Welding transformer with variac in the control winding supply line

Claim 1

IN AN ELECTRIC WELDER; A BANK OF MAIN TRANSFORMERS EACH HAVING A SECONDARY WINDING, WELDING CURRENT OUTPUT TERMINALS, A PLURALITY OF SATURABLE CORE REACTORS, EACH REACTOR HAVING AN IRON CORE AND A LOAD WINDING AND A CONTROL WINDING THEREON, SAID LOAD WINDINGS BEING CONNECTED IN CIRCUIT INDIVIDUALLY WITH THE SECONDARY WINDINGS OF SAID MAIN TRANSFORMERS, A CONTROL TRANSFORMER HAVING A SECONDARY WINDING, AN AUTO TRANSFORMER IN CIRCUIT WITH THE SECONDARY WINDING OF SAID CONTROL TRANSFORMER, A RECTIFIER CONNECTED BETWEEN THE AUTO TRANSFORMER AND THE CONTROL WINDINGS OF SAID REACTORS FOR EFFECTING A VARIABLE SUPPLY OF DIRECT CURRENT TO SAID CONTROL WINDINGS, A SECOND AUTO TRANSFORMER REMOTE FROM SAID FIRST AUTO TRANSFORMER, AND SWITCH MEANS SELECTIVELY OPERABLE FOR CONNECTING EITHER THE FIRST MENTIONED AUTO TRANSFORMER OR THE SAID SECOND AUTO TRANSFORMER IN CIRCUIT WITH SAID SECONDARY WINDING OF THE CONTROL TRANSFORMER AND SAID RECTIFIER, EACH OF SAID AUTO TRANSFORMERS COMPRISING AT LEAST ONE ADJUSTABLE TAP CONNECTED WITH THE RECTIFIER FOR VARYING THE VOLTAGE SUPPLIED TO THE SAID RECTIFIER, THERE ALSO BEING RECTIFIER MEANS IN THE CIRCUIT BETWEEN THE SECONDARIES OF SAID MAIN TRANSFORMER AND SAID TERMINALS.