Abstract: The present invention concerns improvements in electric defrost heaters used in frozen carbonated beverage machines. The frozen carbonated beverage machine includes freeze cylinders used to produce the frozen beverage. One or more tubes are secured in heat exchange relationship along the exterior of the freeze cylinder. Cartridge type heating elements are releasably insertable into the tubes to provide for defrosting of the beverage in the freeze cylinder.

Abstract: The present invention concerns improvements in the electronic control of frozen carbonated beverage machines and improvements in electric defrost heaters used therein. A control scheme is shown that provides for accurately determining the viscosity of a semi-frozen beverage as a function of the torque of a drive motor used in the harvesting and mixing thereof. The torque is first calculated based upon the current and voltage to the motor and the phase difference there between. The torque is adjusted to compensate for motor efficiency after which the net torque value is converted to a viscosity scale. The viscosity scale has a zero value relating to the net torque experienced by the motor when the beverage is known to be completely liquid. Viscosity is maintained within a narrow range based upon pre-defined three level low, medium and high viscosity sets, and wherein compressor short-cycling is eliminated.