Method and Apparatus For Braking and Advancing a Welding Wire

Abstract

A method and apparatus for providing welding-type power include a wire feeder that provides wire to an arc and a power supply that provides power to the arc. A reversible wire feed motor moves the wire to and away from the arc. A controller controls the reversible wire feeder motor to reverse at least once per process cycle, and/or controls the power source to provide a desired mean arc current, and/or controls the reversible motor in response to short detection and short clearing, and/or controls the reversal frequency in response to pool oscillation frequency. A wire feed motor output is slaved to an average of the reversible motor output. The controller may include various control modules, such as a mean arc current control module, and/or a short detection feedback circuit. The reversible motor is a stepper motor, that incrementally turns in a series of steps having a given angle in another embodiment. The controller includes a step size output and the given angle is varied in response to the step size output.

1 - 25 . (canceled) 
   
   
       26 . A welding-type power source, comprising:
 a wire feeder disposed to provide wire to an arc;   a power supply disposed to provide power to the arc;   a reversible wire feed step motor, disposed to move the wire to and away from the arc, whereby the motor incrementally turns in a series of steps having a given angle;   a controller, connected to the power supply and the wire feeder, and including a reversible wire feeder control module connected to the reversible wire feeder and, wherein the reversible wire feeder control module includes a reversible motor output.   
   
   
       27 . The welding-type power source of  claim 26  wherein the controller includes a step size output and the given angle is varied in response to the step size output. 
   
   
       28 . The welding-type power source of  claim 26 , where the controller includes a frequency module, and the frequency module is responsive to at least one control parameter. 
   
   
       29 . The welding-type power source of  claim 28 , including a pool oscillation feedback circuit connected to the controller. 
   
   
       30 - 57 . (canceled) 
   
   
       58 . A method of providing welding-type power, comprising:
 feeding wire to the arc;   providing power to the arc; and   reversing the direction of the wire while continuing to feed wire toward a welding torch, in a series of steps having a given distance.   
   
   
       59 . A method of providing welding-type power, comprising:
 feeding wire to the arc;   providing power to the arc;   reversing the direction of the wire; and   controlling the reversing in response to weld pool oscillations.   
   
   
       60 - 84 . (canceled) 
   
   
       85 . A system for providing welding-type power, comprising:
 means for feeding wire to the arc;   means for providing power to the arc; and   means for reversing the direction of the wire while continuing to feed wire toward a welding torch, in a series of steps having a given distance, disposed adjacent the wire.   
   
   
       86 . A system for providing welding-type power, comprising:
 means for feeding wire to the arc;   means for providing power to the arc;   means for reversing the direction of the wire, disposed adjacent the wire; and   means for controlling the reversing in response to weld pool oscillations, connected to the means for feeding.