Abstract: An apparatus for controlling a synchronous generator having a converter. A voltage detector detects a terminal voltage of a stator of the synchronous generator. A current detector detects a current flowing through the stator. A rotor position estimating part estimates a rotor position of the synchronous generator from the detected voltage and current. An active power detector detects a active power of the synchronous generator. A reactive power detector detects a reactive power of the synchronous generator or a terminal voltage detector detects an effective value of a terminal voltage of the stator. An active power controller adjusts a q-axis current command to control the active power, and a reactive power controller or terminal voltage controller adjusts a d-axis current command to control the reactive power or terminal voltage.

Abstract: An apparatus for controlling a synchronous generator having a converter. A voltage detector detects a terminal voltage of a stator of the synchronous generator. A current detector detects a current flowing through the stator. A rotor position estimating part estimates a rotor position of the synchronous generator from the detected voltage and current. An active power detector detects an active power of the synchronous generator. A reactive power detector detects a reactive power of the synchronous generator or a terminal voltage detector detects an effective value of a terminal voltage of the stator. An active power controller adjusts a q-axis current command to control the active power, and a reactive power controller or terminal voltage controller adjusts a d-axis current command to control the reactive power or terminal voltage.

Abstract: An apparatus for controlling a synchronous generator having a converter. A voltage detector detects a terminal voltage of a stator of the synchronous generator. A current detector detects a current flowing through the stator. A rotor position estimating part estimates a rotor position of the synchronous generator from the detected voltage and current. An active power detector detects a active power of the synchronous generator. A reactive power detector detects a reactive power of the synchronous generator or a terminal voltage detector detects an effective value of a terminal voltage of the stator. An active power controller adjusts a q-axis current command to control the active power, and a reactive power controller or terminal voltage controller adjusts a d-axis current command to control the reactive power or terminal voltage.

Abstract: An apparatus for controlling a synchronous generator having a converter. A voltage detector detects a terminal voltage of a stator of the synchronous generator. A current detector detects a current flowing through the stator. A rotor position estimating part estimates a rotor position of the synchronous generator from the detected voltage and current. An active power detector detects a active power of the synchronous generator. A reactive power detector detects a reactive power of the synchronous generator or a terminal voltage detector detects an effective value of a terminal voltage of the stator. An active power controller adjusts a q-axis current command to control the active power, and a reactive power controller or terminal voltage controller adjusts a d-axis current command to control the reactive power or terminal voltage.

Abstract: An aluminum nitride substrate where an electroconductive metallized layer is formed on a ceramic substrate comprising a sintered substance of aluminum nitride with a high thermal conductivity for example 200 W/m.multidot.K. The sintered substance of aluminum nitride contains a proper amount of a sintering assistance agent component. The density on the surface of an intergranular phase component mainly comprising the sintering assistance agent component is 3 weight % or less. The metallized layer formed on the sintered substance of aluminum nitride defining the density of the intergranular phase component on the surface of the sintered substance has an excellent bonding strength against the sintered substance of aluminum nitride, the bonding strength being nearly stable.

Abstract: This invention is directed to a laser-subdivided aluminum nitride substrate wherein a resolidified layer formed at the laser score lines is constituted by one or more types of material selected from the group consisting of oxides, nitrides and oxynitrides of aluminum and of additives of said aluminum nitride substrate, and to a method of producing an aluminum nitride substrate wherein, subsequent to laser scoring the substrate, a heat treatment step at about 1000.degree. C. to 1800.degree. C. is carried out prior to the step of metallizing. This simple method provides an aluminum nitride substrate having a prescribed withstand-voltage characteristic.

Abstract: This invention is directed to a laser-subdivided aluminum nitride substrate wherein a resolidified layer formed at the laser score lines is constituted by one or more types of material selected from the group consisting of oxides, nitrides and oxynitrides of aluminum and of additives of said aluminum nitride substrate, and to a method of producing an aluminum nitride substrate wherein, subsequent to laser scoring the substrate, a heat treatment step at about 1000.degree. C. to 1800.degree. C. is carried out prior to the step of metallizing. This simple method provides an aluminum nitride substrate having a prescribed withstand-voltage characteristic.

Abstract: When molded plates of aluminum nitride obtained by molding a ceramic powder formed preponderantly of aluminum nitride powder are superposed on a support base with a ceramic powder interposed between the support base and the superposed plates and between the superposed plates and are fired in a non-oxidative atmosphere, the sintered plates consequently produced are prevented from sustaining crack or fracture.When warped and undulated sintered plates of aluminum nitride are superposed on a support base with a ceramic powder interposed between the support base and the superposed plates and between the superposed plates and are heated in a non-oxidative atmosphere, the heated plates are relieved of warp and undulation.The sintered plates of aluminum nitride are enabled to acquire improved adhesiveness to a metal film or foil when they are subjected to a heat treatment adapted to reduce the surface roughness to or below 10 .mu.m (Rmax).

Abstract: A highly thermoconductive ceramic substrate, which is characterized by having formed on a ceramic substrate an electroconductive coating of a mixture of tungsten and/or molybdenum with the nitride of a transition metal belonging to Group IVa of the Periodic Table of Elements. As the ceramic substrate in the present invention, a non-oxide type ceramic substrate is used because of satisfactory strength. The formation of the electroconductive coating consisted preponderantly of a mixture of tungsten and/or molybdenum with the nitride of a metal belonging to Group IVa of the Periodic Table Elements is accomplished, for example, by preparing a metallizing composition in the form of a paste or solution containing a metal salt of tungstic acid or molybdic acid and a transition metal of Group IVa or a compound thereof, applying the metallizing composition on the ceramic substrate, heating the resulting composite, then firing the composite.

Abstract: Sine wave signals generated from a position detector are used as analog values to detect a fine position of a rotating or moving body, a rise or fall edge of the sine wave signal is used to detect a coarse position of the rotating or moving body, and the position or speed of the rotating or moving body is detected based on a signal indicative of the detected coarse position when the rotating or moving body is at high speed and based on a signal indicative of the detected fine position when the rotating or moving body is at low speed to thereby provide optimal control from high speed to low speed. Especially at extremely low driving, speed detection with superhigh resolution is effected using the analog value to decrease an uneven rotation of the rotating body.

Abstract: Disclosed is a position detecting method and apparatus which are suitable for detecting the position of a moving body on the basis of the output of a position detector for generating two-phase periodic waves having a phase difference of a quarter period, the method comprising the steps of: comparing either one of the two-phase periodic waves with a predetermined reference value having hysteresis to thereby obtain a roughly estimated position for every half period of the one periodic wave; analog-to-digital converting the two-phase periodic waves and a zero-cross value for every sampling period to thereby obtain a finely estimated position; and detecting the position of the moving body on the basis of the roughly estimated position and the finely estimated position while correcting an error due to the hysteresis at the starting point of the roughly estimated position, by use of the relationship between the roughly estimated position and the finely estimated position.

Abstract: When molded plates of aluminum nitride obtained by molding a ceramic powder formed preponderantly of aluminum nitride powder are superposed on a support base with a ceramic powder interposed between the support base and the superposed plates and between the superposed plates and are fired in a non-oxidative atmosphere, the sintered plates consequently produced are prevented from sustaining crack or fracture.When warped and undulated sintered plates of aluminum nitride are superposed on a support base with a ceramic powder interposed between the support base and the superposed plates and between the superposed plates and are heated in a non-oxidative atmosphere, the heated plates are relieved of warp and undulation.The sintered plates of aluminum nitride are enabled to acquire improved adhesiveness to a metal film or foil when they are subjected to a heat treatment adapted to reduce the surface roughness to or below 10 .mu.m (Rmax).

Abstract: A laminated body comprising a ceramic member and a metal member, and a method of forming the laminated body are described. The laminated body is characterized in that the ceramic member contains in its surface portion a bonding agent and the metal member is directly bonded to the surface of the ceramic member. The method of forming the laminated body is characterized in that a bonding agent-containing layer is first formed in the surface of the ceramic member and then the bonding agent-containing layer is heated while being contacted with the metal member.

Abstract: This invention resides in a substrate structure comprising a ceramic tile, a conductor layer of copper or copper alloy directly joined to the surface of the ceramic tile, and an outgoing terminal connected to the conductor layer, which substrate structure is characterized by the fact that the part of the conductor layer to which the aforementioned outgoing terminal is joined is raised from the ceramic tile so as to bridge an empty space.

Abstract: A laminated body comprising a ceramic member and a metal member, and a method of forming the laminated body are described. The laminated body is characterized in that the ceramic member contains in its surface portion a bonding agent and the metal member is directly bonded to the surface of the ceramic member. The method of forming the laminated body is characterized in that a bonding agent-containing layer is first formed in the surface of the ceramic member and then the bonding agent-containing layer is heated while being contacted with the metal member.

Abstract: A method for detecting the position and the velocity by using an encoder mounted directly on a moving body wherein original signals of the encoder are pulse-width modulated by using a sampling carrier wave and the position is detected by measuring the width of the pulses thus obtained. An apparatus for implementing the method comprises a carrier wave generation circuit, a pulse width modulation circuit which pulse-width modulates the original signals coming from the encoder by using the carrier wave, a pulse width timer which measures the width of the pulses thus modulated, and a microcomputer connected to the pulse width timer.

Abstract: A position/speed detection method and apparatus employing an encoder mounted on the rotary shaft of a motor in order to control the position and speed, wherein the coarse position and fine position are simultaneously detected by an encoder pulse and an encoder original signal, respectively and the detected results are combined to detect the position and speed of the motor with high precision.

Abstract: A method for manufacturing a semiconductor substrate. A copper sheet is placed on a surface of a ceramic plate and bonded thereto. A circuit pattern is then formed on the copper sheet by an etching process.

Abstract: An apparatus for driving a polyphase brushless motor with a resulting torque ripple effectively suppressed. The apparatus comprises a rotor position sensor, a controller responsive to the output of the sensor for generating a control signal and an inverter serving to conduct electric current to each phase of the motor as a result of commutation under control of the control signal from the controller. The controller is particularly provided with a device for increasing the value of integration of the electric current for each phase of the motor with respect to time as measured from the instant of switching among motor phase currents effected with the control signal.

Abstract: This invention relates to a motor control method and a control apparatus therefor in which an electric motor driven by a pulse width modulation inverter is digitally controlled by a digital arithmetic and logic circuit. Register file means including reference register groups, instantaneous register groups, comparison circuits and comparison output latch groups controlled in a time division mode by a stage signal is composed of a plurality of register files and the number of processing frequencies in response to the stage signal is increased, so that the motor can be controlled by a pulse width modulation signal having a fundamental wave frequency ensuring a higher resolution.