Temperature sensor system

Claim 1

IN A TEMPERATURE SENSOR SYSTEM FOR AN ELECTRICALLY OPERATED LOAD ADAPTED FOR ENERGIZATION FROM AN ALTERNATING CURRENT SOURCE: (A) A RELAY INCLUDING A COIL; (B) A TEMPERATURE SENSOR COMPRISING A PAIF OF CONDUCTORS IN CONTACT WITH AND SEPARATED BY A THERMOSENSITIVE LAYER HAVING A RELATIVELY HIGH IMPEDANCE AT NORMAL OPERATING TEMPERATURES AND A LOWER IMPEDANCE AT ABNORMALLY HIGH TEMPERATURES, SAID CONDUCTORS BEING IN A SERIES CIRCUIT WITH SAID RELAY COIL AND SAID RELAY COIL BEING IN ELECTRICAL PARALLEL WITH SAID LAYER, SAID LAYER BEING SUBJECT TO HEAT GENERATED BY SAID LOAD; (C) MEANS RESPONSIVE TO THE OPERATION OF THE RELAY TO ENERGIZE AND DE-ENERGIZE SAID LOAD; (D) A SYMMETRICAL ELECTRICAL IMPEDANCE IN SERIES WITH BOTH SAID RELAY COIL AND SAID THERMOSENSIVE LAYER; (E) AT LEAST ONE UNDIRECTIONAL CIRCUIT ELEMENT IN PARALLEL WITH SAID RELAY COIL TO PROVIDE UNIDIRECTIONAL CURRENT FLOW THROUGH SAID RELAY COIL DURING THE MAJOR PORTION OF A COMPLETE ALTERNATING VOLTAGE CYCLE; AND (F) MEANS CONNECTING SAID SERIES CONNECTED SYMMETRICAL IMPEDANCE AND RELAY COIL ACROSS A SOURCE OF ALTERNATING CURRENT POWER SO THAT SAID COIL IS DE-ENERGIZED SUFFICIENTLY TO CAUSE ITS OPERATION WITH IMPROVED SENSITIVITY IN RESPONSE TO REDUCTION OF IMPEDANCE OF SAID LAYER DUE TO AN ABNORMALLY HIGH TEMPERATURE OF SAID LOAD.