Controller of refrigerator

A controller of a refrigerator comprising a refrigerant passage by connecting a compressor, a condenser, a refrigerator reducing member, a refrigerating evaporator corresponding to a refrigerator compartment, a freezer reducing member and a freezing evaporator corresponding to a freezer compartment;

• said refrigerator being capable of realizing an alternate cooling operation of alternately conducting a refrigerating mode of flowing refrigerant to said refrigerating evaporator and to said freezing evaporator via said refrigerator reducing member and a freezing mode of flowing said the refrigerant only to said freezing evaporator via said freezer reducing member by switching said refrigerant passage by a valve member and comprising defrosting heaters provided for said freezing evaporator and said refrigerating evaporator, respectively, so as to be able to conduct a defrosting operation, respectively;
• said refrigerator further comprising:
• a refrigerator fan for blowing air cooled by said refrigerating evaporator to said refrigerator compartment;
• a freezer fan for blowing air cooled by said freezing evaporator to said freezer compartment;
• a refrigerator compartment sensor for detecting temperature of said freezer compartment;
• and
• a control means for conducting a pre-cooling operation for a preset pre-cooling operation time and for conducting the defrosting operation thereafter;
• said control means setting temperature for ending the freezing mode during the pre-cooling operation at pre-cooling freezing mode ending temperature which is lower than normal freezing mode ending temperature by predetermined temperature and conducting the alternate cooling operation until said pre-cooling operation ends based on the pre-cooling freezing mode ending temperature.