Linear motor references

1.  DIY tubular linear motor: https://hackaday.io/project/202245-diy-tubular-linear-motor
2. Kollmorgen iron less linear drive: https://www.kollmorgen.com/en-us/products/motors/direct-drive/direct-drive-linear
3. PCB linear motors: https://hackaday.com/2022/05/19/pcb-linear-motors-for-model-trains/
4. HP drive circuit details: https://archive.org/details/hp_journal_1979-02/page/n23/mode/2up
5. 2D planar actuator:https://hackaday.com/2018/05/22/smiling-robot-moves-without-wires/
6. 2D planar actuator 2014: https://hackaday.com/2014/04/23/micro-robots-are-scary-awesome/
7. Tolomatic, Irisdynamics