Electron beam welding method with feed back control

Claim 1

IN WELDING APPARATUS OF THE CHARACTER DESCRIBED, THE COMBIN ATION WITH AN ELECTRON FOR PROJECTING AN ELECTRON BEAM FOR WELDING A WORKPIECE, SAID GUN HAVING AN ELECTRODE AND AN ANODE, A HIGH VOLTAGE POWER REGULATOR, CONDUCTORS CONNECTING THE POWER REGULATOR WITH THE ELECTRODE AND WITH THE ANODE, RESPECTIVELY, FOR SUPPLYING ELECTRICAL ENERGY TO SAID PARTS, AN ELECTRICAL MULTIPLIER, MEANS SUPPLYING REPRESENTATIVE VALUES OF THE VOLTAGE AND THE CURRENT OF SAID ELECTRICAL ENERGY TO THE MULTIPLIER, WHEREBY TO OBTAIN A FIRST SIGNAL FROM THE MULTIPLIER PROPORTIONAL TO THE POWER BEING SUPPLIED BY THE ELECTRON BEAM TO THE WORKPIECE, A SUMMING JUNCTION ELECTRICALLY CONNECTED TO THE MULTIPLIER FOR RECEIVING SAID FIRST SIGNAL, A POWER REFERENCE SUPPLY FOR FEEDING TO THE SUMMING JUNCTION A SECOND SIGNAL WHICH IS PROPORTIONAL TO THE POWER DESIRED FOR THE ELECTRON BEAM, A POSITION SERVO AMPLIFIER, A CONDUCTOR FOR FEEDING TO THE AMPLIFIER ANY ERROR SIGNAL SUCH AS MAY BE OBTAINED FROM THE SUMMING JUNCTION, AND A SERVO MOTOR IN ELECTRICAL CONNECTION WITH THE SERVO POSITION AMPLIFIER FOR ADJUSTING THE HIGH VOLTAGE POWER REGULATOR IN RESPONSE TO THE ERROR SIGNAL SO THAT THE PRODUCT OF THE CURRENT AND THE VOLTAGE WILL EQUAL THE POWER DESIRED FOR THE ELECTRON BEAM.