Are cheap capacitors reliable?

Hi

Shopping for some electrolytic capacitors for building a constant 5V power supply around a LM7805 for a PIC project. Saw some (pn : 647-UVR1H220MDD1TA) at Mouser that goes really cheap at US$0.02 each! Of course there are more expensive ones.

Are these 2cents caps any good for the purpose I have? If not, what kind of a price range should a newbie follow as a general rule of thumb.

Many thanks!

Urahara said:

Hi

Shopping for some electrolytic capacitors for building a constant 5V power supply around a LM7805 for a PIC project. Saw some (pn : 647-UVR1H220MDD1TA) at Mouser that goes really cheap at US$0.02 each! Of course there are more expensive ones.

Are these 2cents caps any good for the purpose I have? If not, what kind of a price range should a newbie follow as a general rule of thumb.

Many thanks!

Click to expand...

generally Electrolytic capacitors are rated for their ESR value ( especially so for use in Switch mode supplies of higher capacities)and voltage with standing capacity.
then the price depends on production volumes and of course purchase volumes. Thus the word cheap may not have so much relevance except when old stocks with internal electrolytic pastes dry up.
many people dispose old stocks.
I generally watch for the manufacturing date etc just like meds. while purchasing electrolytic capacitors.

I would say, what the hell, looks good to me. Go for it...

How long does it take in general for the internal electrolytic paste to dry up? What is the average usefull life for an electrolytic capacitor?
Are their certain brands who last longer?

It depends greatly on the operating conditions - some capacitors are truely awful - but for most applications, like this trivial application of capacitors round a 7805, it doesn't really matter much.

High current switching circuits put a real strain on capacitors.

Guess Mouser's website doesn't show product dates of the components.

Guess for simple applications like mine, as Nigel mentioned, it probably doesn't matter.

Thks!