The Esab Group Inc.

Richard Allen Eldridge

David Charles Griffin

Dale Thomas Wiersema

William R Klingbeil

A system and associated method for determining an operational condition of a gas torch are provided. The system includes a diode device that is electrically connected between the workpiece and the nozzle. A sensing circuit is configured to provide an electric potential across the diode device and sense a resulting voltage characteristic of the condition of continuity of the system. For example, the sensing circuit can determine whether the nozzle is otherwise electrically connected to the workpiece and/or whether the nozzle is electrically connected to the electrode. The sensing circuit can determine the condition of continuity throughout the operation of the system, e.g., to verify the proper assembly of the torch, to verify proper movement of the electrode or nozzle, to verify that the torch is separated from the workpiece at start-up, and the like.

System and method for determining an operational condition of a torch

The systems and methods of the present invention provide a circuit for controlling the magnitude of the main and pilot arc current provided to an arc cutting or welding machine. In one embodiment, the circuit allows the user to set the pilot arc current such that it automatically tracks the main arc current setting. The pilot arc current is set to a value that is proportional to the main arc current, such that the pilot arc current value is tailored to the specific cutting operation to be performed and/or the specific nozzle and electrode being used. In an alternative embodiment, the circuit allows the user to select from different pilot arc current levels, such as low, medium, and high current levels. This allows the user to override the pilot arc control in instances where the plasma arc cutting or welding machine is operated under conditions not optimal for the selected nozzle and electrode.

Systems and methods for controlling pilot arc current in an arc cutting or welding machine

The present invention provides a modified buck regulator circuit capable of providing two output voltage levels. The circuit includes an inductive element connected between the input and output of the circuit. Further, the circuit includes an auto-transformer and two switches creating separate current paths with a load connected to the output of the circuit. In one mode, the switches are operated in parallel to provide a first voltage across the load. Because the switches are in parallel with respect to each other, the load current is divided between the two switches. In a second mode, the switches are operated in a push-pull mode. In this mode, the auto-transformer steps down the load voltage and also effectively steps down the current across each switch. As such, the buck regulator circuit of the present invention may provide two separate voltages, while also reducing the current across the switches of the buck regulator circuit.

Buck regulator circuit for use in a power supply

The cutting or welding system includes a power source having, in one embodiment, a stabilization circuit for reducing arc rectification and, in another embodiment, a number of firing circuits for controlling the flow of current through a rectifier in order to more precisely provide a rectified alternating current. The power source also includes a rectifier having a number of current control devices for providing rectified current having alternating positive and negative cycles across the arc gap. Accordingly, the electrode alternates between an electrode negative state and an electrode positive state, respectively. In one embodiment, the stabilization circuit extends across the arc gap and includes an energy storage device and a current control device in series with the energy storage device for blocking current flow to the energy storage device in the electrode negative state such that the energy storage device remains uncharged and for allowing current flow to the energy storage device in the electrode positive state such that the energy storage device rapidly charges from an uncharged state to a charged state upon switching the electrode to the electrode positive state. In another embodiment, the firing circuits are connected to the control electrodes of respective current control devices of the rectifier wherein said current control devices provide a continuous firing current to the control electrode once the firing current control device has been actuated to thereby increasing the reliability of the rectifier.

Stabilization and firing circuit for a power source of a cutting or

A power source apparatus for supplying electrical power for an arc welder includes a frame having a base member and first and second pairs of support members each defining an inverted V-shaped configuration mounted to the opposite side edges of the base member. An inverted channel cross member extends transversely between the upper ends of the support members. The support members each define a U-shaped channel having a pair of sidewalls and a connecting wall therebetween and are oriented such that the connecting walls face away from each other. An associated assembly method includes the steps of adjoining the ends of first and second pairs of support members and connecting them with a cross member to define a frame subassembly. At least a portion of the power circuit of the arc welder power source is then mounted on the frame subassembly before it is attached to the power source frame. A busbar assembly for supporting two rows of capacitors in parallel on the frame of an arc welder is also provided. A fan assembly for generating an airstream through the power source is also provided and includes a frame mounted to the power source defining at least two opposed recessed portions.

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Florence, SC, United States of America

Richard Allen Eldridge