NFIELD OF THE INVENTION
The present invention relates to a refrigerator. More specifically the present invention relates to a control for automatically controlling the temperature of a refrigerator according to changing ambient temperatures.
BACKGROUND OF THE INVENTION
In existing Electromechanical refrigerators there is a control (inside the refrigerator) to control the temperatures in the Freezer and Refrigerator Compartment. In refrigerator compartment there is a thermostat which in turn based on user setting decides the compressor run time in order to maintain a particular temperature in refrigerator compartment. Compressor run time basically depends on the cut in and cut out temperatures for compressor for that particular thermostat setting.
Now to have a right temperature in the product in different seasons (different ambient temperatures) User is supposed to change the thermostat knob position so that to change the compressor run time and that actually annoyed consumers and many times they don't changes it since they don't know about it.
Based on foregoing, there is a need for a system that can automatically change the set points therefore the compressor run time according to season change or ambient temperature change and provide a user convenient and efficient solution.
OBJECTS OF THE INVENTION
By reason of me deficiencies known as discussed above, it is the generic object of the present invention to provide an automatic system which can sense the temperature of the place where the refrigerator is kept and accordingly maintain the required temperature for the food preservation inside the compartments of the
refrigerator in an efficient manner.
It is a further object of the invention to give a User Friendly Electronic Interface to display the various functions including the automatic control of inside temperatures such that the it is convenient for the user to understand and operate.
SUMMARY OF THE INVENTION
In an embodiment of the present invention, a control for automatically controlling the temperature of a refrigerator according to changing ambient temperature is provided. The said control comprises a temperature sensor for measuring the ambient temperature, a main control board coupled to the said temperature sensor for changing a thermostat setting of the refrigerator to a pre-defined value based on the ambient temperature provided by the temperature sensor and an user interface coupled to the said main control board for displaying the operating status of the control and for enabling a user to select an operating mode.
In an embodiment of the present invention the temperature sensor is a thermistor.
In an embodiment of the present invention the main control board have a memory.
In an embodiment of the present invention the memory stores the pre-defined value for the thermostat setting.
In an embodiment of the present invention the user interface is coupled to the main control board by means of point to point protocol.
In an embodiment of the present invention the user interface is provided at the end cap of the door of the refrigerator.
In an embodiment of the present invention the user interface provides four operating modes i.e. fast freezing mode, cool mode, eco mode & defrost mode.
In an embodiment of the present invention, the control have four temperature settings for each ambient temperature i.e. cool, mid cool, high cool & super cool.
In an embodiment of the present invention the user interface incorporates a plurality of LEDs to display the operating status.
In an embodiment of the present invention the user interface incorporates a plurality of push buttons to
enable the user to select an operating mode.
In an embodiment of the present invention the user can change the temperature settings of the refrigerator manually.
These together with other embodiments of the present invention, along with the various features of novelty that characterize the present invention, are pointed out with particularity in the claims annexed hereto and form a part of this present invention. For a better understanding of the present invention, its operating advantages, and the specific objects attained by its uses, reference should be made to the accompanying drawings and descriptive matter in which there are illustrated exemplary embodiments of the present invention.
BRIEF DESCRIPTION OF DRAWINGS
The advantages and features of the present invention will become better understood with reference to the following detailed description and claims taken in conjunction with the accompanying drawings, wherein like elements are identified with like symbols, and in which:
Figure 1. depicts the front view of the refrigerator's
Figure 2. depicts the block diagram of the control
Figure 3. depicts front view of user interface
Figure 4. depicts the operating modes on the user interface
Figure 5. depicts a flow chart of the cool mode
Figure 6. depicts a flow chart of the fast freezing mode
Figure 7. depicts a flow chart of eco mode
Figure 8. depicts a flow chart for auto defrost mode
Like reference numerals refer to like parts throughout the description of several views of the drawings.
DETAILED DESCRIPTION OF THE INVENTION
For a thorough understanding of the present invention, reference is to be made to the following detailed description, including the appended claims, in connection with the above-described drawings. Although the present invention is described in connection with exemplary embodiments, the present invention is not intended to be limited to the specific forms set forth herein. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but these are intended to cover the application or implementation without departing from the spirit or scope of the claims of the present invention. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
The terms "a" and "an" herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item
The present invention provides a control for automatically controlling the temperature of a refrigerator according to changing ambient temperature. The said control comprises a temperature sensor for measuring the ambient temperature, a main control board coupled to the said temperature sensor for changing a thermostat setting of the refrigerator to a pre-defined value based on the ambient temperature provided by the temperature sensor and an user interface coupled to the said main control board for displaying the operating status of the control and for enabling a user to select an operating mode.
Referring to figure 1, a front, view of the refrigerator 100 is depicted. The refrigerator .100 includes a body portion 102 and a door 104. The door includes a end cap 106. The end cap 106 is mounted on the top portion of the door 104. The end cap 106 includes a user interface 108. A temperature sensor 110 is disposed on the body portion 102 of the refrigerator 100. In an embodiment of the present invention the temperature sensor 110 is a thermistor. The refrigerator 100 also includes a main control board 112. The temperature sensor 110 measures the ambient temperature. In an embodiment of the present invention the temperature sensor 110 measures the ambient temperature every minute. The main control board 112 is coupled to the temperature sensor 110. The user interface 108 is coupled to the main control board 112. In an embodiment of the present invention the user interface 108 is coupled to the main control board by means of point to point protocol.
Referring to figure 2. a block diagram of the said control 200. The control 200 comprises a temperature sensor
110, main control board 112, a thermostat 114 and a user interface 108. The main control board comprises a processor, a memory and a control circuit. The main control board 200 set the diermostat 114 based on the ambient temperature measured by the temperature sensor 110. The memory on main control board 112 stores the pre-defined value of thermostat settings for each ambient temperature and each temperature setting setting selected by the user. There will be four temperature settings for each ambient temperature. The said temperature settings will be indicated as COOL, MID COOL, HIGH COOL & SUPERCOOL on user interface 108 for communication to the users. For all seasons MID COOL will be default temperature setting. For temperature Difference of more than 4 degree with respect to cut in temp, the control 200 will go in sixth sense mode and will shift the cut off temp to a colder value. The control 200 will run only one colder cycle in special cooling mode and after completing it will come back to original setting. (Except for the Super Cool where it will remain in Super cool & when shifts from high Cool to super cool it will run one 6th Sense cycle or Max 2 hrs which ever occur first).
In an embodiment of the present invention, the pre-defined value for thermostat settings for a refrigerator with a capacity of 200 & 230 litres are mentioned below in tabular form.
6TH SENSE TABLE -
1) Ambient Temperature x Set Point for 200L and 230L

(Table Removed)
In another embodiment of the present invention, the pre-defined value for diermostat settings for a refrigerator with a capacity of 260 litres are mentioned below in tabular form.
3) Ambient Temperature x Set Point for 260L

(Table Removed)
Referring to figure 3, a front view of the user interface 108 is depicted. The user interface 108 includes a plurality of LEDs and a plurality of push buttons. The plurality of LEDs include four yellow color LEDs that denotes the temperature settings i.e. COOL, MID COOL, HIGH COOL & SUPER COOL. Based on the selected temperature setting the applicable LED will illuminate. The plurality of LEDs further include a green color LED that illuminates when the control 200 is in defrost mode. Furthermore, the plurality of LEDs include a blue LED that illuminate when the control is in auto cool mode. The Plurality of press buttons include a override switch and a fast forward/manual defrost switch. The user by pressing the override switch the can change the temperature settings manually.
Referring to figure 4, different operating modes at the control 200 are depicted. The operating modes may be selected by the user from the user interface 108. The four operating modes comprises fast freezing mode, cool mode, eco mode and defrost mode. The cool mode includes a auto cool mode and a manual cool mode. The control 200 has a default mode as auto cool mode. Therefore, upon switching on the refrigerator 100, the control 200 initiate with auto cool mode. The user may switch to manual cool mode from the auto cool mode by pressing the set cool/ override switch for more than equal to 2 seconds.
Referring to figure 5, a flow chart of cool mode is depicted. The cool mode is provided for normal operation of the refrigerator 100. The cool mode comprises auto cool mode and a manual cool mode. The control 200 has a
default mode as auto cool mode. Therefore, upon switching on the refrigerator 100, the control 200 initiate with auto cool mode. Upon entering in the auto cool mode, the blue LED representing the 6th sense on the user interface 108 will illuminate. The auto cool mode has a default temperature setting of MID COOL. Therefore, upon initiating the auto cool mode, the temperature setting MID COOL is selected. However, the yellow LED on the
user interface 108 will not illuminate when the MID COOL temperature setting is selected by default. Other temperature settings may be selected in the auto cool mode. The user can switch to manual cool mode by pressing the set cool/override switch for more than or equal to two seconds. Upon selecting the manual cool mode, the blue LED representing 6th sense will be off and a temperature setting MID COOL will be selected and the yellow LED on the user interface 108 will illuminate. The user can select another temperature setting by pressing the switch set cool. Based on the selection of the temperature setting the respective LED on the user interface 108 will illuminate displaying the selected temperature setting.
Referring to figure 6, a flow chart of fast freezing mode is depicted. The fast freeing mode may be activated by the user by pressing the frost control switch & set cool switch on the user interface 108 simultaneously for greater than or equal to two seconds. The delta time between the key press on both the switches should be less than or equal to two seconds. Upon activating the fast freezing mode, the temperature of the freezer is pulled down. Also, activation of fast freezing mode is indicated by scroll movement of all four manual cool mode LEDs. The fast freezing mode will by default run for two hours and will revert back to original state as it was before entering the fast freezing mode. Meanwhile, when the fast freezing mode is activated the user may disengage the fast freezing mode by pressing the frost control/defrost button & set cool/override push button simultaneously for greater than or equal to two seconds. Upon disengaging the fast freezing mode, the control will revert back to original state as it was before entering the fast freezing mode.
Referring to figure 7, a flow chart of ECO mode is depicted. The term 'eco' in ECO mode represents the economy mode. The ECO mode is power saving when the refrigerator 100 is not used for long duration such as the user is not at the home and the like. The ECO mode is activated when the refrigerator compartment door is not opened or no key is pressed for greater than or equal to three hours of compressor cumulative run time. Upon entering the ECO mode, temperature settings should become one step lower (one step warmer). Also, blue color 6* sense LED start blinking indicating the activation of ECO mode. The control 200 comes back to normal operation if door is opened or any key switch at the user interface. The ECO mode will function in auto cool mode only. If there is power interrupted during ECO mode, then after power resumes the ECO mode should also be resumed. If there is power cut before the ECO mode occur then the memory should not be refreshed it should continue counting the time until door is opened or key is pressed. If present temperature setting is COOL mode, then it will remain in same state during ECO mode. ECO mode is a power saving mode.
Referring to figure 8, a flow chart of frost control mode is depicted. The frost control mode may be selected in auto cool mode or manual cool mode. In auto cool mode, auto defrost will get engaged automatically and the green LED on the user interface 108 will be illuminated. Auto defrost check for ambient temperature, season band & cumulative compressor run time (CCT). If the ambient temperature band is SI, S2, S3 and CCT is greater than or equal to 12 hours then the defrost cycle will start else after 24 CCT hours defrost cycle will start. During defrost cycle green LED on the user interface will start blinking. Defrost cycle will exit when exit condition is defrost end temperature or timeout. If there is power interrupt during the defrost logic/routine, then after power resumes the defrost routine should continue for the remaining time. In manual cool mode, manual defrost mode will take place. In order to activate/de-activate manual defrost the user has to initiate the defrost cycle by pressing the frost control switch at the user interface 108 for greater than or equal to two seconds. Upon activation, defrost will occur immediately and exit at 10 degrees Celsius. There will be no time limit for de-activation to trigger. During manual defrost green LED on the user interface will start blinking. The exit condition is defrost end temperature.
The present invention is advantageous over the prior art as there is minimum manual interaction with the control 200. The Low cost Dynamic Thermostat for home appliances market to fulfill all the cooling requirements of customers with the help of an easily understandable User Interface 108. Energy saving because of optimized compressor run time to maintain desired temperature in each ambient temperature.
The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions and substitutions of equivalents are contemplated as circumstance may suggest' or render expedient, but such are intended to cover the application or implementation without departing from the spirit or scope of the claims of the present invention.

We claim:
1. A control 200 for automatically controlling the temperature of a refrigerator 100 according to
changing ambient temperature comprising:
a temperature sensor 110 for measuring the ambient temperature;
a main control board 200 coupled to the said temperature sensor 110 for changing a thermostat
setting of the refrigerator 100 to a pre-defined value based on the ambient temperature provided
by the temperature sensor 110; and
an user interface 108 coupled to the said main control board 200 for displaying the operating
status of the control 200 and for enabling a user to select an operating mode.
2. The control 200 for automatically controlling the temperature as claimed in claim 1, wherein the temperature sensor 110 is a thermistor.
3. The control 200 for automatically controlling the temperature as claimed in claim 1, wherein the
main control board 200 have a memory.
4. The control 200 for automatically controlling the temperature as claimed in claim 3, wherein the
memory stores the pre-defined value for the thermostat setting.
5. The control 200 for automatically controlling the temperature as claimed in claim 1, wherein the
user interface 108 is coupled to the main control board 200 by means of point to point protocol.
6. The control 200 for automatically controlling the temperature as claimed in claim 1, wherein the
user interface 108 is provided at the end cap 106 of the door 104 of the refrigerator 100.
7. The control 200 for automatically controlling the temperature as claimed in claim 1, wherein the
user interface 108 provides four operating modes i.e. fast freezing mode, cool mode, eco mode & defrost mode.
8. The control 200 for automatically controlling the temperature as claimed in claim 1, wherein the
control 200 have four temperature settings for each ambient temperature i.e. cool, mid cool, high cool & super cool.
9. The control 200 for automatically controlling the temperature as claimed in claim 1, wherein the
user interface 108 incorporates a plurality of LEDs to display the operating status.
10. The control 200 for automatically controlling the temperature as claimed in claim 1, wherein the
user interface 108 incorporates a plurality of push buttons to enable the user to select an operating mode.
11. The control 200 for automatically controlling the temperature as claimed in claim 1, the user can
change the temperature settings of the refrigerator 100 manually.
12. The control for automatically controlling the temperature of a refrigerator as hereinbefore
described with reference to the accompanying drawings.