Abstract:
According to an aspect of the present invention a control system for an appliance includes a plurality of peripheral devices and a plurality of sensors and a controller. A first communications/DC power bus is coupled to the plurality of sensors and peripheral devices and coupled to the controller. A second communications/ac power bus is coupled to the plurality of sensors and peripheral devices and coupled to the controller. Wherein the controller is configured to receive data from the sensors over the either communications bus and transmit control operations to the peripheral devices based on the data.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    This invention relates generally to control systems for appliances, and more particularly, to a control system for a refrigerator. 
         [0002]    Known household appliances are available in various platforms having different structural features, operational features, and controls. For example, known refrigerator platforms include side-by-side single and double fresh food and freezer compartments, and vertically oriented fresh food and freezer compartments including top mounted freezer compartments, and bottom mounted freezer compartments. Conventionally, a different control system may be used in each refrigerator platform. For example, a control system for a side-by-side refrigerator typically controls the freezer temperature by controlling operation of a compressor and controls the fresh food compartment through the operation of a mullion damper located between the fresh food compartment and the freezer compartment, a fresh food fan and a variable or multi-speed fan-speed evaporator fan. Top mount refrigerators and bottom mount refrigerators however, are available with and without a mullion damper, the absence or presence of which consequently affects the refrigerator controls. 
         [0003]    Other major appliances, including dishwashers, washing machines, dryers and ranges, are available in various platforms and employ different control schemes. 
         [0004]    Known electronically controlled appliances typically employ a dedicated connection between a controller and a plurality of peripheral devices, including but not limited to sensors to monitor various operating conditions of the appliance. Typically, analog signals are transmitted between the sensors and the controller. These analog signals, however, are vulnerable to electrical interference, which can compromise performance of the appliance. To reduce electrical interference, additional electronic circuitry may be employed, but only at increased complexity and cost of the control scheme. Further, ever-expanding appliance features entail relatively sophisticated control schemes and many electrical connections to place all the peripheral devices in communication with the controller. A large number of electrical connections not only increases assembly costs, but presents a possible defect in manufacturing or possibility of failure in use. 
       BRIEF SUMMARY OF THE INVENTION 
       [0005]    According to an aspect of the present invention a control system for an appliance includes a plurality of peripheral devices, a plurality of sensors and a controller. A first communications/DC power bus is coupled to the plurality of sensors and peripheral devices and coupled to the controller. A second communications/AC power bus is coupled to the plurality of sensors and peripheral devices and coupled to the controller. Wherein the controller is configured to receive data from the sensors over either communications bus and transmit control operations to the peripheral devices based on the data. 
         [0006]    According to another aspect of the present invention a refrigerator comprises a control system for an appliance which includes a plurality of peripheral devices, a plurality of sensors and a controller. A first communications bus provides DC power to peripheral devices and is coupled to the plurality of sensors and coupled to the controller. A second communications bus provides AC power to peripheral devices and is coupled to the plurality of of sensors and peripheral devices and coupled to the controller. Wherein the controller is configured to receive data from the sensors over a communications bus and transmit control operations to the peripheral devices based on the data. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a perspective view of a refrigerator. 
           [0008]      FIG. 2  is a perspective view of the refrigerator of  FIG. 1  with the doors in a open position. 
           [0009]      FIG. 3  is a block diagram of a distributed low voltage bus system of the refrigerator of  FIG. 1  according to an aspect of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0010]    It is contemplated that the teaching of the description set forth below is applicable to all types of appliances, including but not limited to refrigerators but include a standalone refrigeration unit or may be connected to ranges, microwaves, and other appliances. The present invention is therefore not intended to be limited to any particular refrigeration device or configuration of cooling circuit  100  for the temperature controlled medium. 
         [0011]      FIGS. 1 and 2  illustrate a side-by-side refrigerator  100  including a fresh food compartment  102  and freezer compartment  104 . Freezer compartment  104  and fresh food compartment  102  are arranged in a bottom mount configuration where the freezer compartment  104  is below the fresh food compartment  102 . The fresh food compartment is shown with French opening doors  134  and  135 . However, a single door may be used. Door or drawer  132  closes freezer compartment  104 . 
         [0012]    The fresh food compartment  102  and freezer compartment  104  are contained within an outer case  106 . As shown in  FIG. 2 , Mullion  114  separates the fresh food compartment  102  and the freezer compartment  104 . 
         [0013]    Door  132  and doors  134 ,  135  close access openings to freezer and fresh food compartments  104 ,  102 , respectively. Each door  134  and  135  is mounted by a top hinge  136  and a bottom hinge  137  to rotate about its outer vertically oriented edge between an open position, as shown in  FIG. 2 , and a closed position shown in  FIG. 1  closing the associated storage compartment. 
         [0014]    In accordance with known refrigerators, refrigerator  100  also includes a machinery compartment (not shown) that at least partially contains components for executing a known vapor compression cycle for cooling air in the compartments. The components include a compressor, a condenser (not shown), an expansion device (not shown), and an evaporator (not shown) connected in series and charged with a refrigerant. The evaporator is a type of heat exchanger that transfers heat from air passing over the evaporator to a refrigerant flowing through the evaporator, thereby causing the refrigerant to vaporize. The cooled air is used to refrigerate one or more fresh food or freezer compartments via fans (shown schematically in  FIG. 3  as  534 ). Collectively, the vapor compression cycle components in a refrigeration circuit, associated fans, and associated compartments are referred to herein as a sealed system. The construction of the sealed system is well known and therefore not described in detail herein, and the sealed system is operable to force cold air through the refrigerator  100 . 
         [0015]      FIG. 3  illustrates an exemplary low voltage bus system  500  with controller  502  in accordance with one embodiment of the present invention. Controller  502  can be used, for example, in refrigerators, freezers and combinations thereof, including but not limited to refrigerator  100  (shown in  FIGS. 1 and 2 ). It is recognized, however, that controller  502  is easily adaptable to control other types of appliances, including but not limited to dishwashers, washing machines, dryers and ranges in light of the principles set forth below. 
         [0016]    Controller  502  includes a diagnostic port  562  and a human machine interface (HMI) board  564  coupled to a main control board  566  by an interprocessor communications bus  568 . HMI board  564  is coupled to a HMI display device  200 , which may include a touch screen or other input as well as a liquid crystal display for outputting features and parameters to a user. It should be realized that HMI display device may be any user input such as buttons, switches, keyboard or mouse as well as the above mentioned touch screen or any other input means. Additionally, the output feature may be any output means including the above referenced LCD screen as well as, light emitting diode signals, or any other known display means. 
         [0017]    Main control board  566 , human machine interface (HMI) board  564  are coupled to a power supply  632  which receives an AC power from a protection unit  634 . Protection unit  634  may sense and protect the unit from current leakage or arcing using ground fault or arc fault technology. The protection unit may communicate with and/or be controlled by the main control board  566 . The input voltage may be 90-265 Volts AC, 50/60 Hz signal. 
         [0018]    Main control board  566  monitors and manages the DC input and output bus  520  and the AC input and output bus  540  as well as power supply current and voltage, brownout detection, compressor cycle adjustment, analog time and delay inputs where the analog input is coupled to an auxiliary device such as a clock or finger pressure activated switch, analog pressure sensing of the compressor sealed system for diagnostics and power/energy optimization. Further input functions include external communication via power line, infrared detectors or sound detectors, human machine interface display dimming based on ambient light, adjustment of the refrigerator to react to food loading and changing the air flow/pressure accordingly to ensure food load cooling or heating as desired, and altitude adjustment to ensure even food load cooling and enhance pull-down rate of various altitudes by changing fan speed and varying air flow. 
         [0019]    A plurality of digital inputs  522 ,  524 ,  526 ,  528 ,  530 ,  532 ,  534 ,  536  and  538  (collectively  522 - 538 ) are disclosed in  FIG. 3 . Digital devices  522 - 538  correspond to, but are not limited to, a condenser fan speed, an evaporator fan speed, a door detector  198 , dispenser ice chute obstruction detection, light emitting diodes and various thermisters. These devices may function as inputs or outputs to the microprocessor and may draw DC power from the bus  520 . 
         [0020]    Main control board  566  also is coupled to an AC input/output bus  540  for managing various AC peripheral devices  542 - 548 . AC input/output bus  540  may be separately wired (not shown) or sent over the conditioned power supply wires, as shown. AC peripheral devices  542 - 548  may include but are not limited to a crusher solenoid, an auger motor, a water dispenser valve, a compressor control, a defrost heater, the operating speed of a variable speed condenser fan, a fresh food compartment fan, an evaporator fan, and a quick chill system feature pan fan. 
         [0021]    Each of the DC peripheral devices  522 - 538  and AC peripheral device outputs  542 - 548  are assigned a unique address by the main control board  566 . By utilizing information from each of the inputs  522 - 538  the main control board  566  may manipulate the various peripheral devices  542 - 548  or  522 - 538 . Manipulation may include safety shutoff of various features, energy efficient operation, and lighting or other human interface programming and control or other features or controls required by the particular application. 
         [0022]    While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.