A welding system includes a welding power supply, wire feeder, and welding circuit connecting the power supply to the wire feeder. The power supply and the wire feeder are configured for bidirectional communication over the welding circuit. The power supply includes a voltage sensor that measures a voltage level, and a current sensor that measures a current level, on the welding circuit. The power supply is configured to operate in a first welding mode to output a power voltage level to the welding circuit to power the wire feeder in response to a communication from the wire feeder over the welding circuit. The power supply generates periodic voltage dip pulses on the welding circuit, and automatically switches to a second welding mode different from the first welding mode based on the voltage level on the welding circuit falling below a threshold voltage level during a voltage dip pulse.

A welding system includes a welding power supply, wire feeder, and welding circuit connecting the power supply to the wire feeder. The power supply and the wire feeder are configured for bidirectional communication over the welding circuit. The power supply includes a voltage sensor that measures a voltage level, and a current sensor that measures a current level, on the welding circuit. The power supply is configured to operate in a first welding mode to output a power voltage level to the welding circuit to power the wire feeder in response to a communication from the wire feeder over the welding circuit. The power supply generates periodic voltage dip pulses on the welding circuit, and automatically switches to a second welding mode different from the first welding mode based on the voltage level on the welding circuit falling below a threshold voltage level during a voltage dip pulse.

A plasma cutting system includes a power supply that outputs first and second plasma cutting currents. A torch is connected to the power supply and includes a first cathode that receives the first plasma cutting current, a first electrode and swirl ring, a second cathode that receives the second plasma cutting current, and a second electrode and swirl ring. The torch simultaneously generates a first and second plasma arcs from the electrodes. A gas controller is configured to separately control a flow of a first plasma gas to the first swirl ring and a flow of a second plasma gas flow to the second swirl ring. A torch actuator moves the torch during cutting, and includes a motor having a hollow shaft rotor for rotating the torch during cutting. A motion controller is operatively connected to the torch actuator to control movements of the torch during cutting.

An example welding or cutting circuit includes: an input leg comprising a capacitor coupled between a high bus and a low bus; a buck converter coupled in parallel with the input leg, wherein the buck converter comprises a first transistor, a first diode, and an output electrically coupled to a node between the first transistor and the first diode, and wherein the buck converter is configured to convert input voltage to current in an inductor coupled to the output of the buck converter; and a steering leg coupled in parallel with the input leg, wherein the steering leg is configured to control a rate at which the current in the inductor decreases, and wherein a current detector is positioned at the output to monitor the current, the current detector providing current level indications to a hysteretic controller, the hysteretic controller providing signals to the first transistor that control the transistor to an on state or an off state to control the voltage applied to the inductor.

An example welding or cutting circuit includes: an input leg comprising a capacitor coupled between a high bus and a low bus; a buck converter coupled in parallel with the input leg, wherein the buck converter comprises a first transistor, a first diode, and an output electrically coupled to a node between the first transistor and the first diode, and wherein the buck converter is configured to convert input voltage to current in an inductor coupled to the output of the buck converter; and a steering leg coupled in parallel with the input leg, wherein the steering leg is configured to control a rate at which the current in the inductor decreases, and wherein a current detector is positioned at the output to monitor the current, the current detector providing current level indications to a hysteretic controller, the hysteretic controller providing signals to the first transistor that control the transistor to an on state or an off state to control the voltage applied to the inductor.

A method for healing surface irregularities in a weld joint includes generating a healing energy beam by a focused energy device, where the healing energy beam includes a predefined energy density. The method also includes scanning the healing energy beam along at least a portion of a periphery of the weld joint, where the weld joint includes at least an upper layer and a lower layer. The method also includes melting less than half a thickness of the upper layer of the weld joint. The predefined energy density of the healing energy beam is based on the thickness of the upper layer of the weld joint.

A method for healing surface irregularities in a weld joint includes generating a healing energy beam by a focused energy device, where the healing energy beam includes a predefined energy density. The method also includes scanning the healing energy beam along at least a portion of a periphery of the weld joint, where the weld joint includes at least an upper layer and a lower layer. The method also includes melting less than half a thickness of the upper layer of the weld joint. The predefined energy density of the healing energy beam is based on the thickness of the upper layer of the weld joint.

Methods for forming pierce holes in a metal workpiece are disclosed. According to one implementation, upon a plasma torch be energized, the cutting axis of the torch is rotated repeatedly between first and second angular positions to produce successively deeper pierces in a workpiece until a pierce hole is produced through a thickness of the workpiece. According to other implementations pierce holes are produced by rotating the cutting axis of the plasma torch tip around a designated central axis of the pierce hole in a diametrically reducing manner so that the produced pierce hole has a tapered profile with a cross-sectional area of the pierce hole at a top surface of the workpiece being greater than a cross-sectional area of the pierced hole at a bottom surface of the workpiece.

Methods for forming pierce holes in a metal workpiece are disclosed. According to one implementation, upon a plasma torch be energized, the cutting axis of the torch is rotated repeatedly between first and second angular positions to produce successively deeper pierces in a workpiece until a pierce hole is produced through a thickness of the workpiece. According to other implementations pierce holes are produced by rotating the cutting axis of the plasma torch tip around a designated central axis of the pierce hole in a diametrically reducing manner so that the produced pierce hole has a tapered profile with a cross-sectional area of the pierce hole at a top surface of the workpiece being greater than a cross-sectional area of the pierced hole at a bottom surface of the workpiece.

A metal cutting device, including a main body, a plurality of legs pivotally disposed on at least a portion of the main body to suspend the main body over a surface, a handle assembly removably connected to at least a portion of the main body to facilitate gripping thereof, and a torch removably connected within at least a portion of the main body to cut the surface in response to contact with the surface.