Patent ID: 8280673

Claim:
A method for determining ambient temperature comprising: determining a first set of temperatures from a first sensor at a first location within an enclosure having an apparatus that generates heat; determining a second set of temperatures from a second sensor at a second location within the enclosure; generating a two-dimensional relationship with a processor having inputs of the first and second sets of temperatures; generating an equation with the processor as an approximation of the two-dimensional relationship; and determining an ambient temperature proximate to and external of the enclosure from the equation with the processor; wherein: the two-dimensional relationship of the first and second temperatures is generated with the processor from the first and second sets of temperatures determined approximately simultaneously at several levels of power consumed by the apparatus; the first set of temperatures at the several levels of power is represented as a first plot; the second set of temperatures at the several levels of power is represented as a second plot; and the first and second plots are combined into a third plot representing the first set of temperatures versus the second set of temperatures with a portion of the plots representing the several levels of the power dropping out; generating the equation as an approximation of the third plot; and solving for the ambient temperature from the equation; wherein: the equation is T a =( T 1 −AT 2 −B )/(1 −A ); A is a slope of the third plot; B is an offset of the third plot; T 1 is a temperature at the first location; and T 2 is a temperature at the second location.