This invention concerns power supplies suitable for electric arc gas heaters such a plasma torches. It more particularly relates to the dimensioning of the inductor in the switched-mode DC to DC converter used for feeding the torch. The invention concerns in particular a DC power supply for driving a non-transferred electric arc gas heater, comprising: an AC to DC rectifier providing a potential U.sub.0; a DC to DC switching converter having a switching frequency f.sub.S; a current control loop having a latency Formula (I); and, a ballast inductor having an inductance L; characterized in that inductance L is such that Formula (II) and Formula (III). Such a design ensures the stability of the current control loop, while also ensuring a sufficient amount of current ripple to spread out the erosion zone on the electrodes of the torch. $\begin{array}{cc};& \left(I\right)\\ L>\left(\frac{U_0}{1500}\right),& \left(\mathrm{II}\right)\\ L<\frac{1}{f_s}\left(\frac{U_0}{200}\right).& \left(\mathrm{III}\right)\end{array}$

This invention concerns power supplies suitable for electric arc gas heaters such a plasma torches. It more particularly relates to the dimensioning of the inductor in the switched-mode DC to DC converter used for feeding the torch. The invention concerns in particular a DC power supply for driving a non-transferred electric arc gas heater, comprising: an AC to DC rectifier providing a potential U.sub.0; a DC to DC switching converter having a switching frequency f.sub.S; a current control loop having a latency Formula (I); and, a ballast inductor having an inductance L; characterized in that inductance L is such that Formula (II) and Formula (III). Such a design ensures the stability of the current control loop, while also ensuring a sufficient amount of current ripple to spread out the erosion zone on the electrodes of the torch. $\begin{array}{cc};& \left(I\right)\\ L>\left(\frac{U_0}{1500}\right),& \left(\mathrm{II}\right)\\ L<\frac{1}{f_s}\left(\frac{U_0}{200}\right).& \left(\mathrm{III}\right)\end{array}$

A base material is welded by a first welding method in a case where a welding parameter related to heat input to the base material is less than a first threshold value. The base material is welded by a second welding method in a case where the welding parameter is less than a second threshold value and is more than the first threshold value. The base material is welded by a third welding method in a case where the welding parameter is more than the second threshold value. By adjusting welding conditions regardless of the thickness of the base material, a welding method suitable for the thickness of the base material is determined to provide a welding with little spatter and no meltdown of the base material.

A base material is welded by a first welding method in a case where a welding parameter related to heat input to the base material is less than a first threshold value. The base material is welded by a second welding method in a case where the welding parameter is less than a second threshold value and is more than the first threshold value. The base material is welded by a third welding method in a case where the welding parameter is more than the second threshold value. By adjusting welding conditions regardless of the thickness of the base material, a welding method suitable for the thickness of the base material is determined to provide a welding with little spatter and no meltdown of the base material.

Welding power supplies having adjustable current ramping rates are disclosed. An example welding power supply, comprising: a switched mode power supply to convert primary power to welding-type power having an output current based on a current control loop; a voltage sensing circuit to measure a weld voltage; a voltage comparator to determine whether the weld voltage corresponds to a welding arc condition or a short circuit condition; and a control circuit to: select a current ramping rate; and execute the current control loop to control the output current, the control circuit configured to, while the weld voltage corresponds to the short circuit condition, increase the output current at the current ramping rate.

An example method of controlling a short circuit welding process includes: setting a heat target for at least a portion of a short state; monitoring output parameters during the short state; calculating a measured heat from the measured output parameters; comparing the measured heat and the heat target; adjusting a pinch current in a subsequent short state in response to at least one comparing from at least one previous short state; and repeating these actions.

A method for providing a referenced distance signal which corresponds to the distance between a contact tip of a welding torch and a workpiece to be machined, includes adjusting an operating point on a predetermined welding characteristic, which is defined at least by a wire feed rate, a welding voltage and/or a welding current, and a CTWD distance between the contact tip and the workpiece; determining a target parameter value of at least one parameter dependent on the CTWD distance for the operating point; determining an actual parameter value of the at least one parameter by measuring at least one of the present wire feed rate, welding voltage and/or welding current; modifying the determined actual parameter value as a function of a calculated difference between the target parameter value and a predetermined reference value; and outputting the referenced distance signal corresponding to the modified actual parameter value to a position control system of a robot arm.

A method of preventing arc flaring events for a welding system is provided. The method includes determining, by a controller, a real-time welding output characteristic of the welding system. The method additionally includes comparing, by the controller, the real-time welding output characteristic to a threshold welding output characteristic. The method further includes controlling an operating characteristic of the welding system in response to a determination that the real-time welding output characteristic exceeds the threshold welding output characteristic.

A method of preventing arc flaring events for a welding system is provided. The method includes determining, by a controller, a real-time welding output characteristic of the welding system. The method additionally includes comparing, by the controller, the real-time welding output characteristic to a threshold welding output characteristic. The method further includes controlling an operating characteristic of the welding system in response to a determination that the real-time welding output characteristic exceeds the threshold welding output characteristic.

A pulse arc welding device is controlled so as to weld an object by removing, from a welding wire, a molten droplet produced by melting the welding wire by applying a welding voltage between the welding wire and the object and allowing a welding current to flow through the welding wire such that the welding current alternately repeats, at pulse frequency, a peak current period in which the welding current is a peak current and a base current period in which the welding current is a base current smaller than the peak current. A removal time point at which the molten droplet is removed from the welding wire is determined. In a case where the removal time point is not in the base current period, a pulse waveform parameter which is at least one of the peak current and the peak current period is adjusted, and the pulse frequency based on a predetermined relationship between the pulse frequency and the pulse waveform parameter is adjusted so as to cause the removal time point to be in the base current period. This method allows a stable pulse arc welding.