Foolproof systems for sensing both normal and abnormal conditions

Claim 1

IN AN INDICATING SYSTEM: MEANS PROVIDING A PAIR OF POWER SUPPLY CONDUCTORS ADAPTED TO BE POSITIVELY AND NEGATIVELY BIASED WITH RESPECT TO EACH OTHER, A FIRST TRANSISTOR HAVING ITS EMITTER AND COLLECTOR CONNECTED IN SERIES CIRCUIT BETWEEN SAID POSITIVELY AND NEGATIVELY BIASED POWER SUPPLY CONDUCTORS, A FIRST RESISTANCE HAVING DEVICE IN THE EMITTER PATH OF SAID FIRST TRANSISTOR, SAID FIRST TRANSISTOR BEING CONDUCTIVE WHEN A POTENTIAL OF A GIVEN POLARITY IS SUPPLIED TO THE BASE OF SAID FIRST TRANSISTOR, A SECOND RESISTANCE HAVING DEVICE CONNECTED BETWEEN SAID BASE OF SAID FIRST TRANSISTOR AND THE ONE OF SAID POWER SUPPLY CONDUCTORS OF THE POTENTIAL WHICH MAKES SAID FIRST TRANSISTOR CONDUCTIVE, A SECOND TRANSISTOR HAVING ITS EMITTER AND COLLECTOR CONNECTED IN SERIES BETWEEN THE OTHER OF SAID POWER SUPPLY CONDUCTORS AND SAID BASE OF SAID FIRST TRANSISTOR, SAID SECOND RESISTANCE HAVING DEVICE BEING A SIGNAL PRODUCING ELECTRICAL SOLENOID WHICH IS OPERATIVE TO PRODUCE A CONTROL SIGNAL WHEN ELECTRICITY FLOWS THROUGH THE EMITTER-COLLECTOR CIRCUIT TO WHICH IT IS CONNECTED, SAID SECOND TRANSISTOR BEING CONDUCTIVE WHEN BIASED BY A RELATIVE VOLTAGE OF ONE OF SAID CONDUCTORS, A THIRD RESISTANCE DEVICE CONNECTING THE BASE OF SAID SECOND TRANSISTOR TO THE OTHER ONE OF SAID CONDUCTORS, A THIRD TRANSISTOR HAVING ITS EMITTER AND COLLECTOR CONNECTED IN SERIES CIRCUIT BETWEEN SAID BASE OF SAID SECOND TRANSISTOR AND SAID ONE OF SAID CONDUCTORS WHOSE RELATIVE VOLTAGE MAKES SAID SECOND TRANSISTOR CONDUCTIVE, SAID THIRD TRANSISTOR BEING CONDUCTIVE WHEN BIASED BY A RELATIVE VOLTAGE BY ONE OF SAID CONDUCTORS, A RESISTANCE BETWEEN THE BASE OF SAID THIRD TRANSISTOR AND THE ONE OF SAID CONDUCTORS WHICH MAKES SAID THIRD TRANSISTOR NOT CONDUCTIVE, AND MEANS INCLUDING A CONDUCTIVE LIQUID DETECTING PROBE HAVING SPACED APART ELECTRODES IN SERIES CIRCUIT BETWEEN SAID CONDUCTORS AND ADAPTED TO BE CONTACTED BY SAID LIQUID, SAID MEANS CAUSING A POTENTIAL TO BE APPLIED TO THE BASE OF THE THIRD TRANSISTOR WHICH MAKES SAID THIRD TRANSISTOR CONDUCTIVE WHEN THE CONDUCTIVE LIQUID BRIDGES SAID ELECTRODES.