Harbor Freight/Chicago Electric Welder 90A modifications

When striking an arc with the wire, the wire feed motor suffers from a temporary slowdown as the current draw is large for the weld and the voltage sags for a second at first.  The power for the wire feed comes from the secondary of the main transformer.  It's no load voltage is around 24 something volts AC.  Once an arc is struck the voltage goes down significantly. The first idea was to place a capacitor on the output of the bridge rectifier on the motor control board.  This resulted in the motor remaining on after the trigger was pulled and not turning off.  Must have had something to do with how they control the motor speed... my second idea was a series inductor in line with the motor and it WORKED.  You don't want a capacitor across the motor because it will slow down startup and make the motor run longer after the trigger is released.  With a series DC inductor in line with the motor it helps to provide constant current to the motor when an arc is first drawn. I wound the inductor on a ferrite toroid from a atx psu.  It's wound with 20ga wire and measures around 120uH.  It's a simple fix and the first of a series of fixes to the Welder.