Electrolytic caps?

M

Melissa

Guest
I used to work in electronics and have several large boxes of electrolytic
caps in my lab. Does anyone still use them for anything? Is there even any
electronics still being built in this country?

--
Yours In Liberty, Melissa - Colorado, U.S.A.
http://lakewoodcolorado.net/MailOrderPrototypes.htm
 
Melissa wrote:
I used to work in electronics and have several large boxes of electrolytic
caps in my lab. Does anyone still use them for anything? Is there even any
electronics still being built in this country?

--
Yours In Liberty, Melissa - Colorado, U.S.A.
http://lakewoodcolorado.net/MailOrderPrototypes.htm
Click to expand...
What type / voltage/ capacitance are they?

--
Beware of those who post from srvinet.com!

Michael A. Terrell
Central Florida
 
"Melissa" <melissa@colorado.xxx> wrote in message
news:QYedncdMwIethb3fRVn-3A@forethought.net...
I used to work in electronics and have several large boxes of
electrolytic
caps in my lab. Does anyone still use them for anything? Is there even
any
electronics still being built in this country?
Click to expand...
Yes and yes, but it depends on how old those caps are. Over five years
old, and they're not 'fresh'; ten years and they're 'stale'.


--
Yours In Liberty, Melissa - Colorado, U.S.A.
http://lakewoodcolorado.net/MailOrderPrototypes.htm
Click to expand...
 
Hello Watson,

Yes and yes, but it depends on how old those caps are. Over five years
old, and they're not 'fresh'; ten years and they're 'stale'.
Click to expand...
Nah. I have some 40+ year old radios where the electrolytic caps are
just fine. A couple times I actually did a resistor charge and leakage
test just to see. They were nearly as good as new.

But sometimes when they had been in storage for decades they may have to
be "formatted" slowly to get them used to the job of "being a capacitor"
again.

Regards, Joerg

http://www.analogconsultants.com
 
On Sat, 26 Feb 2005 21:51:38 GMT, Joerg
<notthisjoergsch@removethispacbell.net> wrote:

Hello Watson,

Yes and yes, but it depends on how old those caps are. Over five years
old, and they're not 'fresh'; ten years and they're 'stale'.



Nah. I have some 40+ year old radios where the electrolytic caps are
just fine. A couple times I actually did a resistor charge and leakage
test just to see. They were nearly as good as new.

But sometimes when they had been in storage for decades they may have to
be "formatted" slowly to get them used to the job of "being a capacitor"
again.

Regards, Joerg

http://www.analogconsultants.com
Click to expand...
Hi, Joerg. I do, literally, have some 40 year-old aluminum
electrolytics in my part bins.

What's the best way to "format" them?

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.
 
Jim Thompson wrote:

On Sat, 26 Feb 2005 21:51:38 GMT, Joerg
notthisjoergsch@removethispacbell.net> wrote:


Hello Watson,


Yes and yes, but it depends on how old those caps are. Over five years
old, and they're not 'fresh'; ten years and they're 'stale'.



Nah. I have some 40+ year old radios where the electrolytic caps are
just fine. A couple times I actually did a resistor charge and leakage
test just to see. They were nearly as good as new.

But sometimes when they had been in storage for decades they may have to
be "formatted" slowly to get them used to the job of "being a capacitor"
again.

Regards, Joerg

http://www.analogconsultants.com


Hi, Joerg. I do, literally, have some 40 year-old aluminum
electrolytics in my part bins.

What's the best way to "format" them?

...Jim Thompson
Click to expand...
Its "forming" (technically "reforming" since it was already done once at
the factory long long ago). You can do a web search on electrolytic
forming.

Basically you feed it rated voltage through a big current limiting
resistor -- what you're doing is restoring the aluminum oxide layer on
the foil. There are a number of techniques for verifying that the
forming is complete (vs. the cap being bad) -- basically when you think
you're done you test with more than the rated voltage to see if the
thing leaks -- if so, you scrap it.

I've never done it, but it's a common thing with tube-equipped boat anchors.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com
 
Jim Thompson wrote:
Hi, Joerg. I do, literally, have some 40 year-old aluminum
electrolytics in my part bins.

What's the best way to "format" them?

Jim Thompson
Click to expand...
I prefer to go for "High density". :)


Actually, after you re-form the oxide layer with a limited current
(<.1 ma) at the rated voltage you check the ESR to made sure the cap is
good. Any signs of leaked electrolyte automatically makes it a bad
part.


--
Beware of those who post from srvinet.com!

Michael A. Terrell
Central Florida
 
"Watson A.Name - \"Watt Sun, the Dark Remover\"" <NOSPAM@dslextreme.com>
wrote :

"Melissa" <melissa@colorado.xxx> wrote in message
news:QYedncdMwIethb3fRVn-3A@forethought.net...
I used to work in electronics and have several large boxes of
electrolytic
caps in my lab. Does anyone still use them for anything? Is there even
any
electronics still being built in this country?

Yes and yes, but it depends on how old those caps are. Over five years
old, and they're not 'fresh'; ten years and they're 'stale'.
Click to expand...
And that means what?

--
Grassroots
( no email - spoofed )
 
Grass roots wrote:
And that means what?
Click to expand...
It means that caps made during certain time periods and some
companies are prone to failure from dried out seals and depending on the
electrolyte used, the cpacitors may neeed to be re-formed.

--
Beware of those who post from srvinet.com!

Michael A. Terrell
Central Florida
 
John Woodgate wrote:
I read in sci.electronics.design that Michael A. Terrell
mike.terrell@earthlink.net> wrote (in <42210247.53923FA3@earthlink.net
) about 'Electrolytic caps?', on Sat, 26 Feb 2005:

Actually, after you re-form the oxide layer with a limited current
(<.1 ma) at the rated voltage you check the ESR to made sure the cap is
good. Any signs of leaked electrolyte automatically makes it a bad
part.

Both residual leakage current and ESR are important, but for ESR you
need some guidance on what is 'good' and 'bad'. It depends on a number
of factors.
--
Regards, John Woodgate
Click to expand...
I try to find the OEM specs for the cap and check it with my Bob
Parker ESR meter. Failing that, I compare the capacitor(s) to others on
hand, or to the specs of similar caps from other OEMs.

I have been running about a 50% failure rate for new old stock and
salvaged electrolytics over the last year. I did the tests to entertain
myself while I couldn't work, and had nothing to do and couldn't get on
line for a year.

I used to have a Sprague TO-6 capacitor analyzer to check capacitance
and leakage. I'm thinking about designing a digital unit to replace it
and maybe sell kits.

--
Beware of those who post from srvinet.com!

Michael A. Terrell
Central Florida
 
"Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
news:Kb6Ud.7462$OU1.5066@newssvr21.news.prodigy.com...
Hello Watson,

Yes and yes, but it depends on how old those caps are. Over five
years
old, and they're not 'fresh'; ten years and they're 'stale'.



Nah. I have some 40+ year old radios where the electrolytic caps are
just fine. A couple times I actually did a resistor charge and leakage
test just to see. They were nearly as good as new.
Click to expand...
Depends on a lot of factors including how long they have set without
being used, how long they have been used, how high a temp they have been
exposed to, etc. And of course how well they were made. The old timers
seem to be better made back then, and withstand the test of time better.
But the stuff being made today isn't as well made, IMHO. Smaller size,
les ofecerything, etc, means they don't last like they used to.

I just got thru replacing the main filter caps on two different HP PSes;
both were dead and gone. In one case the PS was 40+ yrs old, so it's
understandable. But 5 years is usually what they aim for. Hey, they're
full of juice, don'tcha know.

But sometimes when they had been in storage for decades they may have
to
be "formatted" slowly to get them used to the job of "being a
capacitor"
again.
Click to expand...
That's reformed, as opposed to the original forming. And even so, you
may find that some of the juice has leaked, so you won't get the full
rated capacitance, but just a fraction.

Regards, Joerg

http://www.analogconsultants.com
Click to expand...
 
"Michael A. Terrell" wrote:

Grass roots wrote:

And that means what?

It means that caps made during certain time periods and some
companies are prone to failure from dried out seals and depending on the
electrolyte used, the cpacitors may neeed to be re-formed.
Click to expand...
I think the Japanese choice of calling electrolytics 'chemical caps' or
chemicons makes this more obvious. Probably the least reliable components
still in use but regrettably necessary.


Graham
 
On Mon, 28 Feb 2005 00:13:22 +0000, Pooh Bear wrote:

"Michael A. Terrell" wrote:

Grass roots wrote:

And that means what?

It means that caps made during certain time periods and some
companies are prone to failure from dried out seals and depending on the
electrolyte used, the cpacitors may neeed to be re-formed.

I think the Japanese choice of calling electrolytics 'chemical caps' or
chemicons makes this more obvious. Probably the least reliable components
still in use but regrettably necessary.
Click to expand...
Ok, why is "electrolytic" any worse of a term? Certainly we all know what
is bing talked about.

--
Keith
 
Pooh Bear wrote:
I think the Japanese choice of calling electrolytics 'chemical caps' or
chemicons makes this more obvious. Probably the least reliable components
still in use but regrettably necessary.

Graham
Click to expand...
Yes, electrolytics are a cheap way to get a large capacitance and it
is a trade-off between size and cost against reliability. I have to
laugh at some of the people who condemn radio manufactures for using
cheap paper caps 75 years ago, yet they brag about tracking down the
cheapest chinese no name parts they can find for their restorations.
Not all plastic insulating films are of the same quality and I wonder
how long it will be before these new high voltage caps last before they
start breaking down. Will people be condemning them for their bad
choices in say, ten years?

On the other hand you can find NOS Sprague and other American made
electrolytic caps that are fifty years old with good seals and still
have the marked capacitance along with a good ESR. Not all of them, but
a lot higher percentage than current production electrolytic caps will
be at that age.

--
Beware of those who post from srvinet.com!

Michael A. Terrell
Central Florida
 
I read in sci.electronics.design that Pooh Bear <rabbitsfriendsandrelati
ons@hotmail.com> wrote (in <422263B9.C57CD3F9@hotmail.com>) about
'Electrolytic caps?', on Mon, 28 Feb 2005:

It was finally found that the the nichrome wire that they were using in
the ovens was quenched in a salt solution during the manufacturing
process. Sodium ions were 'boiling out' of the wire and entering the
chips. Initially this caused no problem until the sodium ions migrated
into the active region and threw the threshold voltages of the fets all
over the place.
Click to expand...
One of the most spectacular of these trace effects is just touching a
THICK tungsten wire used for the filaments of big transmitting valves
with nickel-plated tweezers. Just try to bend the wire a bit and it
snaps like glass rod where it was touched.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk
 
On Mon, 28 Feb 2005 18:45:01 -0600, Melissa <melissa@colorado.xxx>
wrote:

"Watson A.Name - \"Watt Sun, the Dark Remover\"" <NOSPAM@dslextreme.com
wrote :


"Pooh Bear" <rabbitsfriendsandrelations@hotmail.com> wrote in message
news:4222608A.D8502E31@hotmail.com...


Melissa wrote:

Melissa <melissa@colorado.xxx> wrote :

"Michael A. Terrell" <mike.terrell@earthlink.net> wrote :

Melissa wrote:


I don't recall, I'd have to go look. I have boxes of them all over
the
place in my lab, which still hasn't been unpacked since we moved.


Here, I have a huge case of these, for starters:
http://dimensional.com/~melissa/photos/Cap1500uf100v.JPG

As they're designed for hand wiring as opposed to pcb mount, I doubt
many
ppl would be interested in them these days.

You could always try shifting them on ebay though.

Audio repair guys can use those for the DC blocking cap on the output
stage of power amps.

So what are they worth to someone? $1 each?
Click to expand...
---
I doubt it. A Panasonic equivalent (1500ľF 100V) goes for $1.74 each
in quantities of 200 from Digi-Key, and they're new.

--
John Fields
 
Rich Grise wrote:
OK, I give up. There are a lot of surplus dealers selling "Mallory Type FP"
capacitors, but haven't found a definition yet. Is Mallory out of
business? One of the sellers said, "made to the original Mallory spec on
original Mallory equipment..."

But I'm at a loss as to "FP", unless it's something like "footprint" or
"four-prong". Flame-proof?

Any hints?

Thanks,
Rich
Click to expand...
Its a "Fiber Plate". It was named after the insulated mounting plate
made to mount the can on a chassis without special tooling. I think it
used the same chassis punch as an octal tube socket so prototypes and
home brewers could mount it with little trouble. Most individually
boxed caps were shipped with the fiber plate as well as a metal plate to
use if the case was grounded. Small production runs would rivet the
metal plate in, but larger runs would have the four slots punched into
the chassis. The fiber plate was almost always riveted.

There was also a smaller three tab version with up to three sections.

Both types could also be mounted with a heavy clip that snapped
around the side of the can.

I may still have a couple new plates her to take pictures if you need
to see the shape.

--
Beware of those who post from srvinet.com!

Michael A. Terrell
Central Florida
 
I read in sci.electronics.design that Rich Grise <richgrise@example.net>
wrote (in <pan.2005.03.01.16.29.41.32566@example.net>) about
'Electrolytic caps?', on Tue, 1 Mar 2005:

I don't recall if I've actually seen it, or just dreamt or fantasized
it, but it seems that one of those could be put on a PCB by poking
slotted holes.
Click to expand...
Indeed: that's what we did for many years after the first printed boards
were introduced into the company's products (in 1957).
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk
 
Rich Grise wrote:
On Tue, 01 Mar 2005 21:29:16 +0000, Michael A. Terrell wrote:
Rich Grise wrote:
OK, I give up. There are a lot of surplus dealers selling "Mallory Type FP"
capacitors, but haven't found a definition yet. Is Mallory out of
business? One of the sellers said, "made to the original Mallory spec on
original Mallory equipment..."
But I'm at a loss as to "FP", unless it's something like "footprint" or
"four-prong". Flame-proof?
Its a "Fiber Plate". It was named after the insulated mounting plate
made to mount the can on a chassis without special tooling. I think it
used the same chassis punch as an octal tube socket so prototypes and
home brewers could mount it with little trouble. Most individually
boxed caps were shipped with the fiber plate as well as a metal plate to
use if the case was grounded. Small production runs would rivet the
metal plate in, but larger runs would have the four slots punched into
the chassis. The fiber plate was almost always riveted.

There was also a smaller three tab version with up to three sections.

Both types could also be mounted with a heavy clip that snapped
around the side of the can.

I may still have a couple new plates her to take pictures if you need
to see the shape.

I don't think that'll be necessary, but you can if you want to. :)

Thanks!
Rich
Click to expand...
I figured that you could visualize it, but I offered in case someone
had never seen the way they were used and couldn't wrap their mind
around it.

--
Cyber stalking is a crime!

Michael A. Terrell
Central Florida
 
"Watson A.Name - \"Watt Sun, the Dark Remover\"" wrote:

"Pooh Bear" <rabbitsfriendsandrelations@hotmail.com> wrote in message
news:4222608A.D8502E31@hotmail.com...


Melissa wrote:

Melissa <melissa@colorado.xxx> wrote :

"Michael A. Terrell" <mike.terrell@earthlink.net> wrote :

Melissa wrote:


I don't recall, I'd have to go look. I have boxes of them all over
the
place in my lab, which still hasn't been unpacked since we moved.


Here, I have a huge case of these, for starters:
http://dimensional.com/~melissa/photos/Cap1500uf100v.JPG

As they're designed for hand wiring as opposed to pcb mount, I doubt
many
ppl would be interested in them these days.

You could always try shifting them on ebay though.

Audio repair guys can use those for the DC blocking cap on the output
stage of power amps.
Click to expand...
I doubt there's that many audio amps with ac coupled outputs still around
these days actually.


Graham
 
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