Plural magnetic core and multiple winding current comparator device with outer winding means for passing error current therethrough

Claim 1

THE COMBINATION OF (A) A PRIMARY CIRCUIT AND A SECONDARY CIRCUIT, THE CURRENTS IN WHICH ARE TO BE COMPARED, (B) A CURRENT COMPARATOR DEVICE COMPRISING (I) AN INNER MAGNETIC CORE CLOSED ON ITSELF TO FORM A MAGNETIC CIRCUIT, (II) A DETECTION WINDING AROUND SAID CORE, (III) A SECOND MAGNETIC CORE CLOSED ON ITSELF TO FORM A MAGNETIC CIRCUIT, SAID SECOND CORE EXTENDING COAXIALLY WITH THE INNER CORE AND BEING POSITONED RADIALLY OUTWARDLY OF SAID DETECTION WINDING, (IV) TWO OUTER WINDINGS EXTENDING AROUND BOTH SAID CORES, (V) AND A FURTHER WINDING POSITIONED RADIALLY BETWEEN SAID CORES, (VI) SAID FURTHER WINDING HAVING THE SAME NUMBER OF TURNS AS A SELECTED ONE OF SAID OUTER WINDINGS, (C) MEANS CONNECTED TO SAID DETECTION WINDING FOR DETECTING ZERO OUTPUT THEREFROM, (D) MEANS CONNECTING SAID OUTER WINDINGS RESPECTIVELY IN SAID PRIMARY AND SECONDARY CIRCUITS, WITH SAID SELECTED OUTER WINDING IN THE SECONDARY CIRCUIT, (E) MEANS CONNECTING SAID FURTHER WINDING IN SERIES OPPOSITION WITH SAID SELECTED OUTER WINDING, (F) MEANS FOR EXCITING SAID SERIALLY CONNECTED WINDINGS WHEREBY TO GENERATE NO FLUX IN SAID INNER CORE WHILE GENERATING FLUX IN SAID SECOND CORE AND INDUCING A VOLTAGE IN EACH OF THE OUTER WINDINGS, (G) MEANS FOR PRODUCING AN ERROR CURRENT INCLUDING MEANS FOR CONTROLLING THE MAGNITUDE AND PHASE OF SUCH ERROR CURRENT IN RELATION TO THE CURRENT IN SAID SECONDARY CIRCUIT, (H) AND MEANS FOR INJECTING SAID ERROR CURRENT INTO SAID DEVICE COMPRISING MEANS FOR PASSING SAID ERROR CURRENT THROUGH SAID SELECTED OUTER WINDING.