Actions
Forum Thread Details
  • State Verified Answer
  • Replies 5 replies
  • Answers 1 answer
  • Subscribers 179 subscribers
  • Views 1881 views
  • Users 0 members are here
Related

Add power plane to circuit

Pedro147

Hello.

 

I am working on a board file for a quadcopter flight control board. I only had access to the Eagle schematic under Creative Commons so I developed a board file from it but got some help with the routing. The person who did this work didn't seem to understand the currents involved in the control of the four brush less motors this board controls and consequently did not make the power circuit traces for motor control wide enough for the current flow. I do not have specs for the motors but I have access to a very similar circuit, nearly exactly the same but with the more suitable power traces discussed. The mosfets in this circuit are rated at 6.3 amps continuous drain current. My Eagle and general electronics skill set is not particularly high and that is why I am asking for a little help here. The board already has a power plane so I just added the VCC pins from the motor sockets D5, D6, D9 and D10 to this power plane in increased the trace size from the four mosfet drain pins Q1, Q2, Q3 and Q4 to the four motor sockets  D5, D6, D9 and D10.

 

However when I run "run length" from the command line to check for unrouted lines it shows VCC as being unrouted but I cannot see it if I only show layer 19 on the board file. Also after I hit Ratsnest it shows 5 air wires as being hidden,  in the bottom left status box.

 

I have linked to  my board file with my problematic VCC routing added (AW_V7.brd) and also the other board file that I mentioned with VCC added to the power plane and the bigger mosfet drain to motor socket traces (Classic-Narrow-5V.brd) which I know is a good circuit and capable of handling the current involved.

 

I would really appreciate some help here as I have wasted time by already submitting the faulty board design to a fab house for manufacture and wish to resubmit well before Christmas.

 

Thanks for reading  Pedro.

 

Both files, AW_V7.brd and Classic-Narrow-5V.brd are available in this Mediafire folder 

 

https://www.mediafire.com/folder/lj7ncj4ja6djn/AW_V7_Comparison

Parents
  • 0

    I've had a quick look. You can't easily convert either the top side of

    bottom side GND fills to VCC without other nets becoming disconnected. The

    easiest way if you are in a hurry is go to a 4 layer board and make the two

    inner layers VCC and GND (do both so you have even copper balance in the

    PCB stack). Then you are left with just as single VCC net to get to route.

    This can be done in about 5 minutes as follows:

     

    1) Change the rank of the top layer polygon to 2.

    2) Add VCC vias (I squeezed 4 in) near the SMT connector pad above and to

    the right of the fixing hole.

    3) Add a new polygon around the pad and vias.

    4) Name the polygon VCC.

    5) In the polygon properties check that width is 10, rank is 1 and thermals

    are off.

    6) Hit ratsnest.

     

    You should now have a fully routed board.

     

    1) A couple of last things to change, the VCC trace U3 to C10 and D9 could

    be fattened up or replaced by a polygon fill.

    2) You could put a polygon around U1 on the top layer for 3.3V so you end

    up with a filled 3.3V are underneath U1 rather than connecting it with

    wires.

     

    Best Regards,

     

    Rachael

     

    --

    Web access to CadSoft support forums at www.eaglecentral.ca.  Where the CadSoft EAGLE community meets.

     

Reply
  • 0

    I've had a quick look. You can't easily convert either the top side of

    bottom side GND fills to VCC without other nets becoming disconnected. The

    easiest way if you are in a hurry is go to a 4 layer board and make the two

    inner layers VCC and GND (do both so you have even copper balance in the

    PCB stack). Then you are left with just as single VCC net to get to route.

    This can be done in about 5 minutes as follows:

     

    1) Change the rank of the top layer polygon to 2.

    2) Add VCC vias (I squeezed 4 in) near the SMT connector pad above and to

    the right of the fixing hole.

    3) Add a new polygon around the pad and vias.

    4) Name the polygon VCC.

    5) In the polygon properties check that width is 10, rank is 1 and thermals

    are off.

    6) Hit ratsnest.

     

    You should now have a fully routed board.

     

    1) A couple of last things to change, the VCC trace U3 to C10 and D9 could

    be fattened up or replaced by a polygon fill.

    2) You could put a polygon around U1 on the top layer for 3.3V so you end

    up with a filled 3.3V are underneath U1 rather than connecting it with

    wires.

     

    Best Regards,

     

    Rachael

     

    --

    Web access to CadSoft support forums at www.eaglecentral.ca.  Where the CadSoft EAGLE community meets.

     

Children
No Data