Routing 25v and 50v on a PCB?

Discussion in 'General Electronics Chat' started by joe426, Mar 24, 2012.

  1. joe426

    Thread Starter Active Member

    Aug 11, 2009
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    I have a PCB which manages some LiPo batteries (switching them on and off). As a result, I have traces on a PCB which are 25v and 50v. What precautions do I need to take when routing traces for these wires? Do they need to be a certain thickness or stay a certain distance away from other traces? They are low current as they just monitor the voltage of the LiPo pack's cells.

    Thanks!
     
  2. wmodavis

    Well-Known Member

    Oct 23, 2010
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    No specific precautions.
     
  3. joe426

    Thread Starter Active Member

    Aug 11, 2009
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    That's surprising. Thanks!
     
  4. wmodavis

    Well-Known Member

    Oct 23, 2010
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    Why is it so surprising?
     
  5. joe426

    Thread Starter Active Member

    Aug 11, 2009
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    Because typically with even lower voltages such as 5v or 12v, people tend to make these "power traces" thicker and separate from other traces. I believe this thickness is simply due to the current traveling through the trace, not the voltage. Regardless though, I thought there might be a similar rule for high voltages.
     
  6. wmodavis

    Well-Known Member

    Oct 23, 2010
    737
    150
    Size of traces due to current yes. But you have low current.

    And I consider that voltage to be low also. Likelyhood of arcing is miniscule.

    Use standard spacing between traces. Or if you are uncertain more spacing certainly will not hurt, even if unnecessary.
     
  7. joe426

    Thread Starter Active Member

    Aug 11, 2009
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    0
    Awesome, thank you.
     
    Last edited: Mar 25, 2012
  8. t06afre

    AAC Fanatic!

    May 11, 2009
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    Up to 50 volt the recommendations are as follows regarding spacing
    Internal conductors 0.1mm
    External conductors uncoated sea level up to 3050m 0.6mm
    External conductors uncoated sea level over 3050m 0.6mm
    External conductors permanent polymer coating any elevation 0.13mm
     
  9. atferrari

    AAC Fanatic!

    Jan 6, 2004
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    What parameter changes when you go higher? Air conductivity? (Seen it stated at 20 or 25º C but not at any specific atmospheric pressure - equivalent to change in altitude).
     
  10. t06afre

    AAC Fanatic!

    May 11, 2009
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    The electrical conductivity of air. Starts to increases at an altitude of 300 feet or so above Earth's surface. This is because the atmosphere is thinner, or less viscous. At high altitudes as large particles become less frequent. Allowing ions to move more freely than in lower altitudes.
    http://www.geocities.ws/amselvam/electric/electric1.html
    By the way the numbers in replay #8 is from the IPC2221 standard
     
  11. THE_RB

    AAC Fanatic!

    Feb 11, 2008
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    It's professional to keep 50v traces well away from regulated 5v traces. And to have solder mask so the traces are not bare copper that might short out when a bug craps on it.
     
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