Place the controll electronics at least 30cm from the transformer.
At the beginning I fitted everything, including the controller and transformer, into the housing from the ATX computer power supply. Unfortunately, this was not a good idea, because the magnetic field from the transformer generated interference and badly affected the micro-controller. The effect was that sometimes during welding the welding pulse did not disappear !!! Copper wire electrodes were evaporating at that moment, and there was a big hole in the tape ….
After moving the controller to the top of the welding machine (to the top of the drill stand – this can be seen in the first photo and in the film about welding the battery) everything is OK.