Abstract: A method and apparatus for providing welding power includes two power sources (first and second), each having an output. A linking circuit selectively connects the power sources in one of an independent mode (such that each is connected to a separate welding output whereby the first welding output is independent of the second welding output) or a combined mode (such that the power sources are connected in parallel and connected to one welding output whereby the outputs of the first power source and second power source are combined). A controller includes a mode selector to allow the user to select between the independent mode and the combined mode. Also, the controller includes a master output magnitude selector, which is a single selector, that controls the magnitude of the output of both power sources when the user has selected the combined mode. The power sources can be operated in a CV or CC mode when independent, or a CC mode when combined.

Abstract: A method and apparatus for plasma cutting includes a cutting power supply, preferably a buck converter, and a compressor. The cutting power supply provides power to a plasma torch, and the compressor provides air to the torch. The air compressor is integrated into the plasma cutter, and includes a compressor motor, preferably with a buck convertor power supply, or having the motor windings are part of the buck converter that is the cutting power supply. The motor is regulated regulator to a fixed setpoint or a user setpoint by a compressor regulator in response to a feedback signal, preferably a compressor motor voltage feedback signal. The compressor also turns the compressor on and/off in response to a trigger and/or cutting current feedback signal and has an on/off circuit responsive thereto in various alternatives.

Abstract: A method and apparatus for providing a welding output is disclosed. The apparatus includes a an ac generator having a field winding, a welding output winding and an electronic field controller connected to the field winding. The controller receives a current feedback signal and a voltage feedback signal, and shapes the output curve in response to the desired output command signals. According to one embodiment the controller also receives a field current feedback signal. The controller may shape the output curves to emulate a DC generator, for example by causing the welding output V-A curves to have multiple breakpoints, and/or a substantially preset slope over a welding range wherein the preset slope does not vary over the output current range of the power supply. Also, the slope of the V-A output curve below the welding range may be different than the slope in the welding range.

Abstract: A welding power supply includes an ac generator with a field winding and a welding output winding. An electronic field controller receives current and voltage feedback from the welding output. This electronic field controller is connected to the field winding, controlling the current through this winding in such a way that the volt-ampere output curve at the welding output winding consists of a plurality of selected nominal output current curves, each of these curves including at least two breakpoints.

Abstract: A welding arc stabilizer including a source of high voltage and a switch for switching the source of high voltage across the electrode and the workpiece in the event the arc rectifies. The high voltage is switched across the electrodes within the completion of the half cycle in which rectification occurred. The source of high voltage includes a resonant LC circuit. An arc sensing circuit, including a resistor, a capacitor, and a zener diode is provided in parallel with the arc. In the event the voltage applied to the electrode and workpiece exceeds the zener diode breakdown voltage, indicating the arc has rectified, an SCR disposed between the resonant circuit and one of the electrode and the workpiece is turned on, thus connecting the source of high voltage to the electrode and workpiece.