Lincoln Electric POWER WAVE SVM156-A Service Manual page 44

E-10
Current
Current
Time
GENERAL DESCRIPTION OF
THE STT (SURFACE TENSION
TRANSFER) PROCESS
The STT process cannot be classified as either a con-
stant current (CC) or a constant voltage (CV) applica-
tion. The STT function produces current of a desired
waveform to reduce spatter and fumes.
process is optimized for short-circuit GMAW welding
only.
THEORY OF OPERATION
FIGURE E.8 – STT WAVEFORMS
Time
STT Wave control characteristics
STT Trim control characteristics
The STT
POWER WAVE 455/R
Wave Control +10.0
Wave Control 0.00
Wave Control -10.0
E-10
Trim 1.50
Trim 1.00
Trim 0.50