Need help with capacitor

Discussion in 'General Electronics Chat' started by coma, Jul 16, 2008.

  1. coma

    Thread Starter New Member

    Jul 16, 2008
    4
    0
    hello im pritty new to this stuff allways like to solder things to gether see what happens with led lights and simple stuff like that but now im stuck iv got a aliminum electrolytic capacitor i think as some thing seems not right so not sure its says 250v 10uf and its got pn 105c but where it would usaly have that band with a negative sighn in the band and the band is like arrows this on isnt its band has the negative sighn but it seems to have arrows in both directions so it kind of looks like a black dimond shape in btween the negative sighns any one know what that is iv got a pic of it but cant see how to upload it so you can all see it so hope you know what i mean from that lamm basic discription :)
     
  2. SgtWookie

    Expert

    Jul 17, 2007
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    If you click on the "Go Advanced" button below the text box, there are other buttons that you can click below the text box to add files and images to your posts.

    I suggest .jpg or .png format files. Try to crop your photo as much as possible so that it will be small in size. Large photos won't upload.

    If your capacitor's leads are both coming out of one end, the shorter lead is the negative lead.
     
  3. coma

    Thread Starter New Member

    Jul 16, 2008
    4
    0
    ok i see the bit to add images thanks and cant work it out by legs on it as its on a pcb so cant tell but got a good shot of the band thats on the side and cut the pic down so it isnt to big here it is anyone know why it has it like that with what seems to me like the polarity is in both directions ?
     
  4. NM2008

    Senior Member

    Feb 9, 2008
    135
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    It appears to be a manufactures mark/symbol?
    The grey band is always taken as negative.
    Regards NM
     
  5. coma

    Thread Starter New Member

    Jul 16, 2008
    4
    0
    ok thanks for that but still would like to know what it realy means as never seen it on another one of them type of caps before and is stoping me from learning as i see something contradicting what im being lernt from around the net so confusing me :confused: :D
     
  6. SgtWookie

    Expert

    Jul 17, 2007
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    It's a stylized '-' band. See the minus in the ">-<" ?

    There's also a '-' on the board next to the negative indicator stripe.

    Electrolytic capacitors can be marked lots of different ways, but when you get down to basics, for polarized radial caps there is always a stripe of some sort on the negative side.

    (Radial = both leads come out of one end of the cap)
     
  7. coma

    Thread Starter New Member

    Jul 16, 2008
    4
    0
    ok thanks man id seen the marks and new it was the negative just that stylized band made me think id better get this checked out to see why they had made the mark that way as if to say its can be used a diferent way to normal but heres the negative anyway marked up just strange and made me qeustion it so i should just ignor the artrows then on any other one that i see and just use the negative mark then or will that course me problem with other Radial Electrolytic capacitors in the future
     
  8. SgtWookie

    Expert

    Jul 17, 2007
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    I think they made the arrow "bi-directional" as it is so that if for some reason they were feeding the caps in the heat-shrink machine upside-down, it wouldn't really matter.

    It's not so much "ignoring the arrows" as just realizing that the lead nearest the stripe is the negative terminal side.
     
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