All-Optical Control

A project log for Simple Arc Welder & Optically Controlled Plotter

A simple arc welding circuit with high voltage arc starter and an optically controlled plotter.

dominik-meffertDominik Meffert 09/27/2020 at 22:440 Comments

Now, that the welding system can operate relatively stable it's time for the printer controller and because the machine creates strong electromagnetic interferences, which can turn my TV on and crash its display, the display of my notebook running on battery and every printer controller that I connected to it, I decided to control the machine from a separate completely electrically isolated unit via fiber optic (toslink) cables.

Maybe there could be a way to get a printer controller running in the same machine frame with shielding + filtering, but I think that would be much more complicated and time consuming than just placing the printer controller some distance away from the machine. I also think transmitting endstop, stepper and trigger signals via laser is an interesting approach.

Like you can see/or hear in the video the stepper driver or even the motor get affected by the noise and "stalls" a bit, which could be something that needs to be fixed. Maybe shielded motor cables, DC line filtering, ferrite cores on the cables or/and a grounded enclosure for the stepper drivers could help. I'm very glad that the stepper drivers are less noise sensible than the printer controller which crashes as soon as the HF starter turns on, when placed in the machine.

I ordered one more stepper driver for 2D pattern powder sintering tests.