Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Doubts about electrolytic capacitor

Status
Not open for further replies.

John rodrigues

Member level 4
Joined
Aug 14, 2020
Messages
77
Helped
0
Reputation
0
Reaction score
0
Trophy points
6
Activity points
464
Electrolytic capacitor kept unused for many months or year suffers depolarization, short circuit and loss of capacitance?

I have a technical friend in electronics and he instructed me to use my old electronic devices once a month for 30 minutes because if I do not follow this guidance, electrolytic capacitors can depolarize, short circuit and lose capacitance

is this information true or false?
 

Partially true. They do degrade over time but in almost all cases they recover 're-polarize' within a few seconds of having power applied to them. I certainly wouldn't advise power cycling them just to keep them 'awake'. With very large capacitors, particularly high voltage (>100V) ones it is generally recommended that after prolonged storage you charge them through a current limiting resistor, then discharge them again before putting them into use. By prolonged storage I mean several years rather than a few months.

Brian.
 

My friend told me to use the electronic devices once a month for 30 minutes to preserve the electrolytic capacitors by avoiding short circuit and depolarization, the manufacturers of electrolytic capacitors also say to use once a month for 30 minutes to keep the electrolytes good?
 

Welcome to the never ending riddle......Electro caps suffer "higher leakage current" when powered up after a "certain time" in storeage. This leakage current reduces the longer the electro cap has a decent amount of voltage on it. (eg near rated voltage)

...for any particular electro cap...to try finding exactly how much leakage current would flow , and for how long, is almost impossible.

....The datasheets and app notes seem very unclear about this whole issue......i read one app note that said that caps should be taken out of storeage every year and get rated voltage applied to them via a 1k resistor........this then stops high leakage currents.

Electro caps arent date coded...so with any cap, youve no idea how old it is and therefore how leaky it might be if you put it in your product.

I must admit all the electro caps that i see, even after 2 years in storeage, the leakage is said to be not that much, so why they say its a problem i dont know.....the leakage seems never to be more than a few mA......so i cant see why its a problem....maybe it was a problem in the old days with old caps.

I understand your question though...finding the truth on this is very difficult.
 

I need to find a maximum interval to use the devices and preserve the useful life of the electrolytic capacitors, my friend said to use every month for 30 minutes
 

For usual ambient conditions (5 - 35 °C), capacitor reforming isn't necessary before two years of voltage-free storage. After that period, it depends on the circuit conditions. Capacitors that are charged with high currents, or even operated in series connection may fail.

On the other hand, we are powering instruments after 5 or even 10 years of storage without problems.
 

In my city the temperature varies 30-35.5% but it is rarely above that I must follow the guidance of using the devices 1 x per month for 30 minutes to prevent the electrolytic capacitors from depolarizing, short circuit, loss of capacitance or this time interval without using it can be bigger without reducing the useful life of electrolytic capacitors? I own (Snes console, CRT TV 29 ", video game cartridges, smartphone chargers containing electrolytic capacitor and some newer devices that have electrolytic capacitors)
 

There was a time when electronic components were built to last.
In the past 20 years we're seeing more components that fail to live up to specs. Some are plain fake. Useful life is not so predictable.

30 minutes per month is as good a schedule as any.

There were tv's with an 'instant on' feature. While turned off they had a small amount of power running through the tubes. I never heard whether this had an effect on their lifetime. It's not easy to gather such research over a period of decades.

I purchased a plug-in unit that sent partial power to a tv in the first few seconds. The idea was to avoid the shock of applying full power to cold circuits. A similar concept is seen in the ordinary incandescent light bulb. When it blows, it's usually the moment you switch it on.

So electrolytic capacitors might benefit, if you could devise a way to turn on power during a second or two.
 

It is very bad that manufacturers do not provide information on whether I should use the devices that contain electrolytic capacitors 1x per month for 30 minutes or if the interval is longer than this
 

The electrolytic capacitor manufacturers do provide information about required reforming intervals. The discussed one month period doesn't correspond to manufacturer suggestions as far as I'm aware of.
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top