Abstract: A control system for a refrigeration system having a refrigeration compartment and a quick chill/thaw pan. A main controller board, electrically connected to a temperature adjustment board and a dispenser board through the serial communications bus, controls the temperature of the refrigeration compartment and the quick chill/thaw pan. The control system accepts a plurality of inputs to determine a refrigeration mode and to execute a plurality of software algorithms to control the refrigeration compartment as both a chill pan to rapidly chill food and beverage items without freezing and a thaw pan to timely thaw frozen items at controlled temperature levels.

Abstract: A refrigeration system includes a first refrigeration chamber, a second refrigeration chamber in flow communication with said the first refrigeration chamber, a sealed system for producing desired temperature conditions in the first refrigeration chamber and the second refrigeration chamber, and a controller operatively coupled to the sealed system. The controller is configured to accept a plurality of user-selected inputs including at least a first refrigeration chamber temperature and a second refrigeration chamber temperature, and to execute a plurality of algorithms to selectively control the first refrigeration chamber at a temperature above the second refrigeration chamber and at a temperature below the second chamber. Various control algorithms are provided for maintaining desired temperature conditions in the refrigeration chambers.

Abstract: A control system for a refrigeration system having a refrigeration compartment and a quick chill/thaw pan. A main controller board, electrically connected to a temperature adjustment board and a dispenser board through the serial communications bus, controls the temperature of the refrigeration compartment and the quick chill/thaw pan. The control system accepts a plurality of inputs to determine a refrigeration mode and to execute a plurality of software algorithms to control the refrigeration compartment as both a chill pan to rapidly chill food and beverage items without freezing and a thaw pan to timely thaw frozen items at controlled temperature levels.

Abstract: Microprocessor controlled apparatus is provided for automatically diagnosing faults in a heat pump system. Temperature sensors located at strategic points in the system are read periodically in accordance with a preprogrammed diagnostic routine. Temperature measurements preferably representing comparison of two temperature readings that produce temperature differentials outside pre-established tolerance limits are stored with a fault identification representative of the corresponding fault measurement. A service technician can read the fault data from storage by activation of control means for that purpose whereby the nature of the causative fault or faults can readily be determined.

Abstract: A microprocessor based control for a heat pump system providing at least two setback temperature settings individually selected by the system user to be effective during different time periods of the day, also individually selectable by the user. In the event of conflicting setback temperature settings during an overlap in the selected time periods, the microprocessor is programmed to implement the setback temperature that provides the most energy efficient operation of the system. Additionally, the microprocessor automatically assures that any setback temperature settings are at least a minimum temperature differential away from the normal temperature setting in the more energy efficient direction. This override provision is effective whether the invalid setback temperature settings are initially inserted by the user or are the result of a subsequent change in the normal temperature setting.

Abstract: A method of controlling energy usage of a multi-state heat pump system in which the system includes a preprogrammed microprocessor-based controller which places and maintains the system in the most energy efficient mode of operation consistent with achieving a desired room temperature level within a reasonable period of time. The controller responds to actual room temperature and a user-inserted temperature setting to place the heat pump system into an operating state indicated by a predetermined set of operating state criteria which establishes the required operating state and the timing of state changes. Changing to higher (less energy efficient) operating states is enabled only when periodic checks of the rate of change of room temperature indicate the desired temperature will not be achieved in a selected time period.

Abstract: A microprocessor based heat pump control apparatus having a user-operated system console and a system function controller is provided in which normal operating target temperature settings are automatically converted to an expanded operating temperature range (standby operating mode), having preset upper and lower target temperature settings, in response to predetermined operating conditions within the system. The system function controller is preprogrammed to respond to a predetermined number of invalid data signal communications emanating from the user-operated console to switch into the standby operating mode. Provision is made for the user to insert a standby mode instruction at the user-operated console. Provision is also made for the system controller to enter standby during a power-up sequence when invalid user-inserted volatile data is sensed from storage means used to retain the volatile data during the power-off time period.

Abstract: A heat pump having successive defrosting operations initiated, controlled and timed by a microprocessor-based controller. The time intervals between defrost cycles are periodically varied as needed, dependent on outdoor temperature and certain operating conditions of the heat pump system. Initially the microprocessor is programmed to select and establish a minimum outdoor temperature-related defrost lockout time interval which may then be automatically extended during the lockout period by amounts of time during which, simultaneously, the outdoor coil is above a predetermined coil temperature level and the heat pump compressor is not running. The minimum defrost lockout interval is periodically revised and established, within certain limits, at a value which is dependent on outdoor temperature. An optional feature allows different time vs. temperature lockout time interval functions to be established for different geographical areas having marked differences in average cold weather climatic conditions.

Abstract: An electronic circuit for starting and operating gaseous discharge lamps. A DC input is connected to a time-ratio control (TRC) circuit which includes a regulating transistor, a sensing resistor and a coasting inductor connected in series. A flyback diode is connected to the inductor for providing a discharge path for the inductor. The TRC circuit serves to ballast the gaseous discharge lamp. An inverter is connected to the TRC circuit for driving the lamp with square waves. A starting circuit is provided and is connected to one of the lamp electrodes for starting the lamp. A transient protection circuit is provided for the inverter to shunt transients back to the input. A TRC drive and control circuit is connected to the TRC regulating transistor and sensing resistor for controlling the regulating transistor.

Abstract: A ballast especially useful in forming symmetrical half cycles of lamp current during dim light level operation, and thus in overcomming a type of lamp flicker. The light level of the lamp is controlled by an intensity selector circuit which controls an auxiliary circuit that, in turn, controls the ballast circuit. The intensity selector circuit comprises an oscillator which produces timing pulses at a frequency controlled by a potentiometer. The oscillator operates a control switch in the auxiliary circuit and the control switch supplies gate current for a power switch. The power switch controls the ballast circuit which turns on the lamp during a portion of each current half cycle; the light level being determined by the length of the conduction portion of that half cycle. The ballast circuit comprises primary, secondary, and heating windings mounted on a common core. The primary winding is connected to ground through a resistor.