We like to pretend that our circuits are as perfect as our schematics. But in truth, PCB traces have unwanted resistance, capacitance, and inductance. On the other hand, that means you can use those traces to build components. For example, it isn’t uncommon to see a very small value current sense resistor be nothing more than a long PC board trace. Using PC layers for decoupling capacitance and creating precise transmission lines are other examples. [IndoorGeek] takes us through his process of creating coils on the PCB using KiCad. To help, he used a Python script that works out the circles, something KiCAD has trouble with.
The idea is simple. A coil of wire has inductance even if it is a flat copper trace on a PCB. In this case, the coils are more for the electromagnetic properties, but the same idea applies if you wanted to build tuned circuits. The project took inspiration from FlexAR, an open-source flexible PCB magnet.
KiCAD doesn’t like curved traces, but since the file format is open and text-based, it is easy to write scripts that can create shapes for you. [Joan Spark] provided the script. By the way, the goal for these magnets is to improve the mechanical 7-segment display we’ve looked at earlier.
It is really great to be able to work with text files and modify your PCB layouts; it leads to very handy tools. Of course, you can do the same kinds of tricks with gcode, but by that time, you’ve lost a lot of information.