Inert gas welding technology with wolfram electrodes requires DC current for welding steel and AC current for welding aluminium. In the first case a DC welding equipment, while in the latter one an AC welding equipment is necessary. A wide choice of DC welding equipment is available on the market at fairly reasonable prices. Regarding AC welding equipment, the situation is not so simple. They are much more complicated equipment at relatively high prices. For aluminium welding, in the case of an AC welding equipment, welding current has to change with a frequency of Hz periodically and rectangularly that the electron flow of changing direction should break the oxide layer on the aluminium surface. However, this technology requires a fairly smooth, but modulated current amplitude at both polarities. Besides, the polarity change of welding current of high rate of rise is a fundamental requirement to avoid arc extinction. If it is not met the arc should be ignited at every polarity change by a high voltage igniter that has numerous drawbacks. The paper shows a simple, low-cost, modular welding equipment for both DC and AC welding. The solution developed by us contains one or more DC welding equipment, depending on the current requirements, and an output AC inverter of full bridge connection of a suitable rated current. The results of the development are justified by laboratory tests.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.