Abstract: Disclosed herein is an air conditioner having a single oil separator mounted on a confluent discharging channel, to which are connected discharging channels provided at a plurality of compressors, and an electronic expansion valve, of which the opening level is controllable, mounted on an oil collection pipe connected to the oil separator. As a result, the number of the oil separators is decreased. Consequently, the present invention has the effect of simplifying the structure of the air conditioner and reducing the manufacturing costs of the air conditioner. Furthermore, refrigerant is bypassed by controlling the opening level of the electronic expansion valve to control the flow rate of the refrigerant. Consequently, the present invention has the effect of eliminating an additional bypassing device, and therefore, simplifying the structure of the air conditioner and the controlling method of the air conditioner.

Abstract: Air conditioner including a case having air inlet and outlet passages therein perpendicular to each other, and a plurality of air inlet and outlets at ends of the air inlet and outlet passages, a regenerative heat exchanger at a cross point of the air inlet and outlet passages for making indirect heat exchange of the external air and room air flowing through the air inlet and outlet passages, a compressor, a flow path control valve for shifting, and guiding a flow path of refrigerant from the compressor proper to respective operation modes, first and second heat exchangers, an expansion device, a first fan in the air inlet passage for blowing external air into a room through the first heat exchanger, and a second fan in the air outlet passage for blowing the room air to an exterior through the second heat exchanger, thereby ventilating as well as heating or cooling the room at the same time.

Abstract: Air conditioner including a case having air inlet and outlet passages therein perpendicular to each other, and a plurality of air inlet and outlets at ends of the air inlet and outlet passages, a regenerative heat exchanger at a cross point of the air inlet and outlet passages for making indirect heat exchange of the external air and room air flowing through the air inlet and outlet passages, a compressor, a flow path control valve for shifting, and guiding a flow path of refrigerant from the compressor proper to respective operation modes, first and second heat exchangers, an expansion device, a first fan in the air inlet passage for blowing external air into a room through the first heat exchanger, and a second fan in the air outlet passage for blowing the room air to an exterior through the second heat exchanger, thereby ventilating as well as heating or cooling the room at the same time.

Abstract: Air conditioner including a case having air inlet and outlet passages therein perpendicular to each other, and a plurality of air inlet and outlets at ends of the air inlet and outlet passages, a regenerative heat exchanger at a cross point of the air inlet and outlet passages for making indirect heat exchange of the external air and room air flowing through the air inlet and outlet passages, a compressor, a flow path control valve for shifting, and guiding a flow path of refrigerant from the compressor proper to respective operation modes, first and second heat exchangers, an expansion device, a first fan in the air inlet passage for blowing external air into a room through the first heat exchanger, and a second fan in the air outlet passage for blowing the room air to an exterior through the second heat exchanger, thereby ventilating as well as heating or cooling the room at the same time.

Abstract: Disclosed herein is an apparatus for connection to the secondary terminals of a CT to prevent CT damage and electric shock when the secondary terminals are opened, by providing an input signal and operating a relay circuit to short the CT secondary terminals. The apparatus monitors opening of the CT secondary terminals, and to prevent accidental opening, determines opening and provides an over voltage breaking upon opening. To prevent false operation of the protecting relay connected to the secondary terminals caused by the over voltage generated by accident other than opening of the CT secondary terminals, a secondary delay time of operation of the protecting relay is provided that can be variously set by DIP switch or otherwise, allowing the user to choose a desired setting. Further, expected over voltage values can be set according to load characteristics, allowing the apparatus to operate during voltage above the set value.

Abstract: An air-conditioner having multiple compressors includes: an indoor heat-exchanger disposed indoors and heat-exchanging indoor air; an outdoor heat-exchanger disposed outdoors and heat-exchanging a refrigerant with external air; four compressors for compressing the refrigerant to change the refrigerant to have a high temperature and high pressure; and three accumulators disposed at a suction side of the four compressors and separating the refrigerant into a gas and a liquid to supply a gaseous refrigerant to the compressors. Oil can be uniformly supplied to each compressor, thereby enhancing reliability of compressors, and since the three accumulators are small with low capacities, their installation space can be easily secured.

Abstract: A liquid crystal display device that is adapted to reduce flicker. In the device, a plurality of common voltage lines are formed into a spherical shape on a lower substrate to deliver a common voltage to an upper substrate. A plurality of link points are formed between the common voltage delivering lines to deliver the common voltage to a transparent electrode film. A plurality of links are provided between the link points to have a different resistance value. Accordingly, a flicker is prevented to improve a picture quality.