Abstract: An electronic circuit to receive input AC signals having different phases, and to control bidirectional switches corresponding to phases to generate, based on input AC signals having the phases, output AC signals having the phases and having a frequency different from a frequency of the input AC signals, the electronic circuit has reference signal circuitry to generate a reference signal having a frequency higher than the frequency of the output AC signals, and a commutation circuitry to control switching between voltage commutation and current commutation, wherein, in the voltage commutation, the commutation circuitry switches the bidirectional switches corresponding to the phases in sequence based on a voltage level of the output AC signals of the phases before and after a time point when an amplitude of the reference signal becomes a specific amplitude value, and in the current commutation, the commutation circuitry switches the bidirectional switches in parallel.

Abstract: A power transmitting apparatus including a power supply to generate AC power; a power transmitting inductor to transfer the AC power to a power receiving apparatus through magnetic coupling with a power receiving inductor in the power receiving apparatus; a mutual coupling adjusting unit to adjust a relative position between the power transmitting inductor and the power receiving inductor; and a control unit to control the mutual coupling adjusting unit based on a mutual coupling coefficient between the power transmitting inductor and the power receiving inductor. The control unit controls the mutual coupling adjusting unit so that the mutual coupling coefficient falls within a predetermined range and an upper limit of the predetermined range is a value less than a maximum of the mutual coupling coefficient between the power transmitting inductor and the power receiving inductor.

Abstract: An electronic circuit to receive input AC signals having different phases, and to control bidirectional switches corresponding to phases to generate, based on input AC signals having the phases, output AC signals having the phases and having a frequency different from a frequency of the input AC signals, the electronic circuit has reference signal circuitry to generate a reference signal having a frequency higher than the frequency of the output AC signals, and a commutation circuitry to control switching between voltage commutation and current commutation, wherein, in the voltage commutation, the commutation circuitry switches the bidirectional switches corresponding to the phases in sequence based on a voltage level of the output AC signals of the phases before and after a time point when an amplitude of the reference signal becomes a specific amplitude value, and in the current commutation, the commutation circuitry switches the bidirectional switches in parallel.

Abstract: An inductor unit according to one embodiment includes a first inductor comprising a first core and a first winding wound around the first core; and a second inductor comprising a second core and a second winding wound around the second core. The first inductor and the second inductor are disposed so that an angle is larger than 0 degree and smaller than 90 degrees. The angle is formed by: a first straight line coupling a first intersection point of a first center line in parallel with a first magnetic flux direction of the first core and a second center line perpendicular to the first magnetic flux direction, and a second intersection point of a third center line in parallel with the second magnetic flux direction of the second core and a fourth center line perpendicular to the second magnetic flux direction; and the first center line.

Abstract: According to one embodiment, a power transmission device including a housing for landing a vehicle, and a ferromagnetic material and a power transmission coil. An outer shape of a cross-section of the housing becomes larger from a top of the housing toward a bottom of the housing, the outer shape is a non-true circle, and the outer shape is similar to an inner shape of a frame provided in the vehicle. The ferromagnetic material is within the housing, the ferromagnetic material being continuous in an up-and-down direction of the housing. The power transmission coil is within the housing, the power transmission coil being configured to surround the ferromagnetic material.

Abstract: A power transmission apparatus includes a power transmission pad, a base structure, and grout. The power transmission pad for wireless power transmission has a cast resin frame, at least part of the cast resin frame being embedded in the ground. The base structure is disposed below the power transmission pad. The grout is filled around the power transmission pad, including a gap between an upper surface of the base structure and the power transmission pad.

Abstract: A power transmission device according to one embodiment, includes a first power transmission resonator configured to wirelessly transmits power; a second power transmission resonator configured to wirelessly transmits power; a first power supply configured to output AC power to the first power transmission resonator; and a second power supply configured to output AC power having a frequency different from that of the first power supply to the second power transmission resonator. An operating band of the first power transmission resonator includes the frequency of the first power supply and does not include the frequency of the second power supply. An operating band of the second power transmission resonator does not include the frequency of the first power supply and includes the frequency of the second power supply.

Abstract: An inductor according to one embodiment includes a magnetic core, a case, a winding, and a resin. The case is configured to house the magnetic core. The winding is configured to be wound around the case. The resin is configured to be formed of a first resin to cover the case and the winding. A difference between an inside dimension of the case and a dimension of the magnetic core in the same direction is greater than a variation of a dimension of the case in the direction when forming the resin.

Abstract: According to one embodiment, a power transmission device including a housing for landing a vehicle, and a ferromagnetic material and a power transmission coil. An outer shape of a cross-section of the housing becomes larger from a top of the housing toward a bottom of the housing, the outer shape is a non-true circle, and the outer shape is similar to an inner shape of a frame provided in the vehicle. The ferromagnetic material is within the housing, the ferromagnetic material being continuous in an up-and-down direction of the housing. The power transmission coil is within the housing, the power transmission coil being configured to surround the ferromagnetic material.

Abstract: In one embodiment, a coil includes a magnetic core and a winding. The magnetic core includes at least one block provided with a groove or an opening. Each block is arranged so as to make the groove or the opening extend along a direction of magnetic flux. The coil is used as a power transmitting coil or a power receiving coil.

Abstract: According to one embodiment, there is provided a power transmitting device including: a power supply, a resonator, an adjuster and a controller. The power supply supplies AC power. The resonator includes a magnetic core and a coil wound around the magnetic core, the resonator wirelessly transmitting the AC power supplied from the power supply to a different resonator arranged to be opposed to the resonator. The adjuster relatively moves the coil and the magnetic core along a longitudinal direction of the coil. The controller controls the adjuster based on a value of current flowing in the resonator to adjust relative positions of the magnetic core and the coil.

Abstract: According to one embodiment, a power transmission device includes: a power transmitter, a frequency control circuit and a voltage control circuit. The power transmitter transmits AC power by causing a coil to generate a magnetic field in response to AC power and coupling the magnetic field to a coil of a power receiver. The frequency control circuit sweeps a frequency of the AC power during the power transmission. The voltage control circuit controls a voltage of the AC power, based on a target condition of a ratio between a voltage of power received by the power receiver and a voltage of the AC power.

Abstract: A power transmission system according to an embodiment includes a transmitting device and a receiving device. The transmitting (receiving) device includes a transmitting (receiving) housing and a transmitting (receiving) coil. The transmitting (receiving) housing includes a first transmitting (receiving) surface and a second transmitting (receiving) surface. The transmitting (receiving) coil includes a first transmitting (receiving) part and a second transmitting (receiving) part. A first facing area and a second facing area at the reference position are set such that change of strength of magnetic coupling between the transmitting coil and the receiving coil of when the receiving device is moved in a direction perpendicular to the first transmitting surface becomes smaller than change of strength of magnetic coupling between the transmitting coil and the receiving coil of when the receiving device is moved in a direction perpendicular to the second transmitting surface.

Abstract: A power transmission device in a mode of the present invention includes a first power transmitter configured to generate a first magnetic field; and a second power transmitter configured to generate a second magnetic field having a phase opposite to a phase of the first magnetic field. Further, changing a frequency of the first magnetic field to a new value by the first power transmitter and changing a frequency of the second magnetic field to the new value by the second power transmitter are performed at the same timing.

Abstract: A power transmission apparatus includes a power transmission pad, a base structure, and grout. The power transmission pad for wireless power transmission has a cast resin frame, at least part of the cast resin frame being embedded in the ground. The base structure is disposed below the power transmission pad. The grout is filled around the power transmission pad, including a gap between an upper surface of the base structure and the power transmission pad.

Abstract: According to one embodiment, an antenna apparatus includes a waveguide is formed one or more first array elements and one or more second array element, each of the one or more first array elements being formed at a position where a coupling power ratio is no less than a threshold and including a first slot and at least one reflection suppressing element which suppresses a reflection from the first slot, each of the one or more second array elements being formed at a position where the coupling power ratio is less than the threshold and including a second slot and a third slot, the coupling power ratio indicating a ratio of an electric power supplied to each of the first and second array element to an electric power of electromagnetic wave radiated from the each of the first and second array element.

Abstract: According to one embodiment, a mobile machine includes a mobile body and a plurality of power transmission resonators. The mobile body is capable of being tilted in a particular direction such that a distance between a particular part opposed to a travel surface and the travel surface is reduced. The plurality of power transmission resonators are arranged at portions of the particular part of the mobile body, heights of the portions with reference to the travel surface being approximately identical with each other in a state of the mobile body being tilted.

Abstract: According to one embodiment, an inductor includes a magnetic substance core, a coil, a cast case and a cast resin. The coil is wound around the magnetic substance core. The cast case has a body at least partially formed from conductive substance, stores the magnetic substance core and the coil. The cast resin that is formed from a first resin which is an insulator, is located within the cast case, covering the magnetic substance core and the coil.

Abstract: According to an embodiment, there is provided a leak preventing device of electromagnetic wave, including a metal pipe and a magnetic material part. The metal pipe is arranged to surround a periphery of a first electric power transmission device. The first electric power transmission device wirelessly transmits electric power to a second electric power transmission device via an electromagnetic wave. The second electric power transmission device is opposed to the first electric power transmission device. An opening is formed on the metal pipe along a circumferential direction of the metal pipe. The magnetic material part is arranged within the metal pipe along the circumferential direction the metal pipe.

Abstract: A power transmitting apparatus including a power supply to generate AC power; a power transmitting inductor to transfer the AC power to a power receiving apparatus through magnetic coupling with a power receiving inductor in the power receiving apparatus; a mutual coupling adjusting unit to adjust a relative position between the power transmitting inductor and the power receiving inductor; and a control unit to control the mutual coupling adjusting unit based on a mutual coupling coefficient between the power transmitting inductor and the power receiving inductor. The control unit controls the mutual coupling adjusting unit so that the mutual coupling coefficient falls within a predetermined range and an upper limit of the predetermined range is a value less than a maximum of the mutual coupling coefficient between the power transmitting inductor and the power receiving inductor.