Polarity of the capacitor.

Discussion in 'General Electronics Chat' started by Lightfire, May 23, 2011.

  1. Lightfire

    Thread Starter Well-Known Member

    Oct 5, 2010
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    Hello,

    One of the capacitors in my schematic has a polarity (I guess).

    Please take a look at my schematic, please.:DPlease look at the capacitor which is circled by a black circle.:D

    Okay, as you may see on the top, there's a "+" there.

    Thanks. please.
     
  2. debjit625

    Well-Known Member

    Apr 17, 2010
    790
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    Yes,so what?
     
  3. Lightfire

    Thread Starter Well-Known Member

    Oct 5, 2010
    690
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    Ooops, I forgot my question. :D But there is no indication of the polarity in my actual capacitor. :( :(

    pls~
     
  4. ke5nnt

    Active Member

    Mar 1, 2009
    384
    15
    A black stripe on an electrolytic capacitor indicates the negative side. If that doesn't solve your mystery, perhaps a photo of your particular capacitor would help us better guide you.
     
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  5. Lightfire

    Thread Starter Well-Known Member

    Oct 5, 2010
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  6. ErnieM

    AAC Fanatic!

    Apr 24, 2011
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    A part number would help us find it for you, it would also help you find it too.
     
  7. Lightfire

    Thread Starter Well-Known Member

    Oct 5, 2010
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    Number? The number I guess was "1nK63". :)
     
  8. Audioguru

    New Member

    Dec 20, 2007
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    About 40 years ago, polarized electrolytic capacitors had a "+" marked beside their + wire but now an arrow marked with a "-" points to the - wire.

    EDIT: 1nK63 is a non-polarized metalized plastic film capacitor that is 1nF (0.001uF), 10%, 63V.
     
    Last edited: May 23, 2011
  9. Lightfire

    Thread Starter Well-Known Member

    Oct 5, 2010
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    But the capacitors I have purchased is not an electrolytic, I guess. Based on the receipt, it was ceramic. :D

    help please
     
  10. debjit625

    Well-Known Member

    Apr 17, 2010
    790
    186
    By the picture of "1nk63" around 0.001uF ,it looks like metalized polyester film type ,it is non-polarized i.e.. it have no polarity.As per your 555 circuit you should use a one micro-farad (1uF) electrolytic capacitor which are polarized.

    Good Luck
     
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  11. DerStrom8

    Well-Known Member

    Feb 20, 2011
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    It would help if you could tell us what your circuit is supposed to do.

    Also, as AG and debjit625 mentioned, the blue capacitor has a capacitance of 1nF, not 1uF (as needed for your circuit). You will need to find a 1uF capacitor, which is most commonly electrolytic (in my experience). It should be very easy to find.
    Good luck!
    Der Strom
     
  12. Audioguru

    New Member

    Dec 20, 2007
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    I have some 1uf metalized plastic film capacitors that are very small (6mm wide x 8mm tall x 2mm thick) and have a 0.2" leads spacing. I also have some small 1uf monolithic ceramic capacitors marked "105".
    Both are not polarized.
     
  13. DerStrom8

    Well-Known Member

    Feb 20, 2011
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    Okay, I just have seen a lot of 1uF electrolytic caps (polarized). If that is what his circuit requires, it shouldn't be hard to find some.
    Der Strom
     
  14. Audioguru

    New Member

    Dec 20, 2007
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    1uF capacitors are available everywhere but maybe not at the "market" where he shops for electronic parts.

    I shop for food at a nearby market and buy electronic parts at online electronic parts distibutors and at some nearby electronic parts stores. One store has "surplus" new unused parts and products. I bought some Name-brand tiny switching power supplies (made for modems) (5V at 2A and on the case it says they have a trimpot inside for an adjustable voltage) at a very low price.
     
  15. Lightfire

    Thread Starter Well-Known Member

    Oct 5, 2010
    690
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    I want to buy online (if I can only) but there are some reasons;

    I am scared to be scammed.:eek:
    I don't have any credit card.:eek:
    The shifting.:eek:

    The only thing I am thinking why I am receiving wrong electronic parts is because I am not the one who's buying it.:)
     
  16. Wendy

    Moderator

    Mar 24, 2008
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    The person who sold you the parts probably didn't know the difference himself. This problem is world wide, but most small stores have folks who know.

    You can use a nonpolarized capacitor to replace a polarized capacitor, always. The reverse is not true.

    This is why you need to learn how to read the markings off the part, I discussed this in your other thread.

    Many DVM meters have a build in capacitance meter. It isn't quite a standard feature, but it is getting there. I don't remember if the meter I sent you has one or not.
     
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  17. Lightfire

    Thread Starter Well-Known Member

    Oct 5, 2010
    690
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    But as you stated, an 1nK63 is a 0.001μF capacitor. But my schematic required a 1μF. So maybe, I can try what did somebody say 1μF"microfarad" capacitor. is it Ok???
     
  18. debjit625

    Well-Known Member

    Apr 17, 2010
    790
    186
    Catapult,you can post your parts list here so that we could guide you what you need.
    And here is pic of 1000 micro-farad 25V radial electrolytic polarized capacitor.
    [​IMG]

    The dash and arrow mark on the side of the capacitor specifies the negative terminal lead.

    Yes

    Good luck
     
  19. Wendy

    Moderator

    Mar 24, 2008
    20,764
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    Guys, IT DOES NOT MATTER WHAT THE PART LOOKS LIKE!!!

    The part identifier is what is important. PERIOD!!! If he gets an unpolarized 1µF capacitor (which are VERY common) then it will work.

    Lightfire,

    Your cap is a 0.001µF. I am sorry, but you have the wrong part. Look for one that is labeled 1µF or 105 on the package.
     
  20. Lightfire

    Thread Starter Well-Known Member

    Oct 5, 2010
    690
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    But what kind of capacitor:confused:
     
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