1,209,913. Supply systems for arc welding apparatus. BRITISH OXYGEN CO. Ltd. 28 Feb., 1968 [7 March, 1967], No. 10741/67. Heading H2H. Short-circuit, consumable electrode arc welding apparatus is provided with means to prevent weld splatter, such means being in the form of circuit elements which function to cause the weld current to increase when a short circuit of the arc occurs and a decrease in the weld current when the short circuit is broken. A consumable welding electrode 8 and workpiece 14 is fed from a transformer/rectifier combination 2 by way of an inductor L which is shunted by a diode Z. During a welding operation the diode Z will be biased " ON " or " OFF " by the back EMF generated by the inductor L, the operational effect of which is to cause the welding current to have a larger value when the arc is shortcircuited than the value when the arc is present. Furthermore the rise and fall of the welding current occurs at a faster rate. Numerous other embodiments are described wherein the inductor is tapped, the diode is connected across a part only of the inductor, a saturable reactor is connected in series with the inductor, the output of the combination 2 is shunted by a capacitor or a battery, the inductor is shunted by two diodes in series and lastly, in an A.C. arc welding system, a pair of inductors L are used each shunted by a diode the polarities of which are reversed.