摘要:
A rotor position sensorless multiphase motor driving device includes a rotor; a plurality of phase windings; a common terminal to which one terminal of terminals at both ends of each winding is star connected; an upper-side drive transistor and a lower-side drive transistor connected to the other terminal of the winding; a commutation control unit operable to select two terminals other than the common terminal of the windings, and to turn on the corresponding pair of upper-side drive transistor and the lower-side drive transistor; a rotor position search pulse applying unit operable to apply a search pulse to the selected two terminals; and a comparing unit operable to detect a rotor position based on a response signal generated between the terminal which was unselected and the common terminal according to the search pulse application.
摘要:
A light receiving section 27b receives a measurement beam, which is cast from a light projection section 27a and partially blocked by cream solder 19 scraped up by a squeegee 16, whereby a sensor 27 measures a one-dimensional size of a predetermined region of a cross sectional profile of the cream solder 19 as a cross sectional paste length and takes the cross sectional paste length as an index for an amount of residual cream solder 19. The amount of residual cream solder 19 can be numerically grasped at all times, so that versatility and accuracy in detecting the amount of residual cream solder 19 can be assured.
摘要:
A decorative material including a pattern layer formed from an aqueous composition, which can be easily handled without receiving any scratches on the surface upon loading or unloading, allows no possibility of load collapse when stacked, and has durable surface staining resistance. The decorative material includes a substrate, a sealer layer containing an aqueous adhesive on the substrate, a pattern layer formed from an aqueous ink on top of the sealer layer, and a surface protective layer covering the pattern layer to form an outermost surface, wherein the surface protective layer includes an antifouling agent containing a silicone oil in a matrix resin formed by curing of an oily resin or an ionizing radiation curable monomer, and the outermost surface has a dynamic coefficient of friction of 0.1 to 0.3.
摘要:
A motor driving apparatus includes a comparator, a threshold controller, a position determining unit, a phase-switching controller, and a current output unit. While the rotor is stopped, the phase-switching controller supplies a predetermined phase of winding with a current pulse having a predetermined pulse width so as not to cause the rotor to react and operate, in order to determine the initial position of the rotor. The position determining unit determines an initial position of the rotor based on the result of comparison between the induced voltage generated in a non-conduction phase by the current pulse and the threshold. The phase-switching controller performs energization or commutation according to the determined initial position of the rotor to start up the motor.
摘要:
The present invention provides a combination metal gasket that is formed by fitting a ring-shaped metal base elastic structure in at least one trough portion of two trough portions of a ring-shaped metal gasket that has an S-shaped longitudinal cross section. The combination metal gasket does not demonstrate the plastic deformation even when a large compressive load is applied and is not likely to be destroyed even when a pressure of a fluid being sealed is high; that is, stable sealing properties are exhibited.
摘要:
In order to provide a gasket which can be repeatedly used over a temperature range in which a rubber gasket cannot be used, which does not have any risk of damaging a flange, and which can follow the change of the distance between flanges, a gasket is constructed in such a way that two metallic coned disc springs each of which has a circulation opening for a fluid in a central portion and each of which is formed into a seal surface in which an outer peripheral portion with respect to the circulation opening rises having an arc-like curved surface are combined while being oppositely directed and have outer diameter peripheral edge portions which are welded and fixed so that by tightening flanges, repulsive force of the two coned disc springs concentratedly affects the seal surfaces consisting of the arc-like curved surfaces, and a tight fluid seal is formed between the flange surfaces.
摘要:
A disk drive apparatus reproduces an information signal from a disk and/or records an information signal on the disk. FET power transistors of a power supplying part execute high-frequency switching operation and form current paths to three-phase windings so as to rotate the disk. A voltage detecting part compares terminal voltages of the three-phase windings and produces a detected pulse signal in response to a comparison result. An activation operation block controls active periods of the FET power transistors in response to the detected pulse signal. A commanding part produces a command signal in response to an output pulse signal of the voltage detecting part. A switching operation block produces a switching pulse signal in response to a comparison result of a current-detection signal with the command signal, and causes at least an FET power transistor of the power supplying part to perform high-frequency switching in response to the switching pulse signal. The switching operation block changes a timing of the switching pulse signal in response to detection of the detected pulse signal so that the voltage detecting part can accurately achieve the next detection of the detected pulse signal. Further, an excellent speed control of the disk can be achieved by the accurate output pulse signal of the voltage detecting part.
摘要:
A rotating machine having a stator core and coolers for cooling a cooling medium which is circulated inside the machine by the rotation of a fan installed near a rotating axis of the rotating machine. The coolers being installed in a ventilation passage for the cooling medium and including at least one cooler installed in one ventilation passage extending from an exhaust side of the fan to a suction side of the fan via the stator core, and at least another cooler installed in another ventilation passage extending from the exhaust side of the fan in the one ventilation passage to an inside of an inner surface of the stator core.
摘要:
An the electric rotating machine which is compact and of reduced cost by improving the thermal conductivity of the main insulation in the thickness direction while maintaining the insulation breakdown voltage of the main insulation high. The initial breakdown voltage V in the thickness direction of the main insulator 30 of the stator winding 3 is higher than 20 kV/mm, and the thermal conductivity &lgr; in the thickness direction is within a range of 0.35 to 1 W/m·K, and the product V&lgr; of the initial breakdown voltage V and the thermal conductivity &lgr; satisfies a relationship of 7≦V&lgr;≦20 (MWA/m2·K). The amount of resin is within a range of 20 to 50 weight % of the main insulation material.
摘要:
A thermocouple temperature sensor employs a protecting tube made of metal-boride-based ceramics, and a platinum -rhodium-based thermocouple. To prevent a deterioration of the thermocouple due to a reducing gas generated in the protecting when used at a high service temperature, the thermocouple is placed in an insulation tube, which is placed inside the protecting tube. In addition, a front end portion of the insulation tube is covered with a noble-metal cap mainly composed of platinum group metal, to prevent the reducing gas generated in the protecting tube from reaching a connection point of the thermocouple. The top end of the protecting tube is open, and a terminal box with a ventilation means to smoothly discharge the reducing gas in provided. This arrangement remarkably prolongs the service life of the thermocouple, and thus it is able to continuously measure the temperature of molten pig iron and molten steel for a long interval.