An example apparatus to monitor a welding-type system includes: a test signal generator configured to output a test signal to a monitored circuit; and a lock-in amplifier configured to: receive a reference signal based on the test signal; measure a leakage current in the monitored circuit based on the reference signal; and generate an output signal representative of the leakage current.

A method and/or a system estimate a quality of a weld. For example, a weld information algorithm may be generated based on, for each of a plurality of welds, at least two of a first maximum weld force parameter, a minimum weld force parameter, or a second maximum weld force parameter. The weld information algorithm may be used to estimate the weld quality of a particular weld based on weld information obtained for that weld.

The welding operation monitoring system includes an image capturing device that is disposed on a side opposite to a side to which the plasma flow is supplied out of a pipe inside and a pipe outside of the strip-shaped steel sheet formed in a tubular shape, and is configured to capture a color image including a plasma flow over the V-shaped region; and a welding operation monitoring device that is configured to generate a specific color component image obtained by extracting a specific color component from the color image, and specifies a V-shaped display region, which is a region corresponding to the V-shaped region within the color image, on the basis of the V-shaped region shown in the specific color component image, thereby analyzing a state of the welding operation.

The present invention relates to methods and apparatus for detection of fire states in the presence of welding activities. In some examples, the welding detection system may algorithmically calculate a risk of a fire state developing. In some embodiments, the welding fire detection and prevention system may communicate warning states to users, supervisors, equipment and/or building monitoring systems.

A spatter detection method is a method for detecting an occurrence of spatter at the time of joining a workpiece using a spot welding apparatus including a pair of electrode chips, a welding power circuit connected to the pair of electrode chips, and a current sensor configured to detect a current flowing through the pair of electrode chips. A spot welding method using the spot welding apparatus includes supplying a pulse-shaped welding current to the workpiece, the pulse-shaped welding current being generated when the welding power circuit alternately repeats power distribution control and a power distribution pause over a plurality of cycles while the workpiece is sandwiched and pressurized by the pair of electrode chips. The spatter detection method includes determining, based on a current detection value detected by the current sensor in a power distribution pause section for each cycle, whether or not the spatter occurs.

A spot welding method includes supplying a welding current having a pulse-shaped waveform to a workpiece by alternately executing a step of maintaining the welding current within a set peak current range and a step of decreasing the welding current from the peak current range toward a bottom current and then increasing the welding current toward the peak current range when an effective value of the welding current reaches a set target range for a plurality of cycles. The spatter detection method includes measuring a pulse width IW(1), IW(2), . . . in each cycle of the pulse-shaped waveform and detecting the occurrence of spatter when a pulse width difference D(M)=IW(M)−IW(M−1) between a pulse width IW(M) in a target cycle (M-th cycle) and a pulse width IW(M−1) in a cycle immediately before the target cycle exceeds a width threshold value Dth.

A spot welding method using a welding apparatus includes supplying a pulse-shaped welding current to a workpiece, the pulse-shaped welding current being generated when a welding power circuit alternately repeats power distribution control and a power distribution pause over a plurality of cycles, and maintaining, under the power distribution control, the welding current within a set peak current range in a peak holding section. A spatter detection method includes: a step of acquiring an average value of voltage detection values Vpv detected by a voltage sensor in the peak holding section for each of the cycles; and a step of determining whether or not the spatter occurs, based on a difference value between an average value of the voltage detection values Vpv in the peak holding section for an N-th cycle and an average value of the voltage detection values Vpv in the peak holding section for an (N−1)-th cycle.

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.

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.

The present disclosure provides a system for printing a three-dimensional (3D) object. The system may comprise a source of at least one feedstock, a support for supporting at least a portion of the 3D object, a feeder for directing such feedstock from the source towards the support, and a power supply for supplying electrical current. The system may comprise a controller operatively coupled to the power supply. The controller may receive a computational representation of the 3D object. The controller may direct such feedstock through a feeder towards the support and may direct electrical current through such feedstock and into the support. The controller may subject such feedstock to heating such that at least a portion of such feedstock may deposit adjacent to the support. The controller may direct deposition of additional portions adjacent to the support and may direct an additional feedstock through such feeder and subject to heating.