Tantalum caps

[Phil Allison]

"Jan Panteltje"

I just made this up to counter your argument .

I have seen exactly one tantalum blow up,

** Then you are someone who sees no faulty equipment.

Designers are the ** WORST ** people for knowing about or analysing
component failures, cos they never fucking see any.

I have seen hundreds used and used myself without ever having a problem.

** Designers are the ** WORST ** people for knowing about or analysing
component failures, cos they never fucking see any.

I stopped using them a lot because they were much more expensive than the
normal electrolytics.

** The ratio of bead tants to normal electros used in consumer electronics
is about 1:10,000



..... Phil

 

[JW]

I guess you never worked in a repair department Besides that
tantalums may explode when mounted wrong.

A backwards tant is like a ticking time bomb except you never know how
long the fuse is. Could happen in a few seconds, or months later after it
gets to the customer.

Last year one blew up right
in my face when testing a board which just came in from the assembly
company. Fortunately I wear glasses otherwise I would have suffered
serious eye injuries.

I was working on a HP 8561E a few weeks ago that had 3 pin dipped
tantalums all over - they are impossible to put in backwards. IIRC the
center was the + and the two outer leads were the -. (or vice versa, can't
remember.)

 

[Nial Stewart]

Failure to put 15" of 10-mil wide 1/2 oz copper in series with the

That's about 1.5 ohms. I'd go for a little more to be safe, 60" maybe.

I've seen appnotes from the cap manufacturers who seriously suggest
adding a series resistor of 1 or 2 ohms per volt of supply rail. Kinda
alters the concept.

That was the design rule when I started at Nortel (early '90s), the boards
weren't allowed to self ignite under any circumstances.

If you were using a tant you had to have 1 ohm/volt in series.


Nial.

 

[Phil Allison]

"Nial Stewart"

That was the design rule when I started at Nortel (early '90s), the boards
weren't allowed to self ignite under any circumstances.

If you were using a tant you had to have 1 ohm/volt in series.

** Bit like wearing two condoms ....





..... Phil

 

[Boris Mohar]

IME, it's less of a problem where you have internal relatively wimpy
power supplies.

When you give the customer power supply connections or allow hot
plugging of PCBs it's more likely to show up.

That first surface mount Tantalum picture is from one of my boards. It was a
low ESR input filter for switching power supply. Ceramic cap in parallel
cured the problem.

 

[Phil Allison]

"Jan Panteltje = LIAR "

mhh,

** **** off.

considering I spend many of my years in service and repair,

** Shame how you learnt nothing.

Well seems .......

** Get fucking fucked, you stinking, pompous wog ASS.

You could be wrong,

** Get fucking fucked, you stinking, pompous wog ASS.

My god I hate lying, autistic wog cunts like you.





..... Phil

 

[StickThatInYourPipeAndSmokeIt]

Never use a tantalum. They suck. Or, actually, they blow!

The piss poor peanut gallery comment retard shines through with another
retarded comment... AGAIN.

 

[MakeNoAttemptToAdjustYourSet]

Well seems to be 'have to disagree day', designers at least read the dataheets.
Sometimes they test things to the limit before actually using them in a ciruit.

You're an idiot. Component engineers test devices BEYOND their
ratings.

You have never heard of "destructive testing"?

When we sold HV supplies to NOAA, they bought three, tested all three,
and then beat the piss out of one, and only one goes on the balloon,
never to be seen again.

But they make sure all three perform within their design spec window
very precisely, and beyond it, and far beyond it with one unit.

THAT is how the military and science guys work.

The post where you describe your RF burns and "scars" tells me that
there are several things you missed in your education.

 

[John S]

The piss poor peanut gallery comment retard shines through with another
retarded comment... AGAIN.

....said AlwaysWrong who doesn't know any better. AS ALWAYS.

 

[Jeroen Belleman]

Really? How narrow? Have you ever connected one to a network
analyzer to see how it looks?

I have. Your typical Ta cap looks like having about 3nH and
300mOhm in series with it. Small values have more resistance.
It was somewhat of a surprise to me to discover that radial-
leaded Al caps are just as good, at least while they're new.
Axial-leaded Al caps are all over the place.

Jeroen Belleman

 

[Nico Coesel]

Sometimes they do noting when connected backwards. I found one that
had been through production testing & 72 hour burn in without shorting
or exploding. Something else on that board had failed, and I spotted
the backwards tantalum and replaced it.

The manufacturing department of one of the companies I have worked for
connected a few tantalums backwards. We tried to locate those boards
and fix them but for some it was too late as they already burned a
hole straight through the PCB (15A PSU). IIRC it took a year before
the last one blew.

As far as failed tantalums in repair: Tantalums lasted a hell of a
lot longer than aluminum in the broadcast gear I maintained. The

That is true, but ceramics are a superior alternative to tantalum
nowadays.

 

[Nico Coesel]

You could be wrong, it is just that the tants normally never cause problems
that you do not notice it.

I will give an example: little portable stuff full of tants, no problem ever,
Old (first) Sony cassete recorder I had it, expensive, full of tants.

I had a TV service shop, now if you want defective *capacitors*
that is the place to be, dried out electrolitics, exploded electrolytics,
electrolytics with a very high ESR and inductance without any reason (foil come lose?).
I have seen it all, it used to be standard faults for example Philips

Bad electrolytics are a typical failure of TVs, monitors and power
supplies. However, I've come across a lot of failed tantalums in
computer equipment where they where used for decoupling power
supplies.

 

[[email protected]]

Bad electrolytics are a typical failure of TVs, monitors and power
supplies. However, I've come across a lot of failed tantalums in
computer equipment where they where used for decoupling power
supplies.

Sure, there was a spate of bad tantalums some years ago. It was an infamous
industrial espionage thing. Most of them ended up in computer motherboards,
where the manufacturers were trying to save every nickel the could.

I've seen problems with tantalums over the years, too. Most were production
problems and some were defective components and fewer still, design. One rule
we had was that tantalums had to be underrated 50% (resistors, too, but that's
another issue). Only a few manufacturers were qualified and their quality was
strictly monitored. This is likely why most of the issues ended up being
production problems. They just couldn't seem to get the damned things in the
right direction. ;-)

Over the past couple of years I designed most tantalums out because of cost or
availability, not because I was afraid of them. As others have pointed out,
ceramics in the 1-10uF range have gotten cheap. Larger caps have been a
problem because aluminums are pretty bad WRT RoHS. Some high-temp aluminums
have become available but only smaller ones and they're not cheap either.

 

[[email protected]]

IIRC IBM used to have special 3-legged tants, they never put them in the
wrong way round.

Yes, and 4-legged. Since many boards had a hole every .100", it was still
possible to get them a pin off. The 4-legged ones made it more obvious. ;-)
If it was possible, it happened.

There were also big-leg, little-leg tantalums, meant to go into big-hole,
little-hole on the boards. One day my boss got a call from production
bitching that the "girls" were getting sore thumbs stuffing the capacitors
into boards. If it was possible, it happened.

 

[[email protected]]

'came hear'?

Right. That's when he heard it.

 

[Spehro Pefhany]

Sure, there was a spate of bad tantalums some years ago. It was an infamous
industrial espionage thing. Most of them ended up in computer motherboards,
where the manufacturers were trying to save every nickel the could.

Don't remember that. I do remember the bad low-ESR aluminum
electrolytics, allegdly due to a stolen formula for electrolyte that
Taiwanese makers used, which apparently omitted some stabilizers. They
were typically radial caps of something like 1,000uF-2,700uF/6.3V.
Bulging at the top was one symptom.

I've seen problems with tantalums over the years, too. Most were production
problems and some were defective components and fewer still, design. One rule
we had was that tantalums had to be underrated 50% (resistors, too, but that's
another issue). Only a few manufacturers were qualified and their quality was
strictly monitored. This is likely why most of the issues ended up being
production problems. They just couldn't seem to get the damned things in the
right direction. ;-)

It doesn't help that aluminum electrolytics typically have a mark at
the minus side (case) whereas tantalums usually have the + side
marked.

 

[Nico Coesel]

Listen up Phil, you autistic shit. If you won't learn to shut your
mouth, I will shut you down for good.

You DO NOT EVER call people names.
You DO NOT EVER tell people to get fucked
You DO NOT EVER make ethnic based insults
AND you most definitely DO NOT EVER call people "Autistic"

Up until this week you were doing real good, but if you really want to
be publicly humiliated I'm here to help.

Relax. Phil's uncle is called Gilles de la Tourette. It runs in the
family.

 

[Jamie]

Relax. Phil's uncle is called Gilles de la Tourette. It runs in the
family.

Diarrhea is also hereditary for him, it runs in the genes!


Jamie

 

[Jamie]

I've never seen a blown-up tantalum cap, and until I came hear I'd never
even heard of one.

Thanks,
Rich

Because you most likely deal with properly engineered electronics

Jamie

 

[StickThatInYourPipeAndSmokeIt]

On 23/09/2011 2:36 AM, David Eather wrote:

I don't even like you so I have no idea why I give you any chances.

Matbe because you are just as stupid AND ineffectual as he is.