POWER SOURCES FOR ARC WELDING
Electric arc welding processes constitute a majority of all the welding processes. Most of the weldable materials can be joined by arc welding. Due to the versatility of arc welding processes they are employed in many product areas. It would be worthwhile, hence, to know better about arc welding process principles, equipments and applications. The one important equipment that is significant for arc welding processes is the welding power source.NECESSITY FOR A SEPARATE WELDING POWER SOURCEEventhough, electric arc can be struck with higher voltages (100 - 200 V), it is not recommended to use directly an industrial power connection (440 V / 230 V) for welding, for the following reasons. The arc struck with a higher voltage will be inconveniently large and long. Hence, the manipulation of the arc will be difficult to achieve welding. Moreover, the energy loss of such an arc will be uneconomically high making the welding process inefficient in power. The most important reason is that historically the manual arc welding was developed first, hence the safety of the welder for reducing the risk of electric shock hazard, necessitated a separate welding power source to give reduced operating arc voltages. A welding power source converts the input voltage to a conveniently reduced safe operating voltage. Arc struck with such a power supply will be small and can be easily guided and manipulated.