Programmable load compensation method and apparatus for use in a food oven
AssigneeHenny Penny Corporation
InventorsDoug Burkett, Gary Mercer
Life of this patent
Estimating the term…
Abstract
A method and apparatus is disclosed which automatically adjusts the on-time of preferably quartz lamp heating elements in an oven having both quartz lamp and electric heating elements. In such an oven having dual heating elements, the temperature of the oven's cavity increases when numerous food items (loads) are rapidly cooked in succession. The present invention allows a dual heating element oven to automatically compensate for these increases in temperature by preferably shortening a predetermined on-time of the quartz bulbs. The on-time is continuously compensated using a microcomputer, dependent upon the current oven temperature. The microcomputer preferably uses at least two clocks to shorten the predetermined on-time of the quartz bulbs.
Claims27
An oven for cooking food having a cavity and a base comprising:
- first and second heating means for heating food located in the oven, the first heating means having a thermal intensity greater than the second heating means, and the first heating means capable of being activated for a predetermined time;
- first temperature sensing means for sensing the temperature of the oven and located relative to the cavity of the oven;
- and
- automatic controller means, operatively connected to said first and second heating means and coupled to and responsive to the first temperature sensing means, for selectively controlling the first heating means to alter the predetermined time.
A method for controlling a first means for heating food comprising the steps of:
- setting a first clock to a first predetermined clock value corresponding to a time for which the first means is switched to a first state;
- reading a compensation factor from a memory;
- continuously calculating a temperature error;
- calculating a compensated clock value dependent upon at least the compensation factor and the temperature error and setting a second clock to the compensated clock value;
- continuously decrementing the second clock;
- decrementing the first clock when the second clock falls below a second predetermined clock value;
- and
- switching the first means to a second state when the first clock falls below a third predetermined clock value.
A method for cooking food in a an oven comprising a cavity, a base, and first and second heating means for heating food in the oven, the method of cooking comprising the steps of:
- activating the first heating means for a predetermined time;
- sensing the temperature of the oven;
- and,
- selectively controlling the first heating means to alter the predetermined time in response to the first temperature sensing means.
A control system for a food oven having a cavity, a base, and first and second heating means for heating food located in the oven, the first heating means having a thermal intensity greater than the second heating means, comprising:
- means for activating the first heating means for a predetermined time;
- first temperature sensing means for sensing the temperature of the oven, the temperature sensing means being located relative to the cavity of the oven;
- and
- automatic controller means, operatively connected to said first and second heating means and coupled to and responsive to the first temperature sensing means, for selectively controlling the first heating means to alter the predetermined time.
Dependencies are inferred from the claim text.