Refrigeration appliance with pulsed defrost heater

Abstract

A refrigeration appliance is provided having a first compartment to be cooled, at least one evaporator in heat transfer association with the first compartment, a defrost heater associated with the evaporator, a temperature sensor associated with the evaporator, and a control circuit. The control circuit is arranged to selectively energize the defrost heater during a defrost cycle, selectively deenergize the defrost heater during the defrost cycle, generate a timing signal while the defrost heater is deenergized during the defrost cycle, and the control circuit is arranged to receive an input from the temperature sensor, and an accumulation of time from the timing signal. A method of operating such a refrigeration appliance includes operating the evaporator to cool the first compartment, initiating the defrost cycle to defrost the evaporator, repeatedly energizing the defrost heater for a first time period and deenergizing the defrost heater for a second time period during the defrost cycle, and terminating the defrost cycle after said evaporator has reached a predetermined optimum temperature.

Dependencies are inferred from the claim text.