Method and apparatus for welding with CV control

#The present invention relates generally to the art of welding power supplies. More specifically, it relates to welding systems that have a CV control.

#There are many known types of welding systems used for many different welding processes. Welding system, or system for welding, as used herein, includes one or more of a power source, controller, wire feeder, and a source of gas, it may also include peripherals such as robots etc. Welding power supply, as used herein, includes any device capable of supplying welding, plasma cutting, and/or induction heating power including power circuitry, control circuitry and other ancillary circuitry associated therewith.

#One type of welding system includes a CC welding power source. A CC welding power source, as used herein, is a current controlled power source, wherein the output current is monitored, and the output is adjusted, to provide the desired current. The current may be constant during the welding process, or may have a desired waveform of varying current.

#FIG. 1 is block diagram of a system for providing welding power in accordance with the present invention;

#FIG. 2 is a graph showing an output waveform in accordance with the present invention;

#FIG. 3 is a block diagram of a controller in accordance with the present invention; and

#Before explaining at least one embodiment of the invention in detail it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting. Like reference numerals are used to indicate like components.

#While the present invention will be illustrated with reference to a particular system for providing welding power, with particular components, and used for particular processes, it should be understood at the outset that the invention may also be implemented with other welding systems, processes, components, controllers, etc.

#Generally, the invention provides for controlling a welding process, such as pulse CV MIG welding, by sampling the output (or arc) voltage within each segment of the output waveform, and adjusting the output in response to the sampling and a desired voltage, for a very fast control. The output is adjusted in response to each sample, or in response to a plurality of samples, but the adjustment is made within the cycle in which the sample or samples are taken.