Protective relay assemblies

Claim 1

IN A PROTECTIVE RELAY ASSEMBLY, A PAIR OF TERMINALS, MEANS FOR DERIVING FROM CURRENT SUPPLIED TO THE PAIR OF TERMINALS A FIRST DIRECT VOLTAGE HAVING A MAGNITUDE DEPENDENT ON THE MAGNITUDE OF CURRENT FLOWING THROUGH THE PAIR OF TERMINALS OVER A SUBSTANTIAL RANGE OF VARIATION OF THE MAGNITUDE OF SAID CURRENT, MEANS FOR DERIVING FROM CURRENT SUPPLIED TO SAID PAIR OF TERMINALS A SECOND DIRECT VOLTAGE, HAVING A MAGNITUDE WHICH IS SUBSTANTIALLY CONSTANT OVER SAID RANGE OF VARIATION, A CAPACITOR, CIRCUIT MEANS CONNECTING THE CAPACITOR FOR ENERGIZATION IN ACCORDANCE WITH THE FIRST DIRECT VOLTAGE, SAID CIRCUIT MEANS INCLUDING SUBSTANTIAL RESISTANCE WHEREBY THE CIRCUIT MEANS AND CAPACITOR PROVIDE A TIME-DELAY CIRCUIT, CONTROLLABLE DISABLING MEANS RENDERING SAID CAPACITOR INEFFECTIVE FOR RECEIVING A CHARGE THROUGH SAID CIRCUIT MEANS, EFFECTUATING MEANS RESPONSIVE TO A PREDETERMINED RELATION BETWEEN THE FIRST AND SECOND DIRECT VOLTAGES FOR CONTROLLING THE DISABLING MEANS TO CONDITION THE CAPACITOR TO RECEIVE CHARGE FROM SAID CIRCUIT MEANS AND TRANSLATING MEANS RESPONSIVE TO THE VOLTAGE ACROSS SAID CAPACITOR, SAID TRANSLATING MEANS COMPRISING A CIRCUIT ENERGIZED IN ACCORDANCE WITH THE VOLTAGE ACROSS SAID CAPACITOR AND INCLUDING A THRESHOLD DEVICE, SAID THERSHOLD DEVICE HAVING A CHARACTERISTIC WHICH OFFERS A SUBSTANTIAL BLOCKING RESISTANCE TO THE FLOW OF CURRENT UNTIL THE VOLTAGE THEREACROSS REACHES A PREDETERMINED THRESHOLD VALUE AT WHICH THE THRESHOLD DEVICE BREAKS OVER TO OFFER AN UNBLOCKED RESISTANCE TO THE FLOW OF CURRENT WHICH IS MUCH SMALLER THAN SAID BLOCKING RESISTANCE, SAID THRESHOLD DEVICE AFTER BREAKING OVER RETAINING SAID UNBLOCKED RESISTANCE UNTIL THE VOLTAGE THEREACROSS DROPS SUBSTANTIALLY BELOW SAID THRESHOLD VALUE.