Abstract: A power supply device is connectable to a single-phase AC power supply or a multi-phase AC power supply. The power supply device includes power conversion circuits, a relay circuit, and a processor. The relay circuit is capable of switching between a first state and a second state. In the first state, a power supply line of each phase of the multi-phase AC power supply is connected to a corresponding power conversion circuit. In the second state, a power supply line of the single-phase AC power supply is connected to two or more of the power conversion circuits. The processor controls output timing of a control signal for operating the relay circuit on the basis of a detected temperature. The output timing is controlled such that, the first state is switched to the second state at timing when an AC voltage of the single-phase AC power supply crosses zero.

Abstract: A DC-DC converter outputs a DC output voltage between first and second output terminals, and includes: a conversion circuit that outputs an intermediate voltage obtained by performing power conversion on an input voltage, between first and second intermediate terminals; a first coil provided between the first intermediate terminal and the first output terminal; and a diode provided in series with a second coil. A DC voltage is applied to the second coil and the diode, with a polarity in a direction in which a reverse bias is applied to the diode. The first coil and the second coil are magnetically coupled such that a current is made flow through the second coil in a forward direction of the diode by mutual induction as a current flowing through the first coil in a direction from the first intermediate terminal to the first output terminal increases.

Abstract: A DC-DC converter includes: a DC-AC conversion circuit that converts a DC input voltage into a primary AC voltage; a transformer including a primary coil to which the primary AC voltage is applied and generates a secondary AC voltage at a secondary coil; a rectifier circuit that outputs a rectified voltage obtained by full-wave rectifying the secondary AC voltage; a smoothing circuit that smooths the rectified voltage; and a control circuit that causes the rectifier circuit to perform rectification by a diode such that, in a free-wheeling period in which power of the input voltage is not transmitted to the transformer, a current does not flow via the rectifier circuit from a first intermediate terminal to a second intermediate terminal, the first and second intermediate terminals connected to the smoothing circuit, and a current flows via the rectifier circuit from the second intermediate terminal to the first intermediate terminal.

Abstract: A charging system includes an AC/DC converter a DC/DC converter, and a control circuit. The AC/DC converter is connected between first/second input nodes and first/second intermediate nodes and is connected to an AC power supply via the first/second input nodes. The DC/DC converter is connected between the first/second intermediate nodes and first/second output nodes and is connectable to a battery via the first/second output nodes. The DC/DC converter includes an isolation transformer, a primary circuit, and a secondary circuit. The primary circuit includes switching elements. The control circuit causes the switching elements to start operation at a first frequency when the AC/DC converter and the DC/DC converter are activated, and causes the switching elements to operate at a second frequency when the AC/DC converter and the DC/DC converter are in steady operation. The first frequency is higher than the second frequency.

Abstract: A charging system according to the present disclosure includes an AC-DC converter, a DC-DC converter, and a control circuit. The AC-DC converter is connected between an input node and an intermediate node. The AC-DC converter is connectable to a power source via the input node. The DC-DC converter is connected between the intermediate node and an output node. The DC-DC converter is connectable to a battery via the output node. The control circuit is configured to control a voltage of the intermediate node so as to reduce a sum of a loss in the AC-DC converter and a loss in the DC-DC converter, in accordance with a first parameter, a second parameter, and a third parameter. The first parameter is related to input power of the AC-DC converter. The second parameter is related to output power of the DC-DC converter. The third parameter is related to an ambient temperature.

Abstract: A DC-DC converter includes a DC-AC conversion circuit, a transformer, rectifier circuits, smoothing circuits, and an output circuit. The DC-AC conversion circuit converts a DC input voltage to a primary-side AC voltage. The transformer includes a primary-side coil to which the primary-side AC voltage is applied, and secondary-side coils magnetically coupled to the primary-side coil. The rectifier circuits are provided in one-to-one correspondence with the secondary-side coils. Each of the rectifier circuits outputs a rectification voltage resulting from full-wave rectification on the secondary-side AC voltage output from the corresponding secondary-side coil out of the secondary-side coils. The smoothing circuits are provided in one-to-one correspondence with the rectifier circuits. Each of the smoothing circuits smooths the rectification voltage output from the corresponding rectifier circuit out of the rectifier circuits.

Abstract: A DC-DC converter outputs a DC output voltage between first and second output terminals, and includes: a conversion circuit that outputs an intermediate voltage obtained by performing power conversion on an input voltage, between first and second intermediate terminals; a first coil provided between the first intermediate terminal and the first output terminal; and a diode provided in series with a second coil. A DC voltage is applied to the second coil and the diode, with a polarity in a direction in which a reverse bias is applied to the diode. The first coil and the second coil are magnetically coupled such that a current is made flow through the second coil in a forward direction of the diode by mutual induction as a current flowing through the first coil in a direction from the first intermediate terminal to the first output terminal increases.

Abstract: A DC-DC converter includes a DC-AC conversion circuit, a transformer, rectifier circuits, smoothing circuits, and an output circuit. The DC-AC conversion circuit converts a DC input voltage to a primary-side AC voltage. The transformer includes a primary-side coil to which the primary-side AC voltage is applied, and secondary-side coils magnetically coupled to the primary-side coil. The rectifier circuits are provided in one-to-one correspondence with the secondary-side coils. Each of the rectifier circuits outputs a rectification voltage resulting from full-wave rectification on the secondary-side AC voltage output from the corresponding secondary-side coil out of the secondary-side coils. The smoothing circuits are provided in one-to-one correspondence with the rectifier circuits. Each of the smoothing circuits smooths the rectification voltage output from the corresponding rectifier circuit out of the rectifier circuits.

Abstract: A power transmitting device includes: an inverter circuit; a power transmitting antenna connected to the inverter circuit, and being electromagnetically coupled to a power receiving antenna in a power receiving device to wirelessly transmit electric power thereto; a detector to detect an output voltage and an output current of the inverter circuit; and a control circuit to control the inverter circuit. The control circuit consecutively drives the inverter circuit at a plurality of frequencies, determines from among the plurality of frequencies a frequency at which a phase difference that is indicative of a lag of a phase of the output current relative to a phase of the output voltage becomes largest, and performs power transmission by driving the inverter circuit at an operating frequency that is based on the determined frequency.

Abstract: A power receiving device includes: a power receiving antenna to wirelessly receive AC power from a power transmitting antenna in the power transmitting device; a power receiving circuit to convert the AC power received by the power receiving antenna into DC power and to output the DC power; an impedance adjustment circuit disposed on a transmission path between a load that utilizes the DC power and the power receiving antenna, the impedance adjustment circuit being capable of causing a change in input impedance thereof; and a power reception control circuit to control the impedance adjustment circuit. The power reception control circuit consecutively changes a value of the input impedance of the impedance adjustment circuit to a value selected from among a plurality of values, determines from among the plurality of values a value at which power to be supplied to the load becomes largest, and sets and maintains the input impedance at an operating impedance value that is based on the determined value.

Abstract: Power transmission is properly stopped before an electrical storage device becomes fully charged. A power transmitting device includes two transmission electrodes and a power transmitting circuit to supply AC power to the two transmission electrodes. The power receiving device includes: two reception electrodes being respectively opposed to the two transmission electrodes to receive the AC power from the two transmission electrodes; a power receiving circuit to convert the AC power received by the two reception electrodes into DC power and to output the DC power; a charge-discharge control circuit to control charging and discharging of the electrical storage device; and an impedance adjustment circuit to change an input impedance in accordance with a charge state of the electrical storage device as detected by the charge-discharge control circuit.

Abstract: Provided is an RFID tag, wherein a communication distance of several centimeter or more can be secured and the cost of which can be reduced in comparison to conventional on-chip antennas, even when being compact in size (square shaped with a side of 1.9 to 13 mm). The RFID tag (80) comprises an antenna (20), an IC chip (30) connected to the antenna (20), and a sealing material (10) that seals the IC chip (30) and the antenna (20). The antenna (20) is a coil antenna or a loop antenna, and the resonance frequency (f0) of an electric circuit constituted by the inductance (L) of the antenna (20) and the capacitance (C) of the IC chip (30) is equal to the operation frequency of the IC chip (30), or in the vicinity thereof.

Abstract: A polymer having bis(diphenylphosphino)binaphthyl groups that can be used as a catalyst for an addition reaction, especially an asymmetric 1,4-addition reaction, or a reduction reaction, especially an asymmetric reduction reaction, and that can be easily recovered and recycled. The polymer having the bis(diphenylphosphino)binaphthyl groups is one resulting from repetition of a racemic or optically active 2,2?-bis(diphenylphosphino)-1,1?-binaphthyl compound substituted at 5-position thereof with an unsaturated terminal of one (meth)acryloyl group of a compound having multiple (meth)acryloyl groups, that another 2,2?-bis(diphenylphosphino)-1,1?-binaphthyl compound of a next unit is substituted at 5?-position thereof with an unsaturated terminal of another (meth)acryloyl group of the compound having multiple (meth)acryloyl groups so as to have a molecular weight of 1500 to 10000. The reduction catalyst comprises this polymer and a transition metal.

Abstract: An RFID tag having a resin substrate, an IC chip positioned in the center section on the substrate, a single-layer antenna for forming an electric closed circuit by connecting with the IC chip and positioned in the peripheral section of the IC chip, and a sealing material for sealing the IC chip and the antenna, wherein the antenna is a coil antenna or a loop antenna, the resonant frequency (f0) of the antenna is the operating frequency of the IC chip or thereabouts, the operating frequency of the IC chip is 13.56 MHz-2.45 GHz, or 0.86-0.96 GHz, and the size of the RFID tag is 13 mm or less in length, 13 mm or less in width, and 1.0 mm or less in height; and an automatic recognition system using the same.

Abstract: Provided is an RFID tag, wherein a communication distance of several centimeter or more can be secured and the cost of which can be reduced in comparison to conventional on-chip antennas, even when being compact in size (square shaped with a side of 1.9 to 13 mm). The RFID tag (80) comprises an antenna (20), an IC chip (30) connected to the antenna (20), and a sealing material (10) that seals the IC chip (30) and the antenna (20). The antenna (20) is a coil antenna or a loop antenna, and the resonance frequency (f0) of an electric circuit constituted by the inductance (L) of the antenna (20) and the capacitance (C) of the IC chip (30) is equal to the operation frequency of the IC chip (30), or in the vicinity thereof.

Abstract: A ridge stripe semiconductor laser device includes a first conductivity type cladding layer 103, an active layer 104, a second conductivity type first cladding layer 105, a second conductivity type second cladding layer 108 in a ridge-shaped stripe for confining light in a horizontal transverse direction, and a current blocking layer 107 formed in a region except for at least a part on a ridge that are disposed on a semiconductor substrate 102. In a cross-section perpendicular to a stripe direction of the ridge, each of both lateral surfaces of the ridge includes a first surface 118 that is substantially perpendicular to a surface of the semiconductor substrate and extends downward from an upper end of the ridge, and a second surface 119 that is formed of a substantially linear skirt portion inclined surface that is inclined obliquely downward to an outside of the ridge in a skirt portion of the ridge.

Abstract: A polymer having bis(diphenylphosphino)binaphthyl groups that can be used as a catalyst for an addition reaction, especially an asymmetric 1,4-addition reaction, or a reduction reaction, especially an asymmetric reduction reaction, and that can be easily recovered and recycled. The polymer having the bis(diphenylphosphino)binaphthyl groups is one resulting from repetition of a racemic or optically active 2,2?-bis(diphenylphosphino)-1,1?-binaphthyl compound substituted at 5-position thereof with an unsaturated terminal of one (meth)acryloyl group of a compound having multiple (meth)acryloyl groups, that another 2,2?-bis(diphenylphosphino)-1,1?-binaphthyl compound of a next unit is substituted at 5?-position thereof with an unsaturated terminal of another (meth)acryloyl group of the compound having multiple (meth)acryloyl groups so as to have a molecular weight of 1500 to 10000. The reduction catalyst comprises this polymer and a transition metal.

Abstract: A ridge stripe type semiconductor laser device is provided, on a semiconductor substrate (102), with a first conduction type cladding layer (103), an active layer (104), a second conduction type first cladding layer (105), a second conduction type second cladding layer (108) of a ridge type stripe shape for confining direction, and a current block layer (107) formed by removing at least an upper portion of the ridge. In a section normal to the stripe direction of the ridge, each of the two side faces of the ridge is provided with a first face (118) substantially normal to the semiconductor substrate surface and extending downward from the upper end of the ridge, and a second face (119) formed to have a substantially straight skirt slope face inclined at the ridge skirt portion obliquely downward to the ridge outside. The first face and the second face are made to merge either directly or through a third intermediate face into each other.