Isolating PCB Layout "Pcbnew" from Schematics

I am building a simple “multilayer” transformer winding in the pcb layout of KiCAD “pcbnew”.

For this I just generate the windings using a python code.

I wish to connect each layer of winding to the next layer ( F.Cu to In1.Cu ; In1.Cu to In2.Cu ; In2.Cu to B.Cu - technically 4 layer pcb).

I am unable to connect because the netlist is not built to connect one Cu. trace to the other.

Is there any way to “Force” connection and how to add custom Netlist in pcbnew ?

I am new to KiCAD and just in learning process. I saw many questions on “creating pcb layout alone” as that is what I wanted to do to prevent necessity of netlists generated by the schematics but got no answer to the point.

Kindly advise on what can be done to solve this problem ?

Clear Question : " I just want to connect two traces in Layout section alone without schematics. How do I creat or add netlist for this ? "

For version 5.1 you have to use for example WireIt plugin, WireIt: PCBNEW plugin for adding/cutting/swapping wires in the physical layout.

In the future v6 will have built-in support for adding nets with Net Inspector.

On the other hand, why wouldn’t you create a schematic for it?

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If you’re drawing the windings from a python script it can be an option to not use “tracks” to draw them, but other graphical primitives, such as lines, arcs and polygons, and then treat the whole thing itself as a Footprint.

For the ends of the windings you can then use numbered SMT pads, and use a normal transformer symbol in Eeschema for the schematic.

As an example, have a look at how the footprints for the net-ties are made.

I have not done this myself, but from what I know of KiCad it should be a viable path.

If there are problems with DRC not recognizing your custom drawn artwork on copper, then you can add a keepout zone to prevent other tracks from crossing that area.

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Hi eelik.
Thank you for replying. I am only able to create schematics for the terminal ending of the coil. There are in total 128 windings ( 52 on inner layers and 56-57 on outer layers ). The terminals or “mounting Holes” or SMD pads are in schematic. But the windings was generated in Python as it is a herculean task to do it manually.
I just need to connect the ends of the windings to these pads or holes.
I found I couldn’t create the windings as a footprint in the library as the python code option was not to be found. Thanks for the reply . I will try this.

Thanks for replying with the solutions. I will try them now.

Instead of implementing transformer as a layout of tracks, I’d rather implement it as a footprint. And KicadModTree is extremely usefull in this regard.

If I remember correctly it’s possible to create footprints in pcbnew scripts even though you can’t use scripts in the footprint editor UI.

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Balaji_Subramanian
I am building a simple “multilayer” transformer winding in the pcb layout of KiCAD “pcbnew”.

Hi,
Sorry for the intrusion. I’m highly interested in this post and the solution that will be provided. I’m currently having a project that will be based on a transformer without a physical coil, using burried tracks and vias instead.
Unfortunately I can barely follow this post because of the lack of understanding what you’re trying to do in this matter. Please, may you provide a piece of schema and PCB layout ?
TIA

It’s unclear to me what you mean by:

With the Footprint Wizard scripts, you generate a footprint in the Footprint editor, and can be modified further, such as by adding SMD pads on the ends.

I’ve heard of a script to generate spiral inductors for KiCad, but don’t know it’s name or wherabouts.

You can also directly create your footprint as a file on disk in KiCad, and modify it further in the Footprint Editor as needed.
For more info on KiCad’s file formats see:
https://kicad.org/help/legacy_file_format_documentation.pdf

Note: “Legacy” is I think under the presumption that KiCad V6 will be here soon…
[Edit…]
I had a peek at that document, (The last time I did it was quite some time ago) and now it seems to describe different versions of file formats. The latest versions described are probably for KiCad V5, but if you want to dive into it, then study some current library symbols or footprints as an example, and compare it with the file format descriptions.

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