Abstract: A speaker comprising a diaphragm including a first layer defining a coil receiving opening therein, and a second layer attached to the first layer and traversing the coil receiving opening. The speaker further comprises a coil having an end extending into the coil receiving opening and abutting against a surface of the second layer that traverses the coil receiving opening. Thus, transmission efficiency between the coil and diaphragm is improved, which improves the audio quality of the speaker.

Abstract: A speaker comprising a diaphragm including a first layer defining a coil receiving opening therein, and a second layer attached to the first layer and traversing the coil receiving opening. The speaker further comprises a coil having an end extending into the coil receiving opening and abutting against a surface of the second layer that traverses the coil receiving opening. Thus, transmission efficiency between the coil and diaphragm is improved, which improves the audio quality of the speaker.

Abstract: Disclosed is a hydrogen separation alloy which is adoptable to a product having a large surface area of a side where hydrogen permeates and which has such a metallographic structure as to improve hydrogen permeability and to improve hydrogen-embrittlement resistance. The hydrogen separation alloy used herein is represented by the compositional formula: Nb100?(?+?)M1?M2? where M1 is at least one element selected from the group consisting of Ti, Zr and Hf; M2 is at least one element selected from the group consisting of Ni, Co, Cr, Fe, Cu and Zn; 10???60, 10???50, and ?+??80. The alloy contains inevitable impurities. And the alloy includes two phases, i.e., an Nb-M1 phase serving as a hydrogen-permeable phase, and a M2-M1 phase serving as a hydrogen-embrittlement-resistant phase. The hydrogen-permeable phase and the hydrogen-embrittlement-resistant phase have an elongated structure resulting from rolling.

Abstract: Disclosed is a hydrogen separation alloy which is adoptable to a product having a large surface area of a side where hydrogen permeates and which has such a metallographic structure as to improve hydrogen permeability and to improve hydrogen-embrittlement resistance. The hydrogen separation alloy used herein is represented by the compositional formula: Nb100?(?+?)M1?M2? where M1 is at least one element selected from the group consisting of Ti, Zr and Hf; M2 is at least one element selected from the group consisting of Ni, Co, Cr, Fe, Cu and Zn; 10???60, 10???50, and ?+??80. The alloy contains inevitable impurities. And the alloy includes two phases, i.e., an Nb-M1 phase serving as a hydrogen-permeable phase, and a M2-M1 phase serving as a hydrogen-embrittlement-resistant phase. The hydrogen-permeable phase and the hydrogen-embrittlement-resistant phase have an elongated structure resulting from rolling.

Abstract: An object of the present invention is to provide a power converter in which the open-phase can be detected in a broader frequency region even if a predetermined relation is kept between the output voltage and the frequency. In order to achieve the above objects, a power converter including: an inverter unit having phase unit inverters provided with a plurality of multiple connected single-phase cell inverters for every phase; an inverter controller for controlling the inverter unit so that a predetermined relation is kept between an output voltage and a frequency; and a plurality of transformers for detecting output voltages of the plurality of phase unit inverters, in which the inverter controller is provided with a fault detection unit for detecting whether a phase-to-phase voltage deviation calculated by the output voltage is within range of an allowable voltage deviation calculated as a function of the frequency is provided.

Abstract: An object of the present invention is to provide a power converter in which the open-phase can be detected in a broader frequency region even if a predetermined relation is kept between the output voltage and the frequency. In order to achieve the above objects, a power converter including: an inverter unit having phase unit inverters provided with a plurality of multiple connected single-phase cell inverters for every phase; an inverter controller for controlling the inverter unit so that a predetermined relation is kept between an output voltage and a frequency; and a plurality of transformers for detecting output voltages of the plurality of phase unit inverters, in which the inverter controller is provided with a fault detection unit for detecting whether a phase-to-phase voltage deviation calculated by the output voltage is within range of an allowable voltage deviation calculated as a function of the frequency is provided.

Abstract: A hydrogen-permeable Nb—Ti—Ni alloy having a composition represented by Nb100-x-yTixNiy, wherein 10?x?60, and 10?y?50 by atomic %, with an oxygen content of 1000 ppm or less in an as-cast state, which comprises (a) a hydrogen-permeable primary phase containing 70 atomic % or more of Nb and 10 atomic % or less of Ni, and (b) a eutectic phase having a particle phase comprising Nb and Ti as main components with a small Ni content and having an average particle size of about 5 ?m or less, which is dispersed in a matrix phase comprising 60 atomic % or more in total of Ni and Ti and having hydrogen embrittlement resistance, the alloy having a structure substantially free from an intermetallic compound phase.

Abstract: A resin-bonded magnet composed substantially of (a) an R—T—N-based magnetic powder having a basic composition of R&agr;T100−&agr;−&bgr;N&bgr;, wherein R is at least one selected form the group consisting of rare earth elements including Y, T is Fe or Fe and Co, 5≦&agr;≦20, and 5≦&bgr;≦30, (b) a ferrite magnetic powder having a substantially magnetoplumbite-type crystal structure and a basic composition represented by (A1−xR′x) O[(Fe1−yMy)2O3] by atomic ratio, wherein A is Sr and/or Ba, R′ is at least one selected from the group consisting of rare earth elements including Y, La being indispensable, M is Co or Co and Zn, 0.01≦x<0.4, 0.005≦y≦0.04, and 5.0≦n≦6.4, and (c) a binder. The ferrite magnet powder is preferably an anisotropic, granulated powder or an anisotropic, sintered ferrite magnet powder.

Abstract: A magnet roll has a plurality of magnetic poles on a surface with at least one magnetic pole portion being composed of an anisotropic bonded magnet including magnet powder and binder resin. The anisotropic bonded magnet contains R—T—N magnet powder, wherein R is at least one rare earth element including Y, Sm being indispensable, and T is Fe or Fe and Co. The R—T—N magnet powder may also contain inevitable impurities such as C, O and H. The binder resin constitutes 20-70% of the volume of the anisotropic bonded magnet such that the anisotropic bonded magnet have a maximum energy product (BH)max of 10 MGOe or more and a residual magnetization Br of 2800 G or more.

Abstract: A resin-bonded magnet composed substantially of (a) an R-T-N-based magnetic powder having a basic composition of R&agr;T100-&agr;-&bgr;N&bgr;, wherein R is at least one selected form the group consisting of rare earth elements including Y, T is Fe or Fe and Co, 5≦&agr;≦20, and 5≦&bgr;≦30, (b) a ferrite magnetic powder having a substantially magnetoplumbite-type crystal structure and a basic composition represented by (A1-xR′x)O[(Fe1-yMy)2O3] by atomic ratio, wherein A is Sr and/or Ba, R′ is at least one selected from the group consisting of rare earth elements including Y, La being indispensable, M is Co or Co and Zn, 0.01≦x≦0.4, 0.005≦y≦0.04, and 5.0≦n≦6.4, and (c) a binder. The ferrite magnet powder is preferably an anisotropic, granulated powder or an anisotropic, sintered ferrite magnet powder.

Abstract: A nitride-type, rare earth magnet material having a basic composition represented by R&agr;T100-(&agr;+&bgr;+&ggr;+&dgr;)M&bgr;B&ggr;N&dgr; (atomic %), wherein R is at least one rare earth element including Y, as a rare earth element Sm must be present, T is Fe alone or a combination of Fe and Co and/or Ni, M is at least one element selected from the group consisting of Al, Ti, V, Cr, Mn, Cu, Ga, Zr, Nb, Mo, Hf, Ta, W and Zn, 6≦&agr;≦15, 0.5≦&bgr;≦10, 0≦&ggr;≦4, and 4≦&dgr;≦30, which is substantially composed of a hard magnetic phase of an R2T17-type structure having an average crystal grain size of 0.01-1 &mgr;m, an average area ratio of &agr;-Fe being 5% or less.

Abstract: A control system for determining a control function for a control device on the basis of a transfer function of an object to be controlled and for adjusting an operation quantity of an object to be controlled in accordance with the determined control operation function, wherein an control function of a first control device is determined so that a closed-loop transfer function of a control system including the object to be controlled and the first control device coincides with a predetermined first transfer function, an control function of a second control device is determined, in a closed loop control system including the control system and the first control device, so that a transfer function from a disturbance applied to the object to be controlled to a state variable of a point at which the disturbance is applied to the object to be controlled, and a sum signal indicative of a sum of outputs of the first and second control devices is used as an operation quantity of the object to be controlled.

Abstract: In order to provide a power inverter device which can reduce surge voltages in all of the operating conditions thereof and has a simple structure, in a neutral point clamped 3 level type power inverter device formed by connecting semiconductor switching elements, diodes and smoothing use capacitors connected via plate shaped conductors, a first plate shaped conductor connects the diodes and the smoothing use capacitors and a plurality of plate shaped conductors connecting the elements are disposed over the first plate shaped conductor and separated from it by an insulating material.

Abstract: An SAL-type magnetoresistive playback head that is highly sensitive and that limits Barkhausen noise is provided by optimizing the magnetic properties of the permanent magnet film. On top of a lower insulating layer are stacked a soft magnetic bias film (SAL film), a magnetic separating film (shunt film), a magnetoresistive film (MR film), and an upper insulating layer, in that order. The outer sides of the track of the MR film are in direct contact with the permanent magnet film or in indirect contact via a base film. Alternatively, the present invention relates to a spin-valve magnetoresistive playback head. On top of a lower insulating layer are stacked an anti-ferromagnetic film, a fixed magnetizing film, a magnetic separating film, a movable magnetizing film (MR film), and an upper insulating layer, in that order. The outer sides of the track of the movable magnetizing film are in direct contact with the permanent magnet film or in indirect contact via a base film.

Abstract: A motor controller includes a shaft torsion vibration estimator for estimating a shaft torsion vibration between a motor and a mechanical load and a shaft torque estimator for estimating a shaft torque acting upon a motor shaft, wherein a vibration in a mechanical load driving system is suppressed by utilizing an estimated shaft torsion torque value calculated by the shaft torsion vibration estimator and an estimated shaft torque value calculated by the shaft torque estimator in addition to a detected motor speed value. Using such a system stable speed control having improved response can be achieved since higher order vibration modes can be suppressed without deteriorating its shaft torsion vibration without deteriorating its shaft torsion vibration suppression performance by combining the shaft torsion vibration estimator and the shaft torque estimator.

Abstract: A speed control method and apparatus for a motor driven by output of a power conversion unit, wherein a first current command value is inputted to derive a drooping variable, a deviation between a detected speed value of the motor and a speed command value is derived, the first current command value is derived on the basis of a value obtained by compensating the deviation with the drooping variable, the speed command value is inputted to derive an acceleration or deceleration current value for accelerating or decelerating the motor, and the first current command value and the acceleration or deceleration current value are added together to derive a second current command value and control the output current of the power conversion unit on the basis of the second current command value.

Abstract: A plant controller calculates the updated value of a control parameter for a motor controller for controlling motors for driving process machines in accordance with the change in the operational condition of a process plant so as to transmit it to the motor controller. The motor controller updates the set value of the control parameter relating to the control characteristics of the motor in accordance with the supplied updated value of the control parameter. The plant controller transmits the updated value of the control parameter to the motor controller in such a manner that the parameter code denoting the type of the control parameter and the updated value are allocated to predetermined bits of one word. The motor controller separates the received parameter code and the updated value from each other to change the setting of the control parameter, which corresponds to the parameter code, in accordance with the updated value.

Abstract: A speed control apparatus for a motor comprising a motor model formed of a motor current model and a motor speed model connected in cascade, a basic torque instruction signal being applied to the motor model, and first and second control loops comparing output signals from the motor current model and the motor speed model with an instantaneous actual motor current signal and an instantaneous actual motor speed signal respectively and generating first and second correction signal to be added to the basic torque instruction signal to form a corrected torque instruction signal which is applied to a motor current control circuit, whereby a speed oscillation is suppressed even when the motor is driving an oscillatory load.

Abstract: In a static leonard apparatus, a DC motor is supplied from a thyristor converter through a main circuit switch, and a capacitor is connected between the DC output buses of the thyristor converter. When the main circuit switch is turned off, a grounding switch is turned on to ground one of the DC output buses to form a grounded closed discharge circuit including the DC motor through which the capacitor discharges. During the turned-off period of the main circuit switch, the capacitor is charged with the output voltage of the thyristor converter. The capacitor discharges through the grounded closed discharge circuit. The voltage values of the discharging capacitor at two points on the time axis are detected to compute the discharge time constant of the capacitor, and, on the basis of the computed discharge time constant, the insulation resistance of the DC motor is measured.

Abstract: In a converting device having two sets of converters, each of which includes planar type semiconductor controlled rectifier elements connected in a bridge configuration, with the converters being connected to a load, in a reverse-parallel configuration, so that the anode of one element is connected to the cathode of its parallel connected element, cooling fins are interposed between the planar type semiconductor controlled rectifier elements so that an individual cooling fin serves to cool directly adjacent elements disposed along the same axis in series with each other. As a result, the number of cooling fins can be sharply reduced. The converting device is especially effective for normal and reverse switching operations of a d.c. motor.