Learners read an explanation of the RL time constant and examine the formula for calculating the instantaneous current value. The current is graphed as it climbs to maximum or drops to zero. Note* In the formulas in this module, the Greek letter epsilon should be the mathematical constant 'e'.
Students view a video that shows the correct methods for starting a GTAW weld pool and adding filler. It focuses on the two problems that many students have – adding filler too soon and angling the torch so that the filler melts prematurely on the filler rod. Note: This activity is 3.6 mb.