Abstract: An air conditioner includes: an indoor unit; an outdoor unit; and a control unit that controls operation of the indoor unit and the outdoor unit. The outdoor unit includes: an outdoor unit fan that takes in air; an outside air temperature detection unit that detects an outside air temperature that is a temperature of outside air; and an air pressure acquisition unit that acquires an air pressure of outside air. The control unit calculates an air property value of air at an installation location of the air conditioner based on an outside air temperature acquired by the outside air temperature detection unit and an air pressure acquired by the air pressure acquisition unit, and controls the outdoor unit fan based on the air property value.

Abstract: In a memory, multiple pieces of entry data sorted in ascending or descending order are stored associated with addresses. With whole addresses for storing the multiple pieces of entry data as an initial search area, the search circuit repeatedly performs a search operation for comparing entry data stored in a central address of the search area with the search data, outputting the address as a search result in the case of a match, and narrowing the search area for the next search based on a magnitude comparison result in the case of a mismatch.

Abstract: Examples of an insulation system include a digital isolator for receiving supply of a first power supply on an input side thereof and receiving supply of a second power supply on an output side thereof, and an output adjusting unit for receiving supply of the second power supply, directly outputting an output of the digital isolator when a voltage of the second power supply is larger than a predetermined voltage, and stopping data output irrespective of the output of the digital isolator when the voltage of the second power supply is smaller or equal to the predetermined voltage.

Abstract: A heat pump device includes a compressor including a motor, a heat exchanger, an inverter, and an inverter control unit. The inverter control unit generates a drive signal for the inverter. When the compressor is heated, the inverter control unit applies, to the motor, a high-frequency voltage with which the motor cannot be rotationally driven; estimates a magnetic pole position indicating a stop position of a rotor of the motor; determines an amplitude and a phase of a voltage command based on an estimation result of the magnetic pole position and a necessary amount of heat, and generates a drive signal.

Abstract: Examples of an insulation system include a digital isolator for receiving supply of a first power supply on an input side thereof and receiving supply of a second power supply on an output side thereof, and an output adjusting unit for receiving supply of the second power supply, directly outputting an output of the digital isolator when a voltage of the second power supply is larger than a predetermined voltage, and stopping data output irrespective of the output of the digital isolator when the voltage of the second power supply is smaller or equal to the predetermined voltage.

Abstract: The present disclosure discloses a rooftop air conditioning unit for a bus or other vehicle. The air conditioning unit includes a frame, a condenser section mounted on the frame and a HVAC section mounted on the frame. The condenser section is positioned along a central longitudinal axis of the air conditioning unit, and the HVAC section is positioned in a distributed way on the two opposite sides of the condenser section and comprises at least one pair of HVAC modules, each of which includes a box-shaped base of plastic material mounted on the frame, inside which a respective blower, evaporator and heater are mounted.

Abstract: Examples of an insulation system include a digital isolator for receiving supply of a first power supply on an input side thereof and receiving supply of a second power supply on an output side thereof, and an output adjusting unit for receiving supply of the second power supply, directly outputting an output of the digital isolator when a voltage of the second power supply is larger than a predetermined voltage, and stopping data output irrespective of the output of the digital isolator when the voltage of the second power supply is smaller or equal to the predetermined voltage.

Abstract: In a memory, multiple pieces of entry data sorted in ascending or descending order are stored associated with addresses. With whole addresses for storing the multiple pieces of entry data as an initial search area, the search circuit repeatedly performs a search operation for comparing entry data stored in a central address of the search area with the search data, outputting the address as a search result in the case of a match, and narrowing the search area for the next search based on a magnitude comparison result in the case of a mismatch.

Abstract: In a memory, multiple pieces of entry data sorted in ascending or descending order are stored associated with addresses. With whole addresses for storing the multiple pieces of entry data as an initial search area, the search circuit repeatedly performs a search operation for comparing entry data stored in a central address of the search area with the search data, outputting the address as a search result in the case of a match, and narrowing the search area for the next search based on a magnitude comparison result in the case of a mismatch.

Abstract: A heat pump device includes an inverter control unit for controlling an inverter. The inverter control unit includes a constraint-energization control unit that, during operation standby of a compressor, determines whether heating to the compressor is necessary, on the basis of a refrigeration stagnation amount in the compressor, and, when having determined that heating to the compressor is necessary, selects, according to the refrigeration stagnation amount, any one of direct-current energization for supplying a direct-current voltage to the motor and high-frequency energization for supplying a high-frequency voltage having a frequency higher than a frequency during a normal operation to the motor, so as to output a constraint energization command for carrying out constraint energization of the motor; and a driving-signal generating unit that generates a driving signal on the basis of the constraint energization command.

Abstract: A heat pump device includes: a compressor including a compression mechanism compressing a refrigerant and a motor driving the compression mechanism; an inverter unit applying a voltage for driving the motor; an inverter control unit generating a driving signal for driving the inverter unit; and temperature sensors detecting temperatures of the compressor, wherein the inverter control unit includes a normal operation mode in which a refrigerant is compressed by performing a normal operation of the compressor and a heating operation mode in which a heating operation of the compressor is performed by applying, to the motor, a high-frequency voltage, and in the heating operation mode, the inverter control unit determines an amplitude and a phase of a voltage command for generating the high-frequency voltage on a basis of a temperatures detected by the temperature sensors and a necessary amount of heat specified in advance.

Abstract: An object of the present invention is to maintain a heating amount constant when a compressor is heated at the time of shutdown of the compressor, regardless of the influences of production tolerance and environment variations. An inverter control unit causes an inverter to generate a high-frequency AC voltage having a de-energized section in which a voltage applied from the inverter to a motor is zero between a section in which the voltage is positive and a section in which the voltage is negative. At this time, the inverter control unit detects a value of a current flowing to the inverter in a detection section residing from immediately before a start of the de-energized section to immediately after an end of the de-energized section, and causes the inverter to generate a high-frequency AC voltage adjusted according to the detected current value.

Abstract: A heat pump device includes an inverter control unit outputting PWM signals to an inverter; a current detection unit detecting a current value flowing in the inverter and outputting the current value after reducing a current value having a first frequency or higher in detected current value; and a drive-signal stop unit that, when the current value output from the current detection unit is equal to or larger than an interruption level, stops output of PWM signals to the inverter. Particularly, the inverter control unit generates a voltage command value such that the voltage command value becomes a value equal to or larger than a lower limit determined according to the first frequency and generates PWM signals based on generated voltage command value and a carrier signal, thereby causing a voltage output time to the motor to be a predetermined time or longer.

Abstract: A heat pump device includes: a compressor that compresses a refrigerant; a motor that drives the compressor; a wiring switching unit that switches a wiring structure of the motor; an inverter that applies a desired voltage to the motor; and an inverter control unit that generates a PWM signal for driving the inverter, that includes, as an operation mode, a heating operation mode in which a heating operation is performed on the compressor and a normal operation mode in which a refrigerant is compressed by performing a normal operation on the compressor, and that controls a switching operation of the wiring switching unit in accordance with an operation mode.

Abstract: A heat pump device includes a compressor including a compression mechanism that compresses a refrigerant and a motor that drives the compression mechanism, an inverter that applies a voltage for driving the motor, a converter that applies a voltage to the inverter, an inverter control unit that generates a driving signal for driving the inverter, and a converter control unit that generates a driving signal for driving the converter. The inverter control unit includes a heating-operation-mode control unit that controls a driving-signal generating unit such that the driving-signal generating unit outputs, as inverter driving signals, PWM signals for heating the compressor without rotationally driving the motor by feeding a high-frequency current that the motor cannot follow in a heating operation mode.

Abstract: An adder adds a phase ?plus, which is n times a size of 60 degrees, to a phase output from a phase switching unit and outputs the phase as a voltage command phase ?. A voltage generation unit generates voltage command value based on the voltage command phase output by the adder and outputs the command value. A drive-signal generation unit, based on an output from the voltage generation unit generates drive signals corresponding to respective switching elements of an inverter, and outputs respective generated drive signals to the corresponding switching elements of the inverter, and generates a high-frequency AC voltage in the inverter.

Abstract: A voltage-command correction-value computation unit outputs a correction value for correcting a voltage command value according to a bus voltage. A multiplier calculates a voltage command value acquired by correcting the voltage command value based on the correction value. A voltage-command generation unit generates and outputs three-phase voltage command values based on the corrected voltage command value calculated by the multiplier and a phase. A PWM-signal generation unit generates six drive signals corresponding to switching elements of an inverter based on the three-phase voltage command values outputted by the voltage-command generation unit and a carrier signal. The PWM-signal generation unit outputs the generated drive signals to the corresponding switching elements of the three-phase inverter, to cause the inerter to generate a high-frequency AC voltage.

Abstract: A selection unit switches between a phase ?p and a phase ?n different from the phase ?p substantially by 180 degrees, and outputs one of them in synchronization with a carrier signal. A voltage-command generation unit generates and outputs three-phase voltage command values Vu*, Vv* and Vw* based on the phase outputted by the selection unit. A PWM-signal generation unit generates three-phase voltage command values Vu*?, Vv*? and Vw*? by correcting the three-phase voltage command values Vu*, Vv* and Vw* outputted by the voltage-command generation unit according to a predetermined method, and generates six drive signals corresponding to switching elements of the inverter based on the three-phase voltage command values Vu*?, Vv*? and Vw*? and the carrier signal. The PWM-signal generation unit outputs the generated drive signals to the corresponding switching elements of the three-phase inverter, to cause the inverter to generate a high-frequency AC voltage.

Abstract: An air conditioner equipped with a compressor, an indoor heat exchanger and an outdoor heat exchanger includes: an inverter circuit that drives a motor of the compressor; an inverter-power detecting unit that detects power of the inverter circuit; a PWM-signal generating unit that inverter-current detecting unit generates PWM signals for controlling the inverter circuit; a voltage-command-value generating unit that outputs voltage command values to the PWM-signal generating unit; and an accumulation detecting unit that detects accumulation of a liquid refrigerant within the compressor and outputs a detection result to the voltage-command-value generating unit, wherein when accumulation of a liquid refrigerant within the compressor is detected, the voltage-command-value generating unit outputs the voltage command value so that power of the inverter circuit has a predetermined power value.

Abstract: A high efficiency refrigerant compressor standby heating method reduces vibrations and noise in a bearing of the compressor. The compressor comprises a motor, an inverter, an inverter controller, and a bus voltage detector to detect a bus voltage of the inverter. The inverter controller includes a dormant refrigerant detector to detect a dormant state of refrigerant in the compressor, a high-frequency AC voltage generator to output a high-frequency AC voltage command, which is out of a range of an operating frequency when the compressor is running, to a coil of the motor on the basis of an output of the dormant refrigerant detector, an amplitude, and a phase. A pulse width modulation signal generator to cause the inverter to generate a high-frequency AC voltage by generating a signal on the basis of the output of the high-frequency AC voltage generator and the output of the bus voltage detector.