Abstract: A refrigeration system employing a mechanical thermal expansion valve with a self-heated thermistor sensing saturation temperature at a high pressure inlet and a second thermistor sensing saturation temperature at the evaporator outlet. A microprocessor based controller compares the sensed temperature with stored limits and provides output signals to a relay for cycling the condenser fan responsive to high side pressure and the compressor clutch responsive to the low pressure side temperature. For low pressure drop evaporators, the second thermistor may be disposed at the evaporator inlet.

Abstract: A refrigerating apparatus has a refrigerating cycle including an electromotive compressor whose operational speed is variable in accordance with a drive frequency, and a control unit for operating the compressor at a frequency correspondent to a load so as to control the operation of the refrigerating cycle. Control of the operational frequency of the compressor by the control unit is effected on the basis of target super heat amounts of a discharged gas which is predetermined over an operational frequency range of the compressor. The target super heat amounts are set such that within a lower region of the operational frequency range, each target amount is larger than a super heat amount at which the maximum refrigeration capability is obtained at each operational frequency, so as to suppress a suction pressure of the compressor within an allowable limit for the compressor.

Abstract: An air conditioning control system for an automotive vehicle, comprises a compressor controllable in capacity in response to an external control signal, an evaporator connected to the compressor, a sensor for sensing a temperature of the evaporator, an arithmetic control section for calculating a value of the control signal based upon an output from the sensor, and an output section for supplying the control signal having a value calculated by the arithmetic control section to the compressor. The arithmetic control section carries out first mode control in which it calculates the value of the control signal so that the temperature of the evaporator is held at a predetermined value.

Abstract: An automatic air conditioning system for automotive vehicles with a variable displacement compressor comprises a sensor for detecting an intake air temperature of air flowing through the evaporator placed just behind the evaporator, a control valve for the compressor essentially changing the discharge of said compressor on the basis of the difference between the intake air temperature and its target value, and a CPU for changing the target value of the intake air temperature. When the CPU does not receive a signal indicative of a requirement for quick-cooling, the target value is set to a freezing start possible temperature defined by an intake air temperature such that the freezing of the evaporator starts, and when the CPU receives the signal indicative of a requirement for quick-cooling, the target value is set to a predetermined temperature lower than the freezing start possible temperature.

Abstract: A closed refrigerating circuit for car air conditioning includes a compressor, a condenser, a refrigerant receiver, an expansion valve, and an evaporator. The expansion valve is provided with a constant pressure controlling mechanism for maintaining a pressure in the evaporator at a constant value. The compressor is provided with a continuously variable displacement mechanism for maintaining a superheating temperature of suction refrigerant at a constant value.

Abstract: In a wobble plate type compressor having a wobble plate that converts a rotational motion of a rotatable drive plate having a variable angle of inclination to a linear reciprocating motion of a piston, a method of controlling the wobble plate type compressor to control a displacement of the compressor by changing an angle of inclination of the wobble plate according to a pressure difference between a pressure in a crankcase chamber acting on one side of the piston and a suction pressure acting on the other side of the piston. A solenoid-operated control valve is disposed in a pressure control passage extending from a discharge chamber to the crankcase chamber. The control valve is opened and closed to control the above-mentioned pressure difference, thus controlling the angle of inclination of the wobble plate. An opening of the control valve is increased during a period in which the displacement of the compressor is to be reduced, according to a displacement rapid reduction command signal.

Abstract: A demisting control system of an air conditioner for automotive vehicles, which comprises an evaporator, and a variable capacity compressor capable of being controlled in capacity from the outside. An actual cooling degree of the evaporator is detected. At least two desired cooling degrees of the evaporator are set. The detected actual cooling degree and each of the set at least two desired cooling degrees are compared with each other. On the basis of the comparison results, a value of the capacity to which the compressor is to be controlled is determined. The at least two desired cooling degrees are selected one by one in predetermined sequence and each selected desired cooling degree is compared with the actual cooling degree as above for a predetermined time period exclusively provided therefor. The compressor is driven so that its capacity is brought to the value of capacity determined as above.

Abstract: An air-conditioning control system for automotive vehicles, comprising a compressor variable in capacity in accordance with a change in suction pressure thereof. A controller is provided which carries out demisting control, on the basis of output signals from various sensors, in such a manner that, when outdoor-air temperature is equal to or lower than a predetermined value and at the same time the air-conditioning control system is in the indoor-air recirculating mode, the suction pressure set by the controller is lowered to a value at which temperature on the outlet side of an evaporator is brought to a value equal to or lower than a predetermined freezing temperature, and when a state in which freezing of the evaporator may occur has continued for a predetermined period of time, the set suction pressure of the compressor is raised until the temperature on the outlet side of the evaporator is brought to a value equal to or higher than a predetermined non-freezing temperature.

Abstract: When the temperature of an internal heat-exchanger decreases below a first value in cooling mode, a normal operation, wherein a variable capacity compressor operates in response to the temperature in a space to be cooled, stops temporarily, and a defrost operation, in which the driving frequency of the compressor periodically decreases by a prescribed value until the temperature of the internal heat-exchanger increases above a second value greater than the first value, begins. When the temperature of the internal heat-exchanger increases above a second value greater than the first value, the compressor operates in response to the temperature in the space. When the compressor stops during the defrost operation, the temperature of the internal heat-exchanger is compared with a third value greater than the second value and the operation of the compressor responding to the temperature in the space is inhibited until the temperature of the internal heat-exchanger increases above the third value.

Abstract: A method for controlling the operation of a variable displacement refrigerant compressor arranged in a car air-conditioner circuit and driven by a car engine via a solenoid clutch is carried out in a manner such that, when either an air-conditioner OFF signal or an ignition OFF signal is received by a control device having a CPU unit therein prior to a start of a long time stoppage of the car, a displacement varying wobble plate element is always moved angularly to a predetermined position to obtain a minimum displacement condition of the compressor so that the compressor is restarted from the minimum displacement condition when the car is restarted after a long time stoppage thereof.

Abstract: A method for controlling the displacement changing mechanism of a variable displacement wobble plate type compressor arranged in a car air-conditioning circuit is carried out in a manner such that, when the operating condition of the compressor is stable and when hunting of a controlled variable of the air-conditioner, i.e., hunting of a temperature at the outlet end of an evaporator of the air-conditioning circuit, occurs, a manipulated variable to be given to the displacement changing mechanism to cause a change in the controlled variable is reduced so that hunting of the controlled variable is suppressed and the controlled variable reaches a desired value.

Abstract: A condenser is connected to an outlet of a compressor. An expansion valve is connected to the condenser. An evaporator is connected between the expansion valve and an inlet of the compressor. A sensor detects a condition of refrigerant at an outlet side of the evaporator. A variation in rate of refrigerant flow into the evaporator is detected. A control device determines a variation in the detected condition of refrigerant which occurs in response to the variation in the rate of refrigerant flow. The control device judges a quantity of refrigerant to be insufficient when the determined variation in the refrigerant condition is equal to or smaller than a reference value.

Abstract: An automobile air conditioner system includes a variable displacement compressor having a wobble plate and a pressure control valve disposed in the compressor for controlling the pressure in a crank chamber. The pressure control valve is operative under the control of predetermined conditions, such as the temperature of an evaporator.

Abstract: A refrigeration control system for cooling a vehicle passenger compartment having a compressor/pump for circulating refrigerant between an evaporator located for cooling the compartment air and a condenser located for ambient heat exchange. An expansion valve controls refrigerant flow from the condenser to the evaporator; and, a first thermistor senses directly the temperature of the refrigerant on the high pressure inlet side of the valve and a second thermistor senses refrigerant flow temperature on the low pressure discharge side of the valve. A microprocessor compares the first thermistor output with predetermined first upper and lower values and effects opening and closing of the compressor clutch switch for high pressure cut-off; and, a fan switch is opened and closed for energization and de-energization of a condenser cooling fan.

Abstract: An air conditioning system for automotive vehicles equipped with a control device capable of controlling to different values a setting temperature above which a compressor should operate or a discharge capacity of same in response to an operating position of the blower set by an airflow rate setting switch. Further, the control device is capable of controlling the setting temperature or the discharge capacity in response also to load conditions of the engine of the vehicle. Furthermore, if the blower is in a high rate operating position, the setting temperature or the discharge capacity is controlled to such a value that enables the compressor to achieve sufficient cooling capacity, regardless of the position of the economy switch.

Abstract: A closed-loop, temperature-controlled cooling system includes a Stirling cycle refrigerator driven by a dc motor, wherein the motor excitation derives from pulse width modulation. Temperature control of the cooling system is provided by a temperature-sensitive bridge circuit which responds to variations in temperature by generating an error voltage which effects a change in the modulator duty cycle. The amount of cooling is directly related to the average voltage applied to the motor, which is a function of the modulator duty cycle and the amplitude of the supply voltage. A compensation circuit is disclosed which responds to variations in the voltage amplitude of an unregulated supply by coupling an error signal to the bridge circuit to thereby affect the modulator duty cycle.

Abstract: An automotive air-conditioning apparatus has an air blower and an air mixing damper for adjusting the ratio of a mixture of cool air and hot air. The temperature of air in the automobile cabin is controlled dependent on the amount of air fed from the air blower and the opening of the air mixing damper. In a demisting mode, the amount of air from the air blower is greater than that in a normal temperature adjusting mode, and the opening of the air mixing damper is controlled dependent on ambient-air conditions.

Abstract: A cryopump and a method of operating the same, with the cryopump being provided with a cryopanel adapted to be cooled with cold heat generated by a cold heat generating device, and remove the ambient gas, and a device for regulating the temperature of said cryopanel in accordance with the ambient conditions. The cryopump is capable of varying its pumping speed by regulating in accordance with the ambient conditions the temperature of the cryopanel which is adapted to be cooled with cold heat and remove the ambient gas.

Abstract: A refrigerator temperature and defrost control according to the present invention includes means for sensing the temperature of a portion of cooling means within the refrigerator, means for determining when a particular frost load has accumulated on the portion of the cooling means, means coupled to the determining means for energizing defrost means for de-icing the portion of the cooling means when the particular frost load has accumulated and means coupled to the sensing means for de-energizing the defrost means when at least a portion of the frost load has been removed and for energizing the cooling means when the temperature of the portion thereof reaches a predetermined temperature during the time the defrost means is de-energized. The temperature and defrost control of the present invention makes multiple use various components thereof to reduce the cost and complexity of the control and to increase the effectiveness thereof.

Abstract: An air conditioner having a heat exchange cycle which includes at least a compressor motor that is driven by an inverting apparatus at a variable speed, an indoor heat exchanger and an outdoor heat exchanger is provided.

Abstract: Apparatus and method for controlling compressor operation in conjunction with sensing the lowest temperature operating evaporator coil, or area serviced thereby, of a commonly-piped cooling system. A thermoelectric sensor voltage output is compared with a set-point voltage by an integrator, the output of which is applied to control the pressure for the system.

Abstract: A refrigeration system for use in an automotive air conditioning system has a vane type variable displacement refrigerant compressor drivingly connectable by an electromagnetic clutch to an automotive engine, a refrigerant evaporator through which air is caused to flow by a blower, and a pressure check valve which prevents the refrigerant pressure in the evaporator from lowering under the predetermined pressure, so that frost or icing is not formed on the evaporator fins. The compressor is provided with one or two unloading ports for releasing the refrigerant being compressed and with a valve member or members associated with the unloading port. The refrigerator temperature and the pressure of the refrigerant in the conduit between a throttling valve and the compressor are detected. A signal is emitted to an electric circuit for actuating the valve member or members so that the unloading port is selectively opened to vary the compressor displacement to provide a multi-stage compressor displacement control.

Abstract: An automotive air conditioner has an air duct in which a refrigerant evaporator of a refrigeration cycle is disposed in fluid-flow communication with a variable capacity refrigerant compressor to be drivingly connected to or disconnected from an automotive engine and provided with compressor displacement varying members. The position of the compressor displacement varying members is electronically controlled such that they are placed in the minimum compressor displacement position each time when the compressor operation is started.

Abstract: A temperature control system for a refrigerator including a roll-bonded evaporator in the fresh food compartment in which is formed a non-refrigerant carrying passageway extending the full width of the evaporator. A temperature control located in the compartment includes a temperature sensitive capillary tube portion extending substantially the full length of the passageway so as to be subjected to the limited environment of the passageway and accordingly responsive to the true temperature of the evaporator.

Abstract: A cold storage and refrigeration system includes a single refrigerator, a plurality of cold storage and refrigeration units having evaporators, respectively, connected to the refrigerator for passage therethrough of a refrigerant when the refrigerator is in operation, a plurality of temperature sensors installed respectively in the cold storage and refrigeration units for detecting first and second levels of temperature respectively therein, and a control unit responsive to signals supplied from the temperature sensors for controlling the refrigerator in order to energize the latter in response to the detection of the first temperature level by one of the temperature sensors when the refrigerator is de-energized, whereby the refrigerant can flow through the evaporators simultaneously. With this arrangement, the refrigerator can remain de-energized for an increased interval of time during operation of the system, and hence consumes a reduced amount of electric power.

Abstract: In an air conditioning system for automotive vehicles, an overheat detecting device is provided for detection of overheating of refrigerant circulated in the air conditioning system. The overheat detecting device is arranged in an outlet pipe connected to the evaporator of the air conditioning system, and accommodated within the evaporator case. The interior of the outlet pipe forms a detecting space for detection of overheating of refrigerant, and the overheat detecting device has a thermo-sensitive means arranged in the detecting space which is interior of the outlet pipe.

Abstract: A control system for controlling an air conditioning system having a variable delivery compressor and an evaporator for cooling and dehumidifying air supplied thereto from a blower. The control system comprises sensor means for sensing the evaporator boiling pressure, determining means for determining whether or not the detected value of evaporator boiling pressure has reached either a predetermined upper limit or a predetermined lower limit, and control means for controlling the capacity of the compressor over its maximum variable range and also the quantity of air supplied from the blower so as to maintain the evaporator boiling pressure at one of the predetermined upper and lower limits which is determined to have been reached by the detected boiling pressure value.

Abstract: A cooling control system comprises a cooling apparatus having a refrigerant compressor, a vapor condenser, an expansion valve, an evaporator and a blower, a first temperature detection device for detecting a room temperature, a second temperature detection device for detecting a temperature of the refrigerant which is introduced into the evaporator, a detection device for detecting a temperature difference between a temperature of the refrigerant discharged from the evaporator and the temperature of the refrigerant introduced into the evaporator, and a control device for controlling operations of the compressor as well as the blower and for controlling an opening of the expansion valve in response to the detected inflowing refrigerant temperature, the detected temperature difference and the detected room temperature.

Abstract: A control device is disclosed for controlling the operation of a variable displacement compressor in an air conditioning or refrigerating system. The compressor includes a variable displacement device for changing the cooling capacity of the compressor and a magnetic clutch which operates the compressor in response to an external drive mechanism. The control device controls the operation of the magnetic clutch in response to a comparison of the temperature of the cool air generated by the evaporator of the air conditioning system and a first predetermined temperature. When the temperature is above the first predetermined temperature, the compressor is operated to lower the temperature. The control device also controls the operation of the variable displacement device in the compressor. The control device operates to increase the cooling capacity of the compressor in response to a comparison of the temperature of the cool air with a second predetermined temperature.

Abstract: A control device is disclosed for controlling the operation of a compressor in an air conditioning or refrigerating system. The compressor includes a variable displacement device which changes the capacity of the compressor and a magnetic clutch which operates the compressor in response to an external drive mechanism. The control device controls the operation of both the variable displacement device and the magnetic clutch in response to the temperature of the cool air generated at the evaporation of the air conditioning or refrigerating system. Two temperature detectors having different thermal response characteristics detect the temperature of the cool air. The difference between the temperatures detected by these sensors is used by the control device to control the operation of the variable displacement device.

Abstract: An automotive air conditioner has an air duct in which a refrigerant evaporator of a refrigeration cycle is disposed in fluid-flow communication with a variable capacity refrigerant compressor to be drivingly connected to or disconnected from an automotive engine and provided with compressor displacement varying members. The position of the compressor displacement varying members is electronically controlled such that they are placed in the minimum compressor displacement position each time when the compressor operation is started.

Abstract: An ambient air assisted cooling system comprising: vapor-compression refrigeration means; air-cooled heat exchanger means; and means responsive to the temperature of the ambient air for advancing the matter to be cooled through said refrigeration means and/or said heat exchanger means. Said means for advancing said matter preferably comprises microprocessor means.

Abstract: An air conditioning system for preventing the fogging of vehicle windows includes a defroster switch which is closed to turn on a compressor when the temperature at or around the surfaces of an evaporator drops down to a predetermined off mode level. When the temperature outside the vehicle passenger compartment drops from a relatively high level to a first predetermined level, the off mode level becomes saturated to a constant (maximum) level. As the outside temperature further drops to reach a predetermined second temperature level, the off mode level is progressively lowered from the maximum level to a lower level. With this control, the compressor is turned on again after being closed by closing of the defroster switch, thereby permitting the vehicle windows to be cleared of the fogging from their inner surfaces.

Abstract: In a transport refrigeration system of the type adapted to provide either heating or cooling, loss of refrigerant is detected by first and second sensors 58 and 60 located upstream and downstream, respectively, of the expansion device 34, and with the downstream sensor 60 also being downstream of the location at which hot gas is injected from line 56 to pass to the refrigerant coil 40 in a heating mode of operation. The arrangement includes means for both determining the mode of system operation, either heating or cooling, and comparing the differential temperatures sensed for determining the departures from ranges of temperatures normally expected with an adequate charge of refrigerant.

Abstract: An averaging temperature responsive apparatus for use in an air conditioning system to measure the average temperature of air passing through a duct has a tube extending transversely across the air duct. The tube has a series of spaced inlet openings on the upstream side and at least one exhaust opening on the downstream side. A temperature responsive element is mounted adjacent to the exhaust opening. Each of the inlet openings is made by cutting the tube and bending a portion of the tube inward so that upon air entering the inlet opening, the air is directed through the tube in a direction toward the exhaust opening.

Abstract: A temperature compensated safety control is employed to shut off the compressor at high compression ratios, caused, for example, by reduced air flow over the condenser or other reasons. This is especially useful on both reverse cycle heat pumps and conventional, non-reversible refrigeration and air conditioning systems to protect the compressor. In a preferred embodiment, the temperature compensation is provided by making the control responsive to outdoor ambient air temperatures.

Abstract: In an assembly of a work-performing machine having variable torque demand driven by an asynchronous motor, a phase-angle control device for varying the operating voltage of the asynchronous motor in accordance with the respectively required torque, the asynchronous motor being operable with substantially optimal efficiency, by means of said phase angle control device, with the operating voltage matched to the respectively required torque.

Abstract: A heat pump device and method of controlling the heat pump device which includes a cold generating fluid circuit, a first heat exchanger associated with the circuit in order to draw calories from a heat containing fluid passing through a cooling circuit, and a second heat exchanger associated with the circuit in order to transmit calories to a fluid passing through a utilization circuit.The method comprises the steps of controlling the flow of heat-carrying fluid through the first heat exchanger in dependence upon the temperature of the fluid of the utilization circuit at the output of the second heat exchanger, and controlling the flow of fluid from the utilization circuit through the second heat exchanger in dependence upon the temperature or pressure of the cold generating fluid at the outlet of the second heat exchanger.

Abstract: A variable capacity multiple compressor refrigeration system having first and second compressors with the first compressor to be always running when the system is operating and the second compressor to be cycled off or to vary the capacity of the system on while the first compressor continues to run. The discharge lines of both compressors are connected together in parallel to the system and a check valve is provided in the discharge line connection between the compressors to prevent discharge pressure from the operating compressor from entering the discharge port of the nonrunning compressor. A by-pass line connects the suction of the system at the inlet of the second compressor to its discharge line between the check valve and its discharge port and a solenoid valve in the by-pass line is arranged to be closed when the second compressor is running and open when it is cycled off.