Abstract: The upper limit value and lower limit value of a control target value are alternately supplied to a single D/A converter in synchronism with a clock, an analog output from the D/A converter is compared with an output from a PBR serving as a position detector, and a motor is driven by the difference voltage, thereby positioning the control object. In this case, control of the moving direction and drive/stop of the motor is performed by a combination between the setting states of the upper and lower limit values and the polarity of the difference voltage, and the switching operation of the selector is stopped during a control operation, thereby making it possible to smoothly perform the control operation at a high speed. The control system can be digitized as a whole by detecting a position by an encoder, and integration of the system can be enhanced, thereby realizing a compact and stable control system.

Abstract: A rotary vane compressor comprises a cylinder having two closed ends defining a cylinder chamber in which is rotatably mounted a rotor. The rotor carries a plurality of radially movable vanes which move radially into sliding contact with the inner surface of the cylinder chamber during rotation of the rotor to compress a refrigerant gas. The rotor is rotationally driven by a rotor shaft rotatably mounted by bearings in the cylinder ends. To prevent destruction of the ozone layer, a refrigerant containing no chlorine, such as HFC-134a (1,1,1,2-tetrafluoroethane; CH.sub.2 FCF.sub.3) is used, and to compensate for the inferior lubricating properties of the chlorine-free refrigerant, the bearings are provided with a manganese phosphate coating of 10 .mu.m-15 .mu.m thickness to prevent cohesion and seizure of the mutually contacting surfaces of the bearings and rotor shaft.

Abstract: A flat resistance for a blower control unit of an automobile air conditioner, and a blower control unit using the same. The flat resistance includes: a porcelain enameled metallic substrate including a flat head portion, having an edge and one surface, and parallel terminal supporting portions projecting outwardly from the edge of the head; a resistance circuit printed on the one surface of the head portion, the resistance circuit including a plurality of resistances electrically connected in series; a temperature fuse, interposed in the resistance circuit, for being tripped to break the resistance circuit when the porcelain enameled metallic substrate becomes overheated; and terminals, printed on both the head portion and the terminal supporting portions, each terminal being connected to one end of a corresponding one of the resistances.