Damper door control from adaptive defrost control

Abstract

An adaptive defrost control method and device for controlling a damper door during a defrost cycle is provided. Before entering the defrost cycle, the adaptive defrost control logic determines if the damper door is open. If the damper door is open, the defrost cycle is suspended until the door is closed. If the damper door is closed, the adaptive defrost control logic activates a barrier between the damper door motor and a power supply so that the damper door may not be opened during the defrost cycle. After the defrost cycle is completed, the adaptive defrost control logic removes the barrier between the damper door motor and a power supply. The damper door may then be opened and closed as necessary. Accordingly, warm moist air from the defrost cycle does not enter the fresh food compartment.

1 . An apparatus for preventing warm air generated in a freezer compartment during a defrost cycle from flowing through an opening regulated by a damper door and into a fresh food compartment, comprising: 
 a damper motor adapted to drive the damper door;    a thermostatic switch operatively coupled to the damper motor, the thermostatic switch adapted to actuate the damper motor;    an electronic barrier interposed between the thermostatic switch and a power supply; and    a controller operatively coupled to the electronic barrier, the controller adapted to open the electronic barrier during the defrost cycle thereby prohibiting the damper motor from operating.    
     
     
         2 . The apparatus of  claim 1 , wherein the electronic barrier is a triac.  
     
     
         3 . The apparatus of  claim 1 , wherein the thermostatic switch is disabled when the electronic barrier has been opened by the controller.  
     
     
         4 . The apparatus of  claim 1 , further comprising an additional thermostatic switch interposed between the power supply and the controller, the controller initiating operation of one or more of a compressor motor; a condenser motor, and an evaporator fan upon activation of the additional thermostatic switch.  
     
     
         5 . The apparatus of  claim 4 , wherein the controller is configured to prevent operation of the compressor motor, the condenser motor, and the evaporator fan during the defrost cycle.  
     
     
         6 . The apparatus of  claim 1 , further comprising a defrost heater energized during the defrost cycle.  
     
     
         7 . The apparatus of  claim 1 , wherein the apparatus further comprises one or more redundant switches interposed between the thermostatic switch and the damper motor, the redundant switches configured to prevent the damper door from remaining in an open position during a loss of power.  
     
     
         8 . The apparatus of  claim 1 , wherein the apparatus further comprises a damper door switch, the damper door switch operatively coupled to the controller such that the controller is informed of a position of the damper door.  
     
     
         9 . An apparatus for preventing warm air generated in a freezer compartment during a defrost cycle from flowing through an opening regulated by a damper door and into a fresh food compartment, the apparatus comprising: 
 a damper motor adapted to drive the damper door;    a thermostatic switch operatively coupled to the damper motor, the thermostatic switch adapted to actuate the damper motor to open the damper door;    a switch interposed between the damper motor and a power supply; and    a controller operatively coupled to the switch, the controller programmed to open the switch during the defrost cycle thereby disabling the damper motor to prevent the damper door from opening during the defrost cycle.    
     
     
         10 . The apparatus of  claim 9 , wherein the switch is a triac.  
     
     
         11 . The apparatus of  claim 9 , wherein the thermostatic switch is disabled when the switch has been opened by the controller.  
     
     
         12 . The apparatus of  claim 9 , further comprising an additional thermostatic switch operatively coupled to the controller, the controller configured to initiate operation of a compressor motor; a condenser motor, and an evaporator fan upon actuation of the additional thermostatic switch.  
     
     
         13 . The apparatus of  claim 12 , wherein the controller is configured to prevent operation of the compressor motor, the condenser motor, and the evaporator fan during the defrost cycle.  
     
     
         14 . The apparatus of  claim 9 , further comprising a defrost heater positioned in the freezer compartment.  
     
     
         15 . The apparatus of  claim 9 , further comprising one or more redundant switches interposed between the thermostatic switch and the damper motor, the redundant switches preventing the damper door from remaining in an open position during a loss of power.  
     
     
         16 . The apparatus of  claim 9 , wherein the apparatus further comprises a damper door switch, the damper door switch operatively coupled to the controller such that the controller is informed of a position of the damper door.  
     
     
         17 . A method of preventing warm air from flowing through an opening in a freezer compartment into a fresh food compartment during a defrost cycle, comprising the steps of: 
 disabling operation of a damper door;    performing the defrost cycle; and    enabling operation of the damper door after completion of the step of performing the defrost cycle.    
     
     
         18 . The method of  claim 17 , further comprising the step of sensing a state of the damper door, and wherein the steps of disabling and performing are performed when the step of sensing the state of the damper door indicates that the damper door is closed.  
     
     
         19 . The method of  claim 17 , wherein the step of disabling the operation of the damper door comprises the step of preventing a flow of current to a damper motor.  
     
     
         20 . The method of  claim 17 , wherein the step of disabling the operation of the damper door comprises the step of preventing a flow of current through a thermostatic switch.