extremely clean output signal into
the peak detector, it becomes the obvious choice for hassle-free ESR
measurements.

I'll post the LTspice ASC file here along with the PLT file so you
can see how it works. I changed the bridge resistance to lower
values to allow measuring lower values of ESR.

Here's the LTspice ASC file:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~
Version 4
SHEET 1 880 708
WIRE -496 -112 -528 -112
WIRE -368 -112 -416 -112
WIRE -304 -112 -368 -112
WIRE -192 -112 -224 -112
WIRE -368 -96 -368 -112
WIRE -128 -80 -160 -80
WIRE -48 -64 -64 -64
WIRE -720 -48 -816 -48
WIRE -704 -48 -720 -48
WIRE -592 -48 -624 -48
WIRE -528 -48 -528 -112
WIRE -528 -48 -592 -48
WIRE -368 -48 -528 -48
WIRE -192 -48 -192 -112
WIRE -192 -48 -288 -48
WIRE -128 -48 -192 -48
WIRE -816 -32 -816 -48
WIRE -160 0 -160 -80
WIRE -160 0 -240 0
WIRE 128 16 96 16
WIRE 224 32 192 32
WIRE 240 32 224 32
WIRE 336 32 304 32
WIRE -528 48 -592 48
WIRE -240 48 -240 0
WIRE -240 48 -448 48
WIRE -224 48 -240 48
WIRE -96 48 -144 48
WIRE -48 48 -48 -64
WIRE -48 48 -96 48
WIRE 32 48 16 48
WIRE 128 48 32 48
WIRE -816 64 -816 48
WIRE 32 128 32 48
WIRE -720 144 -720 -48
WIRE -704 144 -720 144
WIRE -592 144 -592 48
WIRE -592 144 -624 144
WIRE -512 144 -592 144
WIRE -416 144 -448 144
WIRE -304 144 -336 144
WIRE -192 144 -224 144
WIRE -592 160 -592 144
WIRE -192 160 -192 144
WIRE 96 176 96 16
WIRE 208 176 96 176
WIRE 336 176 336 32
WIRE 336 176 208 176
WIRE 208 192 208 176
WIRE 336 208 336 176
WIRE 32 224 32 208
WIRE -592 256 -592 240
WIRE -464 272 -480 272
WIRE -432 272 -464 272
WIRE -272 272 -288 272
WIRE -240 272 -272 272
WIRE -480 288 -480 272
WIRE -288 288 -288 272
WIRE 208 288 208 272
WIRE 336 288 336 272
WIRE -480 384 -480 368
WIRE -288 384 -288 368
FLAG -96 48 DIFF
FLAG -592 256 0
FLAG -192 160 0
FLAG -816 64 0
FLAG -368 -96 0
FLAG -592 -48 E2P
FLAG -592 48 E2N
FLAG 32 224 0
FLAG 336 288 0
FLAG 208 288 0
FLAG 336 32 DC
FLAG -480 384 0
FLAG -464 272 VCC
FLAG -288 384 0
FLAG -272 272 VEE
FLAG 224 32 VOP
FLAG 32 48 VIN
FLAG 160 0 VCC
FLAG 160 64 VEE
FLAG -96 -96 VCC
FLAG -96 -32 VEE
SYMBOL res -608 144 R0
SYMATTR InstName R8
SYMATTR Value {Rb}
SYMBOL res -608 128 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R9
SYMATTR Value {Rt}
SYMBOL cap -448 128 R90
WINDOW 0 0 32 VBottom 0
WINDOW 3 32 32 VTop 0
SYMATTR InstName C3
SYMATTR Value {C}
SYMBOL res -320 128 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R10
SYMATTR Value {ERS}
SYMBOL ind -320 160 R270
WINDOW 0 32 56 VTop 0
WINDOW 3 5 56 VBottom 0
SYMATTR InstName L3
SYMATTR Value {L}
SYMBOL Voltage -816 -48 R0
WINDOW 0 42 44 Left 0
WINDOW 3 -22 -62 Left 0
WINDOW 123 15 130 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value PULSE(0 4 0 {Tr} {Tr} 5u 10u)
SYMBOL res -608 -64 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R5
SYMATTR Value {Rt}
SYMBOL res -512 -96 R270
WINDOW 0 32 56 VTop 0
WINDOW 3 0 56 VBottom 0
SYMATTR InstName R11
SYMATTR Value {Rb}
SYMBOL res -320 -96 R270
WINDOW 0 32 56 VTop 0
WINDOW 3 0 56 VBottom 0
SYMATTR InstName R12
SYMATTR Value 47k
SYMBOL res -384 -32 R270
WINDOW 0 32 56 VTop 0
WINDOW 3 0 56 VBottom 0
SYMATTR InstName R13
SYMATTR Value 1k
SYMBOL res -544 64 R270
WINDOW 0 32 56 VTop 0
WINDOW 3 0 56 VBottom 0
SYMATTR InstName R14
SYMATTR Value 1k
SYMBOL res -240 64 R270
WINDOW 0 32 56 VTop 0
WINDOW 3 0 56 VBottom 0
SYMATTR InstName R15
SYMATTR Value 47k
SYMBOL cap 16 32 R90
WINDOW 0 0 32 VBottom 0
WINDOW 3 32 32 VTop 0
SYMATTR InstName C4
SYMATTR Value 2n
SYMBOL res 16 112 R0
SYMATTR InstName R16
SYMATTR Value 47k
SYMBOL diode 240 48 R270
WINDOW 0 32 32 VTop 0
WINDOW 3 0 32 VBottom 0
SYMATTR InstName D1
SYMATTR Value 1N4148
SYMBOL cap 320 208 R0
SYMATTR InstName C5
SYMATTR Value 2nf
SYMBOL res 192 176 R0
SYMATTR InstName R17
SYMATTR Value 470k
SYMBOL Opamps\\1pole 160 32 R0
SYMATTR InstName U1
SYMATTR Value2 Avol=1Meg GBW=100Meg Slew=100Meg
SYMBOL Voltage -480 272 R0
WINDOW 0 42 44 Left 0
WINDOW 3 47 72 Left 0
WINDOW 123 15 130 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V2
SYMATTR Value 10
SYMBOL Voltage -288 384 R180
WINDOW 0 42 44 Left 0
WINDOW 3 47 72 Left 0
WINDOW 123 15 130 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V3
SYMATTR Value 10
SYMBOL Opamps\\1pole -96 -64 R0
SYMATTR InstName U2
SYMATTR Value2 Avol=1Meg GBW=100Meg Slew=100Meg
TEXT -528 -224 Left 0 ;'Tribuzio Bridge ESR Circuit
TEXT -528 -184 Left 0 !.tran 0 2.2m 2m 100n
TEXT 32 -200 Left 0 !.param C = 100uF\n.param L = 2.533E-08\n.param ERS =
0.00005\n.param Rt = 100\n.param Rb = 1\n.param Tr = 100n

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~

Here's the PLT file:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~
[Transient Analysis]
{
Npanes: 3
Active Pane: 1
{
traces: 1 {268959746,0,"V(dc)"}
X: ('µ',0,0,2e-005,0.0002)
Y[0]: (' ',3,0,0.003,1)
Y[1]: ('_',0,1e+308,0,-1e+308)
Volts: (' ',0,0,0,0,0.003,1)
Log: 0 0 0
GridStyle: 1
},
{
traces: 1 {268959747,0,"V(diff)"}
X: ('µ',0,0,2e-005,0.0002)
Y[0]: (' ',1,-1,0.2,1)
Y[1]: ('_',0,1e+308,0,-1e+308)
Volts: (' ',0,0,2,-1,0.2,1)
Log: 0 0 0
GridStyle: 1
},
{
traces: 1 {268959748,0,"V(e2n)"}
X: ('µ',0,0,2e-005,0.0002)
Y[0]: ('m',0,0,0.002,0.04)
Y[1]: ('_',0,1e+308,0,-1e+308)
Volts: ('m',0,0,0,0,0.002,0.04)
Log: 0 0 0
GridStyle: 1
}
}

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~
Regards,

Mike Monett

"J.P." wrote:

On Fri, 06 Jul 2007 08:26:13 -0700, John Larkin
wrote:

On Wed, 04 Jul 2007 08:49:16 -0500, J.P. wrote:

On Wed, 04 Jul 2007 05:24:53 GMT, "Michael A. Terrell"
wrote:

"J.P." wrote:

On Tue, 03 Jul 2007 11:22:41 -0700, John Larkin
wrote:

On Tue, 03 Jul 2007 07:37:11 -0500, J.P. wrote:

http://alytus.auksa.lt/esr/

Bizarre, complex, and doesn't actually measure ESR.

John
Take that up with the inventor


Inventor? Too bad he wasn't a designer.
It does measure ESR and is a viable citcuit. Best look again.Just
because you read some from Eyesore on the RAT group doen't mean it is
true...and disrespecting a well meaning vet doesn't do so much for
your position either...


An Italian veteran?

It's surprising how common schematic plagiarism is.

John
It's surprising how many total assholes stand on quicksand and defend
their position even when proven wrong because they are not man enough
to admit they went off half cocked or in your lover's case - Hanoy
Terril - half pussed...C'ya losers...


Its obvious who the pussy is, jane. That rolled up sock in your pants
and the paintred on facial hair doesn't make you a man.


Once again, your "freind" didn't invent the ESR meter.

Title:Method and apparatus for testing electrolytic capacitors Document
Type and Number:United States Patent 4216424 Link to this
page:http://www.freepatentsonline.com/4216424.html Abstract:An
Equivalent Series Resistance (ESR) measurement device for testing
electrolytic capacitors without removing the test capacitor from the
circuit in which it is being used and without first discharging the test
capacitor prior to testing. A low voltage AC ohmmeter, which operates at
a frequency of approximately 100 KHz, is used as the measurement device
for the in-circuit testing of the ESR and thus as an indication of the
status or usability of the electrolytic capacitor being tested. A
current-blocking capacitor is placed in series with the electrolytic
capacitor being tested to allow in-circuit testing without damaging the
meter since it blocks any DC charge remaining on the test capacitor. A
pair of oppositely poled diodes are coupled in parallel across the
terminals of the meter to protect the meter from surge currents and the
like and a resistor is coupled in parallel with the test capacitor to
provide a discharge path for discharging the series blocking capacitor
when the electrolytic capacitor is removed from testing. The ESR meter
itself is designed with two operational amplifiers forming an oscillator
whose output is relatively immune from fluctuations in supply voltage.
An amplifier network including three operational amplifiers is provided
to amplify the ESR signal to a usable level. A peak-to-peak detector
circuit is used which employs an operational amplifier having a
supplemental feedback resistor which reduces the phase shift at the
output of the operational amplifier to enable the peak detector diodes
to perform their conventional functions. The two outputs of the peak
detector are connected to two DC amplifiers and a conventional meter
movement is driven differentially by the DC amplifiers to provide a
visual readout of the measured ESR of the test capacitor for evaluation
purposes and the like.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

On Mon, 09 Jul 2007 08:36:56 GMT, "Michael A. Terrell"
wrote:

"J.P." wrote:

On Fri, 06 Jul 2007 08:26:13 -0700, John Larkin
wrote:

On Wed, 04 Jul 2007 08:49:16 -0500, J.P. wrote:

On Wed, 04 Jul 2007 05:24:53 GMT, "Michael A. Terrell"
wrote:

"J.P." wrote:

On Tue, 03 Jul 2007 11:22:41 -0700, John Larkin
wrote:

On Tue, 03 Jul 2007 07:37:11 -0500, J.P. wrote:

http://alytus.auksa.lt/esr/

Bizarre, complex, and doesn't actually measure ESR.

John
Take that up with the inventor


Inventor? Too bad he wasn't a designer.
It does measure ESR and is a viable citcuit. Best look again.Just
because you read some from Eyesore on the RAT group doen't mean it is
true...and disrespecting a well meaning vet doesn't do so much for
your position either...


An Italian veteran?

It's surprising how common schematic plagiarism is.

John
It's surprising how many total assholes stand on quicksand and defend
their position even when proven wrong because they are not man enough
to admit they went off half cocked or in your lover's case - Hanoy
Terril - half pussed...C'ya losers...


Its obvious who the pussy is, jane. That rolled up sock in your pants
and the paintred on facial hair doesn't make you a man.


Once again, your "freind" didn't invent the ESR meter.

Title:Method and apparatus for testing electrolytic capacitors Document
Type and Number:United States Patent 4216424 Link to this
page:http://www.freepatentsonline.com/4216424.html Abstract:An
Equivalent Series Resistance (ESR) measurement device for testing
electrolytic capacitors without removing the test capacitor from the
circuit in which it is being used and without first discharging the test
capacitor prior to testing. A low voltage AC ohmmeter, which operates at
a frequency of approximately 100 KHz, is used as the measurement device
for the in-circuit testing of the ESR and thus as an indication of the
status or usability of the electrolytic capacitor being tested. A
current-blocking capacitor is placed in series with the electrolytic
capacitor being tested to allow in-circuit testing without damaging the
meter since it blocks any DC charge remaining on the test capacitor. A
pair of oppositely poled diodes are coupled in parallel across the
terminals of the meter to protect the meter from surge currents and the
like and a resistor is coupled in parallel with the test capacitor to
provide a discharge path for discharging the series blocking capacitor
when the electrolytic capacitor is removed from testing. The ESR meter
itself is designed with two operational amplifiers forming an oscillator
whose output is relatively immune from fluctuations in supply voltage.
An amplifier network including three operational amplifiers is provided
to amplify the ESR signal to a usable level. A peak-to-peak detector
circuit is used which employs an operational amplifier having a
supplemental feedback resistor which reduces the phase shift at the
output of the operational amplifier to enable the peak detector diodes
to perform their conventional functions. The two outputs of the peak
detector are connected to two DC amplifiers and a conventional meter
movement is driven differentially by the DC amplifiers to provide a
visual readout of the measured ESR of the test capacitor for evaluation
purposes and the like.
You legal bunch of mumbo jumbo fails to prove anything to me. I simply
posted a goddamn schematic in a binary news group for the users there
to look at and maybe use and you and your gay sock puppet buddy have
gone on the attack for no reason. If you were half as intelligent as
you try and protray, you would know that the spirit of this posted
file was not intended to waste bandwidth with blowhard facts and mean
spirited abuses. And you are supposedly from the south? Where is your
graciousness Mr. Jackass? You have none. So you are that occassional
chick**** minded asshole that was the latrine maintence private with a
**** attitude and scowl to match. Take your hate and gay sockpuppet
and stuff them both up your sloppy ass dickweed. Suck down another 12
pack and make up 12 more reasons why the government ****ed you around
in the war and why you are now justified blaming everyone else for
your self created misery. Maybe you can cheat your rock star whore out
of another rock and feel like a hero again...see ya superfly...buzz
off

On Sun, 8 Jul 2007 12:27:49 +0100, "john jardine"
wrote:


"John Larkin" wrote in message
.. .
On Fri, 06 Jul 2007 02:54:06 GMT, "Lord Garth"
wrote:


"John Larkin" wrote in
message
.. .


It doesn't measure ESR, it measures a sort of twisted/nonlinear/offset
version of total impedance. It probably will tell open electrolytic
caps from good ones, but the thing the needle indicates isn't ESR. For
very big C's with low ESL (ie, when Z is mostly ESR, and low ESR at
that) then it mostly measures ESR.

For a similar level of complexity, one could measure true ESR. Or for
a lot less complexity, one could measure what this thing measures.

John


Circuit please...


Something roughly like this, maybe. This is a 2-minute hack, so don't
jump all over it right away; a real design would take more time.
Basically, it's an oscillator that dumps current into the cap, and a
synchronous detector to remove most of the orthogonal component. It
ain't perfect, but should be a lot better than a scalar measurement.

John


This was built along similar lines. The synchronous rectification is not
perfect due to phase shift in the forward signal path but the arrangement is
useful for reducing the annoying capacitive quadrature component from Q's up
to about 3 (at the 100kHz). It's usable down to the milliohm area and proved
the (cheap) 1000 off 10uF cap's I bought, had an ESR of between 1 and 3
ohms!.
OTOH, the very expensive "BC" 10,000uF 63V caps I used on a job had an ESR
of 5m ohm. 'Spose you get what you pay for.


The problem with all these circuits is the simplicity of the meter
needle: it can't untangle the inductive, capacitive, and resistive
components. If I were routinely repairing stuff that may have bad
caps, I'd build a scope probe that injected a square wave current into
the tip and displayed the result on the scope, with switchable
frequency between, say, 1 KHz and 100 KHz. The scope vertical gain
switch adds a lot of rangeability. This could be useful for all sorts
of things, not just caps. Diodes, too!



--- esl
/\ --------
/ \ /
/ \ ------- slope = 1/C
/ \ /
/ ------ -- esr
-----------


John