predetermined thickness on the carbonator 30 a three way valve 56 will always direct a high pressure refrigerant to the evaporator 38 by passing the carbonator 30 when the ice bank detector senses a lack of an adequate ice bank on the carbonator 30 a control system 46 will oscillate the three way valve 56 back and forth sending high pressure refrigerant to the carbonator 39 s cooling coils 62 for an appropriate percentage of the compressor 44 run cycle and send high pressure refrigerant to the evaporator 38 for the remainder of the run cycle in the compressor 44 it should be understood that the mechanical refrigeration system used with the first and second embodiments of fig4 and 5 of fig7 includes evaporator 38 condenser 42 and compressor 44 however valve 56 and coil 62 would not be included in those embodiments referring now to fig8 there is shown a block diagram of the essential control components for the carbonator refrigeration system in each of the embodiments of the present invention in particular it can be seen that a temperature sensor 70 is primarily responsible for detecting the temperature within the interior of the refrigerator the interior temperature of the refrigerator is to.