Waht size is this capacitor?

Discussion in 'General Electronics Chat' started by rougie, Dec 5, 2012.

  1. rougie

    Thread Starter Active Member

    Dec 11, 2006
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    2
    Hello,

    I always have trouble reading the values of small tantalum capacitors.

    On the capacitor it clearly say: "u47 35"

    But when I measure it with a multi meter it reads 485nano farad???

    So what is the real value of such a capacitor...

    Please view pics for details!!!!

    thanks!
    r
     
  2. #12

    Expert

    Nov 30, 2010
    16,247
    6,744
    It's pretending to be 47uf at 35 volts, and it's way too big to be 47nf, so I would have to assume it's broken.
     
  3. DerStrom8

    Well-Known Member

    Feb 20, 2011
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    #12, I think the 'u' coming before the 47 is symbolizing 0.47μF, which is equal to 470nF. The 'u' just symbolizes a package type, tolerance, or manufacturer (not sure which in this case). I think it's a 0.47μF, 35 volt capacitor, and the measurements seem to support that conclusion.

    Best wishes,
    Matt
     
  4. rougie

    Thread Starter Active Member

    Dec 11, 2006
    410
    2
    ah yes! this makes sense... I don't why they can't just add a "." in front of the 47???

    Thanks so much guys... your help is appreciated!
    r
     
  5. #12

    Expert

    Nov 30, 2010
    16,247
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    Like my signature says, sometimes I'm wrong.
    But from the size, I'd expect 4.7 uf, not .47 uf.
    Oh well. We all get fooled once in a while.
     
  6. bountyhunter

    Well-Known Member

    Sep 7, 2009
    2,498
    507
    correct. The location of the letter is where the decimal goes. For example a "2R2" resistor is 2.2 Ohms. A "2K2" would be a 2.2K resistor.
     
  7. bountyhunter

    Well-Known Member

    Sep 7, 2009
    2,498
    507
    Because a decimal dot is tiny. It's very hard to see and easily gets rubbed off. That's why they use the letter in place of the decimal.
     
  8. DerStrom8

    Well-Known Member

    Feb 20, 2011
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    I meant no offense, #12. I could very well be wrong as well. ;)

    I have had students use those types of capacitors in their lab experiments here, and I have put together their "kits". Most of the ones I've handed out have been 1μF or below, which is what made me wonder if that's what it was.

    Best wishes,
    Matt
     
  9. bountyhunter

    Well-Known Member

    Sep 7, 2009
    2,498
    507
    It's a solid Tantalum, it's hard to predict value from size.
     
  10. #12

    Expert

    Nov 30, 2010
    16,247
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    No ruffled feathers here. Just taking responsibility for putting up a dubious answer. The other option is to let it stand and have people wonder if I still believe it's right. Better to be clear about it.
     
    DerStrom8 likes this.
  11. MrChips

    Moderator

    Oct 2, 2009
    12,414
    3,353
    It is most definitely 0.47μF or 470nF as confirmed by the meter.

    We discussed this in a previous thread. The μ takes the place of the decimal point because the "dot" is easily missed in a photocopier, scanner or fax, besides other places.
     
  12. rougie

    Thread Starter Active Member

    Dec 11, 2006
    410
    2
    Its rare I use capacitors for other than power rail filters. In this case I did an RC circuit and that particular cap did the job. So I think too that it is a 0.47uF... now that you guys have brought up good points.

    Thanks all for your help!
    r
     
  13. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    5,435
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    There's no "thinking" needed. :)

    As MrChips said u47 is a standard industry code for 0.47uF, it can be relied upon.
     
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