Spring cleaning...

What are the odds that 25 year-old aluminum electrolytics in my junk
box are any good?

Just toss 'em?

...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

On 4/5/2011 8:03 PM, Jim Thompson wrote:
Spring cleaning...

What are the odds that 25 year-old aluminum electrolytics in my junk
box are any good?

Just toss 'em?

...Jim Thompson

How much would it cost you to replace them?

John

Jim Thompson wrote:
Spring cleaning...

What are the odds that 25 year-old aluminum electrolytics in my junk
box are any good?

Just toss 'em?

...Jim Thompson

Depends on the quality level. Really good quality old ones are probably
fine--they were sealed well, so they didn't dry out easily.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058

email: hobbs (atsign) electrooptical (period) net
http://electrooptical.net

Jim Thompson wrote:
Spring cleaning...

What are the odds that 25 year-old aluminum electrolytics in my junk
box are any good?

Just toss 'em?

...Jim Thompson

High, if they've been stored at room temperature. You wouldn't
use them in a product, but they're fine for prototyping,
experimenting, throwing together a quick temporary circuit,
that kind of thing.

Ed

Jim Thompson
wrote:

Spring cleaning...

What are the odds that 25 year-old aluminum electrolytics in my junk
box are any good?

Just toss 'em?

Yes, if the box smells like cat ****.

--
Failure does not prove something is impossible, failure simply
indicates you are not using the right tools...
nico@nctdevpuntnl (punt=.)
--------------------------------------------------------------

"Jim Thompson" schreef
in bericht ...
Spring cleaning...

What are the odds that 25 year-old aluminum electrolytics in my junk
box are any good?

Just toss 'em?

...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

As so often, it depends. Mainly on initial quality and usage/storage.
Sometimes I have to repair vintage tube radios in which electrolitics of
over 60 years old still function properly. If the caps are not used for a
long time I advise to raise voltage slowly to reform whatever part of the
dielectricum might have gone. So you can use them for your goals, especially
as you do not do (mass) production anyway.

petrus bitbyter

Spring cleaning...

What are the odds that 25 year-old aluminum electrolytics in my junk
box are any good?

Just toss 'em?

I'd guess that almost all of them are presently rather leaky, and
would benefit by a gradual re-forming (if you turn the power on
suddenly, some of them might go FOOM).

A lot of them have probably dried out at least somewhat and gone
high-ESR.

I wouldn't use them for anything critical, and if I used one for a
junk-box application I'd charge it up to its WVDC gradually (1-meg
series resistor, a few hours of soaking), check for leakage,
discharge, then test on an ESR meter.

Probably easier to just toss 'em in the electronics-waste bin and buy
fresh ones... unless you've got loads of time to kill, the effort to
weed out the bad ones and find the good ones is probably more than
they're worth.

--
Dave Platt 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!

Jim Thompson wrote:
Spring cleaning...

What are the odds that 25 year-old aluminum electrolytics in my junk
box are any good?

Just toss 'em?

...Jim Thompson
Almost all of them would be OK..just bring up the voltage slowly and
let them re-form for about an hour.

On Wed, 06 Apr 2011 22:27:19 -0700, Robert Baer
wrote:

Jim Thompson wrote:
Spring cleaning...

What are the odds that 25 year-old aluminum electrolytics in my junk
box are any good?

Just toss 'em?

...Jim Thompson
Almost all of them would be OK..just bring up the voltage slowly and
let them re-form for about an hour.

I've reformed many caps with a 1k to 10k resistor in series, with the
bench supply voltage set at 110 percent of the cap's rated working
voltage. Good ones go down to well under one mA leakage, bad ones just
stay leaky and never charge up to even half rated voltage.

I'm thinking it's a good idea to plug in and turn on all "sitting on
the shelf" equipment once or twice a year for a few minutes or hours,
if for no other reason than to make sure the electrolytics stay
formed.

Ben Bradley wrote:

I'm thinking it's a good idea to plug in and turn on all "sitting on
the shelf" equipment once or twice a year for a few minutes or hours,
if for no other reason than to make sure the electrolytics stay
formed.

I powered up an old prototyping breadboard thing with integrated power 5v
and +/- 5 to 15v supplies the other day, been sitting at the back of a
bench for years.

I checked and nothing on the 5v supply, after a few more seconds a
prestigious amount of smoke was released.

Turned out the +5v supply smoothing cap had gone dead short and with no
fuses to be seen it just melted the W05 type bridge rectifier.

Fortunately there was enough PCB left to bodge in a replacement. Two
similar capacitors on the +/- supply were fine.

Ben Bradley wrote:

I'm thinking it's a good idea to plug in and turn on all "sitting on
the shelf" equipment once or twice a year for a few minutes or hours,
if for no other reason than to make sure the electrolytics stay
formed.

I powered up an old prototyping breadboard thing with integrated power 5v
and +/- 5 to 15v supplies the other day, been sitting at the back of a
bench for years.

I checked and nothing on the 5v supply, after a few more seconds a
prestigious amount of smoke was released.

Turned out the +5v supply smoothing cap had gone dead short and with no
fuses to be seen it just melted the W05 type bridge rectifier.

Fortunately there was enough PCB left to bodge in a replacement. Two
similar capacitors on the +/- supply were fine.

On Tue, 05 Apr 2011 18:03:22 -0700, Jim Thompson
wrote:

Spring cleaning...

What are the odds that 25 year-old aluminum electrolytics in my junk
box are any good?

Just toss 'em?

...Jim Thompson

After 16 hours of "forming" on an 8000uF/16V Lytic I'm down to ~1uA.

I'm amazed!

...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

Remember: Once you go over the hill, you pick up speed

On Tue, 05 Apr 2011 18:03:22 -0700, Jim Thompson
wrote:

Spring cleaning...

What are the odds that 25 year-old aluminum electrolytics in my junk
box are any good?

Just toss 'em?

...Jim Thompson

After 16 hours of "forming" on an 8000uF/16V Lytic I'm down to ~1uA.

I'm amazed!

...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

Remember: Once you go over the hill, you pick up speed

Jim Thompson wrote:
On Tue, 05 Apr 2011 18:03:22 -0700, Jim Thompson
wrote:

Spring cleaning...

What are the odds that 25 year-old aluminum electrolytics in my junk
box are any good?

Just toss 'em?

...Jim Thompson

After 16 hours of "forming" on an 8000uF/16V Lytic I'm down to ~1uA.

I'm amazed!

...Jim Thompson
Well, my "answer" or response was based on seeing 15 year old WET
aluminum electrolytics still OK with no apparent regard to being "wet".
Granted, the percentage of decent ones was rather low, but the
"baddies" usually could be "repaired" by adding electrolyte and then
reforming.

Jim Thompson wrote:
On Tue, 05 Apr 2011 18:03:22 -0700, Jim Thompson
wrote:

Spring cleaning...

What are the odds that 25 year-old aluminum electrolytics in my junk
box are any good?

Just toss 'em?

...Jim Thompson

After 16 hours of "forming" on an 8000uF/16V Lytic I'm down to ~1uA.

I'm amazed!

...Jim Thompson
Well, my "answer" or response was based on seeing 15 year old WET
aluminum electrolytics still OK with no apparent regard to being "wet".
Granted, the percentage of decent ones was rather low, but the
"baddies" usually could be "repaired" by adding electrolyte and then
reforming.