A portable stud welder apparatus is provided for welding a stud onto a work piece. The portable stud welder apparatus includes a housing and an energy storage device. A weld stud gun that is configured to hold a weld stud is electrically connected to the energy storage device for receiving energy from the energy storage device to pass a current through the stud and the work piece to form a weldment. At least one battery of the lithium ion type is removeably coupled to the housing to establish an electrical connection with said energy storage device and provide energy to the energy storage device.

A pulsed welding regime includes a peak phase in which energy is added to an electrode and a weld puddle, and a molten ball begins to detach from the electrode, followed by a dabbing phase in which current is significantly reduced to place the ball in the weld puddle with addition of little or no energy. The resulting short circuit clears and the system proceeds to a background phase. The current in the dabbing phase is lower than the current during the background phase. The process may be specifically adapted for particular welding wires, and may be particularly well suited for use with cored wires. The dabbing phase allows for lower energy to be transferred to the sheath of such wires, and resets the arc length after each pulse cycle.

Systems and methods for providing a constant current controller for use in constant current welding applications are described. In one embodiment, a current controller controls the output current of the welding torch without directly measuring the output current of the welding torch. The current controller controls or sets a current in a primary winding of a transformer in an inverter of a welding power supply to control the output current of the welding torch.

An example welding apparatus includes a welding power source configured to output current between a consumable electrode and a workpiece; a feeding apparatus configured to move the consumable electrode toward the workpiece; and circuitry. The circuitry is configured to: control the welding power source to repeat a sequence including: outputting a positive peak current from the workpiece to the consumable electrode during a positive peak period; outputting a first base current between the consumable electrode and the workpiece during a first base period following the positive peak period, an absolute value of the first base current being less than the positive peak current; and outputting a negative peak current from the consumable electrode to the workpiece during a negative peak period following the first base period, an absolute value of the negative peak current being greater than the absolute value of the first base current. The circuitry is further configured to control the feeding apparatus to move the consumable electrode close to the workpiece so as to temporarily short circuit the consumable electrode and the workpiece during the first base period.

A method and apparatus for providing welding-type power is disclosed. It includes an input circuit, a dc bus, an output circuit, and a control module. The input circuit receives power and provides an intermediate signal to the bus. The output circuit receives the dc bus and provides an ac welding-type output. The output circuit includes a half-bridge output inverter with at least first and second switches. The output inverter further includes an output control circuit. The output control circuit provides freewheeling paths that includes control switches, the output, antiparallel diodes. The control module has a four quadrant control module that provides control signals to the half bridge output inverter and provides modulating control signals to the first and second output control switches. The modulating signals cause the output control switches to be turned on and off multiple times to control a rate of change of output current.

To reduce energy losses for a welding device when on stand-by and to enable a clean and controlled start of the welding phase, a DC-to-DC converter of the welding device converts an input DC voltage present at an input connection to an output DC voltage present at an output connection. At least one switch element of a branch of the DC-to-DC converter is switched with a switching frequency, and a welding phase is provided for the welding device, during which the switching frequency corresponds to a normal switching frequency. A stand-by phase is provided for the welding device, during which the at least one switch element is switched with a switching frequency corresponding to a stand-by switching frequency which is lower than the normal switching frequency

Systems and methods for welding are described. The welding system can include, for example, a welding power source, a welding torch, and a computer. The computer and the welding torch can be operatively coupled to the power source. A first weld is performed and its signature is saved by the computer. It is considered a high quality weld and is selected as a weld reference. A second weld is performed and its signature is saved by the computer. The computer then computes a single weld confidence result for the second weld based on a comparison between the signature data of the second weld and the signature data of the reference weld. A weld fault condition is triggered based on the single weld confidence result which causes the welding system to stop or to modify the welding operation, and/or which causes the welding system to send out communications relating to the triggering of the weld fault condition.

Disclosed example welding or cutting circuits include: an input leg including a capacitor coupled between a high bus and a low bus; a buck converter coupled in parallel with the input leg, the buck converter having a first transistor, a second transistor, and an output electrically coupled to a node between the first transistor and the second transistor, 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 provides current level indications to a hysteretic controller, the hysteretic controller providing signals to the first and second transistors that control the first and second transistors to control the voltage applied to the inductor.

An example welding torch includes: a first contact tip configured to conduct welding current to a consumable electrode; a second contact tip configured to conduct preheating current to the consumable electrode; a cooling assembly configured to transfer heat from at least the first contact tip to coolant and to conduct the welding current through the cooling assembly; wherein the first contact tip and the cooling assembly are removable from the welding torch as a single unit.

Apparatus, systems, and/or methods for mitigating audible noise generated by a welding-type power supply are disclosed. In some examples, the switching frequency of the welding-type power supply may be changed to a frequency that is outside the audible range for humans. This strategy takes advantage of the fact that the observed audible noise is generated by vibrating components within the welding-type power supply that vibrate at a frequency related to the switching frequency. Other noise mitigation strategies include dithering and deactivation of portions of the welding-type power supply that vibrate to generate the audible noise.