problem with PCB

Discussion in 'The Projects Forum' started by vivek20055, Feb 1, 2013.

  1. vivek20055

    Thread Starter Member

    Nov 4, 2012
    88
    0
    Hi ,

    I have very high current of 100Amps in my circuit

    My professor suggested me to place input supply (which are also high reverse current path devices) at the edge of the board

    And use copper flooding in 3 layers (including top,power and bottom)???

    For ground layer he suggested to give seperate GND to these components for good return current????

    what does that mean ???

    what is the idea behind using copper in 3 layers and seperate GND for this??

    Regards,
    Vivek Alaparthi
     
  2. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    7,386
    1,605
    3 layers is to get the most copper possible in the high current path. It's the same thing as tripling up the wire used to connect 2 parts.

    By separating the ground it is meant to give one physically very short path for the high current signal, and a separate trace to the rest of the electronics that use this ground point as a reference. The trick here is to imagine the path of the high current flowing thru the copper of the PCB to keep it short and contained, then to connect the rest of your circuit at some (one) appropriate place.
     
  3. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    4,769
    969
    Beware.. you cannot dissipate nearly as much heat as you can on the inner layers as you can with outer layers.
    When running high currents you can simply increase copper weight (maybe use a 4oz board instead of 1 or 2 oz laminate) and just make sure you use a wide enough trace on both sides if possible.
    I run 100 Amps on regular double sided circuit boards all day long. I usually use the 4oz laminate and traces roughly 3/4" wide. but my stuff can tolerate 30-60 deg C temp rises.
    I've done boards with 10oz of copper on them.
     
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