Abstract: A control circuit for a refrigeration system disposed within an outer cabinet having a freezer compartment, a fresh food compartment, a compressor, a condenser fan, an evaporator fan, an evaporator and a freezer thermostat disposed within the freezer compartment to sense temperature therein. Additionally, a fresh food thermostat is disposed within the fresh food compartment to sense temperature therein. A freezer thermostat switch is switched between an open state and a closed state in response to temperature signals generated from the freezer thermostat. A fresh food thermostat switch is switched between an open state and a closed state in response to temperature signals generated from the fresh food thermostat. An energy saver switch is disposed between the fresh food thermostat switch and a power source, which energy saver switch is switched between an open state and a closed state.

Abstract: A refrigeration system includes a phase separator disposed in flow communication with a pulse width modulated solenoid valve. A thermistor is disposed in the phase separator and is submerged in either refrigerant liquid or refrigerant vapor during operation, with the electrical resistance thereof correspondingly changing. In an exemplary embodiment, a second thermistor is used in conjunction with the first thermistor and is disposed in the vapor inside the phase separator to provide a reference. By comparing voltage developed across the two thermistors during operation it may be determined whether one or both of the thermistors are submersed in the vapor. The duty cycle of the valve may therefore be increased when one of the thermistors is submerged in the liquid, and decreased when both thermistors are submersed in the vapor.