Abstract: The disclosure discloses a method and a device for controlling cylinder switching of a compressor, a unit and an air conditioning system. The method includes: determining whether the compressor needs to perform cylinder switching; if so, adjusting current operating frequency according to a system pressure difference so that both the adjusted operating frequency and the system pressure difference meet a cylinder switching condition of the compressor; and controlling the compressor to perform cylinder switching. At the moment, the system pressure difference and the operation frequency are stable, and would not interfere the compressor's maintaining of the single-cylinder or double-cylinder operation state, which guarantees the energy efficiency of the unit where the compressor is located, and improves the use experience of a user.

Abstract: A control device (1) is configured to reduce the commutation angle error ? of a three-phase (u, v, w) EC motor (2.2) connected via a y-configuration. The three phases (u, v, w) are commutated via a motor control (3) including a rotor position sensor (4) and a control circuit (10). The rotor position sensor (4) senses the relative angular position of the rotor using the neutral-point potential at the neutral point of the y-configuration. The control circuit (10) is configured to impose a desired field weakening current component on the motor control (3) for reducing the commutation angle error ?.

Abstract: An HVAC controller provides control values to or more output ports of the HVAC controller. Operation of the HVAC controller is monitored for one or more irregularities. When one or more irregularities in the operation are identified, a hold mode is entered. The hold mode includes holding the one or more current control values on the one or more output ports of the HVAC controller until the one or more irregularities in the operation of the HVAC controller are corrected or a predetermined hold time expires, whichever occurs first. When the one or more irregularities in the operation of the HVAC controller are not corrected before the predetermined hold time expires, a back off mode is entered. The back off mode includes setting each of one or more control values on one or more output ports of the HVAC controller to a corresponding configurable back off value.

Abstract: A switched-mode power supply has a rectifier device, a switching unit which is arranged downstream of the rectifier device, a transmission device which is arranged downstream of the switching unit and a filter device. In order to reduce the sensitivity of the switched-mode power supply to high-energy interferences, it is proposed that the filter device contains a current-compensated choke coil which is connected to a voltage limiter circuit in such a way that in the case of interference signals applied to the choke coil, a damping of the interference signals takes place by way of the voltage limiter circuit.

Abstract: A refrigerator including an inner case having a storage chamber defined therein; a thermoelectric module configured to cool the storage chamber, wherein the thermoelectric module includes a thermoelectric element and a heat sink; a heat-dissipation fan assembly provided adjacent to the heat sink; a heat-dissipation cover spaced apart from the inner case, wherein the heat-dissipation cover has at least one outer intake hole defined therein and wherein the intake hole faces the heat-dissipation fan assembly; and a gasket configured to block a gap between the heat-dissipation cover and the heat-dissipation fan assembly.

Abstract: A vapor compression system that includes a reheat coil that heats a supply air stream flowing across the reheat coil with a refrigerant. A fan forces an environmental air flow across a condenser to remove energy from the refrigerant. A controller adjusts a speed of the fan to control a flow of the refrigerant through the reheat coil.

Abstract: An air-conditioning control apparatus includes an away detector, a position acquisition unit, a distance acquisition unit, and an instrument control unit. The away detector detects that a user is away from a building. The position acquisition unit acquires position information of a portable terminal carried by the user. The distance acquisition unit uses the position information acquired by the position acquisition unit to acquire distance information indicating how far the portable terminal is from the building when the away detector has detected that the user is away from the building. The instrument control unit controls an air conditioner installed in the building based on the distance information acquired by the distance acquisition unit, and the away time calculated by the time estimation unit, so that the air conditioner consumes less energy.

Abstract: An air-conditioning control apparatus includes an away detector, a position acquisition unit, a distance acquisition unit, an instrument control unit, and a learning storage unit. The away detector detects that a user is away from a building. The position acquisition unit acquires position information of a portable terminal carried by the user. The distance acquisition unit uses the position information acquired by the position acquisition unit to acquire distance information indicating how far the portable terminal is from the building when the away detector has detected that the user is away from the building. The instrument control unit controls an air conditioner installed in the building based on the distance information acquired by the distance acquisition unit so that the air conditioner consumes less energy.

Abstract: An air conditioning device for vehicle includes a first water-refrigerant heat exchanger, a second water-refrigerant heat exchanger, a first bypass passage, and a second bypass passage. The first bypass passage branches at a point of a coolant passage from a cooling portion of a heating component in the vehicle to the second water-refrigerant heat exchanger, and the first bypass passage is capable of being communicated with the coolant passage at an upstream side of the first water-refrigerant heat exchanger. The second bypass passage bran at a point of the coolant passage from a heater core to the first water-refrigerant heat exchanger, and the second bypass passage is capable of being communicated with the coolant passage at a downstream side of the first water-refrigerant heat exchanger. A part of the first bypass passage which includes a downstream end and a part of the second bypass passage which includes an upstream end are shared.

Abstract: A compressor, as well as a lightweight and strong casting for a compressor, are disclosed. The compressor, which may be a reciprocating compressor for use in compressing high-pressure refrigerants such as CO2, includes substantially reduced wall thicknesses (t) compared to prior art castings. The side walls of the compressor can be manufactured to such reduced thicknesses (t) through the use of a bridge spanning across the crankcase. This not only allows the opposing side walls to be manufactured of a thinner material, but the bottom cover removably mounted to the crankcase can be manufactured from a thinner and lighter material as well. Through the use of such a bridge, the resulting compressor is not only able to satisfy current strength requirements, but at significant weight, size and cost savings as well.

Abstract: A control system to selectively control the operation of the compressor of a mini-split air conditioning system including at least one remote evaporator operatively coupled to the compressor to receive refrigerant therethrough, a sensor to monitor the operation of the evaporator and to generate an operating control signal to turn-off the compressor when a predetermined operating condition is sensed at the evaporator and a condensate drain pan to receive or catch condensate from the evaporator, the control system comprising a condensate sensor disposed to sense condensate in the condensate drain pan at a predetermined level and to generate a condensate level signal fed to a battery powered control device including an isolated solid state relay coupled to the sensor by a control coupling device to generate a condensate level control signal fed to the sensor causing the sensor to generate the operating control signal fed to turn off the compressor when condensate within the condensate drain pan reaches the prede

Abstract: In one embodiment, a cryocooler drive circuit for a cryocooler motor is provided that includes: a first switching power converter configured to track a first sinusoidal input voltage signal to provide a first sinusoidal output voltage signal at a first output node; and a second switching power converter configured to track a second sinusoidal input voltage signal to provide a second sinusoidal output voltage signal at a second output node, wherein the second sinusoidal input voltage signal is an inverted version of the first sinusoidal input voltage signal such that the cryocooler motor is driven by an alternating current flowing between the first and second output nodes.

Abstract: An air conditioner for a vehicle, including: a discharge capability control section that controls refrigerant discharge capability of a compressor; an upper limit value determination section that determines an upper limit value of the refrigerant discharge capability; and a gear shift position detection section that determines a gear shift position of a gear shift device of a vehicle, wherein the gear shift device having a forward range for moving the vehicle forward and a range other than the forward range as the gear shift position; when the gear shift position determined by the gear shift position detection section is in a range other than the forward range, the upper limit value determination section decreases the upper limit value compared to when the gear shift position determined by the gear shift position detection section is in the forward range.

Abstract: A method and a system control an operation of a vapor compression system using a set of control inputs. A control value is determined based on an output of the operation of the vapor compression system and a setpoint for the operation of the vapor compression system. The control value is used to select at least a subset of the set of control inputs from a computer-readable medium, wherein the subset of control inputs, along or in combination with a function of the control value, forms the set of control inputs.

Abstract: An air conditioner for a vehicle equipped with a motor for driving the vehicle has a vehicle speed detecting unit, an electric compressor, an evaporator, an electric compressor rotation speed controlling unit, a controlling unit and a refrigerant pressure detecting unit. The controlling unit calculates a first candidate for a rotation speed upper limit value of the electric compressor based on a vehicle speed detected by the vehicle speed detecting unit, calculates a second candidate for the rotation speed upper limit value of the electric compressor based on a refrigerant pressure detected by the refrigerant pressure detecting unit, and decides a minimum value of the first and second candidates for the rotation speed upper limit value of the electric compressor, as the rotation speed upper limit value of the electric compressor.

Abstract: In a thermoacoustic refrigerator, operating temperatures, ambient temperature, and selected user input are utilized to control frequency and/or input power in order to optimize the efficiency of the thermoacoustic refrigerator operation. In a thermoacoustic heat engine, operating temperatures, ambient temperature, and selected user input are utilized to control impedance of a load to optimize the efficiency of the thermoacoustic heat engine operation.

Abstract: In a thermoacoustic refrigerator, operating temperatures, ambient temperature, and selected user input are utilized to control frequency and/or input power in order to optimize the efficiency of the thermoacoustic refrigerator operation. In a thermoacoustic heat engine, operating temperatures, ambient temperature, and selected user input are utilized to control impedance of a load to optimize the efficiency of the thermoacoustic heat engine operation.

Abstract: The present invention relates to a method for controlling a vehicle air-conditioner, which can prevent undershoot of an evaporator by performing a maximum capacity control or controlling an discharge capacity of a compressor through the outputting of an discharge capacity control value of the compressor directly before the stop of the air conditioner, and can improve the pleasant feelings of the passengers by preventing delay of response, which converges into the target temperature of the evaporator due to the delay of the decrease of the temperature of the evaporator.

Abstract: A system for cancelling or attenuating noise in at least two positive displacement compressors proximately located from each other for use with a heating or cooling system. A lead compressor and a lag compressor have a controllable rotational speed and phase of operation. A controller selectably controls the rotational speed and the phase of operation of each of the compressors. The controller controls the rotational speed of the compressors at substantially the same speed for each compressor, with a phase-lock loop and a comparator circuit for each compressor. The controller controls the phase of operation of the compressors through an oscillator so that the lead and lag compressor pressure pulses are spaced between successive outlet pressure pulses to effectively double the combined pulsation frequency for noise attenuation.

Abstract: The invention relates to a method for regulating a coolant circuit (2) of a vehicle air conditioning system (4). According to said method, a target value (SW(VT)) for an evaporator temperature (VT) is predetermined in a base control circuit. Said value is used to determine a control value (U) for controlling the evaporator temperature (VT) by means of an evaporator temperature regulator (16). Said control value is also fed to a ventilator fan controller (26).

Abstract: A noise control method is provided for a cooling system having at least one refrigerant circuit. The refrigerant circuit includes a compressor, a condenser, at least one condenser fan, and an evaporator. Noise control is only performed periodically in response to requirements for reduced operation at predetermined times. The request for reduced noise triggers the commencement of the noise control method. The noise control method involves reducing the operating speed of the compressor, as well as reducing the operating speed of at least one condenser fan, to within a predetermined range of allowable reduced operating speeds. The noise control method temporarily overrides the ability of the cooling system to fully respond to increased cooling or heating demands.

Abstract: A control device for an air-conditioning system of a vehicle comprises an evaporator, a compressor with externally controlled variable displacement, and an expansion valve. The control device comprises a control block that receives a reference temperature indicating a desired temperature of the air downstream of the evaporator, and an effective temperature of the air present downstream of the evaporator. The control device-supplies a control signal for the compressor to bring the effective temperature substantially equal to the reference temperature. An observer module receives the control signal and supplies a temperature disturbance indicating an estimate of the oscillatory effect generated by an expansion valve on the temperature of air downstream of the evaporator when a compressor is driven by the control signal. An adder block removes from the effective temperature the temperature disturbance so as to eliminate the oscillatory effect on the effective temperature downstream of the evaporator.

Abstract: A system is provided to control and operate a compressor to have two or more discrete output capacities in response to an outdoor temperature measurement. During operation of the compressor in an air conditioning or cooling mode, the compressor has a first output capacity in response to the outdoor temperature being greater than a first temperature setpoint and the compressor has a second output capacity in response to the outdoor temperature being less than a second temperature setpoint.

Abstract: A control for a compressor motor is programmed to operate the motor at at least one low capacity and at least one higher capacity. The control is operable to estimate an amount of oil which will have migrated from said compressor shell, at least when the compressor is operating at the lower capacity rate. The motor control moves the compressor motor from the lower capacity to at least one higher capacity once the estimated quantity of oil exceeds a predetermined limit. The capacity may be related to space.

Abstract: The invention relates to a method for regulating the maximum speed of a working machine (12), in particular an air compressor in a vehicle. Said working machine is driven by means of a motor (10), using a hydrodynamic coupling (11), which comprises a working chamber (3) that is partially or fully filled with a working medium for transmitting a torque from a drive side (11.1) equipped with an impeller (1) to a driven side (11.2) equipped with a turbine wheel (2).

Abstract: Devices and methods for moisture removal from conditioned air. A speed control is provided that selectively operates the blower motor of an air conditioning system at a lower speed. The speed control may include a time delay circuit and single pole, double throw relay. The speed control is used to slow the speed of the air cycler during the initial stage of a cooling cycle. This initial stage is typically the first 5–7 minutes of the air conditioning cycle. In a further aspect, a humidistat is operably associated with the system for detection of humidity levels within the air of a home or other structure. The system is programmed to close the motorized outside air damper in the event that humidity levels exceed a predetermined level, thereby limiting further entry of humid outside air into the home.

Abstract: An electric motor 25 for driving a compressor 21 that composes a refrigerating cycle is speed-controlled by an inverter circuit 31. When an inside temperature Tx detected by an inside temperature sensor 35 is not less than a predetermined temperature (for example, 5° C. in the case of a refrigerator and ?18 C in the case of a freezer), a microcomputer 34 suppresses the rotational speed of the electric motor 25 via the inverter circuit 31 to thereby restrict current flowing through the electric motor 25 and a power circuit 40. Accordingly, great current does not flow through the electric motor 25 upon the start of the operation in a refrigerator or a freezer. Further, in this case, the rotational speed of the electric motor 25 is controlled to be increased as the inside temperature Tx becomes lower, whereby the cooling speed of the inside 10 is increased with the current flowing through the electric motor 25 prevented from increasing.

Abstract: In a vehicle air conditioner, a compressor is driven by a vehicle engine when an actual temperature of an evaporator is higher than a basis temperature that is higher than a target temperature by a predetermined temperature, and is driven by an electrical motor when the actual temperature of the evaporator is lower than the basis temperature. The predetermined temperature is set to be higher as the target temperature of the evaporator decreases such that the basis temperature is not higher than a comfortable limit temperature. Accordingly, the compressor can be driven by the electrical motor in a range where the actual temperature can be controlled to be not higher than the comfortable limit temperature. Therefore, fuel consumption efficiency of the engine can be improved, while a minimum of cooling capacity can be ensured.

Abstract: A vapor compression system includes a compressor, a gas cooler, an expansion device, and an evaporator. Refrigerant is circulated through the closed circuit cycle. Preferably, carbon dioxide is used as the refrigerant. Adaptive control is employed to optimize the coefficient of performance of the vapor compression system. As the system changes over time, a model that operates the system is modified. The model is determined by an adaptive control algorithm including variable coefficients. As the model changes, the variables of the adaptive control algorithm change. A control of the gas cooler is then adjusted to regulate the high pressure of the system, and therefore the coefficient of performance. In a first example, Least Mean Squares (LMS) is used to modify the variables of the adaptive control algorithm to optimize the coefficient of performance. In a second example, the coefficient of performance is optimized by a slowly varying periodic excitation method.

Abstract: Disclosed is a property box of a cabinet/wall-hanging type requiring low temperature. The property box of a cabinet/wall-hanging type requiring low temperature according to the present invention provides advantages of being attachable to a wall surface or a corner of living space such as a bedroom of a married couple, a dress room or a bathroom in a newly-built or an existing apartment, an ordinary house or in lodging so as to store and make easily available of cosmetics, pharmaceuticals, films, beverage, beer or wine requiring low temperature whenever necessary. When protection of a privacy is required, unlike the conventional refrigerator shared by others in a shared living space, the property box according to the present invention can be installed at a desired position, thereby achieving the protection of privacy and resolving the problem of narrowing the living space subsequent to installation of the property box.

Abstract: A controlling device of a compressor is provided. A noise filter is arranged at an input of the inverter circuit that converts the commercial frequency to a driving frequency to control a motor driving a compressor mechanism, for suppressing a common mode noise of the commercial power source and the inverter circuit, and is connected to a ground through a metal frame used for receiving a compressor main body. The noise filter comprises coils connected between first capacitors and second capacitors that are connected in series between the AC power lines, and further comprises a clamper connected between nodes of the second capacitors and the metal frame for clamping a voltage and a third capacitor connected to the clamper in parallel. even though the new refrigerant, such as R410A, and the three-phase AC power source are used, the leakage current can be reduced by a simple structure and the increase of the noise terminal voltage can be also suppressed.

Abstract: The present invention aims at providing an air conditioner used in an electric vehicle which can exert a sufficient cooling performance without enlarging the size of a motor for driving a compressor or supplying an excessive amount of driving current to the motor. The air conditioner of the invention is provided with a condenser fan for cooling a condenser and a motor for driving the condenser fan. A driving current Ap of a motor for driving a compressor is detected and compared with respect to reference currents A1 and A2 to select a driving current Vd0 (low voltage), Vd1 (moderate voltage) or Vd2 (high voltage) for controlling the rotation speed of the condenser motor.

Abstract: In an apparatus and a method for controlling a linear compressor, an apparatus for controlling a linear compressor includes a linear compressor adjusting a refrigerating capacity by a stroke voltage according to a stroke reference value, a current detecting unit detecting a current applied to the linear compressor, a work operation unit generating a work operation signal by integrating a current detected from the current detecting unit, a suction/discharge pressure difference storing unit storing a suction/discharge pressure difference according to the work operation signal, a microcomputer outputting a switching control signal according to the work operation signal and displaying the suction/discharge pressure difference according to the work operation signal, and an electric circuit unit controlling the linear compressor in accordance with the switching control signal.

Abstract: An air-conditioning apparatus having a refrigerant circuit including a condenser, a pressure reducing device, an evaporator, and a variable displacement compressor. The air-conditioning apparatus has a torque detecting device and an external information detecting device. The torque detecting device directly or indirectly detects the reaction torque acting on the compressor, and the external information detecting device detects various external information other than the torque. The air-conditioning apparatus further has a control device for determining a target torque in accordance with the external information provided by the external information detecting device. The control device executes a feedback control program for controlling the displacement of the compressor such that the torque detected by the torque detecting device approaches the target torque.

Abstract: A refrigerant circulation system of the present invention includes a compressor, a condenser, a evaporator, a throttle device and a control unit. The control unit controls a composition of a refrigerant circulating in the refrigerant circulation system based on a temperature and pressure of the refrigerant of an inlet and outlet portion of the compressor, condenser, evaporator and throttle device. The control unit controls to open and close the throttle device to change the composition of the refrigerant circulating in the refrigerant circulation system.

Abstract: A method and circuit are provided for on/off control of the compressor of a motor vehicle air conditioner, in which the compressor is shut off when the evaporator temperature measured by an evaporator temperature sensor drops below a presettable shutoff temperature value located above 0.degree. C. The shutoff temperature value is set to fall as a function of the evaporator blower power and/or the temperature of the air drawn in by the evaporator blower with rising blower power or with rising intake air temperature. The circuit includes a control stage whose output signal is fed to an on/off switching element of the compressor and depends on the voltage level at an input node, which varies with the supply voltage of the evaporator blower and/or the output voltage of the intake air temperature sensor.

Abstract: Improved refrigeration system, in particular for domestic use, with a compressor (2), a condenser (3), an evaporator (4) and a valve (5) arranged between the condenser (3) and evaporator (4). The system includes a three-way valve (6) between the condenser (3) and the compressor (2) which establishes a bypass (7) between the compressor (2) and the suction pipe (8) of the system (1) during stoppage of the compressor (2) which blocks the reflux of refrigerant contained in the condenser (3) to the compressor.

Abstract: A single phase motor system and method for preventing excessive circulating currents in the motor. The motor has a power supply link including power switches responsive to a motor control signal for connecting the motor winding to a power supply in alternating on and off intervals. A current sensing circuit senses current in the power supply link during the on intervals. A current regulation circuit generates a current regulation signal representative of the difference between the sensed current and a peak regulated current level that is a function of desired motor speed and/or torque. An overcurrent circuit generates an overcurrent signal in response to the sensed current exceeding a maximum current level greater than the peak regulated current level. The motor also has a control circuit responsive to the current regulation signal for generating the motor control signal thereby to regulate current in the winding and control the motor speed and/or torque.

Abstract: A system for driving a blower of a heating, ventilating, and/or air conditioning (HVAC) system. The blower discharges heated or cooled air to a space for conditioning the air in the space by changing its temperature. A motor drives the blower at a speed or torque defined by a motor control signal thereby to control air flow rate of the HVAC system. The system includes a temperature sensor generating a temperature signal representative of the temperature of the air discharged to the space by the blower. In response to the temperature signal, a control circuit generates the motor control signal to cause the motor to operate at a minimum speed or torque until the temperature of the discharged air as represented by the temperature signal reaches a reference temperature.

Abstract: A current regulation circuit for a motor. The motor includes a stationary assembly having windings adapted for energization in at least one preselected sequence and a rotatable assembly in magnetic coupling relation to the stationary assembly. A power supply link connects the windings to a power supply and includes power switching devices for selectively energizing the windings in the preselected sequence by selectively connecting the power supply link to the windings to produce an electromagnetic field for rotating the rotatable assembly. The power switching devices each have a conducting state and a nonconducting state. The current regulation circuit includes a timing circuit, a current sensing circuit and a control circuit. The timing circuit defines preset periods during which each of the power switching devices may be nonconducting. The current sensing circuit senses current in the power supply link.

Abstract: A system which drives a compressor of a refrigeration system at one or more preset speeds. The system includes a motor having a stationary assembly and a rotatable assembly. The stationary assembly includes windings adapted to be commutated in at least one preselected sequence. The rotatable assembly is in magnetic coupling relation to the stationary assembly and in driving relation to the compressor. The motor drives the compressor at a desired speed corresponding to a speed select signal representative of one of the preset speeds. The system further includes an application specific integrated circuit (ASIC) connected to the motor. The ASIC receives the speed select signal and is responsive to it for generating a commutation reference signal. The commutation reference signal in combination with the commutation signal generates a peak current demand signal and thereby cause the motor to operate at the desired speed.

Abstract: An environmental control system for ground vehicles and low flying aircraft that supplies purified and conditioned ambient air to the vehicle's crew compartment is provided. The system integrates catalytic and particulate filters, that remove nuclear, biological, and chemical warfare agents from ambient air, with a source of compressed ambient air, and an air cycle refrigeration unit.

Abstract: A cooling device for a plurality of coolant circuits for equipment to be cooled, also those having greatly differing cooling power requirements, whose evaporator is disposed in a refrigerant circuit including a compressor, a condenser and an expansion valve. A thermostat switches on the compressor, dependent on the temperature of the coolant in the cooling circuits as measured upstream of the evaporator, if the switching temperature of the coolant is reached and switches off the compressor if the switching temperature is no longer reached.

Abstract: An integrated heat pump and hot water system of the type having a variable speed compressor is controlled during a water heating mode, in which outdoor air serves as the heat source. The controlling is carried out on the basis of a field of outside temperature and water temperature. The compressor speed is controlled based on the outdoor air temperature, and the compressor is run at a maximum speed between a minimum outdoor temperature and a low temperature somewhat above the minimum, at minimum speed for outdoor air temperature between a maximum temperature and a high temperature below the maximum temperature, and at a speed that depends linearly on outdoor temperature for intermediate outdoor temperatures. There is a permissible temperature field or envelope bounded by the minimum and maximum outdoor temperatures, by minimum and maximum water temperatures, and by an efficiency floor and a torque limit ceiling.

Abstract: The discharge of a variable displacement wobble plate compressor is varied by selectively controlling the pressure prevailing in the crankcase of the device. The duty cycle of a signal controlling the pressure is determined in accordance with the ambient air temperature, the temperature required in the cabin and pressure prevailing in the evaporator.

Abstract: A frequency control apparatus of a multi-refrigeration cycle is provided with a current sensor to detect a primary current for a motor or a pressure sensor to detect a pressure at the discharge side of a compressor to detect a load in the refrigeration cycle. When a value detected by the sensor is estimated as being lower than a predetermined value range, the frequency of a current to be supplied to the motor is increased, and when the value detect by the sensor is estimated as being higher than the predetermined value range, the frequency is decreased, whereby the rising time of the refrigeration cycle can be shortened. Further, the frequency is determined by a weighted error average value of the difference between target room temperature in the rooms and detected temperature in the rooms to thereby control the multi-refrigeration cycle to provide an appropriate performance.

Abstract: A refrigeration compressor system using a reciprocating compressor with continuously variable capacity. The speed of the compressor can be varied substantially continuously over predefined range of speeds. A controller for the compressor monitors one or more physical parameters indicative of the temperature of the application being refrigerated, such as the temperature itself and/or the pressure in the compressor's refrigerant suction line. Using a predefined algorithm, the controller adjusts the speed of said compressor so as to keep said monitored parameter within a predefined target range. In a preferred embodiment, the compressor is an open direct drive compressor. The compressor's motor has a substantially continuous range of useable operating speeds which varies by a ratio of more than two to one.

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: A pressure control override apparatus for overriding a conventional pressure control starting switch on a refrigeration system is provided. The apparatus includes a power supply that receives power only when the valve in the liquid line of the refrigeration system is open. The apparatus also includes a temperature sensor for sensing the ambient temperature in the area of the compressor and condenser. The apparatus further includes a circuit to start the compressor that is separate from the normal pressure control starting switch when the apparatus is energized and the ambient temperature sensed by the temperature sensor is lower than a preselected temperature.

Abstract: A refrigeration compressor system using a reciprocating compressor with continuously variable capacity. The speed of the compressor can be varied substantially continuously over predefined range of speeds. A controller for the compressor monitors one or more physical parameters indicative of the temperature of the application being refrigerated, such as the temperature itself and/or the pressure in the compressor's refrigerant suction line. Using a predefined algorithm, the controller adjusts the speed of said compressor so as to keep said monitored parameter within a predefined target range. In a preferred embodiment, the compressor is an open direct drive compressor. The compressor's motor has a substantially continuous range of useable operating speeds which varies by a ratio of more than two to one.