Method of controlling the flow of heat transfer fluid

Claim 1

A METHOD OF CONTROLLING THE FLOW OF HEAT TRANSFER FLUID TO MEANS, THE TEMPERATURE OF WHICH IS TO BE CONTROLLED, AND TO A SENSOR HAVING A NEGATIVE TEMPERATURE COEFFICIENT OF RESISTANCE WHOSE HEAT TRANSFER PROPERTIES ARE A FUNCTION OF THE HEAT TRANSFER PROPERTIES OF SAID MEANS, AND WHICH HAS A CURRENT PASSING THERETHROUGH OF SUCH A MAGNITUDE THAT A FLOW OF SAID FLUID IS REQUIRED TO MAINTAIN ITS TEMPERATURE AT A DESIRED LEVEL, WITH SAID SENSOR AND SAID MEANS BEING SUBJECT TO THE SAME AMBIENT TEMPERATURE CONDITIONS, WHICH METHOD COMPRISES: DISPOSING SAID SENSOR DIRECTLY IN SAID FLOW; APPLYING A VOLTAGE ACROSS SAID SENSOR SUFFICIENT TO PASS A CURRENT THERETHROUGH OF SUCH A MAGNITUDE AS TO OPERATE SAID SENSOR WITHIN A RANGE WHERE SAID CURRENT WILL EFFECT A GENERATION OF HEAT WITHIN THE SENSOR GREATER THAN THE HEAT DISSIPATED THEREFROM IN A STATIC FLOW CONDITION SO THAT THE RESISTANCE OF THE SENSOR IS DIRECTLY INDICATIVE OF THE WEIGHT FLOW RATE AND TEMPERATURE OF SAID FLUID, WITH THERE BEING A DIFFERENTIAL IN TEMPERATURE BETWEEN SAID SENSOR AND SAID HEAT TRANSFER FLUID TO CAUSE HEAT TRANSFER THEREBETWEEN; ADJUSTING THE RESISTANCE VALUE OF SAID SENSOR TO A PREDETERMINED VALUE INDICATIVE OF A PREDETERMINED FLUID FLOW REQUIRED TO DISSIPATE HEAT FROM SAID MEANS, THE TEMPERATURE OF WHICH IS TO BE CONTROLLED; MAINTAINING SAID APPLIED VOLTAGE SUBSTANTIALLY CONSTANT THROUGHOUT THE OPERATION OF SAID SENSOR EXCEPT AS AFFECTED BY INTERNAL CHANGES IN RESISTANCE; AND MODULATING THE FLOW OF FLUID TO MAINTAIN THE RESISTANCE OF SAID SENSOR AT SAID PREDETERMINED VALUE THROUGH VARIATION IN THE HEAT DISSIPATION THEREFROM, WITH THE MODULATED FLUID FLOW AT ANY TIME BEING THAT REQUIRED TO ESTABLISH SAID PREDETERMINED SENSOR RESISTANCE VALUE.

Claim 2

A METHOD OF CONTROLLING THE FLOW OF HEAT TRANSFER FLUID TO MEANS, THE TEMPERATURE OF WHICH IS TO BE CONTROLLED, AND TO A SENSOR HAVING A NEGATIVE TEMPERATURE COEFFICIENT OF RESISTANCE WHOSE HEAT TRANSFER PROPERTIES ARE A FUNCTION OF THE HEAT TRANSFER PROPERTIES OF SAID MEANS, AND WHICH HAS A CURRENT PASSING THERETHROUGH OF SUCH A MAGNITUDE THAT A FLOW OF SAID FLUID IS REQUIRED TO MAINTAIN ITS TEMPERATURE AT A DESIRED LEVEL, WITH SAID SENSOR AND SAID MEANS BEING SUBJECT TO THE SAME AMBIENT TEMPERATURE CONDITIONS, WHICH METHOD COMPRISES: DISPOSING SAID SENSOR DIRECTLY IN SAID FLOW; APPLYING A VOLTAGE ACROSS SAID SENSOR SUFFICIENT TO PASS A CURRENT THERETHROUGH OF SUCH A MAGNITUDE AS TO OPERATE SAID SENSOR WITHIN A RANGE WHERE SAID CURRENT WILL EFFECT A GENERATION OF HEAT WITHIN THE SENSOR GREATER THAN THE HEAT DISSIPATED THEREFROM IN A STATIC FLOW CONDITION SO THAT THE RESISTANCE OF THE SENSOR IS DIRECTLY INDICATIVE OF THE WEIGHT FLOW RATE AND TEMPERATURE OF SAID FLUID, WITH THERE BEING A DIFFERENTIAL IN TEMPERATURE BETWEEN SAID SENSOR AND SAID HEAT TRANSFER FLUID TO CAUSE HEAT TRANSFER THEREBETWEEN; ADJUSTING THE RESISTANCE VALUE OF SAID SENSOR TO A PREDETERMINED VALUE INDICATIVE OF A PREDETERMINED FLUID FLOW REQUIRED TO DISSIPATE HEAT FROM SAID MEANS, THE TEMPERATURE OF WHICH IS TO BE CONTROLLED; MAINTAINING SAID APPLIED VOLTAGE SUBSTANTIALLY CONSTANT THROUGHOUT THE OPERATION OF SAID SENSOR EXCEPT AS AFFECTED BY INTERNAL CHANGES IN RESISTANCE; AND MODULATING THE FLOW OF FLUID TO MAINTAIN THE RESISTANCE OF SAID SENSOR AT SAID PREDETERMINED VALUE THROUGH VARIATION IN THE HEAT DISSIPATION THEREFROM, WITH THE MODULATED FLUID FLOW AT ANY TIME BEING THAT REQUIRED TO ESTABLISH SAID PREDETERMINED SENSOR RESISTANCE VALUE.