Abstract: A welder using a circuit or method of changing polarity of an AC welding current comprising: the generation of a polarity changing signal, commanding a change in the polarity of the current a given time after generation of the polarity changing signal and reducing the given time upon detection of a short in the welding current.

Abstract: An electric arc welder for depositing weld metal along a groove between two edges of a metal workpiece where the welder comprises a first electrode driven by a first wire feeder toward a point in said groove, a second electrode driven by a second wire feeder toward the point and a main power source with a first output terminal connected to the first electrode and a second output terminal connected both to the second electrode and directly or indirectly to the metal workpiece to create a second electrode path and a workpiece path. The power source includes a high speed switching output stage for creating current with a selected AC waveform between the first and second output terminals where the waveform of the main power source is generated by a waveform generator controlling a pulse width modulator circuit to determine the current operation of the output stage.

Abstract: An electric arc welding system and method for creating a first AC welding arc with a first current waveform between a first electrode and a workpiece by a first power supply and a second AC welding arc with a second current waveform between a second electrode and a workpiece by a second power supply as the first and second electrodes are moved in unison along a welding path where the first and second power supply each comprising an high speed switching inverter creating its waveform by a number of current pulses occurring at a frequency of at least 18 kHz with the magnitude of each current pulse controlled by a wave shaper and the polarity of the waveforms controlled by a signal. The first and second AC waveforms each have a positive portion and a negative portion and a cycle period of about 10–20 ms and timing circuits for determining the push and pull times between the arcs and a waveform adjusting circuit to limit the push and pull times to less than about 5.0 ms.

Abstract: Electric arc welder (10) performs a given weld process with selected current waveform performed between electrode (24) and workpiece (26). Welder (10) includes a controller with a digital processor (30), sensor (44) for reading instantaneous weld current, and circuit (56) to convert the instantaneous current into a digital representation of the level of instantaneous weld current. Digital processor (30) has program circuit (64, 66) to periodically read and square the digital representation at a given rate, register (70, 72) for summing a number N of square digital representations to give a summed value, and an algorithm (82, 84, 86, 88) for periodically dividing the summed value by the number N to provide a quotient and then taking the square root of said quotient to thereby digitally construct rms signal (40) representing the root mean square of the weld current.

Abstract: An operating system is provided for an electric arc welder including a high switching speed inverter power source for creating an arc voltage and arc current between an electrode and a workpiece. This operating system regulating the arc voltage to provide a voltage with a slope by using an error circuit to create an error output and having a first input with a signal representing the set voltage and a second input representing the sum of the actual arc voltage and the actual arc current multiplied by a slope constant. A DSP program reduces the error output by adjusting the voltage output of the inverter power source to change the actual arc voltage. The slope constant is in the range of 0–10%.

Abstract: An electric arc welding system for creating an AC welding arc between an electrode and a workpiece wherein the system comprises a first controller for a first power supply to cause the first power supply to create an AC current between the electrode and workpiece by generating a switch signal or command with polarity reversing switching points in the first controller, with the first controller operated at first welding parameters in response to first power supply specific parameter signals to the first controller. The system has at least one slave controller for operating a slave power supply to create an AC current between the electrode and workpiece by reversing polarity of the AC current at switching points where the slave controller is operated at second welding parameters in response to second power supply specific parameter signals to the slave controller.

Abstract: An electric arc welder for performing a given weld process with a selected A.C. pulse current waveform performed between an electrode and a workpiece, where the current waveform includes a positive segment and a negative segment, with at least one segment including a peak current and background current. The welder comprises: a power source with a controller having a digital processor including a program to calculate the real time power factor of the weld current and weld voltage where the program includes an algorithm to calculate the rms weld voltage, the rms weld current and the average power of said power source; a circuit to multiply the rms current by the rms voltage to produce an rms power level; a circuit to divide the average power by the rms power to create a value representing the actual real time power factor of said power source; and, a circuit to adjust said background current to maintain said power factor at a given level, which is manually adjusted to set the heat of the weld.

Abstract: An electric arc welding system for creating an AC welding arc between an electrode and a workpiece wherein the system comprises a first controller for a first power supply to cause the first power supply to create an AC current between the electrode and workpiece by generating a switch signal or command with polarity reversing switching points in the first controller, with the first controller operated at first welding parameters in response to first power supply specific parameter signals to the first controller. The system has at least one slave controller for operating a slave power supply to create an AC current between the electrode and workpiece by reversing polarity of the AC current at switching points where the slave controller is operated at second welding parameters in response to second power supply specific parameter signals to the slave controller.

Abstract: An electric arc welding system for creating a first AC welding arc with a first current waveform between a first electrode and a workpiece by a first power supply and a second AC welding arc with a second current waveform between a second electrode and a workpiece by a second power supply as the first and second electrodes are moved in unison along a welding path, where the first and second power supply each comprising a high speed switching inverter creating its waveform by a number of current pulses occurring at a frequency of at least 18 kHz with the magnitude of each current pulse controlled by a wave shaper and the polarity of the waveforms is controlled by a signal. The first AC waveform has a positive portion substantially different in energy than its negative portion and/or has either a different shape and/or a synthesized sinusoidal portion.

Abstract: A welder using a circuit or method of changing polarity of an AC welding current comprising: the generation of a polarity changing signal, commanding a change in the polarity of the current a given time after generation of the polarity changing signal and reducing the given time upon detection of a short in the welding current.

Abstract: An electric arc welding system for creating a first AC welding arc with a first current waveform between a first electrode and a workpiece by a first power supply and a second AC welding arc with a second current waveform between a second electrode and a workpiece by a second power supply as the first and second electrodes are moved in unison along a welding path, where the first and second power supply each comprising a high speed switching inverter creating its waveform by a number of current pulses occurring at a frequency of at least 18 kHz with the magnitude of each current pulse controlled by a wave shaper and the polarity of the waveforms is controlled by a signal. The first AC waveform has a positive portion substantially different in energy than its negative portion and/or has either a different shape and/or a synthesized sinusoidal portion.

Abstract: Electric arc welder (10) performs a given weld process with selected current waveform performed between electrode (24) and workpiece (26). Welder (10) includes a controller with a digital processor (30), sensor (44) for reading instantaneous weld current, and circuit (56) to convert the instantaneous current into a digital representation of the level of instantaneous weld current. Digital processor (30) has program circuit (64, 66) to periodically read and square the digital representation at a given rate, register (70, 72) for summing a number N of square digital representations to give a summed value, and an algorithm (82, 84, 86, 88) for periodically dividing the summed value by the number N to provide a quotient and then taking the square root of said quotient to thereby digitally construct rms signal (40) representing the root mean square of the weld current.

Abstract: An electric arc welding system for creating an AC welding arc between an electrode and a workpiece wherein the system comprises a first controller for a first power supply to cause the first power supply to create an AC current between the electrode and workpiece by generating a switch signal or command with polarity reversing switching points in the first controller, with the first controller operated at first welding parameters in response to first power supply specific parameter signals to the first controller. The system has at least one slave controller for operating a slave power supply to create an AC current between the electrode and workpiece by reversing polarity of the AC current at switching points where the slave controller is operated at second welding parameters in response to second power supply specific parameter signals to the slave controller.

Abstract: An electric arc welding system for creating an AC welding arc between an electrode and a workpiece wherein the system comprises a first controller for a first power supply to cause the first power supply to create an AC current between the electrode and workpiece by generating a switch signal or command with polarity reversing switching points in the first controller, with the first controller operated at first welding parameters in response to first power supply specific parameter signals to the first controller. The system has at least one slave controller for operating a slave power supply to create an AC current between the electrode and workpiece by reversing polarity of the AC current at switching points where the slave controller is operated at second welding parameters in response to second power supply specific parameter signals to the slave controller.

Abstract: A device for terminating operation of the power source of an electric arc welder for passing a current between an electrode and work piece from a first stud connected to the electrode by a first cable and a second stud connected to the work piece by a second cable to perform a welding process. The welder includes an output transformer with a known turns ratio, a primary winding and secondary winding. A first voltage sense lead is connected to the electrode and a second voltage sense lead connected to the work piece. The novel device comprises an executive program to implement a test sequence involving (a) a program routine for comparing a real time theoretical voltage, determined by the pulse waveform at a given time of the waveform, and the voltage at the sense leads at the given time; (b) a program routine to terminate operation of the power source when the theoretical voltage substantially exceeds the sense lead voltage; and, (c) a timing routine to perform the executive program at a set period.

Abstract: An electric arc welding system for creating an AC welding arc between an electrode and a workpiece wherein the system comprises a first controller for a first power supply to cause the first power supply to create an AC current between the electrode and workpiece by generating a switch signal or command with polarity reversing switching points in the first controller, with the first controller operated at first welding parameters in response to first power supply specific parameter signals to the first controller. The system has at least one slave controller for operating a slave power supply to create an AC current between the electrode and workpiece by reversing polarity of the AC current at switching points where the slave controller is operated at second welding parameters in response to second power supply specific parameter signals to the slave controller.

Abstract: An electric arc welding system for creating an AC welding arc between an electrode and a workpiece wherein the system comprises a first controller for a first power supply to cause the first power supply to create an AC current between the electrode and workpiece by generating a switch signal or command with polarity reversing switching points in the first controller, with the first controller operated at first welding parameters in response to first power supply specific parameter signals to the first controller. The system has at least one slave controller for operating a slave power supply to create an AC current between the electrode and workpiece by reversing polarity of the AC current at switching points where the slave controller is operated at second welding parameters in response to second power supply specific parameter signals to the slave controller.