Electrolytic ESR verus temperature test

[tuinkabouter]

On 7/8/2013 4:36 PM, Arfa Daily wrote:

"Phil Allison" <phil_a@tpg.com.au> wrote in message
news:b3uqfmFc5lbU1@mid.individual.net...

"Arfa Daily"
"Phil Allison"

** Would you be thinking of low value electros ( like 1 or 2.2 uF at
400V ) that are used to " kick start" SMPS ?

I was thinking more the typical 47uF 35v ones that hang across the
supply pin to the controller IC,

** Like the UC3842N ?

Yes, that series of IC. There are quite a few UC38xx chips about



see so many caps in that position that are high ESR and stop the
supply from starting, that I order them fifty at a time.

** So you are doing warranty work on home studio powered speakers that
run 24/7 ?

I do work for several hifi shops, and see quite a few powered subs, some
of which have switchers in them, and suffer from caps, but I also do a
fair bit of work on other items that are powered 24/7 like DVD players /
home cinema systems and set top boxes.


And one particular supply that I repair lots of for a company, has
the Yellow Glue syndrome as well, and where is it ? Yep, all around
the base of that same 47uF cap ...

** The PSU board in the " Alesis M1 Active" - right ?

The actual one that I was thinking of is from a commercial hot drinks
machine. The company that sends me them, has them rented out into
workplaces and takeaways and educational establishments all over the
country, so there's never any shortage of them for repair. It has a
small vertical sub-pcb that has the switch mode controller and driver on
it. The 47uF is laid over on its side, and then fixed to the board with
the dreaded yellow glue. The actual mix of faults is about 50 / 50. If
the glue has started to go brown, chances are that's the primary
problem, and the cap is actually ok, reading normally on the ESR meter.
If the glue hasn't gone yellow, then most times, the cap reads bad. But
to be honest, whether it's actually cap or glue, I always just go ahead
and remove the cap, clean up the board, and then fit a new cap. They are
so cheap, it's not worth doing anything else and risking it bouncing a
couple of months later.

Where the problem is not due to bad electros at all.

But a 2W resistor that almost touches the cap and heats it to a high
temp for 8,760 hours per year.

Yes, I've never understood this. It seems to be almost a 'design rule'
that any electrolytic should be mounted as close to a heat source on the
PCB as possible ... Anyone in the repair business knows that this is
going to lead to problems after not too long a life. If I suspect a cap
problem on any piece of circuitry, the first ones that I check are those
near to big resistors and heatsinks. How come this has never managed to
get back to the designers, and the supervisors who approve the designs ?

Probably it is intentionally.

Seems to be common across all manufacturers.

First manufacturers learned how to make almost perfect stuff.
But then they sell less. Remember the TV sets working for 20 years or more.

Now they cripple the equipment. Most flat screen TV sets do 5 to 8 year.

 

[Phil Allison]

"tinkerbell"

First manufacturers learned how to make almost perfect stuff.

** Huh ? On what planet was this ?

Remember the TV sets working for 20 years or more.

** No, that was never the case.

Now they cripple the equipment. Most flat screen TV sets do 5 to 8 year.

** And cost less to own per year in real terms that any TV set previously
available.

Piss off, fool.


..... Phil

 

[Michael Black]

On Mon, 8 Jul 2013, tuinkabouter wrote:

First manufacturers learned how to make almost perfect stuff.
But then they sell less. Remember the TV sets working for 20 years or more.

Are you talking about tube tv sets?

A significant issue is that in the age of tubes, electrolytic capacitors
were relatively uncommon. ONe or two in the power supply filter, then to
bypass the audio output amplifier cathode, maybe a few more. Tubes were
high impedance, so the capacitor values matched. If you don't need high
value capacitors, then you don't need electrolytics. Most tube equipment,
besides not using many electrolytics, used relatively small value
electrolytics.

Then the solid state age came along. Low impedance devices, so high value
capacitors became pretty common. Look at a transistor radio from the
sixties and wham, a whole lot of electrolytics, because they were the only
way to get the needed higher value capacitors. And it got worse, since a
transistor radio was pretty simple, but once ICs and specifically digital
ICs came along, the need for high value capacitors kept going up.

The filter capacitors in many a tube equipment was 40uF or so, really
quite small in value. IN the solid state age, 40uF was a low value,
hundreds of uF became common.

Suddenly electrolytic capacitors were everywhere, so the chance of failure
went up. IN the digital age, the capacitors weren't even seeing low 60Hz
AC, like the old tube radios saw, they were dealing with much higher
frequencies. In 1975, all the home computers coming on the market used
massive power supplies, big transformers and coke can size electrolytics.
But those were heavy and used up space, so when the Apple II came along,
it used a switching supply, something that was relatively unknown in hobby
circles, or consumer electronics. That really put the electrolytics to
the test, putting them against high frequencies, and putting them against
high temperature devices. It was a whole different world from the days of
tubes.

Virtually nobody talked about ESR in the days of tubes. But sometime into
the digital age, suddenly ESR became a factor for a whole lot more people,
suddenly you could buy ESR meters. That's the transition, the number of
electrolytics in any device went up, their values went up, and the
frequencies they dealt with went up. And so it's natural that they'd
start failing faster than in the days of tubes, and maybe more important,
the failure wnas't as obvious as in a tube radio (where you'd hear the hum
in the spaeker when the capacitors went bad) and since there were now so
many electrolytics, it wasn't an easy matter of "just replace the handful
of electrolytics". You needed to find out which was bad, and thus the
rise of ESR meters.

Micahel

 

[William Sommerwerck]

Remember the TV sets working for 20 years or more.

** No, that was never the case.

I've had a Sony and an NAD that lasted 20 years. The Sony WEGA in my bedroom
is almost 13 years old, and going strong.

 

[Michael A. Terrell]

Michael Black wrote:

Virtually nobody talked about ESR in the days of tubes.

That's because it was called 'Power Factor'.

 

[Jeff Liebermann]

On Mon, 8 Jul 2013 17:02:56 -0400, Michael Black <et472@ncf.ca> wrote:

Nicely written description. Permit me to add a few comments.

The filter capacitors in many a tube equipment was 40uF or so, really
quite small in value. IN the solid state age, 40uF was a low value,
hundreds of uF became common.

Well, let's do the math. The energy stored in a capacitor is:
E = 1/2*C*V^2
which means that for the same energy storage, if you cut the operating
voltage in half, you have to increase the capacitance by a factor of
four (assuming a load with the same number of watts). So, when we go
from 40 uf at 300 VDC B+, to a switcher running at 5 VDC, the
capacitor has to be:
40 * (300/5)^0.5 = 2400 uf
for the same energy storage.

so when the Apple II came along,
it used a switching supply, something that was relatively unknown in hobby
circles, or consumer electronics. That really put the electrolytics to
the test, putting them against high frequencies, and putting them against
high temperature devices.

Steve Jobs also didn't want to have a cooling fan in the Apple ][
making thermal management was a big problem. More on the Apple ][
power supply:
<http://www.righto.com/2012/02/apple-didnt-revolutionize-power.html>

Virtually nobody talked about ESR in the days of tubes.

True. We dealt with capacitor "Q" or its inverse, which is
dissipation factor:
<http://en.wikipedia.org/wiki/Dissipation_factor>
Dissipation factor is more correct because it includes the phase angle
between the resistive (ESR) and reactive parts. However, only the
resistive (ESR) actually produces heat, so it's understandable that
the reactive part should be ignored.

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

 

[Jeff Liebermann]

On Mon, 8 Jul 2013 01:21:37 -0700 (PDT), jurb6006@gmail.com wrote:

I think to be properly persnickety you are going to have to change
the vertical scale on those graphs from "ESR" to "impedance".

Nope. The correct measurement would be dissipation factor:
<http://en.wikipedia.org/wiki/Dissipation_factor>
which is a conglomeration of the resitive part of the impedance (ESR),
and the capacitive reactance part (1/2PiFC). For this exercise, I'm
only interested in the part that actually produces heat, which is ESR.
The reactive parts generates no heat and can therefore be ignored.

I have a bunch more to say on this but it is late and I
am half drunk. Off work tomorrow...

Alcohol should best be used for removing solder flux residue.

I wonder what kind of readings you might see out of things like
motor start or run caps, or speaker crossover caps.

Dunno. I don't work on speakers and the motor caps are really obvious
when they need replacement.

I am lazy when it coes to that. I would like easy ways do calculate
Xc, Xl and do vector math. there is probably a way out ther eI
just haven't found it. In fact I would be happy with a reactance/resonance
table. Damn, with a computer it could be zoomable and just eliminate all this.....

In the bad old daze, I used nomograms for all that. These days, I
just Google for a suitable Javscript based online calculator. I also
have reactance and resonance calcs programmed into my HP41CX and other
HP programmable calculators. However, the online version is easer to
read and use.

Until I fell behind on programming. Well I was never really ahead,

I don't have much trouble programming for myself and on my own
projects. However, I don't like programming and am not very good at
it. To avoid dissapointing friends and customers that want me to
program, I plea ignorance.

I got a bone to pick with time, I lack my ambition, something
took it ! Call the electron police.....

Sorry, but the electron police had its funding redirected by the
government so that the NSA can built the ultimate telephone directory.


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

 

[Peter]

On Sun, 07 Jul 2013 00:52:47 -0700, Jeff Liebermann <jeffl@cruzio.com>
wrote:

The data is rather interesting, and somewhat revealing.
It occurred to me to wonder what the actual leakage current, and
capacitance was for similiar conditions in each case.

peter

 

[tm]

"Jeff Liebermann" <jeffl@cruzio.com> wrote in message
news:ttfmt89mo53poi2pnsv17kd2bg8hu6v63h@4ax.com...

On Mon, 8 Jul 2013 01:21:37 -0700 (PDT), jurb6006@gmail.com wrote:

I think to be properly persnickety you are going to have to change
the vertical scale on those graphs from "ESR" to "impedance".

Nope. The correct measurement would be dissipation factor:
http://en.wikipedia.org/wiki/Dissipation_factor
which is a conglomeration of the resitive part of the impedance (ESR),
and the capacitive reactance part (1/2PiFC). For this exercise, I'm
only interested in the part that actually produces heat, which is ESR.
The reactive parts generates no heat and can therefore be ignored.

I have a bunch more to say on this but it is late and I
am half drunk. Off work tomorrow...

Alcohol should best be used for removing solder flux residue.

I wonder what kind of readings you might see out of things like
motor start or run caps, or speaker crossover caps.

Dunno. I don't work on speakers and the motor caps are really obvious
when they need replacement.

I am lazy when it coes to that. I would like easy ways do calculate
Xc, Xl and do vector math. there is probably a way out ther eI
just haven't found it. In fact I would be happy with a reactance/resonance
table. Damn, with a computer it could be zoomable and just eliminate all
this.....

In the bad old daze, I used nomograms for all that. These days, I
just Google for a suitable Javscript based online calculator. I also
have reactance and resonance calcs programmed into my HP41CX and other
HP programmable calculators. However, the online version is easer to
read and use.

Until I fell behind on programming. Well I was never really ahead,

I don't have much trouble programming for myself and on my own
projects. However, I don't like programming and am not very good at
it. To avoid dissapointing friends and customers that want me to
program, I plea ignorance.

I got a bone to pick with time, I lack my ambition, something
took it ! Call the electron police.....

Sorry, but the electron police had its funding redirected by the
government so that the NSA can built the ultimate telephone directory.


--

LOL.

The NSA Yellow Pages.

 

[Jeff Liebermann]

On Tue, 09 Jul 2013 10:00:06 +1000, Peter <peter@arin.htlm.com> wrote:

On Sun, 07 Jul 2013 00:52:47 -0700, Jeff Liebermann <jeffl@cruzio.com
wrote:

The data is rather interesting, and somewhat revealing.
It occurred to me to wonder what the actual leakage current, and
capacitance was for similiar conditions in each case.

peter

I was going to do that, just to see what happened. However, it was
midnight and I had just enough time to write it up before I fell over.
I need to measure the capacitance over temperature in order to remove
the capacitive reactance from the ESR measurements on the small value
cap (Cap-D).

I don't consider leakage current to be significant at the voltages
found in computer power supplies and motherboards, but testing might
prove otherwise.

Application Guide Aluminum Electrolytic Capacitors:
http://electrochem.cwru.edu/encycl/misc/c04-appguide.pdf
DC Leakage Current (DCL)

DC Leakage Current is the DC current flowing through
the capacitor with the rated voltage applied. The value
of leakage current depends on the voltage applied, the
charging period and capacitor temperature.

DCL Method of measurement

Measure leakage current at 25 °C with the
rated voltage applied through a protective
resistance of 1000 Ohm in series with the capacitor
in the measuring circuit. Five minutes after the
application of voltage, the leakage current is
not to exceed the maximum value indicated in
the specification.

The 5 minutes delay is to reduce the effects of forming current and
dielectric absorption. There are some typical graphs of leakage
versus temperature and voltage on Pg 2.191. I guess the easy way to
measure current is to just measure the voltage across the 1000 ohm
resistor and compute the current.

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

 

[Arfa Daily]

"Michael A. Terrell" <mike.terrell@earthlink.net> wrote in message
news:XN2dnZgeoZu0f0fMnZ2dnUVZ_sadnZ2d@earthlink.com...

Arfa Daily wrote:

"Michael A. Terrell" <mike.terrell@earthlink.net> wrote in message
news:lLmdnXuJBOexVETMnZ2dnUVZ_qydnZ2d@earthlink.com...

Arfa Daily wrote:

I haven't had a chance yet to fully examine your results links, but I
thought that I would just wade in to say that your last observation is
very
common with other equipment such as TV sets, and indeed switchmode
power
supplies in general. I see examples of this most every week where a
piece
of
equipment has a power supply that only goes to a standby mode when the
owner
of the equipment switches it "off". Then they go on holiday, and
switch
it
off for real, and when they come back and try to start it up again -
nothing. And the cause is always bad electros that were fine when they
were
kept warm but went too high on their ESR to fulfill their circuit
function,
when thy fully cooled.


Has anyone tried one of these $18 ESR meters?

http://www.ebay.com/itm/190859294488


I recently bought one of the similar ones that has component testing on
it
as well as ESR

http://www.ebay.co.uk/itm/181072329707?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2648


Don't you love that they never bother to mount the LCDs in these
designs?


and I have to say that it works very well. ESR function agrees nicely
with
my Bob Parker


The original, or the newer one? I have the original, bought as a
kit.

The original, also bought as a kit. Did you see the other post that I did
today that detailed a comparison between the Bob P and the little Chinese
job on a faulty cap that I had cause to replace ?

Arfa

 

[Phil Allison]

"Jeff Liebermann is bad at math"

The filter capacitors in many a tube equipment was 40uF or so, really
quite small in value. IN the solid state age, 40uF was a low value,
hundreds of uF became common.

Well, let's do the math. The energy stored in a capacitor is:
E = 1/2*C*V^2
which means that for the same energy storage, if you cut the operating
voltage in half, you have to increase the capacitance by a factor of
four (assuming a load with the same number of watts). So, when we go
from 40 uf at 300 VDC B+, to a switcher running at 5 VDC, the
capacitor has to be:
40 * (300/5)^0.5 = 2400 uf
for the same energy storage.

** How about 40* (300/5)^2 = 144,000 uF

But energy storage is simply NOT the issue.

Electros used at the output of SMPSs are there to suppress ripple voltage
down to a few mV at currents of many amps. So their impedance at frequencies
between 20kHz and 100KHz must be as low as possible.

Modern electros in the thousands of uF have very low, broad impedance curves
due to having a very low Q.

Eg: a 2200uFcap with ESR of 10mohms at 100kHz.

Q = reactance / resistance = .0007 /.01 = 0.07



.... Phil

 

[Phil Allison]

"William Sommerwanker = Fuckhead "

** FFS asshole STOP removing the CONTEXT !!!!!!!!!!
--------------------------------------------------------------

tinkerbell"

First manufacturers learned how to make almost perfect stuff.

Remember the TV sets working for 20 years or more.

** No, that was never the case.

I've had a Sony and an NAD that lasted 20 years.

** Statements like that are stupid and worthless.

Examples ONLY count as evidence if they are of common knowledge.

The TRUTH is that manufactures NEVER learned how to make "almost perfect
stuff " and that TV sets were never anything of the sort.

I had a colour TV set that " lasted " 24 years - made by Pye here in
Sydney.

Just needed a bit of service every couple of years and re-gunned tube to
cover the last 10.

In its last year, it was probably the longest surviving set of that make in
the country.

So fucking what ?



.... Phil

 

[Jeff Liebermann]

On Tue, 9 Jul 2013 11:50:30 +1000, "Phil Allison" <phil_a@tpg.com.au>
wrote:

"Jeff Liebermann is bad at math"

Close. I'm horrible at math. Even worse, I usually get it right the
first time, but then change it to something wrong during double
checking. Thanks for the correction.

** How about 40* (300/5)^2 = 144,000 uF

Oops(tm). Checking, both the 40 uF 300 v and the 144,000 uF 5V caps
can store 1.8 joules.

But energy storage is simply NOT the issue.

Electros used at the output of SMPSs are there to suppress ripple voltage
down to a few mV at currents of many amps. So their impedance at frequencies
between 20kHz and 100KHz must be as low as possible.

Agreed. If I think of the ripple voltage in terms of percent of the
operating voltage, I get an odd result. The 5V power supply probably
wants 50mv of ripple or less for 1% regulation:
<http://www.imcpower.com/prodigit/an_403.htm>
Scaled to 300V, that would be:
300 / 5 * 50mv = 3.0 V
of ripple which would be awful. That makes the filtering requirements
for high voltage power supply more stringent than a low voltage power
supply. I would have expected the opposite.

Modern electros in the thousands of uF have very low, broad impedance curves
due to having a very low Q.

Eg: a 2200uFcap with ESR of 10mohms at 100kHz.
Q = reactance / resistance = .0007 /.01 = 0.07

Good point.

How to measure ESR and lead inductance with pulse generator and a
scope.
<http://www.emcesd.com/tt020100.htm>

More fun, with parallel resonant capacitors:
<http://www.users.on.net/~glenk/capacitor/capacitor.htm>

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

 

[Phil Allison]

"Jeff Liebermann is bad at math"

Close. I'm horrible at math. Even worse, I usually get it right the
first time, but then change it to something wrong during double
checking. Thanks for the correction.

** How about 40* (300/5)^2 = 144,000 uF

But energy storage is simply NOT the issue.

Electros used at the output of SMPSs are there to suppress ripple voltage
down to a few mV at currents of many amps. So their impedance at
frequencies
between 20kHz and 100KHz must be as low as possible.


Agreed. If I think of the ripple voltage in terms of percent of the
operating voltage, I get an odd result. The 5V power supply probably
wants 50mv of ripple or less for 1% regulation:
http://www.imcpower.com/prodigit/an_403.htm
Scaled to 300V, that would be:
300 / 5 * 50mv = 3.0 V
of ripple which would be awful. That makes the filtering requirements
for high voltage power supply more stringent than a low voltage power
supply. I would have expected the opposite.

** Really ?

Then FFS compare apples with apples:

Linear, line frequency DC supplies can be simple, well filtered or
regulated:

1. Simple = bridge plus electro.

2. Well filtered = bridge, electro, inductor and another electro.

3. Regulated = bridge, electro, pass transistor and control circuit or
regulator IC.

In the last case, the output voltage is steady with line and load changes
and there is almost no ripple.

----------------------------------

The Switch Mode case:


SMPSs electronically regulate against line variations, load variations and
line frequency ripple on the incoming DC.

But crucially, they can do NOTHING about ripple voltage ( after
rectification) at the *switching frequency* - that job is done by passive
filtering using just electros and small inductors.

The electro's value is NOT chosen cos you need large numbers of uFs for it
to work - it IS chosen for its high frequency ESR value and ripple
rating - plus the fact it will have a low Q.

Look at any table of similar voltage electros and see how the ESR figure
goes down as the uFs go up.

If one electro will not do, then use two or more in parallel to get the ESR
and ripple current rating you want.

Simple.


.... Phil

 

"The electro's value is NOT chosen cos you need large numbers of uFs for it
to work - it IS chosen for its high frequency ESR value and ripple

rating - plus the fact it will have a low Q.
"
The values are also chosen for an orderly power down. In many devices you don't want, for example, the 5V line to slam down while the 3.3V line is still up. Sometimes it doesn't matter, sometimes it does.

Also sometimes even though one larger value cap would work, but they'll use more in parallel because of ripple current. Having been burned a few too many times I just bridge in caps in a PS and see if the unit comes up. If so I replace all of them in any given bank. however during the time when there is only one (good) cap in the circuit it will get quite hot, even during a few minutes of testing. I've had a couple get almost too hot to touch when running like that.

 

[John-Del]

Remember the TV sets working for 20 years or more.

On Monday, July 8, 2013 4:42:15 PM UTC-4, Phil Allison wrote:

** No, that was never the case.

I do agree with one thing; anecdotal evidence from a couple of examples doesn't mean squat.

I don't know about Australia Phil, but here in the States, TVs made in the 80s were extraordinarily reliable. U.S., Japan, and even the Korean models were reliable. Indiana built RCAs such as the 10X series (except early production, bad epoxy in flybacks), the 12X, the 13X series ran from new to the end of their lives, most of them never needing any sort of repair. We sold tons of these, gave a three year warranty at no charge (in house warranty), and had just one fail within the three years. When these were traded in later for big CRT models, most had never been serviced or required anything more than basic cabinet cleaning\detailing and grey scale\focusing to be put out in the used TV department where they were again sold with a one year warranty, despite being well past 10 years old.

I will concede that these were far simpler TVs that those that came later in 90s, but we never saw wholesale capacitor failures or crappy solder either.

On Monday, July 8, 2013 4:42:15 PM UTC-4, Phil Allison wrote:

Piss off, fool.

Funny how every thread you respond to becomes a shrub for you to piss in. You must be quite the charmer with the ladies...

 

[Arfa Daily]

Agreed. If I think of the ripple voltage in terms of percent of the
operating voltage, I get an odd result. The 5V power supply probably
wants 50mv of ripple or less for 1% regulation:
http://www.imcpower.com/prodigit/an_403.htm
Scaled to 300V, that would be:
300 / 5 * 50mv = 3.0 V
of ripple which would be awful. That makes the filtering requirements
for high voltage power supply more stringent than a low voltage power
supply. I would have expected the opposite.

The power supplies in guitar tube amps are universally linear. Simple
transformer, full wave rectifier, reservoir cap followed by L-C or R-C
filtering. Rails up to 500v can typically be found feeding the output stage,
and it's not at all unusual to see ripple voltages of 5 volts or more on
these high voltage rails. The hum on the output is barely noticeable, and
just makes it sound like a 'tube amp'. The rails feeding the front end tend
to be somewhat lower in voltage, and often have several stages of R-C
filtering ahead of them, and as a result, tend to be rather 'quieter' in
terms of residual ripple voltage.

Arfa

 

[Michael A. Terrell]

Arfa Daily wrote:

"Michael A. Terrell" <mike.terrell@earthlink.net> wrote in message
news:XN2dnZgeoZu0f0fMnZ2dnUVZ_sadnZ2d@earthlink.com...

Arfa Daily wrote:

"Michael A. Terrell" <mike.terrell@earthlink.net> wrote in message
news:lLmdnXuJBOexVETMnZ2dnUVZ_qydnZ2d@earthlink.com...

Arfa Daily wrote:

I haven't had a chance yet to fully examine your results links, but I
thought that I would just wade in to say that your last observation is
very
common with other equipment such as TV sets, and indeed switchmode
power
supplies in general. I see examples of this most every week where a
piece
of
equipment has a power supply that only goes to a standby mode when the
owner
of the equipment switches it "off". Then they go on holiday, and
switch
it
off for real, and when they come back and try to start it up again -
nothing. And the cause is always bad electros that were fine when they
were
kept warm but went too high on their ESR to fulfill their circuit
function,
when thy fully cooled.


Has anyone tried one of these $18 ESR meters?

http://www.ebay.com/itm/190859294488


I recently bought one of the similar ones that has component testing on
it
as well as ESR

http://www.ebay.co.uk/itm/181072329707?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2648


Don't you love that they never bother to mount the LCDs in these
designs?


and I have to say that it works very well. ESR function agrees nicely
with
my Bob Parker


The original, or the newer one? I have the original, bought as a
kit.


The original, also bought as a kit. Did you see the other post that I did
today that detailed a comparison between the Bob P and the little Chinese
job on a faulty cap that I had cause to replace ?

Arfa

This?

-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
As a matter of particular interest to Michael T, I hung the faulty one
across the little Chinese component tester that I mentioned elsewhere in
the
thread. That made it 42 ohms, so pretty good agreement with Bob's meter.
But
what was also of note was the fact that the tester showed it to have a
value
of 44.6 uF, so not far from its nominal 47uF, even though it was clearly
well out of spec on its ESR. This underlines what we have discussed on
here
before in that you cannot determine the condition of an electrolytic by
measuring its capacitance alone. It has to have its ESR checked to get a
meaningful result, and that is best, and most conveniently, done with a
proper in-circuit ESR meter, that's designed for the job.
-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*


I've seen very high capacitance readings on failing electrolytics, on
some cheap meters. About 20 years ago, I went through my inventory of
caps and chuck any electrolytics that read higher than specs. When I
got the ESR meter and built it, I tossed another 20%. Being in my 60s,
some parts were made in the '40s since I had bought out a number of old
shops in the '70s & '80s. ;-)


The cap you described was just starting to fail. First, the ESR
starts to rise, then the capacitance drops as it dries out, even more.
I used to do some failure analysis on components at one plant.

 

[Arfa Daily]

"Michael A. Terrell" <mike.terrell@earthlink.net> wrote in message
news:IbudnYTpCoAOw0HMnZ2dnUVZ_oOdnZ2d@earthlink.com...

Arfa Daily wrote:

"Michael A. Terrell" <mike.terrell@earthlink.net> wrote in message
news:XN2dnZgeoZu0f0fMnZ2dnUVZ_sadnZ2d@earthlink.com...

Arfa Daily wrote:

"Michael A. Terrell" <mike.terrell@earthlink.net> wrote in message
news:lLmdnXuJBOexVETMnZ2dnUVZ_qydnZ2d@earthlink.com...

Arfa Daily wrote:

I haven't had a chance yet to fully examine your results links, but
I
thought that I would just wade in to say that your last observation
is
very
common with other equipment such as TV sets, and indeed switchmode
power
supplies in general. I see examples of this most every week where a
piece
of
equipment has a power supply that only goes to a standby mode when
the
owner
of the equipment switches it "off". Then they go on holiday, and
switch
it
off for real, and when they come back and try to start it up
again -
nothing. And the cause is always bad electros that were fine when
they
were
kept warm but went too high on their ESR to fulfill their circuit
function,
when thy fully cooled.


Has anyone tried one of these $18 ESR meters?

http://www.ebay.com/itm/190859294488


I recently bought one of the similar ones that has component testing
on
it
as well as ESR

http://www.ebay.co.uk/itm/181072329707?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2648


Don't you love that they never bother to mount the LCDs in these
designs?


and I have to say that it works very well. ESR function agrees nicely
with
my Bob Parker


The original, or the newer one? I have the original, bought as a
kit.


The original, also bought as a kit. Did you see the other post that I did
today that detailed a comparison between the Bob P and the little Chinese
job on a faulty cap that I had cause to replace ?

Arfa


This?

-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
As a matter of particular interest to Michael T, I hung the faulty one
across the little Chinese component tester that I mentioned elsewhere in
the
thread. That made it 42 ohms, so pretty good agreement with Bob's meter.
But
what was also of note was the fact that the tester showed it to have a
value
of 44.6 uF, so not far from its nominal 47uF, even though it was clearly
well out of spec on its ESR. This underlines what we have discussed on
here
before in that you cannot determine the condition of an electrolytic by
measuring its capacitance alone. It has to have its ESR checked to get a
meaningful result, and that is best, and most conveniently, done with a
proper in-circuit ESR meter, that's designed for the job.
-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*


I've seen very high capacitance readings on failing electrolytics, on
some cheap meters. About 20 years ago, I went through my inventory of
caps and chuck any electrolytics that read higher than specs. When I
got the ESR meter and built it, I tossed another 20%. Being in my 60s,
some parts were made in the '40s since I had bought out a number of old
shops in the '70s & '80s. ;-)


The cap you described was just starting to fail. First, the ESR
starts to rise, then the capacitance drops as it dries out, even more.
I used to do some failure analysis on components at one plant.

Yes, that was the post, and yes, I think you are right that the cap was in
early stage failure. For sure, it showed no external signs of stress

Arfa