Method and apparatus for regulating power to a heating element surrounding a freezer door

Abstract

A freezer has a freezer access door and an ice dispensing door between a freezer enclosure and the ambient through which ice is dispensed. Both doors are closeable against an associated doorframe. A heater is provided in one of the door and doorframe for each of the doors to prevent the doors from freezing to their associated frames, and a switch and controller are provided to control the application of power to each of the heating elements. Heat is applied to the heating elements when a sensor senses that the humidity of the ambient is above a given threshold and terminates power to the heating elements when the sensor senses that the humidity of the ambient is below the given threshold.

1 . A freezer having an enclosure and having a door moveable in a door frame for separating the interior of said freezer enclosure from the ambient, a heating element in one of said door and said door frame for preventing said door from becoming frozen to said frame, said heating element connectable to a power source, the improvement comprising 
 a switch having a open condition and a closed condition,    said switch between said heating element and said power source,    a sensor for sensing the humidity of said ambient, and    means responsive to said sensor for opening said switch when said sensor senses a humidity of said ambient that is below a given threshold and for closing said switch when said sensor senses a humidity that is above said threshold.    
   
   
       2 . A freezer in accordance with  claim 1  wherein said door is an ice dispensing door for dispensing ice outside said enclosure.  
   
   
       3 . A freezer in accordance with  claim 1  wherein said door is an access door to said freezer.  
   
   
       4 . The method of controlling the energy drawn by a freezer having a freezer enclosure and having a door moveable in a doorframe for separating said enclosure from said ambient, said method comprising the steps of 
 providing a heating element in one of said door and said door frame for preventing said door from being frozen to said frame,    providing a power source for applying power to said heating element,    providing a sensor for sensing the humidity of the ambient, and    providing a controller between said power source and said heating element for controlling the power applied from said power source to said heating element in response to said humidity sensor, wherein power is applied to said heating element when said sensor senses a humidity above a given threshold and for terminating power to said heating element when said sensor senses a humidity below said threshold.    
   
   
       5 . A freezer comprising in combination 
 an enclosure having an icemaker and an ice dispenser for dispensing ice outside said freezer enclosure,    a door moveable in a door frame in said enclosure through which ice from said ice dispenser is dispensed from said enclosure,    a heating element in one of said door and said door frame for preventing the freezing of said door to said frame,    a switch for controlling the application of power to said heating element,    a sensor for sensing a humidity of the ambient, and    means responsive to said sensor for connecting power to said heating element when said sensors sense a humidity above a given threshold and for discontinuing said power to said heating element when said sensor senses a humidity below said given threshold.