Patent ID: 6667869
Filing Date: 2003-12-23
Classification: H05B

Abstract:
A power control system for controlling power supplied from a power source to a resistive load to prevent said resistive load from exceeding a predetermined high temperature limit, wherein a regulator circuit is coupled between said power source and said resistive load for supplying controllable power levels to said resistive load, said power control system comprising:a pulse train generating circuit for converting power impulses received from said regulator circuit into a heating pulse train representing power flowing to said resistive load; a load temperature calculation circuit coupled to said pulse train generating circuit, wherein said load temperature calculation circuit includes digital logic for producing a temperature out value substantially representing a present temperature of said resistive load; and a temperature comparison circuit coupled to said load temperature calculation circuit and said regulator circuit, wherein said temperature comparison circuit selectively compares said temperature out value to at least one of a high temperature limit value and a base temperature value, wherein said temperature comparison circuit causes said power source to be disconnected from said resistive load when said temperature out value reaches said high temperature limit value, and wherein said temperature comparison circuit causes said power source to be reconnected to said resistive load when said temperature out value reaches said base temperature value.