A tangible medium having a machine-readable symbol printed thereon, such that the symbol encodes a specified digital value in a set of color elements having different, respective colors, to be identified in an image of the symbol as red, green, blue, cyan, magenta and yellow color elements, respectively. The symbol is produced by applying cyan, magenta and yellow pigments to a substrate so as to produce the color elements, such that the color elements exhibit certain red, green, and blue intensity characteristics when measured in an sRGB color space.

A tangible medium having a machine-readable symbol printed thereon, such that the symbol encodes a specified digital value in a set of color elements having different, respective colors, to be identified in an image of the symbol as red, green, blue, cyan, magenta and yellow color elements, respectively. The symbol is produced by applying cyan, magenta and yellow pigments to a substrate so as to produce the color elements, such that the color elements exhibit certain red, green, and blue intensity characteristics when measured in an sRGB color space.

In arc welding, determining a current value to be high in an early stage of the arc period is effective in reducing spatters caused by feeble short circuit in the arc period. In that case, to sharply decrease the voltage that has increased with increase in current, an inductance value of a reactor has to be kept small. However, a small inductance value causes a problemweakness against disturbance. The present invention provides an arc welding control method that performs arc welding while repeating the short-circuit period and the arc period. According to the method, changing an inductance value relating to welding output in the arc period offers stable arc welding with fewer spatters and insusceptibility to disturbance.

In arc welding, determining a current value to be high in an early stage of the arc period is effective in reducing spatters caused by feeble short circuit in the arc period. In that case, to sharply decrease the voltage that has increased with increase in current, an inductance value of a reactor has to be kept small. However, a small inductance value causes a problemweakness against disturbance. The present invention provides an arc welding control method that performs arc welding while repeating the short-circuit period and the arc period. According to the method, changing an inductance value relating to welding output in the arc period offers stable arc welding with fewer spatters and insusceptibility to disturbance.

A welding power supply device includes an inverter for converting DC power into AC power outputted to a welding load, and a voltage circuit for superimposing a restriking voltage on an output to the welding load when the polarity of output current of the inverter switches. The voltage circuit includes a restriking capacitor charged with the re-striking voltage, a charging circuit to charge the capacitor with the restriking voltage, and a discharging circuit to discharge the voltage in the capacitor. The charging circuit includes a DC power supply and a booster to boost DC voltage from the DC power supply. The charging circuit charges the restriking capacitor in first and second states. In the first state, the DC voltage from the DC power supply is directly applied to the re-striking capacitor. In the second state, DC voltage boosted by the booster is applied to the restriking capacitor.

A welding power supply device includes an inverter for converting DC power into AC power outputted to a welding load, and a voltage circuit for superimposing a restriking voltage on an output to the welding load when the polarity of output current of the inverter switches. The voltage circuit includes a restriking capacitor charged with the re-striking voltage, a charging circuit to charge the capacitor with the restriking voltage, and a discharging circuit to discharge the voltage in the capacitor. The charging circuit includes a DC power supply and a booster to boost DC voltage from the DC power supply. The charging circuit charges the restriking capacitor in first and second states. In the first state, the DC voltage from the DC power supply is directly applied to the re-striking capacitor. In the second state, DC voltage boosted by the booster is applied to the restriking capacitor.

A control method for gas-shielded arc welding includes providing a normal arc period in which the welding current is maintained at a setting current Icc set in advance, and providing a separation control period after the separation timing of the molten droplet is detected in the normal arc period, the separation control period including a current decreasing section, a current maintaining section, and a current increasing section. In the separation control period, at least one of the following controls for preventing a short circuit is performed: control of an output voltage, control of a feeding speed, and control of a gas ratio.

A control method for gas-shielded arc welding includes providing a normal arc period in which the welding current is maintained at a setting current Icc set in advance, and providing a separation control period after the separation timing of the molten droplet is detected in the normal arc period, the separation control period including a current decreasing section, a current maintaining section, and a current increasing section. In the separation control period, at least one of the following controls for preventing a short circuit is performed: control of an output voltage, control of a feeding speed, and control of a gas ratio.

A welding-type system includes a welding torch comprising a contact tip to provide an electrode wire. A secondary contact in electrical contact with the electrode wire, the secondary contact located along a length of the electrode wire and before the contact tip. Each of the contact tip and the secondary contact are connected to a welding-type power source. A current limiting device coupling located between the welding-type power source and the secondary contact and configured to limit a current at the secondary contact.

Embodiments of the present invention are directed to systems and methods of controlling wire feeding in a welding operation, where the wire feeding has a plurality of positive and negative pulses. Embodiments determine an average wire feed speed and compare the average to a desired wire feed speed and then change a parameter of the wire feed pulses to achieve a desired wire feed speed.