| • |
In AC welding, Alternating Current (AC) is used i.e. the direction of current flows changes every 1/120 of a second that is the electron travels alternately from anode to cathode (Fig. 1-3) and the electrode & work gets heated alternately. |
| • |
The rapid reversal of the current flow causes the welding heat to be evenly distributed on both the work and the electrode. The even heating given the weld bead a balance between penetration & buildup. |
| • |
They are quieter, more energy efficient. |
| • |
Requires less maintenance. |
| • |
Less expensive |
| • |
In AC welding a step down Transformer is used |
| • |
It takes high voltage, low current & changes into high current, low voltage |
| • |
Except for some power lost by heat within T/F, the power (watts) into T/F equals the power (Watts) out because the volts & amperes are mutually increased or decreased |
| • |
Welding T/F can be classified by the method by which they control or adjust the welding current. The major classification are multiple coil called Taps, movable coil or movable core (Fig. 1-1) |
| Features |
| • |
It is a moving core type Welding Transformer |
| • |
Current adjusted by tuning a handle wheel/lever that moves the internal parts closer together or farther apart |
| • |
Moving the core which concentrates more of the magnetic force on the secondary coil thus increasing the current |
| • |
Moving the core out allows the field to disperse and the current is reduced (Fig. 1-2) |
| • |
Versatile |
| • |
Can be used in variety of metals and position |
| • |
Low cost machine |
