초록 ▼

An adaptive demand defrost control system controls the length of an interval between defrost operations in accordance with the number and duration of compartment door-openings, the duration of a previous defrost operation as corrected by the temperature of the evaporator prior to defrost, and the le

An adaptive demand defrost control system controls the length of an interval between defrost operations in accordance with the number and duration of compartment door-openings, the duration of a previous defrost operation as corrected by the temperature of the evaporator prior to defrost, and the length of time the compressor has been energized. A count is stored which is varied according to a decrementing schedule, with the decrementing schedule in turn being based upon a comparison of the corrected defrost duration with either a desired defrost duration or a range of desired defrost durations. A defrost operation is initiated when the count reaches a predetermined value. An alternative embodiment of the invention develops an indication of the ambient humidity and controls humidity-dependent apparatus in accordance with the indication.

대표청구항 ▼

A method of initiating a defrost operation in a refrigerator at the end of a defrost interval, the refrigerator including a refrigerated compartment, an evaporator for cooling the compartment and defrosting means for removing frost from the evaporator during a defrost operation including means respo

A method of initiating a defrost operation in a refrigerator at the end of a defrost interval, the refrigerator including a refrigerated compartment, an evaporator for cooling the compartment and defrosting means for removing frost from the evaporator during a defrost operation including means responsive to the temperature of the evaporator for terminating the defrost operation, the method comprising the steps of: (a) developing a measure of the temperature of the evaporator during a defrost interval; (b) initiating a defrost operation; (c) measuring the duration of said defrost operation; (d) correcting the measured duration of said defrost operation by an amount determined by said measured evaporator temperature to derive a corrected defrost duration; and (e) initiating a subsequent defrost operation at the end of a subsequent defrost interval that is determined in accordance with the corrected defrost duration. A method of defrosting a refrigeration apparatus at the end of a variable interval, the refrigeration apparatus having defrosting means, a cabinet defining a refrigerated space, and a door for providing access to said space, the method comprising the steps of: (a) storing a signal having a first predetermined value; (b) sensing when the door is open; (c) changing the stored signal at a varying rate which decreases with time from an initial rate during a first door-open interval until a certain rate is reached; (d) changing said stored signal at a fixed rate less than the certain rate for door-open times in excess of the first door-open interval; and (e) initiating a defrost operation when the stored signal has been changed to a second predetermined value.