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Electrolytic capacitor

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Is it necessary to use my electronic devices from the 90's that have electrolytic capacitors every month to prevent them from having depolarization and failures of electrolutic capacitor due to disuse? I don't know the manufacturers of these electrolytic capacitors

when plugging the devices into the socket and using them, how many minutes for the total reform of the electrolytic capacitor?
 

rjenkinsgb

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Low voltage caps do not seem to have any real problems like that.
I've "new" ones I have had for 30 years and they are still fine when used; I tested some unused ones last time this subject came up, and they were all still good.


The only known cap depolarisation problem I've encountered was with a 1950 valve (tube) machine, where the main 350V reservoir cap had severely depolarised in the 40 years or so since I last powered it up. That took a couple of days of gradually increasing voltage from a temporary supply (as the leakage reduced) for it to re-form enough for use.

Considering the cap was 70 years old and little used for the last 60+ years, that is understandable.

I cannot really see any such problems with 90s gear.
edit - typo
 
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unclejed613

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the formulation of modern caps is much different from the 1950s and 60s and before. the oxide layers formed on the aluminum are much more stable because the electrolytes used aren't as chemically active.
 

rjenkinsgb

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No recommendations for my specific case?

Yes: Done - first answer. They will be OK.

Low voltage caps do not seem to have any real problems like that.
I've "new" ones I have had for 30 years and they are still fine when used; I tested some unused ones last time this subject came up, and they were all still good.

Again; these are leftovers from a 1990/1991 project:

IMG_5166.jpgIMG_5168.jpgIMG_5169.jpgIMG_5170.jpgIMG_5171.jpgIMG_5172.jpgIMG_5173.jpg

All still fine; low ESR and leakage in the multi-megohm range. They should be OK so several decades more.

There is no problem with the capacitors from 1990s equipment!
 

Tony Stewart

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When I had 100kuF computer caps when I was young , I learnt to use a current limiting R with full voltage bias that matches the idealized leakage current, the process involves detonating dendritic shorts inside the electrolyte with self-healing until the insulated is breakdown voltage proof. The R value chose depends on the c size of approximately ESR*C=T and Rl/ESR = 1e7 depending on quality. +/- a couple decades. Then Pd rated for worst case. Modern caps are rated somewhat like Il= 3 sqrt(CV) (μA) thus Rs= Vmax/Il to safely deiodize the cap until V= 50% rated . E.g. C=0.1F 63V thus R= 8 MOhm the time constant is thus 0.1Fx 8M = 0.8 e6 seconds or about a week. You can accelerate this with a higher power lower R Resistor but if you accelerate too much risk fusing the conductor layers causing a short. 100k would be my choice for an absolute min.
 
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Which recommendation For electrolytic capacitors of any brand, manufactured in the early 90's and mounted in electronic circuit, what is the interval for me to use these devices and avoid problems with electrolytic capacitors?
 

rjenkinsgb

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what is the interval for me to use these devices and avoid problems with electrolytic capacitors?
Every hundred years or so probably would not hurt, if you wish.

For the (I've lost count)th time...
Consumer electronics from the 90s does not any special attention because of the electrolytic capacitors!

Can someone lock this....
 
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