Abstract: A welding machine for GMA using digital controlling method based on DSP (digital signal process) is introduced. By means of flexible programming according to welding technologies and experiences, the suitable characteristics of welding machine such as line compensation, welding voltage and current feedback, wire-feed driving, SCR trigging and so on, can be controlled and self-adjusted using digital signals. Through the designing based on DSP it is put out that the traditional hardware of control circuit is decreased greatly which can en-hance the stability and reliability of welding machine. Finally, the welding experiments using CO2 shielding gas proves that the welding process is stable.

Key words: Digital signal process, GMAW, Welding machine, cutting force, cutting temperature, damage, edge trimming, carbon fiber reinforced polymer(CFRP)