Abstract: A characteristic detection apparatus includes: a characteristic detector that detects an electrical characteristic of an electronic component placed on a substrate; and a pressing member that is provided separately from the characteristic detector, and generates a pressing force to press the characteristic detector to the substrate, causing the characteristic detector to be electrically connected to the electronic component.

Abstract: A characteristic detection apparatus includes: a characteristic detector that detects an electrical characteristic of an electronic component placed on a substrate; and a pressing member that is provided separately from the characteristic detector, and generates a pressing force to press the characteristic detector to the substrate, causing the characteristic detector to be electrically connected to the electronic component.

Abstract: An electric power converter includes a semiconductor module, a cooler, and a pair of direct current bus bars. The direct current bus bars are connected to the semiconductor. The direct current bus bars serve as current paths between the direct current power supply and the switching element. The cooler is made of metal, and is electrically connected to ground. A proximal bypass capacitor is formed close to the switching element by a heat radiating plate integrated with the semiconductor module, the cooler, and an insulating layer interposed between them. The electric power converter further includes a pair of distal bypass capacitors, each of which has a larger capacitance than the proximal bypass capacitor has, and has a current path to the switching element of which a length is longer than a current path to the switching element from the proximal bypass capacitor.

Abstract: In a power converter, a housing is grounded. A power converter circuit is installed in the housing and configured to perform power conversion of input power into output power. An external terminal is electrically connected to the power converter circuit for connection of an external device to the power converter circuit. A first capacitor has first and second electrodes. The first electrode of the first capacitor is connected to the external terminal, and the second electrode thereof is connected to the housing. A second capacitor has first and second electrodes. The first electrode of the second capacitor is connected to the external terminal, and the second electrode thereof is connected to the housing. The first capacitor, the external terminal, the second capacitor, and the housing is arranged to provide a conductive loop.

Abstract: In a power converter, an external terminal, a case, and capacitors are arranged to provide a conductive loop. The conductive loop defines thereinside a first region through which magnetic flux of an AC magnetic field penetrates, and a second region through which the magnetic flux penetrates. A magnetic-flux shielding member partly shields at least one of the first region and the second region from penetration of the magnetic flux of the AC magnetic field to adjust at least one of an amount of the magnetic flux penetrating through one of the first region and the second region, and an amount of the magnetic flux penetrating through the other thereof.

Abstract: A noise filter is assembled to an electric power conversion device and has a metal housing casing and two capacitors connected to an external terminal of the device through which an electric power conversion circuit is connected to an external device. The two capacitors, the housing casing and the external terminal make a current loop. A magnetic flux of an alternating magnetic field generated in a part of the electric power conversion circuit penetrates in a first area and a second area formed in the current loop. A first induced noise current is induced in the current loop when the magnetic flux of the generated magnetic field penetrates in the first area. A second induced noise current is induced in the current loop when the magnetic flux penetrates in the second area so that the first induced noise current flows in a reverse direction to the second induced noise current.

Abstract: An electric power converter apparatus incorporates a plurality of electric power converter circuits having respective output terminals connected in common, with output power being produced from the common output terminals. Each converter circuit uses an identical switching frequency, in executing power conversion based on PWM control of switching by a plurality of switching elements. The switching operations of the respective converter circuits mutually differ in phase, by an amount determined in accordance with the currently applied PWM duty ratio. The phase difference value is predetermined for minimizing the amplitude of specific harmonic frequency components of a ripple current component in the output current from the apparatus.

Abstract: An electrical device has a housing that includes a main body and a lid both of which are electrically conductive. The lid is fastened to a top surface of a sidewall of the main body so as to cover the main body. On at least one of a bottom surface of the lid and the top surface of the sidewall of the main body, there are formed a plurality of protrusions at predetermined positions; each of the protrusions abuts against that one of the bottom surface of the lid and the top surface of the sidewall which is opposed to the protrusion. Except at those predetermined positions where the protrusions are formed, there is provided, between the bottom surface of the lid and the top surface of the sidewall of the main body, a gap via which the internal and external spaces of the housing communicate with each other.

Abstract: An electric power converter apparatus incorporates a plurality of electric power converter circuits having respective output terminals connected in common, with output power being produced from the common output terminals. Each converter circuit uses an identical switching frequency, in executing power conversion based on PWM control of switching by a plurality of switching elements. The switching operations of the respective converter circuits mutually differ in phase, by an amount determined in accordance with the currently applied PWM duty ratio. The phase difference value is predetermined for minimizing the amplitude of specific harmonic frequency components of a ripple current component in the output current from the apparatus.

Abstract: An electric power converter includes a semiconductor module, a cooler, and a pair of direct current bus bars. The direct current bus bars are connected to the semiconductor. The direct current bus bars serve as current paths between the direct current power supply and the switching element. The cooler is made of metal, and is electrically connected to ground. A proximal bypass capacitor is formed close to the switching element by a heat radiating plate integrated with the semiconductor module, the cooler, and an insulating layer interposed between them. The electric power converter further includes a pair of distal bypass capacitors, each of which has a larger capacitance than the proximal bypass capacitor has, and has a current path to the switching element of which a length is longer than a current path to the switching element from the proximal bypass capacitor.

Abstract: In a power converter, an external terminal, a case, and capacitors are arranged to provide a conductive loop. The conductive loop defines thereinside a first region through which magnetic flux of an AC magnetic field penetrates, and a second region through which the magnetic flux penetrates. A magnetic-flux shielding member partly shields at least one of the first region and the second region from penetration of the magnetic flux of the AC magnetic field to adjust at least one of an amount of the magnetic flux penetrating through one of the first region and the second region, and an amount of the magnetic flux penetrating through the other thereof.

Abstract: A power supply apparatus includes a magnetic component having a coil section, a conductive case body housing the magnetic component and having an opening plane facing an axial direction of the coil section, a case lid closing the opening plane, and conductive parts electrically connecting the case body and the case lid to each other at the opening plane. The conductive parts are provided so as to satisfy a positional relationship that at least one of the conductive parts is disposed at an intersection point at which a straight line making an angle within a range of 45±15 degrees with a perpendicular line drawn from a center of the coil section to a closest one of the side plate portions of the case body to the center intersects with the closest one of side plate portions when viewed from the axial direction.

Abstract: In a power converter, a housing is grounded. A power converter circuit is installed in the housing and configured to perform power conversion of input power into output power. An external terminal is electrically connected to the power converter circuit for connection of an external device to the power converter circuit. A first capacitor has first and second electrodes. The first electrode of the first capacitor is connected to the external terminal, and the second electrode thereof is connected to the housing. A second capacitor has first and second electrodes. The first electrode of the second capacitor is connected to the external terminal, and the second electrode thereof is connected to the housing. The first capacitor, the external terminal, the second capacitor, and the housing is arranged to provide a conductive loop.

Abstract: A noise filter is assembled to an electric power conversion device and has a metal housing casing and two capacitors connected to an external terminal of the device through which an electric power conversion circuit is connected to an external device. The two capacitors, the housing casing and the external terminal make a current loop. A magnetic flux of an alternating magnetic field generated in a part of the electric power conversion circuit penetrates in a first area and a second area formed in the current loop. A first induced noise current is induced in the current loop when the magnetic flux of the generated magnetic field penetrates in the first area. A second induced noise current is induced in the current loop when the magnetic flux penetrates in the second area so that the first induced noise current flows in a reverse direction to the second induced noise current.

Abstract: A power supply apparatus includes a magnetic component having a coil section, a conductive case body housing the magnetic component and having an opening plane facing an axial direction of the coil section, a case lid closing the opening plane, and conductive parts electrically connecting the case body and the case lid to each other at the opening plane. The conductive parts are provided so as to satisfy a positional relationship that at least one of the conductive parts is disposed at an intersection point at which a straight line making an angle within a range of 45±15 degrees with a perpendicular line drawn from a center of the coil section to a closest one of the side plate portions of the case body to the center intersects with the closest one of side plate portions when viewed from the axial direction.

Abstract: An electrical device has a housing that includes a main body and a lid both of which are electrically conductive. The lid is fastened to a top surface of a sidewall of the main body so as to cover the main body. On at least one of a bottom surface of the lid and the top surface of the sidewall of the main body, there are formed a plurality of protrusions at predetermined positions; each of the protrusions abuts against that one of the bottom surface of the lid and the top surface of the sidewall which is opposed to the protrusion. Except at those predetermined positions where the protrusions are formed, there is provided, between the bottom surface of the lid and the top surface of the sidewall of the main body, a gap via which the internal and external spaces of the housing communicate with each other.

Abstract: A power converter that is able to lower the level of switching noise in a wide frequency range is disclosed. In detail, the power converter converts an input power by controlling a switching element on the basis of a switching frequency discrete pattern. The switching frequency discrete pattern is composed in such a manner that a main discrete pattern and a sub discrete pattern are synthesized. The main discrete pattern is regulated by a plurality of transitionally discrete frequencies. Also the sub discrete pattern is regulated by a plurality of transitionally discrete frequencies in which a gap of the magnitude among consequent frequencies is smaller than that of the main discrete pattern.

Abstract: An antenna for a portable radio communication device is constructed with a conductive shield plate provided in a casing made of resin and shaped to be worn on a human body. The shield plate is capacitively coupled with a part of the human body to operate as an antenna element. A conductive cover of a battery is disposed in the casing to operate as the other antenna element. The antenna elements thus form an electric field-type dipole antenna. The conductive cover of the battery may also be capacitively coupled with the other part of the human body, so that the antenna operate as a loop antenna which uses the human body. The electric field-type antenna may be combined with a magnetic field-type antenna to make the directivity of the antenna to be isotropic.

Abstract: An antenna for a portable radio communication device is constructed with a conductive shield plate provided in a casing made of resin and shaped to be worn on a human body. The shield plate is capacitively coupled with a part of the human body to operate as an antenna element. A conductive cover of a battery is disposed in the casing to operate as the other antenna element. The antenna elements thus form an electric field-type dipole antenna. The conductive cover of the battery may also be capacitively coupled with the other part of the human body, so that the antenna operate as a loop antenna which uses the human body. The electric field-type antenna may be combined with a magnetic field-type antenna to make the directivity of the antenna to be isotropic.

Abstract: A finger-ring-type radio device is worn by a person to wirelessly transmit his physical data such as blood pressure or pulsation. The radio device is composed of a finger ring having a slot antenna as a magnetic-field-mode antenna and a flat plate having a patterned antenna as an electric-field-mode antenna. A transmission circuit for generating high frequency signals representing the physical data is also mounted on the flat plate. Both antennas having respective characteristics and radiation directivities are combined to form a composite antenna from which the high frequency signals are radiated. The radiation efficiency of the composite antenna is improved by combining both antennas. The slot length of the slot antenna is extended by forming it in a zigzag shape, so that the slot length properly corresponds to the high frequency to be radiated and the antenna efficiency is improved.