Abstract: An system for controlling the operation of the circulating fan of a closed central air conditioning(CAC) system is disclosed. The system periodically activates and deactivates only the circulating fan after a preselected delay time from the normal running of the cooling and heating modes of the CAC system. The preselected delay time is adjustable based on non thermostat parameters and include parameters such as room volume size to be ventilated and the number of occupants in the room. The control can periodically distribute and mix ventilation air or spot-conditioned (humidified, de-humidified, or cleaned) air while the CAC system is not running in the heating, cooling or constant fan modes. The cooling and heating modes of the CAC system operate independently of the fan recycling control.

Abstract: A method of controlling the temperature of air inside two compartments of a refrigerator or similar appliance utilizing a single temperature sensor and the known air temperature external of the appliance. Based on knowledge of the temperature relationship between both compartments, the appliance performance is optimized based on outside temperatures. As a result of this process, the compartment without a sensor functions with increased temperature control accuracy.

Abstract: A minimum off-time device according to the present invention that delays the restart of a compressor motor of a refrigeration system after power provided to the motor has been interrupted. The minimum off-time device is a standalone unit that is located outside the refrigeration system. The device is retrofitted to the refrigeration system by simply plugging the power line of the system into the device, which is then plugged into an AC wall receptacle, or alternatively, the device can be connected between the power line of the refrigeration system and an electrical circuit breaker panel. The minimum off-time device normally allows power from the AC power source to reach the refrigeration system. However, when a power interruption occurs at the AC power source, and subsequently, power is reapplied, the minimum off-time delay device immediately disconnects the refrigeration system from the AC power source and begins a timing sequence.

Abstract: A purge supplement includes a vessel that attaches to a gas discharge line of a purge system. Adsorbent material is disposed within the vessel. In a Vent Mode the purge system vents into the vessel and the vessel vents to the atmosphere, whereby the purge system effectively vents through the vessel and the adsorbent material in the vessel adsorbs refrigerant. The purge supplement senses, by employing a weight scale or a refrigerant detection monitor, when the adsorbent material has adsorbed a certain amount of refrigerant, and at that time operation of the purge supplement switches from the Vent Mode to a Recycle Mode. When the transition is made to the Recycle Mode the vessel is isolated from the purge system and, after a slight delay, the atmosphere. After the slight time delay, the vessel is placed in fluid communication with an evaporator of a refrigeration system that the purge supplement is associated with. Refrigerant is drawn out of the adsorbent material and into the evaporator.

Abstract: A pattern classification system includes a plurality of classification sections. Each of the classification sections includes a device for storing information of N coefficients W representing a reference pattern, a device for calculating an evaluation value V on the basis of N input signals S and the N coefficients W, the N input signals representing an input pattern, the evaluation value V representing a relation between the input pattern and the reference pattern, a device for storing information of a fixed threshold value R, and a device for comparing the evaluation value V and the threshold value R and for outputting an estimation signal depending on a result of the comparing, the estimation signal including a category signal P which represents a category. A selection section is operative for selecting one of categories in response to the category signals outputted from the classification sections and for outputting a signal Px representing the selected one of the categories.

Abstract: In general, clean cold water can be made available in a household by means of either an expensive refrigerator with a cold water dispenser or a separate cooler and bulky, replaceable water bottles. A simple solution to the problem involves a carbon filter and cooling reservoir combination for mounting in a refrigerator, a pipe system containing a faucet for dispensing cold water and returning water to the filter, and a pump/timer combination for periodically recycling the water in the pipe system through the filter, whereby cold water is always virtually instantaneously available at the faucet.

Abstract: An air-conditioned booth for accommodating a small number of people. The air-conditioned booth includes a transparent wall structure extending from a base to a top and enclosing an interior space. The booth includes a duct system and connected air conditioner for cooling air and directing the cooled air into the interior space of the booth. A damper system is operatively connected with the duct system and is positionable to place the booth in a non-cooling mode and a cooling mode. Air cooled by the air conditioner is directed to the ambient air surrounding the booth by the damper system when the booth is in the non-cooling mode and air cooled by the air conditioner is directed into the interior space of the booth when the booth is in the cooling mode. A vending unit is operatively connected to the damper system and controls the damper system to place the booth from the non-cooling mode to the cooling mode in response to the input of currency into the vending unit.

Abstract: In order to perform a heating operation with the correct quantity of coolant at all times by retaining an approximately fixed quantity of coolant in a main condenser during the initial stage of a heating operation in an air conditioning system, a first valve is opened and, at the same time, a second valve is closed before executing the heating operation to run the cooling/heating cycle as a cooling cycle for a specific length of time. Then, after opening a bypass passage by opening the second valve, the first valve is closed to close off the passage leading to the main condenser to start the heating cycle. As a result, a fixed quantity of coolant can always be retained within the main condenser, realizing the operation of a heating cycle with a correct coolant quantity.

Abstract: An air conditioner for a vehicle having a compressor, an outer heat exchanger, a heat-radiating inner heat exchanger an expansion valve, a heat-absorbing inner heat exchanger which are connected therebetween. A connecting condition of these elements is changed into one of a cooling, a first heating and a second heating, by controlling a refrigerant passage switching device. During the cooling, refrigerant in the air conditioner is circulated in the order of at least the outer heat exchanger, the expansion valve, the heat-absorbing inner heat exchanger and the compressor. During the first heating the refrigerant is circulated in the order of the heat-radiating inner heat exchanger, the expansion valve, the heat-absorbing inner heat exchanger and the compressor while bypassing the outer heat exchanger. During the second heating, the refrigerant is circulated in the order of the heat-radiating inner heat exchanger, the expansion valve, at least the outer heat exchanger and the compressor.

Abstract: A self-regulating swimming pool heater unit to be utilized with single or dual pump pool filtration systems, the unit including a main unit housing wherein there is contained a refrigeration unit structured and disposed to emit heat, as a byproduct of its cooling cycle, so as to heat filtered pool water passing through an internal, coiled flow through path within the refrigeration unit. The heater unit further including a plurality of internally contained single pole, double throw switches, a first, second, third, fourth, and fifth of those switches being connected in series with one another such that only when all of those switches are positioned in their normally closed position, will the refrigeration unit be able to operate. Each of those first, second, third, fourth, and fifth switches being connected to a regulating device which will cause switches to move to an open position and will cause a particular indicator light to turn on.

Abstract: A compressor is prevented from the problem of seizure at start-up even when return of lubricant to the compressor is delayed. In such a refrigerant cycle, a bypass passage bypasses an expansion member and an evaporator. The bypass passage opens for a predetermined time when the compressor starts. The predetermined time is dependent upon external temperature, the compressor speed, compressor capacity, etc.

Abstract: A refrigeration appliance is provided having at least two refrigeration compartments, each compartment having its own access door. The appliance includes a single evaporator located in a plenum which is selectively in communication with each of the compartments, a single compressor, preferably run by a variable speed motor, and a refrigerant circuit including a series of conduits for providing a flow of refrigerant to the evaporator and compressor. A control determines which of the compartments is demanding cooling and operates the refrigeration device until the detected demand for cooling has been satisfied for the particular compartment. Prior to terminating the operation of the refrigeration device, the control determines if the second compartment is demanding cooling or was within a predetermined temperature range prior to demanding cooling. If either condition exists, the refrigeration device is switched to the second compartment until the demand for cooling therein has been satisfied.

Abstract: A fuel-saving air conditioner compressor timer is adapted for simple connection to motor vehicle air conditioner systems of the type that are manually controlled and not of the expensive climate control type. An adjustable timer may be set by the driver by means of one or more front panel controls to repeatedly cycle the vehicle's air conditioner compressor on and off in order to take advantage of the thermal time constant of the air conditioner duct system, which results in the continuing flow of cool air therefrom for a period of time after the compresor is cycled off. The on and off cycling of the compressor is adjusted by the driver so that the compressor will cycle on when the temperature of the air flowing from the duct system rises to an uncomfortable level. An optional overriding temperature control, such as a thermostat, may be provided to prevent the compressor timer from engaging the compressor until the temperature inside the vehicle reaches a predetermined level.

Abstract: An air conditioning system suitable for use in an electric vehicle. In the air conditioning system, a refrigerant gas circulatory system of the heat pump type for selectively effecting cooling and heating is disposed inside the electric vehicle and comprises lines which interconnect three heat exchangers, a directional control valve, a compressor and an expansion valve to one another. A control device is provided so as to activate and inactivate the heat exchanger, the directional control valve and the compressor. Before the expected running of the vehicle, at least a portion of the refrigerant gas circulatory system can be operated by the control device using a drive source different from the drive source used for running the vehicle. Accordingly, a comfortable room environment can be established for the expected time on riding by activating the air conditioning system in an unmanned state.

Abstract: A method of operating a refrigeration unit to improve the uniformity of temperature distribution in a conditioned space, with the refrigeration unit including a refrigerant compressor and an evaporator fan driven at a selectable one of high and low operating speeds by a prime mover arrangement. The method includes the step of periodically operating the compressor and evaporator fan at the higher of the two operating speeds, notwithstanding a set point temperature control algorithm calling for operation of the compressor at the lower of the two speeds. When the refrigeration unit is operating in a continuous mode, the value of a constant entered into an operating program by the user determines the minimum number of minutes of each hour the prime mover should be forced to operate in the higher speed mode.

Abstract: The noise emission from the centrifuge refrigeration system, and in particular, from the condenser fan therein, are minimized by monitoring the time duration during which the refrigeration compressor is asserted and, in accordance with the time duration of compressor assertion, controlling the speed of rotation of the condenser fan.

Abstract: An adaptor is designed to mount a duty cycling control switch for a furnace or air conditioning system which has flexible duct work. The adaptor includes two opposite cylindrical sections with a central section which includes an arcuate portion and a planar rectangular portion. The planar rectangular portion is tangential to the surfaces of the first and second cylindrical sections. The duty cycling control switch is mounted to this planar portion. Thus, air passing through the duct work will pass through this adaptor altering the temperature of the rectangular plate, thus, altering the temperature of the duty cycling switch causing it to activate.

Abstract: The present invention relates to a plural temperature adjustment apparatus for a refrigerator whereby adequate cooling grades are automatically changed based on the temperature changes inside a refrigerator and driving time, and more particularly to a plural temperature adjustment apparatus for a refrigerator whereby prolonged of life time of a compressor, reduction of electric power consumption by way of the control of frequent intermittency of a compressor and the effect of temperature adjustment by timer operation even during blackout can be achieved by adequate control of the present temperatures in a refrigerator detected by a temperature detecting part and appropriate control of compressor drivings based on door open/close status detected at a door open/close detecting part and driving time by a timer when temperatures and driving time according to respective cooling grades randomly set up by the user thru the operation part are inputted into a micro computer.

Abstract: An air conditioning system (10) for an aircraft, the air conditioning system (10) having a separator (14) located between the high pressure side of a compressor (12) and a condenser (18). A timer (34) activated normally open solenoid (32) is located on a separator drain line 28 to periodically dump the lubricant accumulated in the separator (14) back into the compressor (12).

Abstract: A refrigerant recovery and purification system that includes a refrigerant compressor having an inlet for connection to refrigeration equipment under service from which refrigerant is to be recovered. The outlet of the compressor is connected through a condenser to a refrigerant storage vessel or container, with the condenser at least partially liquifying refrigerant prior to passage to the storage container. A liquid refrigerant pump is connected for selectively circulating refrigerant in liquid phase in a closed path from the storage container through a filter for removing contaminants from the refrigerant, and then through the condenser back to the storage container. Refrigerant circulated by the liquid pump in the closed path is thus simultaneously purified by passage through the filter and cooled by passage through the condenser.

Abstract: A control system for use in an air conditioner including a room heat-exchanger and an outside heat-exchanger. For controlling the room temperature, the control system sets a plurality of cooling start temperatures and a plurality of heating start temperatures and compares the room temperature, sensed by a temperature sensor, with the plurality of cooling start temperature and the plurality of heating start temperatures so as to control the outside heat-exchanger in accordance with the comparison results. The plurality of cooling or heating start temperatures includes a first cooling or heating start temperature and a second cooling or heating start temperature lower or higher than the first cooling start temperature. The control system first performs the temperature control on the basis of the first cooling or heating start temperature and then controls it on the basis of the second cooling or heating start temperature under predetermined conditions.

Abstract: A method of logging the operating time of a plurality of predetermined timeable functions of a transport refrigeration unit which includes the step of providing a plurality of hourmeters, at least certain of which are programmable. One of the plurality of timetable functions is selected for each programmable h ourmeter. Each hourmeter includes a first memory, with the operating time of the associated selected timeable function being stored in the first memory. The times stored in the first memories of the hourmeters are individually transferred to a second memory which is common to all of the hourmeters in response to a predetermined event. In a preferred embodiment, the second memory has a plurality of memory banks, one of which is an active storage location for all hourmeters, until the occurrence of a predetermined event, at which time another of the memory banks becomes the active storage location for all hourmeters.

Abstract: An improved vacuum tumble mixer (10) is provided, the mixer having a horizontal drum (11) with a cylindrical mid-section (12), frusto-conical or dished entry and discharge ends (13, 14), and entry and discharge openings (16, 17) axially into the ends, the drum (11) being rotatable in one direction to tumble products therein and rotatable in the other direction to discharge the contents from the dischage opening. A plurality of primary vanes (26) are secured helically to the interior of the mid-section (12) of the drum, the primary vanes having radial tumbling surfaces (27) to tumble the product and to move the product gently towards the entry end of the drum, the vanes (26) having opposed channel-shaped discharge surfaces (28) which progressively increase in height to convey the products in the drum to discharge chutes (31) that extend helically along the discharge end (14) of the drum to the discharge opening (17). A chilling system (50) can be provided with one or more CO.sub.

Abstract: An electronic evaporative cooler controller includes a clock into which desired on and off times may be programmed. A pre-wet feature provides for engagement of the water pump for a period of time following turn on of the evaporative cooler to permit the cooler pads to become wet before the blower fan is engaged. A plurality of diagnostic visual indicators are provided to allow the user to quickly recognize faults that may occur in various components of the controller.

Abstract: A drive control apparatus for controlling the operation of an air conditioner comprises a 24-hour air-conditioning mode, a selector for selecting one of drive and release positions of the 24-hour air-conditioning mode, a load-responsive air-conditioning mode under which the air conditioner is operated in dependence on a load in a space to be air-conditioned, a drive control for effecting one of drive and stop controls of the load-responsive air-conditioning mode, and a preferential output unit for outputting a signal from the drive control in preference to an output signal from the selector. An output from the preferential output unit may be used to drive the operating frequency of the compressor at a predetermined number of revolution, to drive an indoor fan either continuously or intermittently at a predetermined number of revolution, and/or to deflect a vertical deflector blade to a predetermined position.

Abstract: Body cooling apparatus for removing body or external heat in an environment where sufficient cooling by perspiration is not available. The apparatus includes a compressor and a condenser which feeds liquid coolant to a flexible tube network which is held adjacent the body to be cooled. The cooling takes place by the boiling of the liquid within the flexible tube network. The flow of liquid into the network is controlled depending upon the amount of cooling needed.

Abstract: A control system for regulating electrical power input to the refrigeration mechanism or defrost mechanism in an atmospheric cooling apparatus, including domestic refrigeration appliances, is provided which employs at least one piezoceramic relay device. The electrical power is applied with the piezoceramic relay device responsive to control signals and with the control circuitry being directly and ohmically connected to the power source. In one embodiment, the control means employs individual piezoceramic relay devices for power regulation to the respective mechanisms while in a different embodiment a single piezoceramic relay device regulates power input between the refrigeration mechanism and the defrost mechanism. A method of operating the controlled apparatus in such manner and a refrigeration apparatus having such control means are also disclosed.

Abstract: An air-conditioning control system for use in an automotive vehicle comprises a variable capacity compressor having capacity thereof being variable by an external control signal, at least one first cooling unit for cooling a vehicle compartment, and a second cooling unit for cooling a refrigerator. A first valve is arranged between the compressor and the first cooling unit for connecting them to cause same to form a cooling circuit when the first valve is open. A second valve is arranged between the compressor and the second cooling unit for connecting them to cause same to form a refrigerating circuit when the second valve is open. A valve control unit controls opening and closing of the first and second valves.

Abstract: An air-conditioner comprises a refrigerating circuit having a compressor, a condenser, an expansion device and an evaporator which are connected by suitable refrigerant conduits. An electric current path for making a current flow through the compressor includes an AC power source, to which a current transformer is coupled, and an output of the current transformer is converted into a DC voltage which is then given as a (+) input of a comparator. A reference voltage is given to a (-) input of the comparator. When the DC voltage exceeds the reference voltage of the comparator, the high level is outputted from the comparator. When the high-level output from the comparator persists for three seconds, the compressor is stopped forcedly and a three-minute timer is turned on. After a lapse of three minutes, the flow of the current through the current path of the compressor is resumed. Thereby, a lightly locked state is removed.

Abstract: Disclosed is an operation control system for a refrigerator which can prevent extreme change of the internal temperature by an extra method when abnormality occurs in its cooling state. This system judges whether the temperature change is abnormal or not, stops an operation control method based on temperature when the change is abnormal, and controls the operation of the refrigerator by another operation control method based on time in which the stop and the restart are repeated at predetermined intervals respectively.

Abstract: A control apparatus for a multi-air-conditioner system provided with a freezing cycle wherein refrigerant is supplied from a common outdoor unit to a plurality of indoor units via respective control valves. In order for a compressor to recover refrigerant and oil contained therein remaining in an indoor unit under interception, the control valve of the indoor unit under interception is opened cyclically to a degree of opening corresponding to the rated capacity of the indoor unit for the predetermined time while circulating the refrigerant cyclically for a predetermined time to the indoor unit.

Abstract: A control device for a freezer in which a compressor whose operation has been stopped due to low lubricating oil pressure may be automatically restarted. This control device eliminates manual restarting of the compressor repeatedly until it becomes fully operational and facilitates discovery of the true malfunctioning of lubrication mechanisms for bearings in freezer compressors, by prohibiting automatic restarting once the compressor has been operating at normal oil pressure for a preset amount of time.

Abstract: An air baffle for a refrigeration apparatus is provided with means for preventing freeze up of the baffle. The baffle includes a fixed plate and a movable plate each having corresponding apertures therethrough for permitting the control of air flow to a fresh food compartment. The fixed plate is provided with a heating device molded therein which is operable to maintain the fixed plate above the freezing temperature to prevent moisture from freezing thereon. Additionally, spacer means are provided for maintaining the movable plate in spaced relation with the fixed plate, and for preventing the movable plate from coming into contact with an actuator device. The spacer means add to the prevention of freeze up problems as by minimizing moisture which might bridge and freeze up between the movable plates and the fixed plate, or the movable plate and the actuator device.

Abstract: A method of controlling a refrigeration compressor involves momentarily energizing the compressor after extended off periods. When the temperature of a comfort zone remains below its set point temperature for an extended period, such as at night, periodically energizing the compressor for brief periods improves the confort level of the zone.

Abstract: A cold-accumulation type refrigerator having variable length cycle for cooling by means of the cold-accumulation material. The cycle length is a function of refrigerator load. The refrigerator includes a refrigerating cycle to cool a refrigerator compartment and the cold-accumulation material, a load detecting device, such as a room temperature detecting device, to measure an amount of a load to be cooled, clock counting device to generate a time data, and a control device, such as microcomputer. The control device controls the operation of the refrigerator which operates in a first mode (ordinary cooling operation), a second mode wherein the refrigerator compartments are cooled by means of the cold accumulation material and a third mode wherein the cold accumulation material is cooled. The control device controls the time period for second and third mode operation as a function of load to be cooled.

Abstract: A refrigeration system that maintains the temperature of products continuously within prescribed limits, while using electrical power only during selected time periods of each day, when the cost of that power is relatively low. During that time period, the refrigeration system cools the product to a temperature significantly lower than its normal storage temperature, such that subsequently, during a time period when electrical power is relatively expensive, the compressor and fan of the refrigeration system are disabled and the inherent thermal storage capacity of the product, itself, ensures that the product temperature will not rise above a predetermined maximum temperature.

Abstract: A refrigeration system control for minimizing cycling losses of a refrigeration system having an indoor coil, an indoor coil fan, an outdoor coil, an outdoor coil fan, a refrigerant line between one end of the indoor coil and one end of the outdoor coil, a compressor apparatus and a reversing valve connecting the compressor apparatus between the other end of the indoor coil and the other end of the outdoor coil includes the steps of operating the reversing valve to a state opposite to the one representative of the operating condition of the refrigeration system for a predetermined period of time starting prior to an energization of the compressor apparatus and ending after the energization of the compressor apparatus, restoring the reversing valve to a state needed for the operating condition of the refrigeration system at the end of the period of time while continuing the energization of the compressor apparatus.

Abstract: Method and apparatus of discharging non-condensable gases from the circuit of a compression refrigeration machine, wherein a part of the circuit through which there is no flow is indirectly cooled by a smaller secondary refrigeration machine in order to condense the condensable refrigerant vapor in that part and thus to lower the content of non-condensable gases to be discharged in that part, whereby the value of the suction pressure of the refrigerant circuit of the secondary refrigerating machine is used for automatically starting and stopping the discharge of non-condensable gases.

Abstract: A device is disclosed which causes a fan of a heating and/or air conditioning system to continue to run until the temperature in the duct work of the system reaches a desired temperature, so as to remove all heated and/or cooled air from the system, however, the device is designed so as to not cause the fan to be actuated due to changes in the duct work temperature which are due to changes in outside temperature or causes other than the operation of the system. A sensor which is located in the duct work controls the operation of the fan in response to temperature changes only if the sensor control circuit is first energized by the operation of the system.

Abstract: A refrigeration system control method for minimizing off cycle losses in a heating mode of operation includes the steps of closing a valve in a refrigerant line between an indoor coil and an outdoor coil for a first predetermined period of time starting with a deenergization of a compressor and ending before a reenergization of the compressor to retain the refrigerant in the indoor coil and maintaining an energization of an indoor coil fan for a second predetermined time period after the deenergization of the compressor which second time ends before the first time period.

Abstract: A refrigeration system control method and apparatus for minimizing off cycle losses during a cooling mode of operation of a refrigeration system having an indoor coil, an indoor coil fan, an outdoor coil, an outdoor coil fan, a refrigerant line between one end of the indoor coil and one end of the outdoor coil, a valve in the refrigerant line and a compressor apparatus connecting the other end of the indoor coil to the other end of the outdoor coil includes the steps of sensing the humidity of an indoor space to be cooled by the refrigeration system to determine whether the sensed humidity is below a preset humidity setpoint level or above the preset humidity level, and controlling an energization of an indoor coil fan during a time period starting with an energization of the compressor apparatus and ending after the deenergization of the compressor apparatus and having a fan energization duration during the time period dependent on the sensed humidity.

Abstract: An air conditioning apparatus to which an operating current is supplied through a plug includes a compressor and a detector for detecting one of the temperature level of the plug and the operating current level flowing through the plug. When the detected level of the plug is above a first upper limit during a predetermined time after the start of the compressor, the output level of the compressor is reduced for decreasing one of the temperature level of the plug and the operating current level flowing through the plug below the first upper limit. When the detected level of the plug is above a second upper limit below the first upper limit after the predetermined time, the output level of the compressor is reduced for decreasing one of the temperature level of the plug and the operating current level flowing through the plug below the second upper limit.

Abstract: A control system for controlling operation of a compressor of a vehicular air conditioning system. The control system comprises an electromagnetic clutch which is adapted to disengage so as to cut the drivable connection of the compressor with an engine. The electromagnetic clutch is in an electric circuit including a first switch adapted to close in the overheat condition of a fuel system, and a second switch adapted to close at an abrupt vehicle acceleration. Additionally, a timer is provided in the electric circuit to maintain the disengaged state of the electromagnetic clutch for a predetermined time upon close of both the first and second switches thereby to stop the operation of the compressor, thus improving vehicle acceleration performance under the fuel system overheat condition.

Abstract: A heating system and air conditioning system incorporating a duty cycling control switch are disclosed. The duty cycling control switch for either the furnace or air conditioning system is mounted within the supply side duct of the system, i.e., the hot air duct for a furnace or cold air duct for an air conditioner. The duty cycling control is a bi-metal switch totally enclosed within a case having a metal base whereby the heat from the air in the duct contacts the metal base which is transferred to a bi-metallic element which in turn opens or closes a switch. This makes the switch particularly responsive to gradual changes in the temperature of the output air but prevents the duty cycling switch from responding to rapid fluctuations of air temperature within the duct.

Abstract: A rapid chill refrigerator has a first chill refrigeration system a second maintenance refrigeration. A product temperature probe and an adjustable timer control the chill refrigeration system to turn it off when a pre-selected product interior temperature is reached or after a predetermined time has elasped.

Abstract: A control system for heating and cooling devices is disclosed which increase the total running time for the heating and cooling devices as the ambient temperature sensed deviates from the set-point temperature. Five states of ON-time modulation of 2, 5, 10, 15 and 20 minutes are preferred in response to this deviation. Constant periods of OFF-time of 2 or 5 minutes occur after each period of ON-time. Within a small deviation of the ambient temperature around the set-point temperature no conditioning equipment is operated. Beyond a large deviation, the respective heating or cooling equipment is operated continuously. A manual override is disclosed, and the system is manually switched from a heating to a cooling mode. A fan control line switches on whenever a heating or cooling device is actuated and the control system can be used with a heat pump.

Abstract: A furnace fan control for providing operation of the fan after the termination of the furnace burner in an adaptive manner to provide for longer fan operations after the burner turns OFF, as the burner ON time increases.

Abstract: A method of increasing the efficiency of a cooling system by measuring the temperature differential across the cool air inlet and outlet which occurs during normal operation of the cooling system to reduce the room temperature from its turn-on point to its turn-off point. The temperature differential so determined is then utilized to cycle the cooling system to increase efficiency thereof.

Abstract: A control system having combined closed loop and duty cycle functions uses a differential amplifier for amplifying the difference between a setpoint or reference temperature for a system to be controlled and a detected system temperature, a thermostat having a differential circuit for providing a predetermined hysteresis lag for an output of the amplifier and a duty cycle generating circuit for changing the operating potential of the differential circuit in accordance with a predetermined duty cycle to shift the operating point of the differential circuit.

Abstract: A system of preserving fresh produce in a refrigerator displayed for observation and selection by the public, such as in a grocery store. Moisture is applied to the articles, in the form of an extremely fine mist, made up of particles in the range of about 75-150 micron diameter, suspended in air, and slowly falling. The moisture applied to the produce articles is only film-thick so as to minimize flow-off from the articles. Producing the mist includes selectively, hydraulic pressure means, or air pressure means. The mist is controlled by automatic on-off control means and is produced by misting nozzles centrally positioned above the shelf means for supporting various produce articles within the refrigerator display means.