Typical ESR values

[Dishum]

I'm a hobbyist who doesn't have an ESR meter or (usually) a
choice of specific capacitor models and I'd like to have some
idea of the kind of ESR values one would expect from capacitors
that are neither particularly good nor particularly crappy in
that respect. I'll really appreciate it if you could cite some
ballpark figures for -

1. 1uF/50V wet Al electrolytic
2. 100uF/25V wet Al electrolytic
3. 1000uF/50V wet Al electrolytic
4. 1uF/25V tantalum

[Phil Allison]

"Dishum"

** Measured from my parts bins:

1 = 3.1 ohms
2 = 0.5 ohms
3 = 0.06 ohms
4 = 4.2 ohms

In each case, the figure is for high frequency ESR or impedance at 100kHz.

ESR rises at low frequencies ( under 500Hz ) and falls with increasing
temperature.

Also, when an electro goes bad (ie dries out ) - ESR rises first followed
much later by a reduction in actual uF.



... Phil

[Dishum]

"Phil Allison" <phi...@tpg.com.au> wrote in message
news:9o7bok...@mid.individual.net...

Thanks a lot.

[Phil Allison]

"Dishum"
> "Phil Allison"

** Thank you for a refreshingly clear question.




.... Phil

[John Larkin]

On Tue, 24 Jan 2012 20:25:32 +1100, "Phil Allison" <phi...@tpg.com.au>
wrote:

That seems high for the tantalum. I seem to recall numbers like a
couple tenths of an ohm. I'll try a couple. I don't have an ESR meter,
but I can just apply a square wave from a 50 ohm generator and scope
the voltage.

Hmmm, both of the 1u caps have about the same ESR.

John

[John Larkin]

I tried a standard leaded gumdrop tantalum, 1 uF at 35 volts, and got
about 0.75 ohms.

22u 16v was about 0.35 ohms.

Tantalum ESR tends to be in sort of a sweet spot for taming voltage
regulators, both switchers and linear.

John

[Simon S Aysdie]

On Jan 24, 11:59 am, John Larkin

> John- Hide quoted text -
>
> - Show quoted text -

I haven't used these spice models, but maybe something can be gleaned
from them:

http://www.kemet.com/kemet/web/homepage/kechome.nsf/weben/kemsoftNetList

A brief Kemet paper:
http://www.kemet.com/kemet/web/homepage/kfbk3.nsf/vaFeedbackFAQ/53D5333B4453253585256BCD004EBC04/$file/TechTopics%20Vol4No5%20Sep94.PDF)

[Phil Allison]

"John Larkin"
"Phil Allison"

>"Dishum"
>>>
>>> I'm a hobbyist who doesn't have an ESR meter or (usually) a choice of
>>> specific capacitor models and I'd like to have some idea of the kind of
>>> ESR values one would expect from capacitors that are neither
>>> particularly
>>> good nor particularly crappy in that respect. I'll really appreciate it
>>> if
>>> you could cite some ballpark figures for -
>>>
>>> 1. 1uF/50V wet Al electrolytic
>>> 2. 100uF/25V wet Al electrolytic
>>> 3. 1000uF/50V wet Al electrolytic
>>> 4. 1uF/25V tantalum
>>
>>
>>** Measured from my parts bins:
>>
>> 1 = 3.1 ohms
>> 2 = 0.5 ohms
>> 3 = 0.06 ohms
>> 4 = 4.2 ohms
>>
>>In each case, the figure is for high frequency ESR or impedance at 100kHz.
>>
>>ESR rises at low frequencies ( under 500Hz ) and falls with increasing
>>temperature.
>>
>>Also, when an electro goes bad (ie dries out ) - ESR rises first followed
>>much later by a reduction in actual uF.
>>
>>
>

> That seems high for the tantalum. I seem to recall numbers like a
> couple tenths of an ohm.

See page 5:

http://www.farnell.com/datasheets/33794.pdf

For a 1uF example at 25V or 35V, ESR values of 8 to10 ohms are quoted.



... Phil

[Joerg]

Until they have exploded, that is :-)

--
Regards, Joerg

http://www.analogconsultants.com/

[John Larkin]

On Tue, 24 Jan 2012 17:02:23 -0800, Joerg <inv...@invalid.invalid>
wrote:

Tantalums can be very reliable, much better than aluminums. You just
have to handle them properly.

John

[John Larkin]

On Tue, 24 Jan 2012 11:59:47 -0800, John Larkin

ftp://jjlarkin.lmi.net/Tant_ESR_Rig.JPG

ftp://jjlarkin.lmi.net/Tant_ESR_Scope.JPG

John

[Tim Williams]

"John Larkin" <jjla...@highNOTlandTHIStechnologyPART.com> wrote in
message news:7n0vh7do0pn8unfpn...@4ax.com...

>>Tantalum ESR tends to be in sort of a sweet spot for taming voltage
>>regulators, both switchers and linear.
>

> ftp://jjlarkin.lmi.net/Tant_ESR_Rig.JPG
>
> ftp://jjlarkin.lmi.net/Tant_ESR_Scope.JPG

Yes, suffice it to say, even though (dry slug) tantalums tend to have ESR
comparable to (higher grade) electrolytics, they are far, far simpler:
while lytics suffer from complicated ESL effects, tantalums are
essentially the inductance of the body length and that's it. The
equivalent circuit of C, ESR and ESL is very representative, and this
makes ripple voltage much more manageble.

And of course, polymers are just about ideal, yadda yadda.

Tim

--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms

[Phil Allison]

"Tim Williams is so full of shit "

> Yes, suffice it to say, even though (dry slug) tantalums tend to have ESR
> comparable to (higher grade) electrolytics, they are far, far simpler:

** Their failure modes are many and failures far more common too.

> while lytics suffer from complicated ESL effects,

** Horse poo.

> tantalums are essentially the inductance of the body length and that's it.

** Same goes for most electros too.


... Phil

[John Larkin]

On Tue, 24 Jan 2012 22:30:27 -0600, "Tim Williams"
<tmor...@charter.net> wrote:

>"John Larkin" <jjla...@highNOTlandTHIStechnologyPART.com> wrote in
>message news:7n0vh7do0pn8unfpn...@4ax.com...
>>>Tantalum ESR tends to be in sort of a sweet spot for taming voltage
>>>regulators, both switchers and linear.
>>
>> ftp://jjlarkin.lmi.net/Tant_ESR_Rig.JPG
>>
>> ftp://jjlarkin.lmi.net/Tant_ESR_Scope.JPG
>
>Yes, suffice it to say, even though (dry slug) tantalums tend to have ESR
>comparable to (higher grade) electrolytics, they are far, far simpler:
>while lytics suffer from complicated ESL effects, tantalums are
>essentially the inductance of the body length and that's it. The
>equivalent circuit of C, ESR and ESL is very representative, and this
>makes ripple voltage much more manageble.

Yup. On the gumdrops the leads are the most inductive part.

>
>And of course, polymers are just about ideal, yadda yadda.

Yupyup.

John

[John Larkin]

On Wed, 25 Jan 2012 15:49:22 +1100, "Phil Allison" <phi...@tpg.com.au>
wrote:

>

>"Tim Williams is so full of shit "
>
>
>> Yes, suffice it to say, even though (dry slug) tantalums tend to have ESR
>> comparable to (higher grade) electrolytics, they are far, far simpler:
>
>** Their failure modes are many and failures far more common too.

If you keep dV/dT down, they are very reliable.

John

[Phil Allison]

"John Larkin"
"Phil Allison"

>
>>"Tim Williams is so full of shit "
>>
>>
>>> Yes, suffice it to say, even though (dry slug) tantalums tend to have
>>> ESR
>>> comparable to (higher grade) electrolytics, they are far, far simpler:
>>
>>** Their failure modes are many and failures far more common too.
>
> If you keep dV/dT down, they are very reliable.

** Absolute crap.

As fucking usual, Larkin has no idea of what he speaks and does not give a
shit either.

FOAD - septic pisshead.



... Phil

[John Larkin]

On Wed, 25 Jan 2012 16:00:38 +1100, "Phil Allison" <phi...@tpg.com.au>
wrote:

>

I've used well over 100,000 tantalum caps in the last 6 years or so.
53,000 of 2.2u 20v alone. The only ones that failed were loaded
backwards or were on power rails that had high dV/dT available.

Soft-starting regulators, or derating the tants about 3:1 on voltage,
takes care of the dV/dT problem. Then they are beautifully reliable.

Of course, ceramics are cheaper and smaller, so I use them when I can.

John

[Phil Allison]

"John Larkin"
> "Phil Allison"
>>>
>>>>"Tim Williams is so full of shit "
>>>>
>>>>
>>>>> Yes, suffice it to say, even though (dry slug) tantalums tend to have
>>>>> ESR
>>>>> comparable to (higher grade) electrolytics, they are far, far simpler:
>>>>
>>>>** Their failure modes are many and failures far more common too.
>>>
>>> If you keep dV/dT down, they are very reliable.
>>
>>
>>** Absolute crap.
>>
>> As fucking usual, Larkin has no idea of what he speaks and does not give
>> a
>>shit either.
>
>
> I've used well over 100,000 tantalum caps in the last 6 years or so.
> 53,000 of 2.2u 20v alone. The only ones that failed were loaded
> backwards or were on power rails that had high dV/dT available.

** So you have NOT seen the general failure rates with all brands of tants
and across all types of equipment.

You know no-one who has and do not give a shit either.

Fuck off to hell - you rabid, septic psychopath.

[John Larkin]

On Wed, 25 Jan 2012 16:33:54 +1100, "Phil Allison" <phi...@tpg.com.au>
wrote:

>"John Larkin"
>> "Phil Allison"
>>>>
>>>>>"Tim Williams is so full of shit "
>>>>>
>>>>>
>>>>>> Yes, suffice it to say, even though (dry slug) tantalums tend to have
>>>>>> ESR
>>>>>> comparable to (higher grade) electrolytics, they are far, far simpler:
>>>>>
>>>>>** Their failure modes are many and failures far more common too.
>>>>
>>>> If you keep dV/dT down, they are very reliable.
>>>
>>>
>>>** Absolute crap.
>>>
>>> As fucking usual, Larkin has no idea of what he speaks and does not give
>>> a
>>>shit either.
>>
>>
>> I've used well over 100,000 tantalum caps in the last 6 years or so.
>> 53,000 of 2.2u 20v alone. The only ones that failed were loaded
>> backwards or were on power rails that had high dV/dT available.
>
>
>** So you have NOT seen the general failure rates with all brands of tants
>and across all types of equipment.

I see very low failure rates in the equipmennt I design. I'm sure
there is badly designed gear that blows tantalum caps.

I'm not a repair tech, so I don't deal with a lot of equipment
designed by somebody else.

John

[Phil Allison]

"John Larkin"
> "Phil Allison"
>>>>>
>>>>>>"Tim Williams is so full of shit "
>>>>>>
>>>>>>
>>>>>>> Yes, suffice it to say, even though (dry slug) tantalums tend to
>>>>>>> have
>>>>>>> ESR
>>>>>>> comparable to (higher grade) electrolytics, they are far, far
>>>>>>> simpler:
>>>>>>
>>>>>>** Their failure modes are many and failures far more common too.
>>>>>
>>>>> If you keep dV/dT down, they are very reliable.
>>>>
>>>>
>>>>** Absolute crap.
>>>>
>>>> As fucking usual, Larkin has no idea of what he speaks and does not
>>>> give
>>>> a shit either.
>>>
>>>
>>> I've used well over 100,000 tantalum caps in the last 6 years or so.
>>> 53,000 of 2.2u 20v alone. The only ones that failed were loaded
>>> backwards or were on power rails that had high dV/dT available.
>>
>>
>>** So you have NOT seen the general failure rates with all brands of
>>tants
>>and across all types of equipment.
>>

>> You know no-one who has and do not give a shit either.
>>
>> Fuck off to hell - you rabid, septic psychopath.
>
>

> I see very low failure rates in the equipmennt I design. I'm sure
> there is badly designed gear that blows tantalum caps.
>
> I'm not a repair tech, so I don't deal with a lot of equipment
> designed by somebody else.

** SO SHUT THE FUCK UP

- YOU BLOODY IMBECILE !!!!!!!




.... Phil

[JW]

On Wed, 25 Jan 2012 09:42:50 +1100 "Phil Allison" <phi...@tpg.com.au>
wrote in Message id: <9o8qfj...@mid.individual.net>:

I thought the same thing that JL did, so taking a look at Digikey:
http://search.digikey.com/scripts/DkSearch/dksus.dll?x=0&y=0&lang=en&site=us&KeyWords=1uf+25v+tantalum
7.5 to 8 ohms.

[JW]

On Wed, 25 Jan 2012 05:53:25 -0500 JW <no...@dev.null> wrote in Message id:
<amnvh71uc445lvmju...@4ax.com>:

Sorting by ESR there's some as high as 20 ohms!

[Martin Brown]

That sounds very reasonable. But there seems to be another quicker form
of "goes bad" that happens with annoying regularity on PC motherboards -
usually to the low voltage ram PSU capacitors but sometimes elsewhere.

I have just had an annoying incident with my own main PC motherboard
where the ram PSU capacitors ATWB 1800uF 6.3v (nominally ultra low ESR)
had started to bulge and over the past month a rock solid machine turned
into something that required a several goes just to get past the POST.
The situation seemed to be worst from a cold start after a weekend off
and once warmed up the machine would become "reliable" after a fashion.

I thought all the bother with dodgy electrolytes outgassing had been
fixed a long time ago, but I seem to have a similar fault on a modern
board :(

I finally attacked the motherboard with a soldering iron today and was
quite disappointed to find that at the low power and frequency my basic
tester uses they measured as OK at 1820 and 1940uF and <0.05R. I presume
they only give up the ghost at ~100kHz and a couple of amps ripple. The
ends were obviously bulging and they had taken on a rakish angle on the
board as they expanded. I was a bit surprised that they still measured
OK but went ahead and put new Rubicon 1800uF 10v caps in their place.

It seems to have done the trick <FX> crosses fingers </FX>.

Regards,
Martin Brown

[Phil Allison]

"Martin Brown"

> I finally attacked the motherboard with a soldering iron today and was
> quite disappointed to find that at the low power and frequency my basic
> tester uses they measured as OK at 1820 and 1940uF and <0.05R.

** Low ESR types of that value should be no more than 3 to 10 milliohms.

At 10 times over and bulging - they are comprehensively stuffed.



... Phil

[Martin Brown]

Phil Allison wrote:
> "Martin Brown"
>
>> I finally attacked the motherboard with a soldering iron today and was
>> quite disappointed to find that at the low power and frequency my basic
>> tester uses they measured as OK at 1820 and 1940uF and <0.05R.
>
>
> ** Low ESR types of that value should be no more than 3 to 10 milliohms.

Thanks for this, but I can't measure series resistance down that low.
It's just a quick and dirty tester.

>
> At 10 times over and bulging - they are comprehensively stuffed.

That is certainly true. It seems to behave with the new capacitors in.

The bulging was the give away. The ones that bulged all had brown
sleeves, an "X" on the end cap and were ATWB by maker Toshin Kogyo.

Datasheet tends to suggest that about 15mR is normal at 100kHz.
(reading between the lines at 1800uF which isn't listed here)
http://www.ost.com.tw/PDF/TK/EC_TK_ATWB.pdf

The Rubicon 10v ZLJ part from its datasheet was good for 2.5A ripple and
about 30mR @ 100kHz which is in the right ballpark.

Basically I couldn't measure the differences between them on the bench
with a simple quick tester (and at low current).

Regards,
Martin Brown

[John Larkin]

On Wed, 25 Jan 2012 16:53:17 +1100, "Phil Allison" <phi...@tpg.com.au>
wrote:

I think your ESR tester doesn't work very well with low-uF parts.

John

[Robert Macy]

On Jan 25, 9:48 am, John Larkin

Use your SoundCard and a little fussing and you can get down to
milliohms between the ranges of 1000Hz to 90kHz. Actually, 89kHz, but
can't get to 100kHz.

A little software and your Soundcard 24bit? running at 192kS/s dual
channel

[Tim Wescott]

"The image “ftp://jjlarkin.lmi.net/Tant_ESR_Rig.JPG” cannot be displayed
because it contains errors."

I thought you were getting a real web site? Can't you use flikr in the
mean time?

--
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?

Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com

[John Devereux]

Tim Wescott <t...@seemywebsite.com> writes:

> On Tue, 24 Jan 2012 20:21:25 -0800, John Larkin wrote:
>

[...]

>>
>>
>> ftp://jjlarkin.lmi.net/Tant_ESR_Rig.JPG
>>
>> ftp://jjlarkin.lmi.net/Tant_ESR_Scope.JPG
>>
>> John
>
> "The image “ftp://jjlarkin.lmi.net/Tant_ESR_Rig.JPG” cannot be displayed
> because it contains errors."
>
> I thought you were getting a real web site? Can't you use flikr in the
> mean time?

It's fine, never had a problem with any of Johns FTP images.

Must be you!


--

John Devereux

[John Larkin]

The signal generator+scope thing I posted is simple. No software. And
it gives you the full time-domain current step response, down to
nanoseconds, which contains a lot of information. 90 KHz is slow for a
lot of applications.

John

[Dave Platt]

In article <87r4ynl...@devereux.me.uk>,

John Devereux <jo...@devereux.me.uk> wrote:

>> "The image “ftp://jjlarkin.lmi.net/Tant_ESR_Rig.JPG” cannot be displayed
>> because it contains errors."
>>
>> I thought you were getting a real web site? Can't you use flikr in the
>> mean time?
>
>It's fine, never had a problem with any of Johns FTP images.

Both download and display fine for me, using Mozilla Firefox.

Possibly Tim is retrieving the files through a client which isn't
switching to "binary" mode before retrieving? Doing ASCII-file
newline/carriagereturn translation on a JPEG is very likely to
mangle it badly...

--
Dave Platt <dpl...@radagast.org> AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

[David Eather]

On Thu, 26 Jan 2012 04:37:53 +1000, John Devereux <jo...@devereux.me.uk>
wrote:

I have had trouble and I have a very standard install. I'm on the wrong
computer to suggest the solution given to me.

[George Herold]

On Jan 24, 11:21 pm, John Larkin

> John- Hide quoted text -
>
> - Show quoted text -

Nice trick. I slapped in a 10uF 35 V tant.

~80mV or 80mV/10 *50 =0.4 ohms.
http://imageshack.us/photo/my-images/545/tek0017.png/

lotsa ringing at the step...
What’s that about? Bad technique on my part?

http://imageshack.us/photo/my-images/40/tek0018.png/

George H.

[Jamie]

works for me?

Jamie

[Jamie]

Put a 50 ohm R across your gen output..


Jamie

[John Larkin]

That ringing is about 40 MHz. The edge from my function generator
probably isn't fast enough to excite something like that. Still, it's
probably lead lengths or something causing all that ringing.

John

[Jamie]

I find that some gen outputs have reactive circuits in them. Not
properly terminated to bring the Q down to 1 or less.

Also, I've seen problems with lack of shoot through on complemary
emitter followers as unity buffers on equipment exhibiting this effect.

A non reactive fixed load on the output normally fixes this. Ringing
can be suppressed if the device that is delivering the signal
has a high gain loop back and enough current handling to counter the
reaction.

Many signal generators do not have feed back on their final stage to
help the driving circuit maintain the output.

I've designed amplifiers to drive magnetic scan and focus coils and
one of the items in the design is to have the amplifier attempt to
counter act any reactive response, other wise, it'll show in the sweeps
and focusing.

That's my take on it :)

Jamie

[John Larkin]

On Wed, 25 Jan 2012 11:35:08 -0600, Tim Wescott <t...@seemywebsite.com>

Does this work?

http://dl.dropbox.com/u/53724080/Circuits/Tant_ESR_Rig.JPG

http://dl.dropbox.com/u/53724080/Circuits/Tant_ESR_Scope.JPG

The web site needs work, and it's kind of a nuisance to throw files up
onto. The FTP is really fast and easy, but some people can't see it.

John

[Jamie]

Do you have a lot of smokers in your work area? why is that scope so
yellow? Or is that the natural color? my Rigol is near white.

btw, I have the 100mhz version, not the software hacked 50mhz, if
that makes any difference?

Jamie

[John Larkin]

No. I'd never hire anybody who smokes.

why is that scope so
>yellow? Or is that the natural color? my Rigol is near white.

The Rigol is a little off-white, a faint cream color. Probably the
camera is set for daylight mode or something. But you're supposed to
be admiring the fabulous waveform, not the photography.

>
> btw, I have the 100mhz version, not the software hacked 50mhz, if
>that makes any difference?

This one isn't hacked. Risetime measures 5.6 ns, which is a 63 MHz
bandwidth. That's fine for most of what I do. If it's not, there's my
20 GHz 11801 right beside it.

John

[George Herold]

On Jan 25, 6:21 pm, John Larkin

Yeah, the sharp edge. I tried the x10 probe but there was too little
signal and too much noise... pickup... My lab bench seems to live in a
bath of 100MHz.

I was thinking after bad mouthing my x1 probes I now have to dig one
out.

George H.

[Jamie]

Yeah, forgot, the wave form looks nice ;)
Jamie

[Tim Williams]

On Jan 24, 10:58 pm, John Larkin
<jjlar...@highNOTlandTHIStechnologyPART.com> wrote:

> On Wed, 25 Jan 2012 15:49:22 +1100, "Phil Allison" <phi...@tpg.com.au>
> wrote:
>
>
>
> >"Tim Williams is so full of shit "
>
> >> Yes, suffice it to say, even though (dry slug) tantalums tend to have ESR
> >> comparable to (higher grade) electrolytics, they are far, far simpler:
>
> >** Their failure modes are many and failures far more common too.
>
> If you keep dV/dT down, they are very reliable.
>

> John

Now, the funny thing I've got right now:
I have 8 channels in parallel, supplied from a single current-limited
supply. But the thing is, if the current from 8 channels at full
power, flows into one channel as fault current, that's four amperes
more than it was designed to run... Ever had a case like this?
What's the best way to handle it?

Tim

[John Larkin]

I don't exactly understand the situation. Got a sketch?

Does this involve tantalum caps?

John

[Tim Williams]

On Jan 25, 9:55 pm, John Larkin

<jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
> I don't exactly understand the situation. Got a sketch?
>
> Does this involve tantalum caps?

A description should suffice [rum disclaimer inserted here]:

Yes -- I have eight output transformers in parallel from the same
current-limited PWM driver. Now, under normal conditions, all eight
channels are working correctly, so the current shares evenly, and all
the caps are happy (the maximum supply is 5A, so they each see a
maximum of 5A / 8 = 0.6A peak, so the RMS ripple is under 0.42A, fine
for a chip tantalum, though I have ceramic specified at the moment).
But under fault, the whole 5A could flow into just one channel, which
makes things "interesting". I may implement a "max-of-channels"
current limit for this.

Tim

[John Larkin]

On Wed, 25 Jan 2012 20:07:30 -0800 (PST), Tim Williams
<tmor...@gmail.com> wrote:

>On Jan 25, 9:55 pm, John Larkin
><jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
>> I don't exactly understand the situation. Got a sketch?
>>
>> Does this involve tantalum caps?
>
>A description should suffice [rum disclaimer inserted here]:

Have you tried this?

http://tinyurl.com/7xqed3l

Once you sip this, cognac has no purpose any more.

>
>Yes -- I have eight output transformers in parallel from the same
>current-limited PWM driver. Now, under normal conditions, all eight
>channels are working correctly, so the current shares evenly, and all
>the caps are happy (the maximum supply is 5A, so they each see a
>maximum of 5A / 8 = 0.6A peak, so the RMS ripple is under 0.42A, fine
>for a chip tantalum, though I have ceramic specified at the moment).
>But under fault, the whole 5A could flow into just one channel, which
>makes things "interesting". I may implement a "max-of-channels"
>current limit for this.

I wouldn't use a tantalum cap here. Current is what detonates them.
Stick with ceramics, or if you really need a lot of C, use a polymer
aluminum.

John

[Martin Brown]

Yes. These are much more user friendly to the outside world.

>
> The web site needs work, and it's kind of a nuisance to throw files up
> onto. The FTP is really fast and easy, but some people can't see it.

You should be able to throw files up onto your website by ftp if you
want to and then publish their URL. Try creating a directory "temp" or
even "ftp" on your website and treat it like you do with ftp:://

Then you can ftp stuff up and others can look at it how they like.

Regards,
Martin Brown

[Robert Macy]

On Jan 25, 12:18 pm, John Larkin

I prefer the HP network analyzer with built in model value generation,
good to 500MHz - especially if you want an eye opener as to EXACTLY
what a component is doing to you over a large spectrum. I was not
disparaging your approach, only mentioning there are 'alternative'
tools out there, for the monetarily challenged.

[John Larkin]

Not having a network analyzer, I can't argue. I hacked the ESR thing
in a couple of minutes from what was in place on my bench. I could
have TDR'd it, too, and got about the same results, but with 20 GHz
effective bandwidth.

I think in the time domain, so the waveform that I posted means a lot
to me. Notice the small cuvature after the initial step, before the
ramp gets linear?

John

[Tim Williams]

On Jan 25, 10:36 pm, John Larkin

<jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
> Have you tried this?
>
> http://tinyurl.com/7xqed3l
>
> Once you sip this, cognac has no purpose any more.

Oooh, fancy. Looks like the Caribbean's answer to Makers Mark :)

Tim

[John S]

Tim -

Try: copy the link and paste into browser address bar.

[John S]

The question mark indicates you don't know whether it does or not. Are
you asking a question Dip Shit?

[John Larkin]

It's actually from Guatemala.

http://en.wikipedia.org/wiki/Ron_Zacapa_Centenario


Try some. Well worth the price.

John

[John Fields]

On Wed, 25 Jan 2012 20:36:24 -0800, John Larkin
<jjla...@highNOTlandTHIStechnologyPART.com> wrote:

>On Wed, 25 Jan 2012 20:07:30 -0800 (PST), Tim Williams
><tmor...@gmail.com> wrote:
>
>>On Jan 25, 9:55 pm, John Larkin
>><jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
>>> I don't exactly understand the situation. Got a sketch?
>>>
>>> Does this involve tantalum caps?
>>
>>A description should suffice [rum disclaimer inserted here]:
>
>
>Have you tried this?
>
>http://tinyurl.com/7xqed3l
>
>Once you sip this, cognac has no purpose any more.

---
For you, perhaps, but a true gourmand would acquiesce to that
some prefer the grape, and some the cane, without incurring judgment
and its attending rancor.
--
JF

[John Larkin]

Whatever you say.

John

[John Fields]

---
Thank you.

--
JF

[josephkk]

On Wed, 25 Jan 2012 09:27:46 -0800 (PST), Robert Macy
<robert...@gmail.com> wrote:

>On Jan 25, 9:48 am, John Larkin

><jjlar...@highNOTlandTHIStechnologyPART.com> wrote:

I don't suppose that you have the source code for that do you? If so i
would like to have a copy.

?-)

[Robert Macy]

My code has the WORST users interface ever made! Source Code contains
too many proprietary processes and algorithms from another project and
is approx 2MB and relies on four libraries to be installed.

Try a search first, there are many prepackaged programs that you can
use.

If you still want your own, get software that exercises your soundcard
and start modifying that.

I'm open to discussion once you're set up.

[Jasen Betts]

Under this fault condition in the fault current passing through the
tantalum cap, or just visiting the neighbourhood?

energy density detonates tantalums, don't get them hot and
charged at the same time.

--
⚂⚃ 100% natural

[josephkk]

No further comment is needed. You cannot provide, that is OK though.
Just asked in case you had something appropriately available.

?-)

[Robert Macy]

contact me offline
robert .DOT. a .DOT. macy .AT.

[John Larkin]

What usually detonates them is high peak current, or equivalently high
dV/dT.


--

John Larkin, President Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom timing and laser controllers
Photonics and fiberoptic TTL data links
VME analog, thermocouple, LVDT, synchro, tachometer
Multichannel arbitrary waveform generators

[Tim Williams]

On Jan 28, 2:48 pm, Jasen Betts <ja...@xnet.co.nz> wrote:
> Under this fault condition in the fault current passing through the
> tantalum cap, or just visiting the neighbourhood?
>
> energy density detonates tantalums, don't get them hot and
> charged at the same time.

Mental picture: suppose you have a standard full-bridge forward
converter, except it's supplied by constant current, allowing you to
use caps directly after the rectifier, rather than an L+C filter
(essentially, the L was moved to the primary side).

Now suppose one channel were accidentally shorted, then unshorted.
Two things happen:
1. While shorted, all the supply current flows into the shorted
channel. The other channels remain at roughly the same level, as they
discharge relatively slowly under nominal load. Depending on just how
short the circuit is, all the ripple will flow past the capacitor, so
this isn't a problem, in and of itself.
2. When unshorted, supply current continues to flow into the formerly-
shorted channel until it reaches the same voltage as the other
channels, when current gets shared again. This charges the capacitor
quite quickly.

I could easily add a shunt and PNP transistor to each side of each
transformer primary as a rudimentary current limit, just dump it into
the current feedback node. Kinda dirties up the circuit with all the
extra hardware, but such is protection.

Tim

[George Herold]

On Jan 30, 10:18 am, John Larkin

<jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
> On 28 Jan 2012 20:48:21 GMT, Jasen Betts <ja...@xnet.co.nz> wrote:
>
>
>
>
>
> >On 2012-01-26, Tim Williams <tmoran...@gmail.com> wrote:
> >> On Jan 25, 9:55 pm, John Larkin
> >><jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
> >>> I don't exactly understand the situation. Got a sketch?
>
> >>> Does this involve tantalum caps?
>
> >> A description should suffice [rum disclaimer inserted here]:
>
> >> Yes -- I have eight output transformers in parallel from the same
> >> current-limited PWM driver.  Now, under normal conditions, all eight
> >> channels are working correctly, so the current shares evenly, and all
> >> the caps are happy (the maximum supply is 5A, so they each see a
> >> maximum of 5A / 8 = 0.6A peak, so the RMS ripple is under 0.42A, fine
> >> for a chip tantalum, though I have ceramic specified at the moment).
> >> But under fault, the whole 5A could flow into just one channel, which
> >> makes things "interesting".  I may implement a "max-of-channels"
> >> current limit for this.
>
> >Under this fault condition in the fault current passing through the
> >tantalum cap, or just visiting the neighbourhood?
>
> >energy density detonates tantalums, don't get them hot and
> >charged at the same time.
>
> What usually detonates them is high peak current, or equivalently high
> dV/dT.
>
> --
>

> John Larkin, President       Highland Technology Incwww.highlandtechnology.com  jlarkin at highlandtechnology dot com

>
> Precision electronic instrumentation
> Picosecond-resolution Digital Delay and Pulse generators
> Custom timing and laser controllers
> Photonics and fiberoptic TTL data links
> VME  analog, thermocouple, LVDT, synchro, tachometer

> Multichannel arbitrary waveform generators- Hide quoted text -

>
> - Show quoted text -

No, the worst thing about tant. caps is they get put in bakcwards*,

I spent an hour today, trying to figure out why the current limit
kept turning on, at ~3 volts, but only under a good load???

George H.

*(at least one spelling mistake intentionally left in.)
(with a failure time that varies between a minute and a day....)
grumble

[k...@att.bizzzzzzzzzzzz]

*MANY* moons ago, my boss was the Tantalum Cap Tzar for the corporation (how
he got that "distinction", I haven't the foggiest). We were having all sorts
of problems with fires caused by tants in backwards. Everything was tried,
three pins (-+-), four pins (-++-), big lead/little lead, fuses, everything.
No matter what, something like 1% of them got stuck in backwards (even to the
point that when all else went right 1% were in the tubes backwards).

One day the manager of the local manufacturing/stuffing department called
complaining that his "girls" were getting sore thumbs from sticking the
capacitors into the boards. Yep, they were big/little lead caps and they were
trying really hard to put the big lead in the little hole. They'd done a few
thousand that way.

>I spent an hour today, trying to figure out why the current limit
>kept turning on, at ~3 volts, but only under a good load???

I had a bunch go off about 2" from my ear, while I was leaning over the bench
try to figure out why the supply was limiting (I always brought systems up the
first time with the supply in constant current mode).

[John Larkin]

On Mon, 30 Jan 2012 19:18:41 -0800 (PST), George Herold
<ghe...@teachspin.com> wrote:


>

>No, the worst thing about tant. caps is they get put in bakcwards*,
>

Yeah, a lot of diodes have that same design defect.

John

--

John Larkin, President Highland Technology Inc

www.highlandtechnology.com jlarkin at highlandtechnology dot com

[George Herold]

On Jan 30, 10:32 pm, "k...@att.bizzzzzzzzzzzz"

> first time with the supply in constant current mode).- Hide quoted text -

>
> - Show quoted text -

Yeah... a backwards cap finally 'dawned' on me and it took less than
30 seconds to lay my fingers on the problem. New run... they're all
in backwards, except for a few I guess.

Does under voltaging (sp) make a few last longer?
I swear I've had stuff powered up for few hours, and then get pictures
sent of a 'brown' tantalum, in backwards.
(Return costs are expensive, but ya gotta take care of your
customers!)

George H.


George H.

[JW]

On Mon, 30 Jan 2012 22:32:49 -0500 "k...@att.bizzzzzzzzzzzz"
<k...@att.bizzzzzzzzzzzz> wrote in Message id:
<3rnei7lerlb7f7s6k...@4ax.com>:

>On Mon, 30 Jan 2012 19:18:41 -0800 (PST), George Herold
><ghe...@teachspin.com> wrote:

[...]

>>No, the worst thing about tant. caps is they get put in bakcwards*,
>
>*MANY* moons ago, my boss was the Tantalum Cap Tzar for the corporation (how
>he got that "distinction", I haven't the foggiest). We were having all sorts
>of problems with fires caused by tants in backwards. Everything was tried,
>three pins (-+-), four pins (-++-), big lead/little lead, fuses, everything.
>No matter what, something like 1% of them got stuck in backwards (even to the
>point that when all else went right 1% were in the tubes backwards).
>
>One day the manager of the local manufacturing/stuffing department called
>complaining that his "girls" were getting sore thumbs from sticking the
>capacitors into the boards. Yep, they were big/little lead caps and they were
>trying really hard to put the big lead in the little hole. They'd done a few
>thousand that way.

I'd like to see them put these in backwards:
http://www.vishay.com/docs/40044/299d.pdf

Even AlwaysWrong couldn't screw up with those. :)

[John Larkin]

Conventional wisdom is that tantalums can run at -3 volts or -10% of
rated voltage, whichever is more. Or less maybe.

Why put them in backwards?


**********************************

John Larkin, President
Highland Technology, Inc

jlarkin at highlandtechnology dot com

http://www.highlandtechnology.com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators

Custom laser controllers

Photonics and fiberoptic TTL data links

VME thermocouple, LVDT, synchro acquisition and simulation

[k...@att.bizzzzzzzzzzzz]

That's sorta the "three pin" cap I was referring to above. These were
"tombstone" variety, but the idea is the same.

>Even AlwaysWrong couldn't screw up with those. :)

Don't bet on it. Get them one position off, and what do you have? BTW, our
boards had a hole every .100" (or .125", depending on the technology in use).

[JW]

On Tue, 31 Jan 2012 19:58:16 -0500 "k...@att.bizzzzzzzzzzzz"

<k...@att.bizzzzzzzzzzzz> wrote in Message id:

<hc3hi7tu2jb56ti99...@4ax.com>:

Oh. That would be a deal killer then. For those to work, you'd need a
reasonable area around the cap with no vias.

[George Herold]

On Jan 31, 2:51 pm, John Larkin <jlar...@highlandtechnology.com>
wrote:

> On Mon, 30 Jan 2012 19:58:18 -0800 (PST), George Herold
>
>
>
>
>

Well some can run at ~ -12V (-33%) for several hours before cooking
themselves.

>
> Why put them in backwards?

It was a mistake. Either we gave the board house the wrong polarity
or they screwed up. There's this very tiny (+) sign on the tant.
(through hole)

George H.

>
> **********************************
>
> John Larkin, President
> Highland Technology, Inc
>

> jlarkin at highlandtechnology dot comhttp://www.highlandtechnology.com

>
> Precision electronic instrumentation
> Picosecond-resolution Digital Delay and Pulse generators
> Custom laser controllers
> Photonics and fiberoptic TTL data links

> VME thermocouple, LVDT, synchro   acquisition and simulation- Hide quoted text -

[k...@att.bizzzzzzzzzzzz]

That's why we also had the 4-pin caps (-++-). If they're off a hole there was
a direct short, which was easily found.