Methods and systems to reduce distortions induced in a voltage measurement wire. In an embodiment, a measurement wire is coupled to a head of an arc welding apparatus and to a feedback circuit to provide a head voltage and noise induced on the measurement wire to the feedback circuit. A reference wire is coupled to a reference node and to the feedback circuit to provide noise induced on the reference wire to the feedback circuit. The reference node may be proximate to and electrically isolated from the head, and the measurement wire and the reference wire may be arranged adjacent to one another (e.g., as a twisted pair), so that the similar distortions are induced in the measurement wire and the reference wire. The feedback circuit determines the head voltage as a difference between noise of the reference wire and the head voltage and noise of the first measurement wire.

Systems and methods are disclosed relating to welding-type power supplies. In some examples, the power supplies may have no vents, which may help prevent environmental contaminants from entering the power supplies. Instead, the power supplies include one or more thermal interfaces configured to conduct heat generated by internal circuitry of the power supply from the interior of the power supply to an exterior of the power supply. Additionally, the thermal interface(s) may be configured for attachment to one or more exterior heat dissipating devices.

An example welding-type power supply includes: power conversion circuitry configured to convert input power to welding-type power, and to output the welding-type power via a welding-type circuit; a temperature sensor configured to measure a temperature of at least one component of the welding-type power supply; and stray current detection circuitry configured to detect stray welding-type current based on the measured temperature of the at least one component.

Methods and apparatus to communicate via a weld cable are disclosed. An example welding accessory includes a first port to receive input power via a first weld cable, a power converter to convert the input power to output power, a second port to output the input power via a second weld cable, and one or more output switches to selectively divert the input power from the power converter to the second port.

A method is performed in a welding or cutting system including a power supply configured to deliver current pulses through a weld circuit to a contact tip extending from a welding torch to create an arc on a workpiece. The method includes: while the contact tip is shorted to the workpiece to set an arc voltage equal to zero: sampling a current pulse to produce current values; and at a voltage sense point, on the power supply or the weld circuit, that is spaced-apart from the welding torch, sampling a voltage pulse associated with the current pulse to produce voltage values that differ from the arc voltage due to an electrical circuit parameter of the weld circuit; and computing a value of the electrical circuit parameter based on the current values, the voltage values, and the arc voltage equal to zero.

Engine driven power supplies with output reduction are disclosed. An example engine-driven welding power supply for providing a welding-type output includes an engine, a generator mechanically linked to the engine, power conditioning circuitry, and a controller. The generator generates output power based on mechanical input from the engine. The power conditioning circuitry converts the output power from the generator to welding-type power based on a commanded output. The controller reduce an output of the power conditioning circuitry from the commanded output by an amount proportional to a difference between a speed of the engine and a commanded engine speed while monitoring the difference, decreases the output in response to determining that the reduction in the output does not result in an acceleration in the engine speed, and increases the welding-type output as the difference between the speed of the engine and the commanded engine speed decreases.

Systems and methods for cleaning a wire electrode after a welding process has ended are described. During a welding process, a wire electrode may be fed forward from a wire feeder through a welding torch to create a molten weld pool. While, conventionally, feeding of the wire electrode stops when the welding process ends, the present disclosure contemplates instead continuing to feed the wire electrode forward after the welding process ends. More particularly, the present disclosure contemplates feeding the wire electrode into the weld pool so that the wire electrode can be “cleaned” in the molten weld pool created by the welding process. The “cleaned” wire electrode end can be more easily used to establish an electrical arc at the beginning of the next welding process.

A power supply may include a power block to receive an input power and generate an output power; and a control system coupled to the power block, wherein the power block and control system are arranged to provide unidirectional current flow and bipolar voltage during operation of the power supply.

A method includes ramping down a welding current, generated by a power supply, that reaches a welding zone via a welding circuit, storing inductive energy from the welding circuit that is generated as a result of the ramping down to obtain stored energy, and selectively feeding the stored energy to the welding circuit.

A welding system and method provide for generating a controlled waveform for welding power output, the waveform comprising a plurality of successive peak phases designed to avoid or reduce micro-arcing when used with metal-cored or flux-cored electrode wires. Ratios of the background current and voltage levels are elevated as compared to conventional techniques, with the levels in most cases exceeding 50% of the peak currents and voltages. Transitions between background and peak levels of current and voltage are also smoothed, and the duration of the peak phase as compared to the duration of each pulse cycle is elongated to further reduce micro-arcing.