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electrolytic capacitor depolarizes

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eletroenergy

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electrolytic capacitor depolarizes by not using? I have a friend technical in electronics and he said that if I don't use my electronic devices with electrolytic capacitors from 1990 with 30 years of use, these electrolytic capacitors will depolarize and lose capacitance, is this true? what do electrolytic capacitor manufacturers say? i have, snes, ps2, tv crt and others electronics
 

Diver300

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Electrolytic capacitors will dry out in time. The temperature is what has the largest effect on that. If they are kept cold they will last for ages.

I think that electrolytic capacitors may also increase their leakage with time, but they will decrease their leakage if powered up. Using the device with them in will prevent that being a problem, but will do nothing about the drying out.
 

eletroenergy

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To preserve electrolytic capacitors (30 years old and used) is it necessary to use the devices every month for at least 30 minutes?
 

gophert

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To preserve electrolytic capacitors (30 years old and used) is it necessary to use the devices every month for at least 30 minutes?
what's the point in owning an SNES if your not going to use it? Either give it to a child that will play it or play it yourself. There are literally milllions sitting in bedroom closets around the world.
 

Nigel Goodwin

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To preserve electrolytic capacitors (30 years old and used) is it necessary to use the devices every month for at least 30 minutes?
No, that's utter rubbish - simply plug them in every five years or so, and make sure they still work.

The fallacy comes from REALLY old paper electrolytics (1940/50's), where they can 'explode' if they haven't been used for a number of decades - and they should be 're-formed' rather than just plugged in.

 

eletroenergy

New Member
Note: my electronic devices are with 30-year-old electrolytic capacitors and are used

What information comes from the manufacturers of electrolytic capacitors for electrolytic capacitors from 1990? what do they say about long periods of storage of electronics with these unused capacitors? this information from my friend confused me but I want the truth

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Nigel Goodwin

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Note: my electronic devices are with 30-year-old electrolytic capacitors and are used

What information comes from the manufacturers of electrolytic capacitors for electrolytic capacitors from 1990? what do they say about long periods of storage of electronics with these unused capacitors? this information from my friend confused me but I want the truth
There is no 'truth' - different makes and types behave differently.

However, there are huge numbers of seriously sub-standard capacitors out there - and nothing you can do will stop those dying.
 

eletroenergy

New Member
I don't know the brands of the electrolytic capacitors in my devices but in general what would be the answer to my question?
 

KaraPelosi

New Member
Hi....It's dependent upon the situation and relies upon the nature of the capacitor, use, temperatures, wattage, fabricating absconds, and so forth I have a 35+ year old Commodore 64 that actually turns out great (covers are acceptable) yet I've additionally seen a 2 year old PC with stretched/spilling covers.

For unused rack time you're actually taking a gander at capacitor quality, stockpiling temperatures, producing absconds, and so forth as factors.

pcb online ordering
 
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rjenkinsgb

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The only times I have seen it mentioned are in relation to vintage valve (tube) equipment that may not have been powered up for decades, and specifically with Siemens machine tool drives - repolarising the capacitors is part of the installation instructions, for if a drive has been stored for over a year (or two years?).

In both cases, the principle is to initially charge the capacitors via a fairly high value resistor and progress through eg. 25% - 50% - 75% - 100% voltage at intervals. Siemens state the intervals in relation to how long the drive has been in storage.

Note that those are both situations with high voltage capacitors, in equipment that is either extremely expensive or possibly irreplaceable if any damage occurs.

I have never seen any mention of anything like that for low voltage capacitors, and I have regularly used electrolytic caps that are 20+ years old without any problems.

edit - Note that "repolarising" before use is to prevent internal flashover. Loss of capacity is a totally different thing and pretty irrelevant as they will naturally reform once in circuit with a voltage applied; any capacity loss in long term storage (if it existed) would be reversed within a few hours of use.

Edit 2 - I could not remember the exact Siemens info so dug out the manual; this was for a piece of equipment rated 90KW & caps operating at 600 - 700V, by the way.

CapacitorReform.png
 
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shortbus=

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Is this the same guy yet again? One other of his names was james23051987. Always asks the same thing, 'a "friend" tells him capacitors go bad in 30 year old electronics'.
 

MacIntoshCZ

Active Member
i remember that my teacher on power electronics in high school say to cure electrolitic caps by connecting it to voltage source.
Also i remeber when i said that at exam, he said i am wrong.
hmmm, uselles information
Happened 3 years ago, dont remember exactly
 

gophert

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Do the manufacturers of electrolytic capacitors have an answer to my question?
No. If the cap is beyond the specified working hours, they'll tell you the manufacturer picked the wrong cap or the product is at end of life. No electronic component [email protected] is going to have advice to rejuvenate a 25-year-old. (Or more) device. Throw it out, replace the caps when needed or just cross your fingers and hope a lot (it might work). What doesn't work? It doesn't help to keep asking the same question on various forums - especially this one.
 

rjenkinsgb

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Do the manufacturers of electrolytic capacitors have an answer to my question?
There is no absolute "lifetime".

The data sheet figure is the minimum life, IF the capacitor is constantly run at the maximum temperature, voltage and ripple current ratings.

There are then equations that predict how many times longer it will last if, run at lower temperatures, voltages and lower ripple currents.
Depending on the design of the circuit one is used in, that could be ten time longer or tens of thousands of times longer that the data sheet basic lifetime.

And the "lifetime" only applies while power is on; hypothetically they do not actually age whilst stored with no power.

Example calculations data for one manufacturer; note there is no mention of power off time:
 

eletroenergy

New Member
I stored some electronics that use electrolytic capacitors for some period but I wanted to know the maximum of unused period until I energize them and do not jeopardize the electrolytic capacitors depolarize
 

Nigel Goodwin

Super Moderator
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I stored some electronics that use electrolytic capacitors for some period but I wanted to know the maximum of unused period until I energize them and do not jeopardize the electrolytic capacitors depolarize
You've already been told repeatedly - try reading the responses.

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