Electromagnetic-testing bridge-net-work with digital programming control for operation under a plurality of initial unbalance conditions

Claim 1

IN COMBINATION WITH A BRIDGE NETWORK FOR ELECTROMAGNETIC TESTING UNDER A PLURALITY N OF INITIAL UNBALANCE CONDITIONS I OF EQUAL AMPLITUDE Z AND PREDETERMINED DIFFERENT PHASE ANGLES $I, WITH I BEING AN INTEGAR FROM 1 TO N, A DIGITAL PROGRAMMING CONTROL INCLUDING FIRST, SECOND, AND THIRD JUNCTIONS, A PLURALITY OF RESISTIVE IMPEDANCES RI= Z COS $I AND A PLURALITY OF RESISTIVE IMPEDANCES XI= Z SIN $I , ZERO VALUES OF RI AND XI BEING COMPRISED BY SHUNTS, AND A MULTI-COMPONENT SWITCH MEANS CONNECTED TO SAID JUNCTIONS AND IMPEDANCES HAVING A PLURALITY N OF DISCREET SWITCH POSITIONS I=1 TO I=N, SAID SWITCH MEANS AT EACH POSITION I CONNECTING RESPECTIVE IMPEDANCES RI AND XI BETWEEN SAID FIRST AND SECOND JUNCTIONS WHEN THE RESISTIVE VALUES OF COS $I AND SIN $I ARE POSITIVE AND BETWEEN SAID FIRST AND THIRD JUNCTIONS WHEN SAID VALUES ARE NEGATIVE, SAID CONTROL BEING ADAPTED FOR CONNECTION WITH A BRIDGE NETWORK DEFINING A FIRST ARM EXTENDING FROM SAID FIRST JUNCTION TO A FOURTH JUNCTION, A SECOND ARM EXTENDING FROM SAID FOURTH JUNCTION TO A FIFTH JUNCTION, A THIRD ARM EXTENDING FROM SAID FIFTH JUNCTION TO A SIXTH JUNCTION, A FOURTH ARM EXTENDING FROM SAID SIXTH JUNCTION TO SAID THIRD JUNCTION, AND INPUT OSCILLATOR AND OUTPUT UTILIZATION MEANS INDIVIDUALLY CONNECTED BETWEEN SAID SECOND AND FIFTH JUNCTIONS, AND BETWEEN SAID FOURTH AND SIXTH JUNCTIONS, TWO OF SAID ARMS BEING COMPRISED OF SIMILAR RESISTIVE IMPEDANCES AND TWO OF SAID ARMS BEING COMPRISED OF ELECTROMAGNETIC TESTING COIL MEANS WHOSE RELATIVE IMPEDANCES VARY WITH PARAMETERS OF A WORKPIECE OPERATIVELY COUPLED WITH AT LEAST ONE OF SAID COIL MEANS.