Electronic control system for a heating apparatus

• US 5,596,514 A
• Filed: 03/23/1995
• Issued: 01/21/1997
• Est. Priority Date: 03/17/1994
• Status: Expired due to Term

• Current Assignee: Ametek Incorporated
• Original Assignee: Tridelta Industries, Inc. (Honeywell International Inc.)
• Inventors: Maher, Charles A. Jr., Larrick, Raymond
• Primary Examiner(s): Cosimano, Edward R.
• Application Number:
  US08/409,166
• Time in Patent Office: 670 Days
• Field of Search: 99/324, 99/325, 99/326, 99/327, 99/328, 99/330, 99/331, 99/332, 99/403, 364/400, 364/569, 364/709.03
• US Class Current: 700/306
• CPC Class Codes: A47J 27/0802 Control mechanisms for pressure-cookers
• CPC Class Codes: A47J 27/62 by devices for automatically controlling the heat supply by switching off heaters or for automatically lifting the cooking-vessels
• CPC Class Codes: A47J 37/1266 Control devices, e.g. to control temperature, level or quality of the frying liquid
• CPC Class Codes: G05D 23/1917 using digital means
• CPC Class Codes: G05D 23/1951 with control of the working time of a temperature controlling device

Abstract

An electronic control for a heating apparatus and specifically a deep fat fryer is provided. The electronic control includes a temperature sensor for sensing the temperature of a cooking medium during a cooking cycle. Cooking medium temperature sensed during the cooking cycle is utilized as a pointer to one of a plurality of time compensation values for corresponding temperatures stored in a memory. The time compensation corresponding to the sensed cooking medium temperature is retrieved from the memory and adjusted by an offset value determined in accordance with the setpoint temperature to obtain an adjusted time compensation value. The adjusted time compensation value is utilized in the adjustment of the cooking time.

Claims

1. A system for adjusting an interval of time for a heating operation comprising:

means for establishing an interval of time;

means for storing a plurality of time compensation factors for a plurality of corresponding temperatures;

means for inputting a setpoint temperature;

means for determining an offset value from said plurality of stored time compensation factors, in accordance with said setpoint temperature;

means for determining an adjusted time compensation factor for a measured temperature based on the time compensation factor corresponding to the measured temperature and the offset value; and

means for utilizing the adjusted time compensation factor to adjust the interval of time.

2. The system of claim 1, wherein said means for determining an offset value in accordance with said setpoint temperature comprises means for determining the difference between the time compensation value at the setpoint temperature and the time compensation value at a predetermined temperature.

3. The system of claim 1, wherein said means for determining an adjusted time compensation value comprises means for determining the difference between the time compensation value corresponding to the measured temperature and the offset value.

4. A method for adjusting a cooking time comprising:

providing a plurality of time compensation factors for a plurality of corresponding temperature;

inputting a setpoint temperature;

determining an offset value from said plurality of time compensation factors, in accordance with said setpoint temperature;

determining an adjusted time compensation factor for a measured temperature based upon the offset value and the time compensation factor for the measured temperature; and

combining the adjusted time compensation factor and the cooking time to obtain an adjusted cooking time.

5. The method for adjusting a cooking time as set forth in claim 4, wherein said step of determining an offset value comprises determining the difference between the time compensation value at the setpoint temperature and the time compensation value at a predetermined temperature.

6. The method for adjusting a cooking time as set forth in claim 4, wherein said step of determining an adjusted time compensation value for an actual temperature comprises determining the difference between the offset value and the time compensation value for the actual temperature.

7. A system for generating a time interval for a heating operation comprising:

means for establishing a first time interval;

means for storing time compensation values for corresponding temperatures;

means for inputting a setpoint temperature;

means for determining the difference between the time compensation value at the setpoint temperature and the time compensation value at a predetermined temperature;

means for determining an adjusted time compensation value for a measured temperature based upon the time compensation value corresponding to the measured temperature and said difference; and

means for establishing a second time interval based upon said first time interval and said adjusted time compensation value.

8. A system for generating a time interval for a heating operation comprising:

means for establishing a first time interval;

means for storing a plurality of time compensation values for a plurality of corresponding temperatures;

means for inputting a setpoint temperature;

means for determining an offset value from said plurality of stored time compensation values in accordance with said setpoint temperature;

means for determining an adjusted time compensation value for a measured temperature based upon the time compensation value corresponding to the measured temperature and the offset value; and

means for establishing a second time interval based upon said first time interval and said adjusted time compensation value.

9. A method for adjusting a cooking time comprising:

establishing a cooking time interval;

providing time compensation values for corresponding temperatures;

inputting a setpoint temperature;

determining the difference between the time compensation value at the setpoint temperature and the time compensation value at a predetermined temperature;

determining an adjusted time compensation value for a measured temperature based upon said difference and the time compensation value for the measured temperature; and

modifying the cooking time interval based upon said adjusted time compensation value.

10. A method for adjusting a cooking time comprising:

establishing a cooking time interval;

providing a plurality of time compensation values for a plurality of corresponding temperatures;

inputting a setpoint temperature;

determining an offset value from said plurality of time compensation values, in accordance with said setpoint temperature;

determining an adjusted time compensation value for a measured temperature based upon the offset value and the time compensation value for the measured temperature; and

modifying the cooking time interval based upon said adjusted time compensation value.

11. A cooking appliance comprising:

a vessel for holding a cooking medium;

a temperature sensor for sensing the temperature of the cooking medium;

a heater for heating the cooking medium; and

a controller for controlling a cook time of a food product disposed in said cooking medium as a function of the temperature of cooking medium during said cook, said controller comprising;

a memory for storing time compensation factors for a time compensation curve having a one-for-one time compensation factor at a preselected temperature;

means for entering a setpoint temperature of the cooking medium;

means for determining a shift constant by combining the time compensation factor from said curve corresponding to the preselected temperature and the time compensation factor from said curve corresponding to the entered setpoint temperature;

means for retrieving from the memory, the time compensation factor corresponding to a measured cooking medium temperature; and

means for determining an adjusted time compensation factor based on said time compensation factor corresponding to said measured cooking medium temperature and said shift constant; and

means for combining the cook time and the adjusted time compensation factor to obtain an adjusted cook time.

12. The cooking appliance as set forth in claim 11, wherein the cook time is comprised of a plurality of intervals of time.

13. The cooking appliance as set forth in claim 11, further including means for combining each interval of time with an adjusted time compensation factor corresponding to the temperature of the cooking medium sensed relative to said each interval of time to obtain an adjusted interval of time utilized in the determination of the adjusted cook time.

14. A method of adjusting cooking time comprising:

providing time compensation factors for a time compensation curve having a one-for-one time compensation factor at a set temperature;

calculating a shift factor by subtracting the time compensation factor corresponding to the set temperature from the time compensation factor corresponding to a selected temperature;

retrieving from the time compensation curve a time compensation factor corresponding to a measure temperature;

adjusting the retrieved time compensation value by the shift factor to obtain an adjusted time compensation factor; and

utilizing the adjusted time compensation factor to adjust the actual cook time.

15. A cooking appliance comprising:

a vessel for holding a cooking medium;

a temperature sensor having an output responsive to the temperature of the cooking medium;

a heater operable to heat the cooking medium; and

a controller operable to control a cook time of a food product disposed in said cooking medium as a function of the output of the temperature sensor during said cook time, said controller comprising;

a memory;

a keypad operable by a user to input a setpoint temperature of the cooking medium to the memory; and

a plurality of time compensation factors stored in said memory comprising a time compensation curve for a corresponding plurality of temperatures, said time compensation curve having a one-for-one time compensation factor at a preselected temperature wherein the controller is operable to;

determine a shift constant for an input setpoint temperature as a function of the one-for-one time compensation factor for said preselected temperature and the time compensation factor corresponding to the input setpoint temperature;

retrieve from the memory, a plurality of time compensation factors corresponding to the output of the temperature sensor; and

determine a plurality of adjusted time compensation factors based respectively on said plurality of retrieved time compensation factors and said shift constant; and

determine an adjusted cook time based upon said plurality of adjusted time compensation factors.

16. The cooking appliance as set forth in claim 15, wherein the cook time is comprised of a plurality of time intervals.

17. The cooking appliance as set forth in claim 16, wherein the controller is operable to determine one of said plurality of adjusted time compensation factors for each of said plurality of time intervals, as a function of the temperature of the cooking medium sensed at each said time interval.

18. The cooking appliance of claim 17, wherein the controller determines the adjusted cook time by determining an adjusted time compensation factor during each of said plurality of time intervals.

19. A method of determining a cooking time comprising:

providing a predetermined cook time;

providing a plurality of time compensation factors comprising a time compensation curve for a corresponding plurality of temperatures, said time compensation curve having a one-for-one time compensation factor at a first temperature;

providing a setpoint temperature, said setpoint temperature having a corresponding time compensation factor;

calculating a shift factor by subtracting the one-for-one time compensation factor at said first temperature from the time compensation factor corresponding to the setpoint temperature;

sensing a cooking medium temperature;

obtaining from the plurality of time compensation factors, a plurality of time compensation factors corresponding to a plurality of sensed cooking medium temperatures;

adjusting each obtained time compensation factor by the shift factor to obtain a plurality of respective adjusted time compensation factors; and

determining an actual cook time based upon said predetermined cook time and said plurality of adjusted time compensation factors.

20. A method according to claim 19, wherein said predetermined cook time is comprised of a plurality of time intervals.

21. A method according to claim 20, further comprising a step of determining one of said plurality of adjusted time compensation factors for each of said plurality of time intervals, as a function of the temperature of the cooking medium sensed at each said time interval.

22. A method according to claim 21, wherein said actual cook time is determined by determining an adjusted time compensation factor during each of said plurality of time intervals.