An augmented reality system including a necklace and a contact lens display can be used to project information from the contact lens display onto the retina of the wearer's eye. In one example, the necklace generates a time-varying magnetic field (TVMF) that provides energy and information to the contact lens display via inductive coupling. The necklace can be configured to decrease the amount of energy absorbed by the body of the wearer and increase power transfer to the contact lens display. The necklace includes a conductive loop and one or more bucking loops that are positioned to increase transmitted energy while reducing the amount of energy absorbed by the human body. The amount of current travelling in one direction through the loops of the necklace is greater than the amount of current travelling in the opposite direction through the loops of the necklace. The necklace can include any number of signal generators and winding patterns for the loops.

A feed unit includes: a power transmission section configured to perform power transmission with use of a magnetic field or an electronic field; a power limiting section provided on a power supply line from an external power source to the power transmission section; and an operation stop section configured to forcibly stop the power transmission. The operation stop section forcibly stops the power transmission when a voltage between an input and an output of the power limiting section exceeds a first threshold. The power limiting section forcibly interrupts power supply to the power transmission section when the voltage between the input and the output exceeds a second threshold that is larger than the first threshold.

A wireless power transfer system may provide coils that are respectively position on upper and lower ends of a pipe to allow power to be wirelessly transferred. Additionally, the system may also provide a soft ferrite layer placed on the upper and lower pipe sections to enhance the magnetic coupling so that the wireless power transfer efficiency can be maintained at a sufficient level when the coil separation is relatively large. Notably, this ferrite layer may span most or the entirely of the region between the coils to further enhance performance. In some cases, a ferrite core may be position between the coils and the pipe as well. In some cases, the pipe may include a tool section that may be non-conductive or results in a discontinuity in the ferrite layer. However, the setup of the system allows power to be wirelessly transferred despite such discontinuity.

A transformer includes a closed loop core having a first leg and a second leg. A first primary winding surrounds the first leg and a second primary winding surrounds the second leg. A first secondary winding surrounds the first leg and a second secondary winding surrounds the second leg. The first primary winding causes a magnetic flux to flow in the first leg in a first direction and the second primary winding causes the magnetic flux to flow in the second leg in a second direction that is opposite from the first direction.

A shielded transformer winding assembly includes a first winding formed on a circuit board. The circuit board includes at least two first board alignment elements formed therein and a casing including an inner portion and one or more tabs that extend outwardly from the inner portion the tabs arranged to form a notch between them. The assembly also includes a lower winding spacer disposed in one of the tabs that includes a stepped mounting member including first and second mounting member portions. The second mounting member portion has a smaller outer perimeter than and extends from the first mounting member portion. The first winding is disposed within the casing and on the lower winding spacer such that the second mounting member portion extends through one of the at least two first board alignment elements and wherein the first printed circuit board is supported by the first mounting member portion.

A shielded transformer winding assembly includes a first winding formed on a circuit board. The circuit board includes at least two first board alignment elements formed therein and a casing including an inner portion and one or more tabs that extend outwardly from the inner portion the tabs arranged to form a notch between them. The assembly also includes a lower winding spacer disposed in one of the tabs that includes a stepped mounting member including first and second mounting member portions. The second mounting member portion has a smaller outer perimeter than and extends from the first mounting member portion. The first winding is disposed within the casing and on the lower winding spacer such that the second mounting member portion extends through one of the at least two first board alignment elements and wherein the first printed circuit board is supported by the first mounting member portion.

A transformer includes a closed loop core having a first leg and a second leg. The transformer also includes a first primary winding surrounding the first and second legs, a second primary winding surrounding the first and second legs, and first and second secondary windings surrounding the first and second legs, respectively, and disposed between the first and second primary windings. A first turn of the first and second secondary windings are disposed on a first interlayer winding layer, and other turns of the first and second secondary windings are disposed on a first layer that is further from the first primary winding than the first interlayer winding layer.

A vehicle includes: a power receiving part; an operating part configured to allow a driver to select a parking lock state or a non-parking lock state; a parking lock device configured to be mechanically switchable between the parking lock state and the non-parking lock state; and a controller configured to control the parking lock device according to an electric signal output from the operating part. While the power receiving part is receiving electric power with the parking lock device being in the parking lock state, the controller: sends a first command that commands stop of power feeding to the power receiving device to the power feeding device when the non-parking lock state is selected; and controls the parking lock device so that the parking lock device is switched from the parking lock state to the non-parking lock state after electric power has decreased to a predetermined value or lower.

An embodiment provides a method of wireless power transmission, including: powering a transmitter that produces electromagnetic waves in a three dimensional structure; selecting a transmission frequency that is a resonance frequency for the three dimensional structure; and transmitting, using the transmitter, electromagnetic waves within the three dimensional structure on the transmission frequency selected. Other systems, methods, apparatuses and products are described and claimed.

Disclosed is an optical disk drive for wireless power transmission. The optical disk drive in an embodiment of the present invention comprises a tray on which a optical disk is to be seated; a driving unit for rotating the optical disk to be seated on the tray and reading or writing the optical disk; a wireless power transmitting module to be seated on the tray and comprising a primary coil and a transmitting circuit unit; a power supply unit for supplying power; and a controller for controlling the power supply unit to supply power to the wireless power transmitting module when determining that the wireless power transmitting module is seated on the tray.