Abstract: An electric vehicle control device includes a first inverter controlling a first group defined by induction motors, and a second inverter controlling a second group defined by induction motors. The first inverter and the induction motors of the first group are connected to each other by a first conductor. The second inverter and the induction motors of the second group are connected by a second conductor. A first length is equal to or less than three times the average value of a second length and a third length. The first length is an inter-center distance between the first conductor and the second conductor, the second length is the maximum length of a conductor portion of the first conductor in the cross section of the first conductor, and the third length is the maximum length of a conductor portion of the second conductor in the cross section of the second conductor.

Abstract: An electric vehicle control device includes a first inverter controlling a first group defined by induction motors, and a second inverter controlling a second group defined by induction motors. The first inverter and the induction motors of the first group are connected to each other by a first conductor. The second inverter and the induction motors of the second group are connected by a second conductor. A first length is equal to or less than three times the average value of a second length and a third length. The first length is an inter-center distance between the first conductor and the second conductor, the second length is the maximum length of a conductor portion of the first conductor in the cross section of the first conductor, and the third length is the maximum length of a conductor portion of the second conductor in the cross section of the second conductor.

Abstract: Provided is a choke coil capable of improving a noise reduction effect by sufficiently attenuating magnetic field coupling between the choke coil and a metal part. A connector connection line includes: a first connection line led out from a connector conductor side of a coil main body of a winding wire along a y-axis direction away from the coil main body; a second connection line led out from the first connection line at a corner portion of a first pier column or a second pier column along a x-axis direction away from a connector conductor; a third connection line led out from the second connection line along a z-axis direction toward a lower yoke; and a fourth connection line led out from the third connection line along the x-axis direction toward the connector conductor.

Abstract: A motor includes a stator formed by stacking a plurality of core sheets. A plurality of stator windings are wound around a plurality of tooth portions of the stator. A rotor is freely rotatable on an inner peripheral side of the stator. A noise bypass line has one end connected to a core back portion of an outermost core sheet included in the stator and another end grounded to a ground (GND) of a power conversion circuit that drives the motor.

Abstract: A motor includes a stator formed by stacking a plurality of core sheets. A plurality of stator windings are wound around a plurality of tooth portions of the stator. A rotor is freely rotatable on an inner peripheral side of the stator. A noise bypass line has one end connected to a core back portion of an outermost core sheet included in the stator and another end grounded to a ground (GND) of a power conversion circuit that drives the motor.

Abstract: A noise filter includes a center conductor, at least one outer conductor, and a core. The outer conductor is cylindrical in shape, and the center conductor is inserted through the interior of the outer conductor. The core is a cylindrical magnetic body, and the center conductor and the at least one outer conductor are inserted through the interior of the core. The center conductor and the at least one outer conductor are insulated from each other. Phase currents for each phase of a symmetrical polyphase alternating current flow through the center conductor and the at least one outer conductor.

Abstract: A dual-mode choke coil includes: a lower core that has a first through fourth columnar body; a first upper core and a second upper core; a first coil in which two coil conductors are respectively wound onto the first columnar body and a third columnar body in mutually different directions and are connected in series; and a second coil in which two coil conductors are respectively wound onto a second columnar body and the fourth columnar body in mutually different directions and are connected in series, and in which the winding direction of the coil conductor of the second columnar body is the same as that of the coil conductor of the first columnar body. With this configuration, both common mode noise and normal mode noise can be reduced.

Abstract: Provided is a choke coil capable of improving a noise reduction effect by sufficiently attenuating magnetic field coupling between the choke coil and a metal part. A connector connection line includes: a first connection line led out from a connector conductor side of a coil main body of a winding wire along a y-axis direction away from the coil main body; a second connection line led out from the first connection line at a corner portion of a first pier column or a second pier column along a x-axis direction away from a connector conductor; a third connection line led out from the second connection line along a z-axis direction toward a lower yoke; and a fourth connection line led out from the third connection line along the x-axis direction toward the connector conductor.

Abstract: An electric-vehicle propulsion control apparatus includes a filter device and a power converter. The filter device is configured such that a first inductance element, a third inductance element, and a capacitor element are connected in series to constitute a series circuit, one end of the series circuit is electrically connected to low-potential-side power supply wiring connecting a rail and the power converter; the other end thereof is electrically connected to high-potential-side power supply wiring connecting an overhead line and the power converter; a second inductance element, provided between an electrical connection point of the other end of the series circuit and the overhead line, and the first inductance element are magnetically coupled; and the magnetic coupling generates mutual inductance having a positive value between the electrical connection point of the one end of the series circuit and the power converter.

Abstract: A dual-mode choke coil includes: a lower core that has a first through fourth columnar body; a first upper core and a second upper core; a first coil in which two coil conductors are respectively wound onto the first columnar body and a third columnar body in mutually different directions and are connected in series; and a second coil in which two coil conductors are respectively wound onto a second columnar body and the fourth columnar body in mutually different directions and are connected in series, and in which the winding direction of the coil conductor of the second columnar body is the same as that of the coil conductor of the first columnar body. With this configuration, both common mode noise and normal mode noise can be reduced.

Abstract: A power conversion device includes an inverter that drives a motor; a fin that cools down the inverter; a first core including a through hole that allows passage of a positive side conductor that connects a power supply system and the inverter and a negative side conductor that grounds the inverter; a ground conductor that grounds the fin; a ground conductor that grounds a motor yoke via a capacitor; and a ground conductor including one end that is connected to the negative side conductor or the ground conductor and the other end that is grounded.

Abstract: A power conversion device includes an inverter that drives a motor; a fin that cools down the inverter; a first core including a through hole that allows passage of a positive side conductor that connects a power supply system and the inverter and a negative side conductor that grounds the inverter; a ground conductor that grounds the fin; a ground conductor that grounds a motor yoke via a capacitor; and a ground conductor including one end that is connected to the negative side conductor or the ground conductor and the other end that is grounded.

Abstract: This invention provides an electronic control unit is capable of suppressing electromagnetic noise having a frequency band used in a portable wireless apparatus, and capable of exhibiting a noise resistance property against electromagnetic noise. The electronic control unit including a constant voltage power supply circuit portion, an analog signal inputting circuit portion, and a conversion processing circuit portion, an analog sensor and a driving power supply being connected to the outside, and the unit being connected to the analog sensor through a power supply line and a signal line, in which the analog signal inputting circuit portion includes a current limiting circuit portion, an integrating circuit portion, a current limiting resistor, a signal noise absorbing circuit, and a first bypass capacitor, and capacitance (C1) and parasitic inductance (L1) of the first bypass capacitor are set in a range of 7×106<1/[2??(L1×C1)]<35×106.

Abstract: This invention provides an electronic control unit is capable of suppressing electromagnetic noise having a frequency band used in a portable wireless apparatus, and capable of exhibiting a noise resistance property against electromagnetic noise. The electronic control unit including a constant voltage power supply circuit portion, an analog signal inputting circuit portion, and a conversion processing circuit portion, an analog sensor and a driving power supply being connected to the outside, and the unit being connected to the analog sensor through a power supply line and a signal line, in which the analog signal inputting circuit portion includes a current limiting circuit portion, an integrating circuit portion, a current limiting resistor, a signal noise absorbing circuit, and a first bypass capacitor, and capacitance (C1) and parasitic inductance (L1) of the first bypass capacitor are set in a range of 7×106<1/[2??(L1×C1)]<35×106.

Abstract: A multi-layer printed board including signal layers, each signal layer including a signal line, a through-hole, and a ground through-hole. The signal layer includes a land connecting the through-hole and the signal line. An external periphery of the land has a first portion farthest from a center of the land, and a second portion extending a shorter distance from the center of the land than the first portion. A portion of the external periphery of the land opposite to the ground through-hole closest to the center of the land is the second portion. Consequently, impedance matching can be improved even if a signal frequency is high.

Abstract: A multi-layer printed board including signal layers, each signal layer including a signal line, a through-hole, and a ground through-hole. The signal layer includes a land connecting the through-hole and the signal line. An external periphery of the land has a first portion farthest from a center of the land, and a second portion extending a shorter distance from the center of the land than the first portion. A portion of the external periphery of the land opposite to the ground through-hole closest to the center of the land, is the second portion. Consequently, impedance matching can be improved even if a signal frequency is high.

Abstract: The invention provides a compact mobile radio transmitter in which deterioration of antenna characteristic due to the influence of human head is decreased. A dielectric material 15 is arranged between a back face of a speaker 12 and a feed point 14 of an antenna 13, and electrical length between the human head and the antenna is increased as compared with the structure without the dielectric material 15.

Abstract: Disclosed is a semiconductor device comprising an undoped GaAs layer, an intermediate undoped layer and an undoped Ga.sub.1-x Al.sub.x As layer which are successively provided on a substrate made of a semiinsulating GaAs crystal; the intermediate undoped layer being an undoped In.sub.y Ga.sub.1-y As layer, an undoped GaAs.sub.1-z Sb.sub.z layer, a superlattice layer which includes an undoped In.sub.y Ga.sub.1-y As layer and an undoped GaAs.sub.1-z Sb.sub.z layer, a superlattice layer which includes an undoped In.sub.y Ga.sub.1-y As layer and an undoped GaAs layer, or a superlattice layer which includes an undoped GaAs.sub.1-z Sb layer and an undoped GaAs layer. When applied to a high electron mobility transistor, this semiconductor device affords a high current and a high speed and has the merit of a small dispersion in the threshold voltage thereof.

Abstract: Disclosed is a semiconductor device comprising an undoped GaAs layer, an intermediate undoped layer and an undoped Ga.sub.1-x Al.sub.x As layer which are successively provided on a substrate made of a semiinsulating GaAs crystal; the intermediate undoped layer being an undoped In.sub.y Ga.sub.1-y As layer, an undoped GaAs.sub.1-z Sb.sub.z layer, a superlattice layer which includes an undoped In.sub.y Ga.sub.1-y As layer and an undoped GaAs.sub.1-z Sb.sub.z layer, a superlattice layer which includes an undoped In.sub.y Ga.sub.1-y As layer and an undoped GaAs layer, or a superlattice layer which includes an undoped GaAs.sub.1-z Sb layer and an undoped GaAs layer. When applied to a high electron mobility transistor, this semiconductor device affords a high current and a high speed and has the merit of a small dispersion in the threshold voltage thereof.

Abstract: In a semiconductor laser device according to the invention, a clad layer includes first clad layers, each of which has a greater band gap than an active layer and has a thickness of 0.003 to 0.3 .mu.m, and second clad layers each of which has a lower refractive index than the active layer, and the first clad layers are disposed nearer to the active layer than the second clad layers, respectively. In this structure, the first clad layers confine carriers in the active layer while the second clad layers confine the light in the active layer. Since each of the first clad layers is formed of a thin film, the carriers are hard to move outwardly from the active layer due to the tunnel phenomenon thereof and, even if the lattice constant thereof is slightly different, the first clad layer can be lattice matched to a substrate. For this reason, the materials of the second clad layers can be selected without taking into consideration the size of the band gap thereof.