Abstract: A system and method for controlling a weld-current in an arc welding apparatus involves programming of a waveform generator to supply a control signal to a weld-current power supply, the control signal being derived from a reference waveform consisting of selected segments having fixed or predetermined amplitudes and variable durations. The reference waveform may be dynamically adjusted in response to changes in welding conditions by feeding the output of an arc current and/or voltage detector back to the waveform generator and varying the duration of selected predetermined amplitude segments.

Abstract: A system and method for controlling a weld-current in an arc welding apparatus involves programming of a waveform generator to supply a control signal to a weld-current power supply, the control signal being derived from a reference waveform consisting of selected segments having fixed or predetermined amplitudes and variable durations. The reference waveform may be dynamically adjusted in response to changes in welding conditions by feeding the output of an arc current and/or voltage detector back to the waveform generator and varying the duration of selected predetermined amplitude segments.

Abstract: An arc welding control method and apparatus includes a voltage control loop in which a pulsation parameter such as pulse width, pulse amplitude, background amplitude between pulses, or frequency, is adjusted to compensate for deviations in the arc voltage, and a second, slower feedback loop which adjusts a second parameter of the system in order to cause the pulsation parameter to return to a desired value as a result of the effect of the adjusted second parameter on the arc voltage.

Abstract: An improved filler wire feed controller for a welding system is described in which the filler wire can be supplied to the vicinity of an arc between an electrode and a workpiece in a four-portion cycle. The cycle can include a feed portion, during which the wire is supplied to the weld pool at a rate at which it is consumed and deposited on the workpiece; a retract portion, during which the wire is rapidly withdrawn from the workpiece; a pause portion, during which the wire is stationary with respect to the arc; and an advance portion, during which the wire is advanced rapidly into the arc. This four-portion cycle provides increased flexibility of control of supply of wire to the weld pool, which can be employed to avoid balling of the end of the wire. The wire feed supply may be synchronized to variations in the current of the arc and also to movement of the wire guide/electrode asembly with respect to the workpiece.

Abstract: A system and method for detecting the position of the welding torch with respect to the workpiece by varying the electrical power to the arc, measuring the effect of such variation on the arc current and/or arc voltage and processing the detected effect to produce welding torch position related information. Also, a welding system and method which comprises utilizing this detection system and method to control the position of the welding torch means with respect to the workpiece.

Abstract: Power delivered to the welding arc from a constant current rapid response power supply is controllable to maximize arc stability particularly in out-of-position welding operations. A first control modulates the output current from the power supply between a high value close to the maximum output value and a minimum value just sufficient to maintain the welding arc. The modulation is effected at a given frequency appropriately adjusted in accordance with the electrode material and diameter to maintain optimum spray metal transfer in the welding arc. A further control is effected by pulse width modulating the output from the power supply in accord with a set-in current programmed signal which is compared with a current feedback signal or, alternatively, a set in voltage programmed signal which is compared with a voltage feedback signal. This latter control provides for operation of the power supply in a constant current control mode or alternatively, a constant voltage control mode.