Electronic – What’s the polarity of this capacitor

electrolytic-capacitorpolarity

Please, help me to determine the polarity of a RWA1C101MEG capacitor. I see a fat stripe on one side of the capacitor:

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Is this a positive or negative terminal?

Best Answer

On those little plastic rectangle surface mount packages, which are most common for Tantalum capacitors from what I've seen, the grey/white stripe on the end of the package indicates the POSITIVE terminal of the capacitor.

In the metal "can" style capacitors, and the usual plastic/polymer round cylinder style packages the marking is usually for the NEGATIVE terminal. The tall round cylinder packages often have a grey-ish stripe, with obvious black minus signs going down it. On the metal can packages, the negative terminal is usually indicated by a solid black semi-circle/area of the circle closest to the pin, on the top of the case.

This is from experience, using products with more useful datasheets that specifically mention the polarity markings - and then it's just an industry standard that you'll see throughout your time designing stuff.