CONTROLLING DEFROST IN A REFRIGERATED COMPARTMENT

摘要

An electromechanical defrost control system for a refrigerator which uses the compressor cycling thermostat to incrementally advance a ratchet each compressor cycle. The ratchet drives a cam which closes a defrost heater selector switch when a predetermined accumulated number of compressor cycles have occurred. Upon the compartment being heated the thermostat incrementally advances the cam which returns the selector switch to the compressor operating position and de-energizes the defrost heater.