Embodiments of the present disclosure generally relate to a wireless identification tag configured to harvest ambient energy and transmit an identification signal intermittently, and system and methods for use thereof. In one implementation, the tag may include a transmitter configured to transmit a first signal to a first receiver in a first frequency, and to transmit a second signal to a second receiver in the first frequency. The tag may also include an energy storage component configured for collecting and storing ambient energy and for powering transmission of the transmitter. The tag may also include a circuit configured to monitor energy stored in the energy storage component, and to prevent the transmitter from transmitting the first signal to the first receiver when the energy stored in the energy storage component is insufficient to transmit the second signal to the second receiver.

A contactless power transmission apparatus includes a receiver that includes a resonant circuit including a receiver coil that receives electric power from a transmitter coil included in a transmitter and a resonant capacitor connected in parallel to the receiver coil. The receiver outputs, through an output coil having fewer turns than the receiver coil and a coil connected to the output coil, electric power received by the resonant circuit and rectifies the output power with a rectifier circuit. The transmitter includes a control circuit that controls a voltage and a switching frequency of alternating current power to be supplied to the transmitter coil from a power supply circuit to allow the contactless power transmission apparatus to continuously perform a constant voltage output operation.

A display system may include a wireless power transmitter that converts power supplied from a power source unit into a first magnetic field and to transmit a first power signal to a speaker; the speaker including a wireless power transmission/reception circuit that converts the first power signal received from the wireless power transmitter into a first current, and to generate a second magnetic field by the first current to transmit a second power signal to a display, a distribution circuit that distributes power received through the first power signal to a sound output unit by distributing the first current and outputting a second current, and the sound output unit that outputs sound using power supplied from the distribution circuit; and the display including a wireless power reception circuit that converts the second power signal received from the speaker into a third current, and an image output unit that outputs an image by using power transferred through the third current.

A display system may include a wireless power transmitter that converts power supplied from a power source unit into a first magnetic field and to transmit a first power signal to a speaker; the speaker including a wireless power transmission/reception circuit that converts the first power signal received from the wireless power transmitter into a first current, and to generate a second magnetic field by the first current to transmit a second power signal to a display, a distribution circuit that distributes power received through the first power signal to a sound output unit by distributing the first current and outputting a second current, and the sound output unit that outputs sound using power supplied from the distribution circuit; and the display including a wireless power reception circuit that converts the second power signal received from the speaker into a third current, and an image output unit that outputs an image by using power transferred through the third current.

An inductive coupling assembly for an electronic device is disclosed. The system may include an electronic device having an enclosure, and an internal inductive charging assembly positioned within the enclosure. The internal inductive charging assembly may include a receive inductive coil positioned within the enclosure. The system may also include a charger in electrical communication with the internal inductive charging assembly of the electronic device. The charger may include a transmit inductive coil aligned with the receive inductive coil. The transmit inductive coil may be configured to be in electrical communication with the receive inductive coil. Additionally, the system can include an inductive coupling assembly positioned between the electronic device and the charger. The inductive coupling assembly may include a field-directing component configured to be in electrical communication with the transmit inductive coil, and/or the receive inductive coil of the internal inductive charging assembly of the electronic device.

A magnetic field which is partially a variable magnetic field with high or low magnetic field strength is formed at a predetermined region. A plurality of coil pieces and generating a variable magnetic field and a power-supplying coil which is provided to generate an induced current for at least one of the coil pieces and are provided, and coil ends of two or more of the coil pieces and are connected to each other.

Methods and apparatus for determining the misalignment and mutual coupling between the transmitter coil and receiver coil, with or without an intermediate relay resonator coil, of a wireless power charging system are provided. The determination can be made without using any direct measurement from the receiver circuit. The technic involves exciting the transmitter coil of the wireless power charging system at several frequencies with equal or different input voltage/current, such that the number of equivalent circuit equations is at least equal to the number of unknown terms in the equations. The methods use the knowledge of only the input voltage and the input current of the transmitter coil. This means that the mutual inductance or magnetic coupling coefficient between the transmitter and receiver coils can be determined based on the information obtained from the transmitter circuit and there is no need for any wireless communication from or direct measurements of the receiver circuit.

Methods and apparatus for determining the misalignment and mutual coupling between the transmitter coil and receiver coil, with or without an intermediate relay resonator coil, of a wireless power charging system are provided. The determination can be made without using any direct measurement from the receiver circuit. The technic involves exciting the transmitter coil of the wireless power charging system at several frequencies with equal or different input voltage/current, such that the number of equivalent circuit equations is at least equal to the number of unknown terms in the equations. The methods use the knowledge of only the input voltage and the input current of the transmitter coil. This means that the mutual inductance or magnetic coupling coefficient between the transmitter and receiver coils can be determined based on the information obtained from the transmitter circuit and there is no need for any wireless communication from or direct measurements of the receiver circuit.

An electric power transmission device capable of efficiently performing contactless electric power transmission to an underwater vehicle in water is provided. The electric power transmission device, which is an electric power transmission device transmitting electric power to an electric power reception device including an electric power reception coil in water, includes one or more transmission coils including an electric power transmission coil which transmits electric power to an electric power reception coil via a magnetic field, an electric power transmission unit which transmits AC power to an electric power transmission coil, a capacitor which is connected to the transmission coil and forms a resonant circuit which resonates with the transmission coil, and a buoyant body connected to at least one of the transmission coils.

An electric power transmission device capable of efficiently performing contactless electric power transmission to an underwater vehicle in water is provided. The electric power transmission device, which is an electric power transmission device transmitting electric power to an electric power reception device including an electric power reception coil in water, includes one or more transmission coils including an electric power transmission coil which transmits electric power to an electric power reception coil via a magnetic field, an electric power transmission unit which transmits AC power to an electric power transmission coil, a capacitor which is connected to the transmission coil and forms a resonant circuit which resonates with the transmission coil, and a buoyant body connected to at least one of the transmission coils.