Patent ID: 8061266

Claim:
A device for heating food comprising: a housing; a plurality of trays supported on said housing, each of said trays including a heater and a temperature sensor associated with said tray, said heater operable to heat said tray, said temperature sensor capable of sensing the temperature of said tray; and a controller electrically coupled to each of said heaters and each of said temperature sensors, wherein said controller automatically determines an amount of time to operate said heater to heat food on said tray, said controller including a timer capable of measuring a first time period, wherein said first time period is an amount of time to raise said tray temperature to a predetermined cook temperature value, said controller configured to operate said heater to heat said tray for a second time period that is greater than said first time period, wherein the duration of said second time period is determined as a function of said tray temperature and said first time period, said controller configured to operate said heater on a first duty cycle to maintain said tray temperature at a hold temperature, wherein said first duty cycle utilizes less power than said operation of said heater to heat said tray for said second time period, said controller configured to automatically deactivate said first duty cycle and operate said heater on a rethermalization cycle to raise said tray temperature to a cook temperature when said tray temperature falls below a lower limit temperature, said controller configured to automatically deactivate said rethermalization cycle and to operate said heater on a second duty cycle when said tray temperature reaches said cook temperature, wherein said first time period measured by said controller is a cook time that is measured during said rethermalization cycle, said controller further configured to measure a loop time during said second duty cycle.