Remote reading temperature indicating system

Claim 1

IN ELECTRICAL APPARATUS, THE COMBINATION OF: (A) A CURRENT-CARRYING CONDUCTOR SUBJECT TO TEMPERATURE CHANGE IN OPERATION; (B) OSCILLATOR MEANS COMPRISING A NETWORK INCLUDING A RESISTOR, A NEGATIVE RESISTANCE DIODE AND A FREQUENCYDETERMINING PARALLEL RESONANT CIRCUIT; (C) AT LEAST ONE ELEMENT IN THE PARALLEL RESONANT CIRCUIT HAVING A TEMPERATURE-DEPENDENT REACTANCE WHEREBY THE NATURAL RESONANT FREQUENCY OF THE CIRCUIT CHANGE WITH VARIATIONS IN TEMPERATURE; (D) MEANS SUPPORTING SAID NETWORK IN A POSITION ADJACENT THE CONDUCTOR, WHEREBY SAID ELEMENT IS IN GOOD HEAT EXCHANGE RELATIONSHIP WITH THE CONDUCTOR; (E) ENERGIZING MEANS CONNECTED TO THE OSCILLATOR MEANS FOR SUPPLYING POWER THERETO COMPRISING TWO VOLTAGE TAPS LONGITUDINALLY SPACED ALONG THE CURRENT-CARRYING CONDUCTOR, THE TAPS BEING CONNECTED TO RESPECTIVE INPUT TERMINALS OF THE SAID NETWORK; AND (F) MEANS REMOTE FROM THE OSCILLATOR FOR MEASURING THE FREQUENCY OF OSCILLATION OF THE OSCILLATOR MEANS TO PROVIDE AN INDICTION OF THE TEMPERATURE OF SAID CONDUCTOR.