Is a higher voltage rating for a capacitor OK

Discussion in 'The Projects Forum' started by pedro147, Jun 6, 2016.

  1. pedro147

    Thread Starter Member

    Jan 1, 2013
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    I have a quadcopter flight control board (only to be built in hobby quantities) and some of the caps are no longer available from my normal supplier and the lead time from alternative sources is too long. The circuit (attached) calls for 6.3v rated 1uF ceramic caps (C1, C2 and C3) and I have found another cap with all the other specs to same apart from it being rated at 50v. Is this something that I should be concerned with aside from any possible cost implications please
     
  2. panic mode

    Senior Member

    Oct 10, 2011
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    no problem whatsoever....
     
  3. WBahn

    Moderator

    Mar 31, 2012
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    Size implications. Higher voltage parts that are otherwise the same specs are usually physically larger, so be sure that there is enough room for the replacement part.
     
  4. WBahn

    Moderator

    Mar 31, 2012
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    Oh, and when you say that the specs are the same, does that go for the self-resonant frequencies?

    That can be a significant concern in high bypass caps, but I suspect it isn't in this case as the fact that they are all just 1 uF indicates that no effort was put into properly sizing the caps. So if the design worked as is it is probably pretty tolerance to the resonant frequencies of those caps.
     
  5. Lestraveled

    Well-Known Member

    May 19, 2014
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    In the schematic you posted, I see no problem. As mentioned before the higher voltage cap are normally bigger. If this is not a problem then you are fine.

    There is something I did not mention, the higher voltage caps will have a much longer "mean time between failures", then the lower voltage caps, which is a good thing.
     
  6. pedro147

    Thread Starter Member

    Jan 1, 2013
    52
    2
    Thank you to you all for your replies. I had not considered a difference in size due to the higher voltage rating so I will check that and any other points you gents have raised. "Self-resonant frequencies" "Temperature and voltage variation of ceramic capacitors" there is always something new for the novice to consider and this is only the easy stuff:)
     
  7. pedro147

    Thread Starter Member

    Jan 1, 2013
    52
    2
    Just one last thing if I may. Are all 0603 packages the same physical size or do I need to check?

    EDIT - and I now see that there is an 0603 in both metric and imperial but to 0805 is only in imperial. All very confusing
     
  8. WBahn

    Moderator

    Mar 31, 2012
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    The footprint for all 0603 packages are the same (or nearly so), but the heights may be different (though it would be unlikely that the height differences would cause you a problem).
     
  9. pedro147

    Thread Starter Member

    Jan 1, 2013
    52
    2
    Thanks for that
     
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