Waveform control in welding power supplies

The convergence of advanced power electronics and fast computation has enabled welding power supply control to become more sophisticated, with power and voltage controlled by means of feedback to follow prescribed periodic waveforms that achieve different requirements at different times. An example of periodic excitation is the proprietary surface tension transfer (STT) process developed by Lincoln Electric. In this process, the melting electrode material contacts the weld pool on the workpiece before detaching, creating a periodic short. The STT process provides several major benefits including substantial reduction in spatter, ease of welding, lower arc radiation, reduced fume generation, and lower heat input on thin-gauge material