capacitor question

[bainsey]

Hi all, I'm building a surf 1.2 pi. I'm a total noob and have not.used a soldering iron since I left school 11 years ago. So far it is going well I have everything in and soldered except the capacitors. My problem is that the 1nf and 100nf capacitors legs where all the same length so I did not know how to work out the polarity. So I ordered some different ones off eBay and they arrived today, thing is the legs are again exactly the same length. How can I work out the polarity of them. All I have is a multi meter and really don't want to order more for the same to happen again. Thanks in advance

Andy

[beerguy]

The only polarity sensitive capacitors that you will see are electrolytics. These are plainly marked, as well as having the long lead on the positive side. You are probably looking at film capacitors, they have no polarity req'ts.

[bainsey]

They are the little wima red plastic caps, so there is no polarity?

[WM6]

If this is related to your previous "noob question" here:

http://www.geotech1.com/forums/showt...-noob-question

it was my graphical made marking on those capacitors, not genuine from producer.
Marking only show how capacitors are polarising loaded by electricity from battery, to retain correct connection to testing clamps of multimeter.

As beerguy say only electrolitic (and small tantal) capacitors are genuine marked by producer using + or - mark. All such capacitorrs are clearly marked by + or by - or both.

All other capacitors can be used in circuits in any orientation of contact leads (pins)

[golfnut]

There is no polarity on 0.1uF of 100nF or 1nF or 10nF or 220pF etc

There is often a breakpoint around 1uF where depending on the construction they either are, or are not polarity concious.


The ones that are, are often cylindrical and have identifiers for one of the terminals. These have a wet electrolyte - like a battery.



There is a special version of these which is a non polarised electrolytic - sometimes used in the filters on here.

S