초록 ▼

A refrigerator includes a compressor, an evaporator fan, a condensor fan and a defrost heater which are controlled by a defrost control system. The control senses the number and duration of freezer and fresh food compartment openings, the duration of the previous defrost operation, and the total acc

A refrigerator includes a compressor, an evaporator fan, a condensor fan and a defrost heater which are controlled by a defrost control system. The control senses the number and duration of freezer and fresh food compartment openings, the duration of the previous defrost operation, and the total accumulated compressor run time since the previous defrosting operation. A stored count is decremented by weighting functions which are adaptably varied in accordance with the number and duration of compartment door openings and the duration of the previous defrosting operation. When the stored count is decremented to zero, the defrosting operation may be initiated, unless inhibited. The defrosting operation is inhibited if the total accumulated compressor run time is less than a predetermined amount. The control is reset to a point just short of a defrosting operation if a power outage occurs.

대표청구항 ▼

In a cooling system having a defrost device and cooled compartment accessible through a door, a defrost control for energizing the defrost device, comprising: door sensing means for detecting an initial open period for said door and a subsequent open period when said door remains open beyond said in

In a cooling system having a defrost device and cooled compartment accessible through a door, a defrost control for energizing the defrost device, comprising: door sensing means for detecting an initial open period for said door and a subsequent open period when said door remains open beyond said initial open period; control means for energizing said defrost device at the end of an interval determined at least partly by the cumulative open period of the door, including: first advance means for advancing toward the end of the interval at a first rate in response to the initial open period to compensate for increased frost occurring during the initial door open period, and second advance means for advancing toward the end of the interval at a second rate less than said first rate in response to the subsequent open period to compensate for lesser frost occurring during the subsequent open period.