Abstract: This power transmission apparatus transmits power to a power reception apparatus by means of a magnetic field resonance system by supplying an output AC voltage (VE) of a class E amplifier to a power-transmission side resonance circuit (TT). Before the transmission of power, the output AC voltage (VE) of the class E amplifier is divided, and a voltage obtained by the division is supplied to the power-transmission side resonance circuit (TT). A current amplitude detection value of a power-transmission side coil (TL) at this time is obtained as an evaluation value, and whether to permit execution of power transmission is controlled on the basis of the evaluation value, through determination as to whether a foreign object is present or not.

Abstract: In a non-contact power feeding system which is formed with a power transmission device having a power transmission-side resonant circuit including a power transmission-side coil and a power reception device having a power reception-side resonant circuit including a power reception-side coil and which can transmit and receive power by a magnetic field resonance method, when the power is transmitted, the power transmission device monitors the amplitude of a current flowing through the power transmission-side coil. Then, when a current amplitude detection value (VmFOD) falls outside a predetermined normal range, it is determined that a foreign object is present, and thus the power transmission is stopped.

Abstract: In this non-contact power feeding system that is capable of transmitting power from a power transmitting device (1) to a power receiving device (2) by a magnetic field resonance scheme, the power transmitting device (1) is provided with first to n-th resonant circuits (TT[1]-TT[n]) which are provided with coils (TL) that are different in size, respectively, and which have a resonant frequency set to a prescribed reference frequency. Prior to power transmission, test magnetic fields are generated in sequence in the first to n-th resonant circuits to detect the amplitude of current flowing through the coils of respective resonant circuits, and the presence/absence of a foreign object is determined on the basis of the obtained first to n-th amplitude detected values, to control execution of the power transmission.

Abstract: In a normal mode, a power receiving device changes the resonant frequency of a power receiving side resonant circuit from a reference frequency or short-circuits a power receiving side coil for a predetermined time and then eliminates the changed or short-circuited state. Meanwhile, in the normal mode, a power transmitting device generates a test magnetic field in a power transmitting side coil during the above changed or short-circuited period and then determines, on the basis of a current amplitude detection value of the power transmitting side coil, whether a foreign object is present or not, thereby determining and controlling whether power transmission is executed or not. In a test mode, the power receiving device maintains the above changed or short-circuited state, and the power transmitting device continuously generates the test magnetic field and continuously obtains the current amplitude detection value of the power transmitting side coil.

Abstract: A power reception device includes a power reception-side resonant circuit which includes a power reception-side coil and a metal plate in which an opening portion is provided in a position opposite the arrangement position of the power reception-side coil, and can receive, by a magnetic field resonance method, power from a power transmission device which includes a power transmission-side resonant circuit including a power transmission-side coil. A cancellation coil is arranged between the power reception-side coil and the opening portion, and a cancellation resonant circuit including a cancellation coil is provided separately in the power reception device. When an alternating magnetic field interlinks the cancellation coil, a current which cancels out variations in the resonant frequencies of the power reception-side resonant circuit and the power transmission-side resonant circuit caused by the presence of the metal plate flows through the cancellation coil.

Abstract: A non-contact power supply system includes a power transmission device including a first resonance circuit having a first coil for transmitting electric power; and a power reception device including a second resonance circuit having a second coil for receiving the electric power. The system is configured to transmit and receive the electric power by a magnetic field resonance method, and to communicate between the power transmission device and the power reception device. The power transmission device includes a power transmission circuit for supplying an AC voltage to the first resonance circuit; a detection circuit configured to detect an amplitude of a current flowing through the first coil; and a control circuit configured to control the power transmission circuit to perform power transmission control of the electric power.

Abstract: Disclosed is a non-contact power supply system wherein power is transmitted by means of a magnetic field resonance method from a power transmission device, which includes a power transmission-side resonant circuit, to a power reception device, which includes a power reception-side resonant circuit. The power transmission device detects, at the time of transmitting the power, a load in the power transmission, and stops the power transmission in the cases where a detection result deviates from a specified normal range. In the power reception device, a power stabilization circuit (270) that maintains output power of the power reception circuit constant is provided between a load circuit (280) and a power reception circuit (230) that outputs, toward the load circuit, power on the basis of power received by the power reception-side resonant circuit.

Abstract: In a non-contact power feeding system which is formed with a power transmission device that includes a power transmission-side resonant circuit including a power transmission-side coil and a power reception device that includes a power reception-side resonant circuit including a power reception-side coil and which can transmit and receive power by a magnetic field resonance method, the control circuit of the power transmission device supplies, before the power transmission, a predetermined determination alternating current voltage to the power transmission-side resonant circuit so as to detect the amplitude of a current flowing through the power transmission-side coil at that time. The control circuit controls the performance of the power transmission based on the current amplitude detection value.

Abstract: Provided is a charging system characterized by being provided with: a mobile device including a first NFC antenna and a rechargeable battery which is charged on the basis of a current induced in the first NFC antenna by electromagnetic induction; and a charger including a second NFC antenna which causes electromagnetic induction to be induced in the first NFC antenna, and a supply unit which supplies the second NFC antenna with a feed current for inducing the electromagnetic induction; and in that the charging system is further provided with a control means for causing an intended electromagnetic induction to arise between the first NFC antenna and the second NFC antenna.

Abstract: A power transmission device has first to nth transmission-side coils (where n is an integer of 2 or more), and can transmit electric power to a power reception device by magnetic resonance. Before performing power transmission operation, the power transmission device feeds an evaluation alternating-current signal to the first to nth transmission-side coils one after another to acquire from the power reception device, by communication, power-related information based on the electric power received by the power reception device meanwhile. Based on the power-related information acquired, the power transmission device selects a transmission-side coil to be used in power transmission operation.

Abstract: In a non-contact power feeding system which is formed with a power transmission device that includes a power transmission-side resonant circuit including a power transmission-side coil and a power reception device that includes a power reception-side resonant circuit including a power reception-side coil and which can transmit and receive power by a magnetic field resonance method, the control circuit of the power transmission device supplies, before the power transmission, a predetermined determination alternating current voltage to the power transmission-side resonant circuit so as to detect the amplitude of a current flowing through the power transmission-side coil at that time. The control circuit controls the performance of the power transmission based on the current amplitude detection value.

Abstract: A power reception device includes a power reception-side resonant circuit which includes a power reception-side coil and a metal plate in which an opening portion is provided in a position opposite the arrangement position of the power reception-side coil, and can receive, by a magnetic field resonance method, power from a power transmission device which includes a power transmission-side resonant circuit including a power transmission-side coil. A cancellation coil is arranged between the power reception-side coil and the opening portion, and a cancellation resonant circuit including a cancellation coil is provided separately in the power reception device. When an alternating magnetic field interlinks the cancellation coil, a current which cancels out variations in the resonant frequencies of the power reception-side resonant circuit and the power transmission-side resonant circuit caused by the presence of the metal plate flows through the cancellation coil.

Abstract: This power transmission apparatus transmits power to a power reception apparatus by means of a magnetic field resonance system by supplying an output AC voltage (VE) of a class E amplifier (440) to a power-transmission side resonance circuit (TT). Before the transmission of power, the output AC voltage (VE) of the class E amplifier (440) is divided, and a voltage obtained by the division is supplied to the power-transmission side resonance circuit (TT). A current amplitude detection value of a power-transmission side coil (TL) at this time is obtained as an evaluation value, and whether to permit execution of power transmission is controlled on the basis of the evaluation value, through determination as to whether a foreign object is present or not.

Abstract: In a normal mode, a power receiving device changes the resonant frequency of a power receiving side resonant circuit from a reference frequency or short-circuits a power receiving side coil for a predetermined time and then eliminates the changed or short-circuited state. Meanwhile, in the normal mode, a power transmitting device generates a test magnetic field in a power transmitting side coil during the above changed or short-circuited period and then determines, on the basis of a current amplitude detection value of the power transmitting side coil, whether a foreign object is present or not, thereby determining and controlling whether power transmission is executed or not. In a test mode, the power receiving device maintains the above changed or short-circuited state, and the power transmitting device continuously generates the test magnetic field and continuously obtains the current amplitude detection value of the power transmitting side coil.

Abstract: In a non-contact power feeding system which is formed with a power transmission device having a power transmission-side resonant circuit including a power transmission-side coil and a power reception device having a power reception-side resonant circuit including a power reception-side coil and which can transmit and receive power by a magnetic field resonance method, when the power is transmitted, the power transmission device monitors the amplitude of a current flowing through the power transmission-side coil. Then, when a current amplitude detection value (VmFOD) falls outside a predetermined normal range, it is determined that a foreign object is present, and thus the power transmission is stopped.

Abstract: In this non-contact power feeding system that is capable of transmitting power from a power transmitting device (1) to a power receiving device (2) by a magnetic field resonance scheme, the power transmitting device (1) is provided with first to n-th resonant circuits (TT[1]-TT[n]) which are provided with coils (TL) that are different in size, respectively, and which have a resonant frequency set to a prescribed reference frequency. Prior to power transmission, test magnetic fields are generated in sequence in the first to n-th resonant circuits to detect the amplitude of current flowing through the coils of respective resonant circuits, and the presence/absence of a foreign object is determined on the basis of the obtained first to n-th amplitude detected values, to control execution of the power transmission.

Abstract: Provided is a charging system characterized by being provided with: a mobile device including a first NFC antenna and a rechargeable battery which is charged on the basis of a current induced in the first NFC antenna by electromagnetic induction; and a charger including a second NFC antenna which causes electromagnetic induction to be induced in the first NFC antenna, and a supply unit which supplies the second NFC antenna with a feed current for inducing the electromagnetic induction; and in that the charging system is further provided with a control means for causing an intended electromagnetic induction to arise between the first NFC antenna and the second NFC antenna.

Abstract: A non-contact power supply system includes a power transmission device including a first resonance circuit having a first coil for transmitting electric power; and a power reception device including a second resonance circuit having a second coil for receiving the electric power. The system is configured to transmit and receive the electric power by a magnetic field resonance method, and to communicate between the power transmission device and the power reception device. The power transmission device includes a power transmission circuit for supplying an AC voltage to the first resonance circuit; a detection circuit configured to detect an amplitude of a current flowing through the first coil; and a control circuit configured to control the power transmission circuit to perform power transmission control of the electric power.

Abstract: Disclosed is a non-contact power supply system wherein power is transmitted by means of a magnetic field resonance method from a power transmission device, which includes a power transmission-side resonant circuit, to a power reception device, which includes a power reception-side resonant circuit. The power transmission device detects, at the time of transmitting the power, a load in the power transmission, and stops the power transmission in the cases where a detection result deviates from a specified normal range. In the power reception device, a power stabilization circuit (270) that maintains output power of the power reception circuit constant is provided between a load circuit (280) and a power reception circuit (230) that outputs, toward the load circuit, power on the basis of power received by the power reception-side resonant circuit.

Abstract: A power reception apparatus includes a power receiving circuit to be connected to a power reception side resonance circuit including a power reception side coil and a power reception side capacitance, for generating an output power based on power received by the power reception side coil utilizing magnetic resonance, a changing/short-circuiting circuit configured to change a resonance frequency of the power reception side resonance circuit from a reference frequency that is the resonance frequency when receiving the power, or to short-circuit the power reception side coil, before receiving the power.