© COPYRIGHT 1998 THE ESAB GROUP, INC. LESSON II This rapid current rise can be by using a device called an (sometimes called a stabilizer) output circuit of the welder.  An merely an iron core wound turns of heavy wire.  It does current flow, but it acts somewhat like a fly wheel or damper by retarding the rate of rise as shown by the solid line.  By preventing the rapid current rise, the arc becomes smoother, spatter is reduced, and bead shape and appearance are improved.  Because the inductor influences the time function, its design determines arc on-off time, and short-circuit frequency.  Some power sources have a selector that can switch in several different inductance values to finely tune the arc. Welding power sources designed for gas metal arc welding have a 115 volt outlet to provide power to operate the wire feeder.  They also have a receptacle to receive the electrical power required to close the main contactor in the power source, which turns on the welding power to the welding gun when the gun trigger is actuated. Additional advancements in equipment technology have introduced many new models.  Inverters, as well as microprocessor controls, have created the greatest attention.  In addition, multipurpose machines have provided the user with greater flexibility with a variety of capabilities. Global competition will continue to have a profound influence on future advancements in arc welding equipment.  As energy prices rise, greater demands for more efficient equipment will follow. 2.4.5 Wire Feeder - When welding with a constant voltage power source, as is the case in most gas metal arc welding applications, the prime function of the wire feeder is to deliver the welding wire to the arc at a very constant speed.  Since the wire feed speed determines the amperage, and the amperage determines the amount of heat at the arc, inconsistent wire feed speed will produce welds of varying penetration and bead width.  Advanced electronics FIGURE 14 TIME - MILLISECONDS EFFECT OF INDUCTANCE ON CURRENT RISE 400 AMPS WITHOUT INDUCTANCE WITH INDUCTANCE 150 AMPS
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Lesson 1
The Basics of Arc Welding
Lesson 2
Common Electric
Arc Welding Processes
Lesson 3
Covered Electrodes for Welding
Mild Steels
Lesson 4
Covered Electrodes for Welding Low Alloy Steels
Lesson 5
Welding Filler Metals for Stainless Steels
Lesson 6
Carbon & Low Alloy
Steel Filler Metals -
Lesson 7
Flux Cored Arc Electrodes Carbon Low Alloy Steels
Lesson 8
Hardsurfacing Electrodes
Lesson 9
Estimating & Comparing Weld Metal Costs
Lesson 10
Reliability of Welding Filler Metals