polarity of small components

[methuso]

*********** N.O.O.B WARNING ***********

How do i determin positive and negative on really small caps? like 0402 or 0201.
the inductors har polarity markings (the pic uploaded), Do i use the side with a darker stripe as negative?

I hope You don't laugh so hard You can't answer ;)

/Ulf

[AndyOne]

Methuso,

I don't know of any capacitors in the package sizes you mention that are polarised so orientation isn't an issue with them. The inductor you show also isn't polarised but the mark is to indicate something about the winding, this may be because it isn't symmetrical.

Andy.

[methuso]

ok thankz.
about the inductor. this sheet http://search.murata.co.jp/Ceramy/image/img/PDF/ENG/L0075S0083LQG15HS.pdf says it a polarity marking. so i thought + -.

[Clarkst]

Methuso,

I don't know of any capacitors in the package sizes you mention that are polarised so orientation isn't an issue with them. The inductor you show also isn't polarised but the mark is to indicate something about the winding, this may be because it isn't symmetrical.

Andy.

This is true. We thought there was an issue with this as well when we started making these little monters:http://www.rcgroups.com/forums/showthread.php?t=949507

[Dan Baldwin]

*********** N.O.O.B WARNING ***********

How do i determin positive and negative on really small caps? like 0402 or 0201.
the inductors har polarity markings (the pic uploaded), Do i use the side with a darker stripe as negative?

I hope You don't laugh so hard You can't answer ;)

/Ulf

On electrolytic surface mount capacitors, the polarity mark is the positive side. As Andy said, inductors have no polarity. You may notice that although the datasheet you referenced shows that the mark is a polarity mark, it doesn't say what it means.

Dan

[methuso]

ok but where is the mark on 0201 CAP ?

[sneasle]

IF there is a polarity mark on an SMT cap, it is the positive end. If there is a polarity mark on a Radial or other TH cap, it is negative.

I've never heard of an inductor having a polarity.

No mark= No polarity

[Martin_G]

Hi,
...
I've never heard of an inductor having a polarity.
...

There are inductors that are biased by a permanent magnet. These do have a polarity.

But in deed they are very rare.

servus,
Martin

[sneasle]

Good point.

[Mr.RC-CAM]

Regarding the inductor's "polarity" mark: On small inductors, such as an 0201 bodies, the placement's orientation will affect the exact inductance value. So, for consistent performance the mark should be observed when soldering the inductor in the circuit. If slight variations in the value are not important, then you can usually ignore the mark.

[methuso]

so i'll just have to take them out of the packet an stare really hard at them and ill see if there is a mark. OK thanks guys. i hope to get around to building this tx/rx from Darkith later today. But there are SOO many projects