First Schematic - Looking for Pointers

You mentioned some high current considerations previously. Have you checked the size of tracks that you need and if you might need more than the standard 1oz board? In your earlier screen shot, none of the connections look particularly ‘high power’ - is this no longer a consideration? Other general observations; you might consider rotating J8. Not sure which nets will go when/if you pop a GND or 12V pour as some of your crossing tracks might go.

I connected this up on a prototype and found that the current draw was way under what I had listed it as. I think the heavy side of this is only when I have injectors connected to the ECM which is not the case so my tracks can be fairly small on this board. I was hoping to keep the orientation of all my connectors the same but good eye on J8. I reversed it and the connections make more sense. Maybe I should repin on the schematic and then I can have same orientation that I want plus proper trace layout. Thanks for the help.

Yes, it should be good for PCBWAY.

I was going over my PCB and noticed that I had put power on a round pad on connector J4 and J8. Should incoming voltage always be placed on the square pad? Is this a PCB naming convention or rule? What are the thoughts? Change the schematic or leave it alone? I already swapped J8 around so the wires came out better on the PCB.

There are only two conventions of round vs square pads that I’m aware of:

  1. Pin one is square to help orient polarized parts. All other pins round.
  2. Pin one and every 10th pin on a connector are square, all other pins are round. This is to help count connector pins, and figure out counting direction for dual row pin header connectors. (I think I first saw this in the standard libraries distributed with OrCad back in the '90s. I don’t know if I’ve noticed this anywhere else.)

I’ve never seen any convention stating that power pins should be square.

if you are actually using digikey for parts, they’ve their own kicad libraries… symbols with associated footprints

how to use the downloaded libraries, check out the tutorials/faqs here -

New question. I rearranged my schematic but want to add a 2 pin male connector so that I can either add an ammeter or a jumper depending on the system I connect it to. Remember this is mostly a power distribution pass through board.
When using power flags, where do I install my ammeter 2 pin connector? Refer to post 86 for a quick visual. I would think putting it on the ground side may be easier but doesn’t matter to me. Just wondering where to insert it. Thanks in advance.

Hey Guys, I revised my schematic somewhat and trying to put it onto PCB now. Any pointers on anything I have done so far? Should I use vias for my last group of connections that are left?

Here is the revised schematic. If you are jumping in now, this is a pass through power distribution board.

Also like to know how to add text to board such as blue text on schematic?

I may be possible to not having any vias… If you restrict wire direction of top and bottom in perpendicular to each other.

Hey nhatkhai, how are you tonight? I am not sure I follow??

Also wondering about line through J6 and J7??? Not sure where this came from.

EDIT: Okay I figured this one out.

I guest, add vias if needed. But your trace seem to be too thin for carry 1A currents.

Right now I am just trying to get the pathways.

If you are planning on having this board professionally made (check out for getting informal quotes from lots of vendors based on board dimensions), I see no reason to avoid vias. Long gone are the days of charging per drill hit.

Also, once you see how boards are priced, you may want to tighten up the design as much as you can so you aren’t paying for excessive board real estate.

That might be a mistake. fatter traces might not fit where you want them (though on this design that might not be too much of a concern, but bad habit to get into), and adjusting trace widths after the fact is more fiddly than defining them properly at the start and drawing them properly in the first place.


After short look at your PCB in the direction to minimal number of vias (I don’t like vias if we speak about who knows how many Ampers).

  1. Can the J9 be moved to the left (or top left) of everything and rotated.
  2. In such placement as you done.
  • the green wire on the right can be put around J9 and can be red,
  • the green wire from F2 can be red and go around 2 pins of J5 to thet third pin,
  • then you have no green wires betwean J4 and J9.

And now these 3 connections you can all done (at green) without any via (one directly one around one connector and one around second connector.

I have moved things around and now I want to head for the finish line. How do I make my traces wide enough for the current they will carry. Should I just set a global width or do each one individually. I have not measured all of them on my board. Just the heavier ones which are running under an amp.

I’ll not help.
In Protel if I change width of one track segment I can click button that I wont to extend my operation. Then if I wont to change all tracks (and lines) I need do nothing - just click OK and all tracks (and lines) will get that width. As I probably don’t wont to change the lines width I would need to chek box named “The same layer” so only line segments at that layer will get that width.
I don’t know yet how such global operations to do in KiCad.

This will depend how @bwilliams60 setup their board. If they have different netclasses for the different current requirements then simply changing the width in the netclass editor should update the board. (Assuming the traces are set to “width equal to netclass”)
It might be necessary to use the tool “Edit --> Edit Track & Via Properties…” and choose the “Set to net class values” option for this to take effect. (I am not sure if one needs to have the traces and vias in question selected.)

If there are no netclasses setup or the traces are not setup to get the width from the netclass then the user needs to select the traces they want to edit and use the change vias and track properties dialog. (I don’t remember the exact wording of the option. It is found in the right click context menu.) This is the only dialog right now that can be used to edit properties of more than one element at once.

There is another possibility of why this might fail. If changing the width would violate DRC then the trace width is not updated. (There is a bug report requesting the opposite behavior.)

I still think there are some further optimisations which might help you here. Unless your layout has to be fixed in the position, I would suggest that you have a look at moving J9 to the far left - in line with your other connectors. Have you considered rotating J5 90º clockwise and J7 90º anticlockwise? There might need to be some tinkering with the fuse position which would give you more room for wide tracks.

You might struggle to get anything high current between the pins of these connectors & you might benefit from putting in a ground fill.

1 Like

Are these connector will connect to the other board via a cable? If not, you may need to make sure all the board not going to kick each other when they directly connect to these connector (board-to-board).
It usually better to start with the right trace width so that you don’t have a change to redo whole thing, it is very import for design that have a lot of traces, and space are constrain.
Now you have to either re-route each of them with thicker traces. Or figure out how to do the global change the traces’ width (which I never like to do, and never do it before). But event that, you still have the risk of DRC violations, and reroute traces. If lucky just couple. If not, every once of them.