Nonconsumable electrode welding method and power supply

Claim 2

In an arc-welding system including an alternating-current power source, an electrode, and a workpiece, the improvement comprising, a welding power supply for providing alternating current from said alternating current power source for forming a welding arc between said electrode and said workpiece over a current range having a high-current portion, said welding power supply comprising, means connected to the power source for supplying a high-current wave of alternately bidirectional half-cycles to said electrode and said workpiece; and means including a variable-impedance reactor for regulating the magnitude of said current wave of bidirectional half-cycles over the current range, said reactor having a magnetic core and load windings wound on said magnetic core and connected in series with said supply means, said electrode and said workpiece for receiving the current wave of bidirectional halfcycles, said core having a minimum cross-sectional area and said load windings having a number of turns such as to provide a maximum flux density in said core of 50,000 lines per square inch or less during normal current regulating action in the high-current portion of the current range.

Claim 3

The welding power system according to claim 1 wherein said saturable reactor is so constructed and formed that the product of the number of load winding turns and twice the cross-sectional area of the portion of the magnetic core surrounded by the turns is greater than where Erms is the voltage of said supply means and f is the frequency of the alternating-current power source.

Claim 4

The welding power system according to claim 1 wherein the magnetic core of said saturable reactor defines an essentially closed magnetic flux path.

Claim 5

The arc-welding system according to claim 1 wherein said saturable reactor includes a control winding wound on said magnetic core and further including a current supply circuit connected to said control winding, and an inductor including a core having a winding thereon connected to said control winding and to said current supply circuit for varying the impedance of said load winding by varying the current energization of said control winding, said inductor being so constructed and formed as to develop a low value of inductance in the high-current portion of said current range and a high value of inductance in the remaining portions of said current range.

Claim 6

The welding system according to claim 4 wherein said core of said inductor includes an airgap for regulating the inductance thereof.

Claim 7

The welding system according to claim 4 wherein said inductor includes means for adjusting the inductance thereof.

Claim 8

In an arc-welding system including an alternating-current power source, an electrode and a workpiece, the improvement comprising an arc-welding power supply for providing an alternating current from the alternating-current power source to the electrode and the workpiece to form a welding arc therebetween over a current range having a high-current portion, said welding power supply comprising, means operatively connected to the power source for supplying a high-current wave of alternating bidirectional half-cycles to said electrodes and said workpiece, a variable-impedance saturable reactor connected to said supply means for regulating the magnitude of the current wave of bidirectional half-cycles, said reactor having a magnetic core, a load winding wound on said magnetic core and connected in series with said electrode and said workpiece said core having a minimum cross-sectional area and said load winding having a number of turns such as to provide a maximum flux density in said core of 50,000 lines per square inch during normal current regulating action in the high-current portion of the current range, and a control winding wound on said magnetic core, a current supply circuit connected to said control winding for varying the impedance of said load winding, and an inductor having a core and a winding thereon connected between said control winding and said current supply circuit, said inductor being so constructed and formed as to develop a low value of inductance in the high-current portion of the current range and a high value of inductance in the remaining portions of the current range.

Claim 9

In an arc-welding system including an alternating-current power source, an electrode and a workpiece, the improvement comprising an arc-welding power supply for providing an alternating current from the alternating-current power source to the electrode and the workpiece to form a welding arc therebetween over a current range having a high-current portion, said welding power supply comprising, means operatively connected to the power source for supplying a high-current wave of alternating bidirectional half-cycles to said electrodes and said workpiece, a variable-impedance saturable reactor connected to said supply means for regulating the magnitude of the current wave of bidirectional half-cycles, said reactor having a magnetic core, a load winding wound on said magnetic core and connected in series with said electrode and said workpiece said core having a minimum cross-sectional area and said load winding having a number of turns such as to provide a maximum flux density in said core of 50,000 lines per square inch during normal current regulating action in the high-current portion of the current range, and a control winding wound on said magnetic core, a current supply circuit connected to said control winding for varying the impedance of said load winding, and an inductor having a core and a winding thereon connected between said control winding and said current supply circuit, said inductor being so constructed and formed as to develop a low value of inductance in the high-current portion of the current range and a high value of inductance in the remaining portions of the current range.

Claim 10

The welding system according to claim 7 wherein said core of said inductor includes an airgap for regulating the inductance thereof.

Claim 11

The welding system according to claim 7 wherein said inductor includes means for adjusting the inductance thereof.

Claim 14

The method in accordance with claim 10 further defined as including the step of controlling the ratio of the magnitude of the alternating half-cycles of current flow in one direction in said current wave to the magnitude of the alternating half-cycles of current flow in the opposite direction in said current wave in order to provide one ratio thereof in the high-current portion of the current range and another ratio thereof in the low-current portion of the current range.

Claim 15

The method in accordance with claim 11, the reactor having a load winding connected in series with the workpiece and the electrode and a control winding connected to a current supply circuit for varying the impedance of the load winding, further defined as controlling said ratio by operating an inductor in series with the control winding, the inductor having a low value of inductance to determine said ratio at the high-current portion of the current range and a high value of inductance to determine said ratio at the low-current portion of the current range.

Claim 18

The method in accordance with claim 13, further defined as controlling said ratio by operating an inductor connected to control the reactor, the inductor having a low value of inductance to determine said ratio at the high-current portion of the current range and a high value of inductance to determine said ratio at the low-current portion of the current range.