Means for protecting power circuits and the like

Claim 1

AN ELECTRIC POWER TRANSMISSION SYSTEM: (A) AN ALTERNATING CURRENT POWER SUPPLY CIRCUIT AND A LOAD CIRCUIT, (B) CIRCUIT INTERRUPTER MEANS INTERCONNECTING SAID CIRCUITS AND TRIP MEANS THEREFOR, (C) FIRST AND SECOND NON-LINEAR IMPEDANCE MEANS, (D) MEANS FOR DERIVING FROM EACH OF SAID CIRCUITS A FUNDAMENTAL FREQUENCY CURRENT AND A SECOND HARMONIC THEREOF AND APPLYING THEM RESPECTIVELY TO SAID MONIC THEREOF AND APPLYING THEM RESPECTIVELY TO SAID GENERATE UNIDIRECTIONAL EFFECTS INDIVIDUAL THERETO CORRESPONDING TO THE FLOW OF ALTERNATING CURRENT IN SAID CIRCUITS RESPECTIVELY, (E) MEAND FOR BALANCING SAID UNIDIRECTIONAL EFFECTS WHEREBY AS LONG AS THE FLOWS OF ALTERNATING CURRENT IN SAID CIRCUITS BEAR A PREDETERMINED RELATION TO EACH OTHER SAID UNIDIRECTIONAL EFFECTS ARE NULLIFIED, AND (F) MEANS RESPONSIVE TO PREDETERMINED UNBALANCING OF SAID UNIDIRECTIONAL EFFECTS CORRESPONDING TO CHANGE IN SAID PREDETERMINED RELATION BETWEEN SAID CURRENT FLOWS IN SAID CIRCUITS FOR OPERATING SAID TRIP MEANS TO OPEN SAID CIRCUIT INTERRUPTER MEANS.