Method of controlling arc welding processes and welder using same
First Claim
1. A method of generating a real time control signal for use in an electric arc welding process having welding voltage and welding current, said method comprising:
- measuring the arc voltage and arc current at a first time, momentarily changing either said arc voltage or arc current by less than about 10%, then measuring said welding voltage and said welding current after said change at a second time, determining the welding voltage difference between said first time and said second time, determining the welding current difference between said first time and said second time, producing a derivative value representing said control signal by dividing said welding voltage difference between said first and second times by said welding current difference between said first and second times and generating said control signal by said derivative value.
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Accused Products
Abstract
A method of generating a real time control signal for use in an electric arc welding process having welding voltage and welding current, said method comprising: measuring the welding voltage and welding current at a first time, momentarily changing either the welding voltage or welding current by less than about 10%, then measuring the welding voltage and the welding current after the change at a second time, determining the welding voltage difference between the first time and the second time, determining the welding current difference between the first time and the second time, producing a derivative value representing the desired control signal by dividing the welding voltage difference between the first and second times by the welding current difference between the first and second times and generating the control signal by the derivative value.
84 Citations
39 Claims
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1. A method of generating a real time control signal for use in an electric arc welding process having welding voltage and welding current, said method comprising:
- measuring the arc voltage and arc current at a first time, momentarily changing either said arc voltage or arc current by less than about 10%, then measuring said welding voltage and said welding current after said change at a second time, determining the welding voltage difference between said first time and said second time, determining the welding current difference between said first time and said second time, producing a derivative value representing said control signal by dividing said welding voltage difference between said first and second times by said welding current difference between said first and second times and generating said control signal by said derivative value.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A system for generating a real time control signal for use in an electric arc welder having a power supply for generating a welding voltage between a contact tip and a workpiece and a welding current through said electrode extending from said tip and through a electric arc, a sensor to sense the welding voltage;
- a sensor to sense the welding current and controller to control said welding voltage and/or said welding current, said system comprising;
a digital device recording the welding voltage and welding current at a first time and then at a second time, a control device to change said welding current between said first time and said second time, a digital device for measuring the difference between said welding voltage and said welding current at said first and second time, and a derivative circuit for measuring the value of the welding voltage difference divided by the welding current difference to produce said control signal.
- a sensor to sense the welding current and controller to control said welding voltage and/or said welding current, said system comprising;
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10. A method of generating a real time control signal for use in an electric arc welding process having a welding voltage and welding current, said method comprising:
- measuring the process welding voltage and process welding current at a first time, increasing the welding current above the process welding current, after a first time delay again measuring the welding voltage and welding current at a second time, then decreasing the welding current to below the process welding current, after a second time delay measuring the welding voltage and welding current at a third time, then increasing said welding current to near said process welding current, after a third time delay measuring said welding voltage and said welding current at a fourth time, determining the difference of said welding voltage and said welding current between said second and third times and dividing said voltage difference by said current difference to generate said control signal.
- View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
- 30. A method of generating a real time control signal for use in an electric arc welding process having a process welding voltage and process welding current, said method comprising sensing the derivative of said welding voltage with respect to welding current to generate said control signal.
- 38. An arc welder for performing an arc welding process comprising a power supply for creating a welding current and welding voltage with a controller for maintaining a preselected established current wave form, said welder including a circuit for increasing said welding current by a level above said established current by less than 10% of said established current at a first time, holding said level for a time delay, then reducing said welding current at least to about said established current at a second time, sensors for measuring said welding voltage and welding currents at said first and said second time, a circuit for subtracting said two voltages to give a value and a circuit for dividing said value by the difference of said two currents to create a signal for use in controlling a selected parameter in said welding process.
Specification