Abstract:
Methods and apparatus for monitoring power outages in a household appliance such as a refrigerator are disclosed. According to the method, a household appliance determines a prior occurrence of a power outage to the appliance. The household appliance then computes a duration of the power outage. Further, the household appliance alerts a user of the duration of the power outage.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to provisional application U.S. Serial No. 60/305,766 filed on Jul. 16, 2001. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates to a method and apparatus for a household appliance such as, but not limited to a refrigerator. More specifically, this invention relates to such an appliance being able to monitor power outage duration. 
     Refrigerating appliances such as refrigerators, freezers, and related appliances require electrical power for refrigeration. For example, electrical power can be used for powering a compressor for compressing a refrigerant, an evaporator for generating cool air and/or a refrigerating fan for discharging cool air, or otherwise using external power to refrigerate. When this external power is interrupted such as during a power outage, refrigeration ceases. If the power outage is sufficiently long in duration, the contents of the refrigerator, typically food, can spoil. 
     Thus, if an individual is aware that a power outage has occurred, an individual is suspect of the food in the refrigerator and its fitness for consumption. If only a very short power outage has occurred, then there is no real cause for concern. However, if a power outage of sufficient duration has occurred, an individual may find it desirable to discard food from the refrigerator and/or otherwise avoid consuming it. Problems relating to power outages can occur in other types of household appliances as well. 
     Unfortunately, an individual may not be able to tell that a power outage has occurred or the duration of that power outage. 
     Thus, it is a primary object of the present invention to provide a method and apparatus for a household appliance that improves over the state of the art. 
     It is a further object of the present invention to provide a household appliance capable of automatically determining that a power outage has occurred. 
     Yet another object of the present invention is to provide a method and apparatus for a household appliance that determines the duration of a power outage. 
     Still another object of the present invention is to provide a method and apparatus for a household appliance that is capable of discerning that multiple power outages have occurred. 
     Yet another object of the present invention is to provide a method and apparatus for a household appliance that alerts a user that a power outage has occurred. 
     Another object of the present invention is to provide a method and apparatus for a household appliance that requires an acknowledgement from the user that the user acknowledges that a power outage has occurred. 
     These and other objects, features, or advantages of the present invention will become apparent from the specification and claims that follow. 
     SUMMARY OF THE INVENTION 
     The present invention is a method and apparatus for monitoring of power outages in a household appliance such as a refrigerator. The household appliance determines that a power outage has previously occurred. The household appliance then determines the duration of the power outage. The household appliance then alerts a user of the duration of the power outage. 
     One methodology of the present invention includes periodically storing a time. A current time is compared to a previously stored time. Based on this comparison, the duration of a power outage can be determined, as the current time is maintained but the times are not stored during power outages. Thus, upon reset after a power outage, the current time can be compared to the last stored time in order to determine the occurrence and duration of a power outage. 
     A refrigerating appliance according to one aspect of the present invention includes a refrigeration system, an external power source operatively connected to the refrigeration system and an intelligent control operatively connected to the external power source. A clock is operatively connected to the intelligent control and a second power source is electrically connected to the clock such that the clock is operable during a power outage of the external power source. The intelligent control is adapted for determining the duration of the power outage. 
     According to another aspect, the present invention provides for determining if more than one power outage has occurred, as well as determining the time and duration of each power outage or a total duration for multiple power outages. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 illustrates an exemplary refrigerator having a display portion for displaying the duration of a power outage effecting the refrigerator. 
     FIG. 2 is a pictorial representation of a user interface according to the present invention. 
     FIG. 3 is a block diagram of a refrigerating appliance according to one embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 illustrates a refrigerator  10  having a side-by-side configuration. In a side-by-side configuration, the refrigerator  10  includes two refrigerating compartments, one being a refrigerator compartment, the second being a freezer compartment. There is a door  12  to the refrigeration compartment and a door  14  provides access to the freezer compartment. The freezer compartment door  14  may contain a water and ice dispenser, generally shown at  16 . In addition, the water and ice dispenser  16  includes a lower receptacle  18  for receiving cups and dispensing water and ice therein. Above the receptacle  18  is a user interface  20  that is used to communicate power outage information. 
     FIG. 2 illustrates the user interface  20  in greater detail to include a central panel display  22  that is preferably a graphic liquid crystal display. Three selection buttons  24 ,  26 ,  28  are located along the lower edge of the display  22 . A menu button  30  is located to the left of the display  22 , and a message button  32  is located to the right of the display  22 . An LED  34  is positioned directly above the message button  32 . 
     In a normal or standard mode (not shown) wherein there has been no power outage, the display  22  may indicate which of the buttons  24 ,  26 ,  28  may be pressed to obtain water, cubed ice or crushed ice in the receptacle  18  of the water and ice dispenser  16 . However, where there has been an interruption of external power and then external power has been restored to the refrigerator  10 , the display  22  displays messages indicating the time and date of the last power outage, the time and date when the power was restored, the duration of the power outage, and the current time and date. Where multiple power outages have occurred, the time and duration of each power outage can be displayed and/or the accumulated total of the duration of each power outage. 
     Thus, after a power outage has occurred, power outage information is displayed to alert a user that a power outage has occurred. Further, the user is alerted of the duration of the power outage. Based on the duration of the power outage, the user can then make an informed decision as to whether or not the contents of the refrigerator are unaffected by the power outage or whether there is some likelihood that the contents of the refrigerator were spoiled or otherwise rendered undesirable by the power outage. 
     FIG. 3 illustrates one embodiment of a system according to the present invention. In FIG. 3, the user interface  20  is operatively connected to an intelligent control  40 . The intelligent control  40  may be one or more microcontrollers, processors, microcomputers, integrated circuits, a portion of an integrated circuit, electronic control circuit, or other type of intelligent control. The intelligent control  40  is also electrically connected to a clock  36 . The clock  36  is preferably a real time clock. 
     An external power source  42  is used to power the system of the present invention including the refrigeration system  44 . In addition, a power source  38  is used to provide power to the clock  36 . When there is an interruption in the external power source  42  and a resulting power outage, the power source  38  continues to power the clock  36 . The power source  38  may be a super capacitor of a type known in the art. Alternatively, the power source  38  can be a battery or other power source that functions independently of the external power source  42 . Preferably, the power source  38  is charged or recharged by the external power source  42  while the refrigerator  10  is operating normally. When the external power source  42  is lost, the power source  38  powers the clock  36 . Preferably, the power source  38  functions as a backup power source that is only needed during times of power outage. 
     The user interface  20  that is operatively connected to the intelligent control  40  includes the display  22  as well as one or more inputs. The inputs can be used for receiving a user acknowledgement of a power outage. After a power outage has occurred, a duration of one or more power outages can be displayed on the display  22 . Then a user can be instructed to press one or more buttons or to otherwise actively acknowledge that the power outage message has been received by the user. 
     The intelligent control  40  is also operatively connected to a memory  46 . The memory  46  is preferably a nonvolatile memory. The present invention contemplates that the memory  46  may be internal to the intelligent control  40 . The memory  46  is used to store time information. For example, the memory  46  can contain prior times during which the refrigerating appliance was in operation and/or one or more durations of a power outage. Where the memory  46  contains a prior time, the intelligent control  40  can determine or compute a duration of the power outage when the intelligent control  40  also uses a current time from the clock  36 . Such a computation can occur upon reset of the intelligent control  40 , such as would happen when a power outage of the external power source  42  results in turning the intelligent control  40  off, and the restoration of power through the external power source  42  results in turning on the intelligent control  40 . Upon the experience of this reset condition, the intelligent control  40  then checks the last stored time in the memory  46  and compares this prior time to a current time from the clock  36 . Comparison of these times allows the intelligent control  40  to determine if a power outage has occurred. If a power outage has occurred this allows the intelligent control to determine the duration of the power outage by determining the difference in time between a stored prior time and the current time. The present invention also contemplates that more than one power outage can be determined by recording the last time before each power outage and storing the then current time once the power outage has been restored. Thus, in this manner multiple power outages can be recorded and their respective durations can be determined. The present invention also provides for the intelligent control  40  being adapted to add or otherwise cumulate multiple power outages so that a total power outage duration can be calculated and displayed. Each of these times can also include a date, so that even extended periods of power outages can be determined. 
     The present invention contemplates use in any number of household appliances, including, without limitation, refrigerators, dishwashers, laundry appliances, and other types of household appliances. 
     Thus, a power outage duration feature has been disclosed. The present invention contemplates variations in the parts and components used, the specific computations used, the type of alert used, if any, and other variations within the spirit and scope of the invention.