Wire feeder with non-linear speed control

Abstract

A welding machine with a wire feeder and a controller is disclosed. The wire feeder includes a wire feed motor with a motor speed input. The controller is coupled to the motor speed control input. A user selectable wire feed speed input is also connected to the controller. The controller has an input circuit coupled with a non-linear stage such that the relationship between the user selectable wire feed speed input and the actual wire feed speed is not linear. The selectable input may be a potentiometer mounted on a front panel as the user selectable wire feed speed input. The non-linearity may be continuous or two discrete gains.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:  
     
         1 . An apparatus for feeding wire at a controllable wire feed speed to a weld comprising: 
 a wire feed motor, having a wire feed speed;    a controller, coupled to the wire feed motor; and    a selectable wire feed speed input;    wherein the controller includes an input circuit coupled to the selectable wire feed speed input, and wherein the input circuit includes a non-linear stage such that the relationship between the selectable wire feed speed input and the wire feed speed is not linear.    
     
     
         2 . The apparatus of  claim 1  wherein the selectable wire feed speed input includes a potentiometer mounted on a front panel.  
     
     
         3 . The apparatus of  claim 2  where the input circuit includes a plurality of gain stages each having gain over one of a plurality of input ranges.  
     
     
         4 . The apparatus of  claim 2  wherein the non-linear stage includes a gain stage having a varying gain.  
     
     
         5 . The apparatus of  claim 1  wherein the controller directly controls wire feed speed.  
     
     
         6 . An apparatus for feeding wire at a controllable wire feed speed to a weld comprising: 
 a wire feed motor, having a wire feed speed;    a controller means for controlling the motor speed; wherein the controller means is coupled to the motor; and    an input means for allowing a user to select a wire feed speed;    wherein the controller means includes an input circuit coupled to the input means, and wherein the input circuit includes non-linear means for creating a non-linear relationship between a setting of the input means and the wire feed speed.    
     
     
         6 . The apparatus of  claim 5  wherein the input means includes a potentiometer mounted on a front panel.  
     
     
         7 . The apparatus of  claim 6  where the input circuit includes a gain stage means for providing at least two gains.  
     
     
         8 . The apparatus of  claim 6  wherein the non-linear means includes a gain stage means for providing a varying gain.  
     
     
         9 . A method of controlling wire feeder comprising the steps of: 
 providing the wire at a controlled speed;    providing a user input; and    creating a non-linear relationship between the user input and the wire feed speed.    
     
     
         10 . The method of  claim 9  wherein the step of providing a user input includes providing a potentiometer mounted on a front panel.  
     
     
         11 . The method of  claim 10  where the step of creating includes the step of providing at least two gains in a gain stage connected to the user input.  
     
     
         12 . An apparatus for controlling the rate at which wire is fed to a weld, comprising: 
 a wire feed motor output;    a selectable wire feed speed input; and    an input circuit coupled to the selectable wire feed speed input, and wherein the input circuit includes a non-linear stage such that the relationship between the selectable wire feed speed input and the wire feed output is not linear.    
     
     
         13 . The apparatus of  claim 12  wherein the selectable wire feed speed input includes a potentiometer mounted on a front panel.  
     
     
         14 . The apparatus of  claim 13  where the input circuit includes a plurality of gain stages each having gain over one of a plurality of input ranges.  
     
     
         15 . The apparatus of  claim 13  wherein the non-linear stage includes a gain stage having a varying gain.  
     
     
         16 . The apparatus of  claim 12  wherein the controller directly controls wire feed speed.  
     
     
         17 . An apparatus for controlling the rate at which wire is fed to a weld comprising: 
 a wire feed motor output, corresponding to a wired feed speed;    controller means for controlling the motor speed, wherein the controller means is coupled to the motor output; and    an input means for allowing a user to select a wire feed speed;    wherein the controller means includes an input circuit coupled to the input means, and wherein the input circuit includes non-linear means for creating a non-linear relationship between a setting of the input means and the motor output.    
     
     
         18 . The apparatus of  claim 17  wherein the input means includes a potentiometer mounted on a front panel.  
     
     
         19 . The apparatus of  claim 18  where the input circuit includes a gain stage means for providing at least two gains.  
     
     
         20 . The apparatus of  claim 18  wherein the non-linear means includes a gain stage means for providing a varying gain.  
     
     
         21 . An apparatus for arc welding comprising: 
 a welding power supply connected to provide welding power to the arc;    a wire feed motor, disposed to provide wire to the arc and having a wire feed speed;    a controller, coupled to the wire feed motor; and    a selectable wire feed speed input;    wherein the controller includes an input circuit coupled to the selectable wire feed speed input, and wherein the input circuit includes a non-linear stage such that the relationship between the selectable wire feed speed input and the wire feed speed is not linear.    
     
     
         22 . The apparatus of  claim 21  wherein the selectable wire feed speed input includes a potentiometer mounted on a front panel.  
     
     
         23 . The apparatus of  claim 22  where the input circuit includes a plurality of gain stages each having gain over one of a plurality of input ranges.  
     
     
         24 . The apparatus of  claim 22  wherein the non-linear stage includes a gain stage having a varying gain.  
     
     
         25 . The apparatus of  claim 21  wherein the controller directly controls wire feed speed.