Abstract: A power supply system includes multiple power supply devices including a first power supply device and a second power supply device that are connected in common to a load. The first power supply device calculates control information for controlling voltage or current to be output to the load and controls the output to the load based on the calculated control information while transmitting the control information to the second power supply device. The second power supply device receives the control information and controls the output to the load based on the received control information while detecting current to be output from its own device to the load and transmitting current information to the first power supply device. The first power supply device receives the current information transmitted from the second power supply device and calculates control information based on the received current information and the current and voltage detected by its own device.

Abstract: A power supply system includes multiple power supply devices connected in common to a load. A first power supply device calculates control information for controlling voltage or current to be output to the load and controls the output to the load based on the calculated control information while transmitting the control information to a second power supply device. The second power supply device receives the control information transmitted from the first power supply device and control the output to the load based on the received control information while detecting current to be output from its own device to the load and transmitting current information to the first power supply device. The first power supply device receives the current information transmitted from the second power supply device and calculate control information based on the received current information and the current and voltage detected by its own device.

Abstract: A power supply system includes multiple power supply devices including a first power supply device and a second power supply device that are connected in common to a load. The first power supply device calculates control information for controlling voltage or current to be output to the load and controls the output to the load based on the calculated control information while transmitting the control information to the second power supply device. The second power supply device receives the control information and controls the output to the load based on the received control information while detecting current to be output from its own device to the load and transmitting current information to the first power supply device. The first power supply device receives the current information transmitted from the second power supply device and calculates control information based on the received current information and the current and voltage detected by its own device.

Abstract: A power supply system includes multiple power supply devices connected in common to a load. A first power supply device calculates control information for controlling voltage or current to be output to the load and controls the output to the load based on the calculated control information while transmitting the control information to a second power supply device. The second power supply device receives the control information transmitted from the first power supply device and control the output to the load based on the received control information while detecting current to be output from its own device to the load and transmitting current information to the first power supply device. The first power supply device receives the current information transmitted from the second power supply device and calculate control information based on the received current information and the current and voltage detected by its own device.

Abstract: A feed control method is provided for consumable electrode AC arc welding, in which the welding wire is fed at a predetermined wire feed rate, and a welding voltage applied to an arc is switched in alternation between positive polarity and negative polarity. In the method, a welding current setting signal is generated. The wire is fed at a first feed rate during a period of the positive polarity, whereas the wire is fed at a second feed rate different from the first feed rate during a period of the negative polarity.

Abstract: A polarity switching control method is provided for consumable electrode AC pulse arc welding. By the method, a peak current and a base current are applied during an electrode-positive polarity period, while an electrode-negative current is applied during an electrode-negative polarity period. For performing the welding, polarity switching is performed to alternate the electrode-positive polarity period and the electrode-negative polarity period. When a consumable electrode and a base metal are in short circuit with each other, the polarity switching is performed after the short circuit is broken and an arc is generated.

Abstract: An arc welding power source supplies a start current, a welding current and a crater current as an output current in accordance with an activating signal supplied from outside. The power source includes a start period setting unit, a crater period setting unit, and a current control unit that controls the output current. The current control unit causes the power source to supply the start current and the welding current consecutively while the activating signal is in an on-state, where the start current is supplied for the start period, and the welding current is supplied for the period following the start period. The current control unit also causes the power source to supply the crater current after the activating signal is turned off, where the crater current is supplied for the crater period.

Abstract: A control method for AC pulse arc welding performed upon application of cyclic AC welding current is provided. The welding current has a cycle including an electrode negative polarity period and an electrode positive polarity period subsequent to the electrode negative polarity period. In the control method, an electrode negative polarity base current and a subsequent electrode negative polarity peak current are applied during the electrode negative polarity period. The electrode negative polarity base current has an absolute value smaller than a first critical value, and the electrode negative polarity peak current has an absolute value greater than the first critical value. Then, an electrode positive polarity peak current is applied during the electrode positive polarity period. The electrode positive polarity peak current has a value greater than a second critical value.

Abstract: A squeezing detection control method is provided for consumable electrode arc welding. The method includes a step of detecting a droplet squeezing phenomenon by checking that a change in a voltage or resistance between the consumable electrode and base material reaches a squeezing detection reference value, and a step of executing output control for rapidly decreasing a welding current passing through a short-circuited load when the squeezing phenomenon is detected, so that arc re-striking occurs in a state of low current. The squeezing detection reference value is set to a first value during the electrode positive polarity, and set to a second value during the electrode negative polarity. The second value is different from the absolute value of the first value, and each of the first and second values is set such that the resultant welding state is satisfactory.

Abstract: A method of performing polarity switching short circuiting arc welding is provided. In the arc welding, a welding wire is fed at a constant feeding rate, a short circuiting state and a arcing state appear repeatedly between the welding wire and a base metal, and the output polarity of a welding power source is switched in accordance with a polarity switching signal for performing electrode positive welding and electrode negative welding. In accordance with the method, the welding current is reduced during a predetermined short circuit initial period, when a first arc is formed after the polarity switching signal changes. Then, the output polarity of the welding power source is changed when the short circuit initial period has lapsed. Further, the welding current is increased for terminating the arc forming between the welding wire and the base metal.

Abstract: A control method for AC pulse arc welding performed upon application of cyclic AC welding current is provided. The welding current has a cycle including an electrode negative polarity period and an electrode positive polarity period subsequent to the electrode negative polarity period. In the control method, an electrode negative polarity base current and a subsequent electrode negative polarity peak current are applied during the electrode negative polarity period. The electrode negative polarity base current has an absolute value smaller than a first critical value, and the electrode negative polarity peak current has an absolute value greater than the first critical value. Then, an electrode positive polarity peak current is applied during the electrode positive polarity period. The electrode positive polarity peak current has a value greater than a second critical value.

Abstract: An arc welding power source supplies a start current, a welding current and a crater current as an output current in accordance with an activating signal supplied from outside. The power source includes a start period setting unit, a crater period setting unit, and a current control unit that controls the output current. The current control unit causes the power source to supply the start current and the welding current consecutively while the activating signal is in an on-state, where the start current is supplied for the start period, and the welding current is supplied for the period following the start period. The current control unit also causes the power source to supply the crater current after the activating signal is turned off, where the crater current is supplied for the crater period.

Abstract: A feed control method is provided for consumable electrode AC arc welding, in which the welding wire is fed at a predetermined wire feed rate, and a welding voltage applied to an arc is switched in alternation between electrode positive polarity and electrode negative polarity. In the method, a welding current setting signal is generated, and the wire feed rate is set to a first feed rate during a period of the electrode positive polarity, based on both the wire welding characteristics for the electrode positive polarity and the welding current setting signal. Further, the wire feed rate is set to a second feed rate during a period of the electrode negative polarity, based on both the wire welding characteristics for the electrode negative polarity and the welding current setting signal.

Abstract: A squeezing detection control method is provided for consumable electrode arc welding. The method includes a step of detecting a droplet squeezing phenomenon by checking that a change in a voltage or resistance between the consumable electrode and base material reaches a squeezing detection reference value, and a step of executing output control for rapidly decreasing a welding current passing through a short-circuited load when the squeezing phenomenon is detected, so that arc re-striking occurs in a state of low current. The squeezing detection reference value is set to a first value during the electrode positive polarity, and set to a second value during the electrode negative polarity. The second value is different from the absolute value of the first value, and each of the first and the second values is set such that the resultant welding state is satisfactory. (FIG .

Abstract: A polarity switching control method is provided for consumable electrode AC pulse arc welding. By the method, a peak current and a base current are applied during an electrode-positive polarity period, while an electrode-negative current is applied during an electrode-negative polarity period. For performing the welding, polarity switching is performed to alternate the electrode-positive polarity period and the electrode-negative polarity period. When a consumable electrode and a base metal are in short circuit with each other, the polarity switching is performed after the short circuit is broken and an arc is generated.

Abstract: A method of performing polarity switching short circuiting arc welding is provided. In the arc welding, a welding wire is fed at a constant feeding rate, a short circuiting state and a arcing state appear repeatedly between the welding wire and a base metal, and the output polarity of a welding power source is switched in accordance with a polarity switching signal for performing electrode positive welding and electrode negative welding. In accordance with the method, the welding current is reduced during a predetermined short circuit initial period, when a first arc is formed after the polarity switching signal changes. Then, the output polarity of the welding power source is changed when the short circuit initial period has lapsed. Further, the welding current is increased for terminating the arc forming between the welding wire and the base metal.

Abstract: An consumable electrode AC pulsed arc welding is performed by repeatedly executing a cycle of supplying a peak current Ip in an electrode positive polarity, then supplying an electrode negative current Ien in an electrode negative polarity and finally supplying a base current Ib in the electrode positive polarity. During a base current supply time, the rate of increase dVb/dt of the base voltage Vb is detected. Should the base voltage increase rate dVb/dt detected be larger than a predetermined determining value &Dgr;Vu, it means that the arc interruption is likely to occur and, therefore, since that timing, the peak current Ip for the subsequent cycle is supplied to thereby prevent the arc interruption from occurring.