Gas shielded-metal arc welding

Claim 1

A WELDING POWER SUPPLY SYSTEM FOR SHORT-CIRCUITING TYPE METAL TRANSFER BETWEEN AN ELECTRODE WIRE AND THE WORK TOWARD WHICH SUCH WIRE IS FED IN CIRCUIT THEREWITH, COMPRISING A TRANSFORMER HAVING AN A.C. INPUT CIRCUIT, A FULL WAVE RECTIFIER THE INPUT CIRCUIT OF WHICH IS CONNECTED BY MEANS OF A RELATIVELY LOW IMPEDANCE CIRCUIT TO THE OUTPUT CIRCUIT OF SAID TRANSFORMER, THE D.C. OUTPUT CIRCUIT OF SAID RECTIFIER BEING ADAPTED TO BE CONNECTED DIRECTLY TO THE INPUT CIRCUIT OF A SIGMA WELDING SET-UP, SAID RECTIFIER OUTPUT CIRCUIT CONTAINING A SERIES CONNECTED FILTER CHOKE THE INDUCTANCE OF WHICH IS SELECTED TO SMOOTH THE WELDING CURRENT WAVE FORM AND PROVIDE ADEQUATE SPEED OF RESPONSE UNDER SHORT-CIRCUITING SIGMA WELDING CONDITIONS, SAID TRANSFORMER COMPRISING PRESELECTABLE MEANS FOR ADJUSTING THE OPEN CIRCUIT OUTPUT VOLTAGE THEREOF THROUGH A RANGE OF 10 TO 30 VOLTS, INCLUSIVE, IN INCREMENTS NO GREATER THAN 0.5 VOLT EACH TO YIELD SUITABLE OPERATOR CONTROL OVER THE WELDING OPERATION, THE RESULTING CHARACTERISTIC BEING SUCH THAT UNDESIRABLE SPATTER AND ERATIC ARC ACTION ARE MINIMIZED BY VIRTUE OF THE FACT THAT SUCH CHARACTERISTIC HAS A MINIMUM SHORT-CIRCUIT CURRENT OF IM=(400$RS) 1/2 IN WHICH R=RADIUS OF THE WIRE ELECTRODE, AND S=SURFACE TENSION OF THE MOLTEN METAL TRANSFERRED FROM SUCH WIRE TO THE WORK TO THEREBY MINIMIZE OBJECTIONABLE SPATTER OF THE SO-TRANSFERRED MOLTEN METAL.