Abstract: The inverter device contains the following structure: an inverter circuit which has upper-arm switching elements that are connected on a positive side of a DC power source and lower-arm switching elements that are connected on a negative side of the DC power source; a current sensor that detects current flowing between the DC power source and the inverter circuit; and a control circuit that controls the inverter circuit by a PWM driving so that the inverter circuit outputs AC current to the motor. The control circuit provides a carrier cycle with a first correction and provides the successive cycle with a second correction, by which the current sensor can detect phase current of the motor. A ripple current caused by the first correction and a ripple current caused by the second correction are opposite in polarity.

Abstract: An inverter has an inverter circuit and a current detector. In the inverter circuit, upper-arm switching elements and lower-arm switching elements, which are connected to DC power supply, provide DC with pulse-width modulation (PWM) so as to output AC to a load. The current detector detects current of the load. With the structure above, the inverter calculates an average value of DC that flows between the DC power supply and the inverter circuit according to a product of an ON-period in which any one of the switching elements maintains ON and a current value detected by the current sensor.

Abstract: An inverter contains the following structure: an inverter circuit having upper-arm switching elements connected on the positive side of a DC power source and lower-arm switching elements connected on the negative side of the DC power source; a current sensor that detects current flowing between the DC power source and the inverter circuit; and a control circuit that not only effects control of the inverter circuit so that AC is fed to a motor from the inverter circuit according to an ON-period controlled by a PWM system, but also makes a correction to the ON-period so as to allow the current sensor to detect phase current. The control circuit determines an amount of the correction by judging a direction of current of a phase having an intermediate length of the ON-period.

Abstract: The inverter device contains the following structure: an inverter circuit which has upper-arm switching elements that are connected on a positive side of a DC power source and lower-arm switching elements that are connected on a negative side of the DC power source; a current sensor that detects current flowing between the DC power source and the inverter circuit; and a control circuit that controls the inverter circuit by a PWM driving so that the inverter circuit outputs AC current to the motor. The control circuit provides a carrier cycle with a first correction and provides the successive cycle with a second correction, by which the current sensor can detect phase current of the motor. A ripple current caused by the first correction and a ripple current caused by the second correction are opposite in polarity.

Abstract: An inverter contains the following structure: an inverter circuit having upper-arm switching elements connected on the positive side of a DC power source and lower-arm switching elements connected on the negative side of the DC power source; a current sensor that detects current flowing between the DC power source and the inverter circuit; and a control circuit that not only effects control of the inverter circuit so that AC is fed to a motor from the inverter circuit according to an ON-period controlled by a PWM system, but also makes a correction to the ON-period so as to allow the current sensor to detect phase current. The control circuit determines an amount of the correction by judging a direction of current of a phase having an intermediate length of the ON-period.

Abstract: An inverter has an inverter circuit and a current detector. In the inverter circuit, upper-arm switching elements and lower-arm switching elements, which are connected to DC power supply, provide DC with pulse-width modulation (PWM) so as to output AC to a load. The current detector detects current of the load. With the structure above, the inverter calculates an average value of DC that flows between the DC power supply and the inverter circuit according to a product of an ON-period in which any one of the switching elements maintains ON and a current value detected by the current sensor.

Abstract: In an air conditioner including a control unit receiving a power from a switching power supply, the switching power supply is connected to a DC power source without passing through a switch device or power application device. The output of the switching power supply is connected to a capacitor via a diode. The control unit is able to operate even when the capacitor to be charged via the power application device is not charged. Accordingly, the motor-driven compressor may start to operate quickly.

Abstract: In an air conditioner having a control unit receiving a power from a switching power supply, a supplied voltage for the control unit is reduced to a possible lowest voltage for the unit to operate. This arrangement provides the air conditioner with less electromagnetic wave noise of the switching power supply, with a quick check and repair, and with having a motor-driven compressor quick start.

Abstract: An automobile air conditioner having a charging device for charging a power source capacitor preliminarily before driving a motor-driven compressor, which comprises a discharge circuit for discharging the electric charge in the capacitor through a power feeding device, and a controller for controlling the discharge by the discharge circuit. Further by comprising a cut-off detecting circuit for detecting when the battery is cut off, it is discharged automatically. Moreover, the voltage of the battery is converted, and supplied as a power source for the controller.

Abstract: In an air conditioner including a control unit receiving a power from a switching power supply, the switching power supply is connected to a DC power source without passing through a switch device or power application device. The output of the switching power supply is connected to a capacitor via a diode. The control unit is able to operate even when the capacitor to be charged via the power application device is not charged. Accordingly, the motor-driven compressor may start to operate quickly.

Abstract: In an air conditioner having a control unit receiving a power from a switching power supply, a supplied voltage for the control unit is reduced to a possible lowest voltage for the unit to operate. This arrangement provides the conditioner with less electromagnetic wave noise of the switching power supply, with a quick check and repair, and with having a motor-driven compressor start quickly.

Abstract: An automobile air conditioner having a charging device for charging a power source capacitor preliminarily before driving a motor-driven compressor, which comprises a discharge circuit for discharging the electric charge in the capacitor through a power feeding device, and a controller for controlling the discharge by the discharge circuit. Further by comprising a cut-off detecting circuit for detecting when the battery is cut off, it is discharged automatically. Moreover, the voltage of the battery is converted, and supplied as a power source for the controller.

Abstract: An automotive air conditioning apparatus 10 is provided which includes a forced water supply system 9 and a heat pump system 14. A controller 16 controls the temperature of a second heat exchanger 38 of the heat pump system 14 to a desired temperature based on a preset temperature. The controller 16 also controls the temperature of the water circulating through the heat exchanger 20 of the forced water supply system 9 to a temperature at which the quantity of heat exchange between the air heated by the second heat exchanger 38 to the desired temperature and the heat exchanger 20 of the forced water supply system is minimized. According to this air conditioning arrangement, the temperature of the vehicle interior can be promptly raised without any capability drop being caused and thus, the heating efficiency of the apparatus being well enhanced.

Abstract: An air-conditioner has a hot-water heating system 110. The system includes a switch 140 for setting a temperature in an interior, a sensor 134 for sensing a temperature of water, a first relay 116 for controlling the water temperature, and a second relay 118 for preventing an overheating. A controller 130 is provided which controls the first relay to adjust the water temperature to a certain temperature based on the set temperature and the detected temperature. When the water temperature has increased to a predetermined temperature, the controller controls the second relay to disconnect between a heater 114 and a power source 120.

Abstract: An air conditioner increases a flow rate of a refrigerant to be sucked to a compressor so that a superheat of the refrigerant is reduced when a coil temperature of a driving motor for a compressor is more than a predetermined temperature.

Abstract: In an air heating system for use in an electric vehicle and the like, a heat-transfer fluid supply apparatus includes, a thermo-control circuit (TCCRT) having a thermo-control valve, a fluid-heating circuit (HCRT) having a high DC voltage battery for supplying a high DC voltage to an electric heater, and a switch control unit operatively associated with both the thermo-control circuit and the fluid-heating circuit, where the switch control unit includes a semiconductor device which is operative by variations in electric current flowing in the thermo-control circuit to thereby control the fluid-heating circuit by switching on and off, and wherein the fluid tank has a metallic outer case to which the semiconductor device is secured in close contact so that the heat generated at the semiconductor device due to consumption of electric power is transferred to the heat-transfer fluid stored in the fluid tank via the metallic outer case.

Abstract: An automotive air conditioning apparatus includes a forced water supply system 12 and a heat pump system 14. The temperature of the vehicle interior is controlled by the heat pump system under ordinary atmospheric temperature conditions. However, at very low temperatures, for example, at the temperature of -5.degree. C. or lower, the temperature of the vehicle interior is controlled by the forced water supply system. According to this air conditioning arrangement, it is possible to achieve energy-efficient air conditioning even under very low temperature conditions and to prevent any compressor damage due to the liquefaction of the refrigerant.

Abstract: An air conditioning apparatus for an electric vehicle includes an electrically-driven compressor. A desired temperature is set which relates to one of a temperature of air discharged into a vehicle interior and a temperature within the vehicle interior. Detection is given of a temperature related to a heat exchanger. An inverter connected to the compressor is operative for driving the compressor at a variable speed corresponding to a desired rotational speed. A target temperature related to the heat exchanger is calculated in response to the desired temperature. Calculation is given of a difference between the detected temperature and the target temperature. Also, calculation is given of a variation in the detected temperature for every given period. A corrective rotational speed is calculated from the temperature difference and the temperature variation for every given period.