Voltage regulating means for impedance bridge measuring circuits

Claim 1

APPARATUS FOR DETERMINING AN UNKNOWN ELECTRICAL PARAMETER OF AN ELECTRICAL COMPONENT, SAID APPARATUS COMPRISING, IN COMBINATION, (A) A BRIDGE NETWORK WITH THE ELECTRICAL COMPONENT WHOSE ELECTRICAL PARAMETER IS TO BE DETERMINED CONNECTED IN ONE ARM THEREOF, SAID BRIDGE NETWORK INCLUDING (1) A PAIR OF INPUT TERMINALS, (2) A PAIR OF OUTPUT TERMINALS, AND (3) A STANDARD BRIDGE CIRCUIT ELEMENT CONNECTED IN ANOTHER ARM THEREOF; (B) MEANS CONNECTED TO SAID BRIDGE INPUT TERMINALS FOR ENERGIZING SAID BRIDGE NETWORK; AND (C) MEANS RESPONSIVE TO THE VOLTAGE DIRECTLY ACROSS SAID STANDARD BRIDGE CIRCUIT ELEMENT FOR CONTROLLING SAID ENERGIZING MEANS SO AS TO REGULATE THE MAGNITUDE OF SAID VOLTAGE ACROSS SAID STANDARD BRIDGE CIRCUIT ELEMENT; (D) WHEREBY THE MAGNITUDE OF A BRIDGE OUTPUT SIGNAL DEVELOPED ACROSS SAID BRIDGE OUTPUT TERMINALS BEARS A LINEAR RELATIONSHIP TO THE UNKNOWN PARAMETER OF THE ELECTRICAL COMPONENT.