Tantalum capacitor ESR

C

Cursitor Doom

Guest
Gentlemen,

I took a crazy risk and got some axial Kemet tantalums off Ebay
(purportedly genuine). These are visually identical to the originals
out of one of my HP boat anchors. And the ESR figures are better than
the equivalent new aluminium (aloominum if you're in the US)
electrolytics. But are these ESRs low enough to be the real thing?
Here's an example of the values I'm seeing:

3.3uF / 60V = 0.68 ohms
1uF / 60V = 1.1 ohms
2.2uF /50V = 0.62

Thanks,

CD
 
Am 20.03.20 um 01:31 schrieb Cursitor Doom:
Gentlemen,

I took a crazy risk and got some axial Kemet tantalums off Ebay
(purportedly genuine). These are visually identical to the originals
out of one of my HP boat anchors. And the ESR figures are better than
the equivalent new aluminium (aloominum if you're in the US)
electrolytics. But are these ESRs low enough to be the real thing?
Here's an example of the values I'm seeing:

3.3uF / 60V = 0.68 ohms
1uF / 60V = 1.1 ohms
2.2uF /50V = 0.62
Click to expand...

I have measured 400 mOhm for 4700 UF / 25V / AVX / wet tantalum
bought from DK or Mouser.
Kinda disappointing for > €100.

But the leakage current was OK, that's what I really needed.

Cheers,
Gerhard
 
On Thursday, March 19, 2020 at 8:53:52 PM UTC-4, Winfield Hill wrote:
Gerhard Hoffmann wrote...

schrieb Cursitor Doom:

I took a crazy risk and got some axial Kemet tantalums ...

I have measured 400 mOhm ...

Perhaps your concern should be whether they will explode
or not. I used 10s of thousands of Kemet rectangular
axial-lead tantalums in oceanographic instruments my
company made in the 70s and 80s, without any incidents.
Click to expand...

I have a Kemet tantalum on the board I produce. The original contract assembler I used would automatically replace that part if the board didn't work.. They never told me there was a problem. Seems some percentage of them would short or open or something. Later with another assembly house they had one scorch the board. I dug into that a bit (with some help here) and added a power on with a series resistor as the initial part of the test procedure. Too soon to know if that has helped the problem, but that is what has been recommended by a number of people.

--

Rick C.

- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209
 
Gerhard Hoffmann wrote...
schrieb Cursitor Doom:

I took a crazy risk and got some axial Kemet tantalums ...

I have measured 400 mOhm ...
Click to expand...

Perhaps your concern should be whether they will explode
or not. I used 10s of thousands of Kemet rectangular
axial-lead tantalums in oceanographic instruments my
company made in the 70s and 80s, without any incidents.


--
Thanks,
- Win
 
On Fri, 20 Mar 2020 01:40:02 +0100, Gerhard Hoffmann <dk4xp@arcor.de>
wrote:

Am 20.03.20 um 01:31 schrieb Cursitor Doom:
Gentlemen,

I took a crazy risk and got some axial Kemet tantalums off Ebay
(purportedly genuine). These are visually identical to the originals
out of one of my HP boat anchors. And the ESR figures are better than
the equivalent new aluminium (aloominum if you're in the US)
electrolytics. But are these ESRs low enough to be the real thing?
Here's an example of the values I'm seeing:

3.3uF / 60V = 0.68 ohms
1uF / 60V = 1.1 ohms
2.2uF /50V = 0.62

I have measured 400 mOhm for 4700 UF / 25V / AVX / wet tantalum
bought from DK or Mouser.
Kinda disappointing for > €100.
Click to expand...

Do they still make those out of silver?



--

John Larkin Highland Technology, Inc

The cork popped merrily, and Lord Peter rose to his feet.
"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"
 
On Thu, 19 Mar 2020 20:39:46 -0700, jlarkin@highlandsniptechnology.com
wrote:

On Fri, 20 Mar 2020 01:40:02 +0100, Gerhard Hoffmann <dk4xp@arcor.de
wrote:

Am 20.03.20 um 01:31 schrieb Cursitor Doom:
Gentlemen,

I took a crazy risk and got some axial Kemet tantalums off Ebay
(purportedly genuine). These are visually identical to the originals
out of one of my HP boat anchors. And the ESR figures are better than
the equivalent new aluminium (aloominum if you're in the US)
electrolytics. But are these ESRs low enough to be the real thing?
Here's an example of the values I'm seeing:

3.3uF / 60V = 0.68 ohms
1uF / 60V = 1.1 ohms
2.2uF /50V = 0.62

I have measured 400 mOhm for 4700 UF / 25V / AVX / wet tantalum
bought from DK or Mouser.
Kinda disappointing for > €100.

Do they still make those out of silver?
Click to expand...

I think you're thinking about the hi-stability mica ones. And get back
to bed, John, you need to strengthen your immune system right now.
 
On 2020-03-20 11:14, Cursitor Doom wrote:
On Thu, 19 Mar 2020 20:39:46 -0700, jlarkin@highlandsniptechnology.com
wrote:

On Fri, 20 Mar 2020 01:40:02 +0100, Gerhard Hoffmann <dk4xp@arcor.de
wrote:

Am 20.03.20 um 01:31 schrieb Cursitor Doom:
Gentlemen,

I took a crazy risk and got some axial Kemet tantalums off Ebay
(purportedly genuine). These are visually identical to the originals
out of one of my HP boat anchors. And the ESR figures are better than
the equivalent new aluminium (aloominum if you're in the US)
electrolytics. But are these ESRs low enough to be the real thing?
Here's an example of the values I'm seeing:

3.3uF / 60V = 0.68 ohms
1uF / 60V = 1.1 ohms
2.2uF /50V = 0.62
Click to expand...

I measured ESR values for some small Ta capacitors many years
ago and these values are about what I found at the time. My
conclusion was that small Ta caps are pretty much useless.

Jeroen Belleman
 
On Fri, 20 Mar 2020 10:14:17 +0000, Cursitor Doom
<curd@notformail.com> wrote:

On Thu, 19 Mar 2020 20:39:46 -0700, jlarkin@highlandsniptechnology.com
wrote:

On Fri, 20 Mar 2020 01:40:02 +0100, Gerhard Hoffmann <dk4xp@arcor.de
wrote:

Am 20.03.20 um 01:31 schrieb Cursitor Doom:
Gentlemen,

I took a crazy risk and got some axial Kemet tantalums off Ebay
(purportedly genuine). These are visually identical to the originals
out of one of my HP boat anchors. And the ESR figures are better than
the equivalent new aluminium (aloominum if you're in the US)
electrolytics. But are these ESRs low enough to be the real thing?
Here's an example of the values I'm seeing:

3.3uF / 60V = 0.68 ohms
1uF / 60V = 1.1 ohms
2.2uF /50V = 0.62

I have measured 400 mOhm for 4700 UF / 25V / AVX / wet tantalum
bought from DK or Mouser.
Kinda disappointing for > €100.

Do they still make those out of silver?

I think you're thinking about the hi-stability mica ones. And get back
to bed, John, you need to strengthen your immune system right now.
Click to expand...

The CSR13-type wet tantalums had hermetrically sealed silver cases.
They were great electrically, but eventually corroded and leaked from
the chemicals inside.



--

John Larkin Highland Technology, Inc

The cork popped merrily, and Lord Peter rose to his feet.
"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"
 
On Fri, 20 Mar 2020 04:24:06 -0700, jlarkin@highlandsniptechnology.com
wrote:

The CSR13-type wet tantalums had hermetrically sealed silver cases.
They were great electrically, but eventually corroded and leaked from
the chemicals inside.
Click to expand...

These are the type I bought:

https://i.pinimg.com/originals/10/ec/68/10ec686628e6233d117c956a1881d6c1.jpg

Smaller capacity values, but *precisely* the same encapsulation.

Now go back to bed.
 
On Fri, 20 Mar 2020 12:34:35 +0100, Jeroen Belleman
<jeroen@nospam.please> wrote:

I measured ESR values for some small Ta capacitors many years
ago and these values are about what I found at the time. My
conclusion was that small Ta caps are pretty much useless.
Click to expand...

Interesting. HP made widespread use of them in their boat-anchors of
25-40 years ago. I'd really like to compare them with their aloominum
electros' equivalent values, but my ESR meter becomes unreliable at
anything sub 1uF so the other tants I bought at the same time (0.22uF,
0.33uF and so forth) are beyond my ability to test. I just have to
assume they're fine because larger ones from the same supplier seem to
compare well with the values of those shown on the datasheets of known
good manufacturers.
 
On Fri, 20 Mar 2020 12:53:11 +0000, Cursitor Doom
<curd@notformail.com> wrote:

On Fri, 20 Mar 2020 04:24:06 -0700, jlarkin@highlandsniptechnology.com
wrote:

The CSR13-type wet tantalums had hermetrically sealed silver cases.
They were great electrically, but eventually corroded and leaked from
the chemicals inside.


These are the type I bought:

https://i.pinimg.com/originals/10/ec/68/10ec686628e6233d117c956a1881d6c1.jpg
Click to expand...

That looks like the classic silver-can wet-slug tantalum. Some later
models had a tantalum case. Silver dollars used to be silver too.

Smaller capacity values, but *precisely* the same encapsulation.

Now go back to bed.
Click to expand...

The problem with this idiotic lockdown is that all days seem the same
when you don't go to work. So we forgot that we have to put the trash
out on Thursday night. We heard the truck outside about 4AM. I had to
open the garage, grab the black and green wheelie bins, and chase the
truck down the block in my socks. He (or maybe she?) was really nice
and we had a little talk about the general situation. But that woke us
up pretty good.

Steering one wheelie bin at walking pace isn't bad. Running with two
is dynamically unstable.

Retirement must feel like this. All days the same, no reason to go to
bed or get up at any particular time, not much to do.



--

John Larkin Highland Technology, Inc

The cork popped merrily, and Lord Peter rose to his feet.
"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"
 
On 2020-03-19 20:31, Cursitor Doom wrote:
Gentlemen,

I took a crazy risk and got some axial Kemet tantalums off Ebay
(purportedly genuine). These are visually identical to the originals
out of one of my HP boat anchors. And the ESR figures are better than
the equivalent new aluminium (aloominum if you're in the US)
electrolytics. But are these ESRs low enough to be the real thing?
Here's an example of the values I'm seeing:

3.3uF / 60V = 0.68 ohms
1uF / 60V = 1.1 ohms
2.2uF /50V = 0.62

Thanks,

CD
Click to expand...

Intermediate values of ESR are basically what tants have to offer.
That's why we didn't have problems with voltage regulators oscillating
back before huge ceramics and alpos were available.

Those values might even be on the low side for a small cap like that.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com
 
On Fri, 20 Mar 2020 12:34:35 +0100, Jeroen Belleman
<jeroen@nospam.please> wrote:

On 2020-03-20 11:14, Cursitor Doom wrote:
On Thu, 19 Mar 2020 20:39:46 -0700, jlarkin@highlandsniptechnology.com
wrote:

On Fri, 20 Mar 2020 01:40:02 +0100, Gerhard Hoffmann <dk4xp@arcor.de
wrote:

Am 20.03.20 um 01:31 schrieb Cursitor Doom:
Gentlemen,

I took a crazy risk and got some axial Kemet tantalums off Ebay
(purportedly genuine). These are visually identical to the originals
out of one of my HP boat anchors. And the ESR figures are better than
the equivalent new aluminium (aloominum if you're in the US)
electrolytics. But are these ESRs low enough to be the real thing?
Here's an example of the values I'm seeing:

3.3uF / 60V = 0.68 ohms
1uF / 60V = 1.1 ohms
2.2uF /50V = 0.62

I measured ESR values for some small Ta capacitors many years
ago and these values are about what I found at the time. My
conclusion was that small Ta caps are pretty much useless.

Jeroen Belleman
Click to expand...

Lots of linear regulators are super stable with one big tantalum and a
bunch of ceramics on their output.



--

John Larkin Highland Technology, Inc

The cork popped merrily, and Lord Peter rose to his feet.
"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"
 
On 20/03/20 14:06, jlarkin@highlandsniptechnology.com wrote:
Retirement must feel like this. All days the same, no reason to go to
bed or get up at any particular time,
Click to expand...

For many people, working in cubicle land can be like
that too :(

> not much to do.

Don't bet on it; many people wonder how they managed
to do things before retirement!

The main difference is that there is less pressure
to do X /today/. "MaĂąana" can can be tempting.
 
On Fri, 20 Mar 2020 07:06:09 -0700, jlarkin@highlandsniptechnology.com
wrote:

Retirement must feel like this. All days the same, no reason to go to
bed or get up at any particular time, not much to do.
Click to expand...

That's *exactly* how it feels. And weekends lose much of their
significance, too. That's why after 2 years of "exquisite pregnant
idleness" I decided to go back to some form of work. Didn't need the
money; just had enough of tumbling helplessly through time with no
reference points to mark the passage towards the grave.
 
On 20/03/2020 14:06, jlarkin@highlandsniptechnology.com wrote:
That looks like the classic silver-can wet-slug tantalum. Some later
models had a tantalum case. Silver dollars used to be silver too.
Click to expand...

You can't tell by just looking because they put the solid type inside
those hermetic glass-metal-seal cases too. Part number (and price) will
distinguish better :)

piglet
 
On 20/03/2020 00:53, Winfield Hill wrote:
Gerhard Hoffmann wrote...

schrieb Cursitor Doom:

I took a crazy risk and got some axial Kemet tantalums ...

I have measured 400 mOhm ...

Perhaps your concern should be whether they will explode
or not. I used 10s of thousands of Kemet rectangular
axial-lead tantalums in oceanographic instruments my
company made in the 70s and 80s, without any incidents.
Click to expand...

Gerhard's hecto-buck wet tants have a much lower risk of exploding than
the far more common sintered solid construction that react badly to
surge currents.

piglet
 
On Friday, March 20, 2020 at 1:27:04 PM UTC-4, Cursitor Doom wrote:
On Fri, 20 Mar 2020 07:06:09 -0700, jlarkin@highlandsniptechnology.com
wrote:

Retirement must feel like this. All days the same, no reason to go to
bed or get up at any particular time, not much to do.

That's *exactly* how it feels. And weekends lose much of their
significance, too. That's why after 2 years of "exquisite pregnant
idleness" I decided to go back to some form of work. Didn't need the
money; just had enough of tumbling helplessly through time with no
reference points to mark the passage towards the grave.
Click to expand...

Reminds me of an episode of Downton Abbey where the men are discussing some business matter at a meal and mention it can be done on the weekend. Maggie Smith playing Violet Crawley, the Dowager Countess of Grantham, says, "What is a week end?"

https://www.youtube.com/watch?v=zhfpBW-nUWk

I suggest you take up some hobby such as kayaking.

--

Rick C.

+ Get 1,000 miles of free Supercharging
+ Tesla referral code - https://ts.la/richard11209
 
On 21/3/20 4:26 am, Cursitor Doom wrote:
On Fri, 20 Mar 2020 07:06:09 -0700, jlarkin@highlandsniptechnology.com
wrote:
Retirement must feel like this. All days the same, no reason to go to
bed or get up at any particular time, not much to do.
That's *exactly* how it feels. And weekends lose much of their
significance, too.
Click to expand...

A weekend is still significant because when you go places, they're full
of kids and their parents.
 
On Friday, 20 March 2020 00:53:52 UTC, Winfield Hill wrote:
Gerhard Hoffmann wrote...

schrieb Cursitor Doom:

I took a crazy risk and got some axial Kemet tantalums ...

I have measured 400 mOhm ...

Perhaps your concern should be whether they will explode
or not. I used 10s of thousands of Kemet rectangular
axial-lead tantalums in oceanographic instruments my
company made in the 70s and 80s, without any incidents.
Click to expand...

Keep them to at most 1/3 rated V and they should be fine.


NT
 
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