Relay testing circuit having monitor relays responsive to improper operation of load-controlling contacts

Claim 1

IN COMBINATION, AN ARRANGEMENT COMPRISING A PLURALITY OF GROUPS OF CIRCUITS, A FIRST SOURCE OF UNIDIRECTIONAL POTENTIAL, A SECOND SOURCE OF UNIDIRECTIONAL POTENTIAL, A REFERENCE POTENTIAL, A FIRST OF SAID CIRCUITS COMPRISING AN ELECTRON DISCHARGE DEVICE COMPRISING A FIRST ANODE, A FIRST CONTROL GRID AND A FIRST CATHODE, A FIRST MONITOR RELAY CONNECTED BETWEEN SAID FIRST SOURCE AND SAID FIRST ANODE, SAID FIRST GRID BEING COUPLED TO SAID REFERENCE POTENTIAL, FIRST RELAY CONTACT TO BE TESTED WHICH ARE OPERATED TO BE IN THE OPEN STATE DURING FIRST CHOSEN TIMES AND THE CLOSED STATE DURING SECOND CHOSEN TIMES, SAID FIRST CATHODE BEING COUPLED TO SAID REFERENCE POTENTIAL THROUGH SAID FIRST CONTACT MEANS, A FIRST LOAD CONNECTED BETWEEN SAID SECOND POTENTIAL SOURCE AND SAID FIRST CATHODE, A SECOND OF SAID GROUP OF CIRCUITS COMPRISING A SECOND ELECTRON DISCHARGE DEVICE COMPRISING A SECOND ANODE, A SECOND CONTROL GRID, AND A SECOND CATHODE, A SECOND MONITOR RELAY CONNECTED BETWEEN SAID FIRST POTENTIAL SOURCE AND SAID SECOND ANODE, SAID SECOND GRID BEING COUPLED TO SAID REFERENCE POTENTIAL, SECOND RELAY CONTACT MEANS TO BE TESTED WHICH IS OPERATED TO BE IN THE CLOSED STATE DURING SAID FIRST CHOSEN TIMES AND IN THE OPEN STATE DURING SAID SECOND CHOSEN TIMES, SAID SECOND CATHODE BEING COUPLED TO SAID REFERENCE POTENTIAL THROUGH SAID SECOND RELAY CONTACT MEANS, A THIRD CIRCUIT OF SAID GROUP COMPRISING A THIRD ELECTRON DISCHARGE DEVICE COMPRISING A THIRD ANODE, A THIRD CONTROL GRID AND A THIRD CATHODE, A THIRD MONITOR RELAY CONNECTED BETWEEN SAID FIRST POTENTIAL SOURCE AND SAID THIRD ANODE, SAID THIRD GRID BEING CONNECTED TO SAID FIRST CATHODE, SAID THIRD CATHODE BEING CONNECTED TO SAID SECOND POTENTIAL SOURCE, A FOURTH CIRCUIT OF SAID GROUP COMPRISING A FOURTH ELECTRON DISCHARGE DEVICE HAVING A FOURTH ANODE, A FOURTH CONTROL GRID AND A FOURTH CATHODE, A FOURTH MONITOR RELAY CONNECTED BETWEEN SAID FIRST POTENTIAL SOURCE AND SAID FOURTH ANODE, AND FOURTH GRID BEING COUPLED TO SAID SECOND CATHODE, SAID FOURTH CATHODE BEING CONNECTED TO SAID SECOND POTENTIAL SOURCE, MEANS FOR APPLYING POTENTIAL FROM SAID SECOND POTENTIAL SOURCE TO SAID FIRST AND SECOND LOADS, MEANS FOR APPLYING POTENTIAL FROM SAID FIRST POTENTIAL SOURCE TO SAID FIRST AND FOURTH ANODES DURING SAID FIRST