DC Brushed Servo Motor Controller Design

Discussion in 'The Projects Forum' started by dksoba, Aug 26, 2010.

  1. dksoba

    Thread Starter New Member

    Jan 8, 2010
    25
    0
    Hi,

    I'm building a board to control 3 dc brushed servo motors using TI microcontrollers + analog power stages. The purpose of building this circuit is just for fun/experience, not a commercial venture.

    While I'm open to ideas on my circuit, I mainly am requesting error checking. I'm new to designing circuits and I have a lot to learn, but I don't particularly want to redesign my whole board to accomplish the same task if it's not necessary. However, if you have these suggestions I'd love to hear them!


    My schematic is here:

    http://mattbockman.com/MotorControllerBoard.pdf

    I haven't started laying the board out. I will do this as soon as I finalize my schematic, since board design might change. Also, if anyone has any tips/pointers on my style of drawing schematics, that would be very useful. I don't think I'm drawing them as efficiently or elegantly as I could be.



    Thanks a bunch,
    Matt
     
  2. dksoba

    Thread Starter New Member

    Jan 8, 2010
    25
    0
    To the top! bump^?
     
  3. windoze killa

    AAC Fanatic!

    Feb 23, 2006
    605
    24
    Hi. I am not responding as to whether this will work or not but more to your design standards. You have a lot of resistors marked with a ?. There are a lot with the component number and value joined eg. R8470Ω. There are a lot with out values.

    I noticed also that there are a lot of extraneous nodes along a lot of the wires. These can create havoc in some PCB programs. Try to check the wire lengths to make sure they join the component correctly.

    You also have a lot of over lapping component names/IDs. Try rearranging your components slightly.

    Some of your net names are not connected eg SB_CURR_SENSE. Either run the wire between the chips or use the I/O symbols as you have for most of the others. Having unterminated net names can sometimes cause problems. Changing between conventions can be confusing. Chose one and stick with it. Using net names and busses can sometimes simplify things as well.

    I don't know what package you are using (looks like Altium/Protel) but I think they all have the capability to add comments. These can very useful for reviewers. Little notes explaining what a certain section is doing can be helpful although most of this circuit is pretty straight forward.

    Hope I have helped a little.

    PS. It seems to be ok as far as I can tell with a quick glance. At least you have remembered all the decoupling caps.

    PPS. Try not to bump posts after only a day.
     
    dksoba likes this.
  4. dksoba

    Thread Starter New Member

    Jan 8, 2010
    25
    0
    Thanks Windoze Killa. I agree w/everything you mentioned and my sloppy drawings *almost* got me in trouble on a PCB design before. I have no excuse, I should know better (And yes, Altium Designer). I will clean it up.

    And the resistors w/ ? designators simply haven't been assigned a designator. Altium can do this automatically, I guess I just forgot to refresh it before printing the PDF output.

    Thanks again,
    Matt
     
Loading...