An intermediate device for supporting a power transfer to an electromagnetic load (505) from a power transmitter (201) comprises a resonance circuit (507) including an inductor (801) and a capacitor (803) where the inductor (801) is arranged to couple to the power transmitter (201) through a first surface area (509) and to the electromagnetic load (505) through a second surface area (511). The resonance circuit (507) is arranged to 5 concentrate energy of the power transfer electromagnetic signal from the first surface area (509) towards the second surface area (511). The device further comprises a communicator (807) for exchanging messages with the power transmitter (201). The communicator (807) transmits a request message to the power transmitter (201) comprising a request for the power transmitter (201) to generate a measurement electromagnetic signal. A load indication 10 processor (813) determines a load indication indicative of a loading of the measurement electromagnetic signal and a detector (815) detects a presence of the electromagnetic load in response to the load indication.

A power transmitting device transmits power to a power receiving device having a power receiving coil in water. The power transmitting device includes a power transmitting coil configured to transmit the power to the power receiving coil via a magnetic field. The power transmitting device also includes a support member that supports the power transmitting coil, and one or more spacers that hold the transmitting coil and the support member.

A power transmitting device transmits power to a power receiving device having a power receiving coil in water. The power transmitting device includes a power transmitting coil configured to transmit the power to the power receiving coil via a magnetic field. The power transmitting device also includes a support member that supports the power transmitting coil, and one or more spacers that hold the transmitting coil and the support member.

A power receiver includes a power reception interface that receives wireless power and a controller that transmits an emergency power transmission request for the wireless power during an emergency.

A power receiver includes a power reception interface that receives wireless power and a controller that transmits an emergency power transmission request for the wireless power during an emergency.

A power receiving device is disposed underwater. The power receiving device includes a housing formed of a weak magnetic material, a ferromagnetic body that surrounds an outer side of the housing and is formed of a ferromagnetic material, and a power receiving coil wound around an outer side of the ferromagnetic body.

In wireless system, radio frequency (RF) energy harvesting addresses the problem of limited battery lifetime in wireless nodes. In this invention, a wireless system for improving performance and prolonging battery life time of node, a battery assisted relay (2) framework is introduced. In this battery assisted relay framework, the energy harvested (EH) relay (2) augments the harvested energy with energy drawn from the battery (10) so as to prolong the battery life. Thus the following optimizations become relevant (i) maximizing throughput performance by using fixed small amount of battery energy in every signaling interval, (ii) minimizing battery energy consumption with predefined throughput performance requirement by optimizing a fixed charging time and energy together (best statistically optimum fixed charging time and energy drawn are determined), (iii) minimizing battery energy consumption by allowing channel-dependent energy harvesting duration, and (iv) minimizing battery energy consumption by drawing energy from the battery dependent on channel values. The suggested method and system can increase throughput as well as battery lifetimes, and are thus of practical value.

A power receiving apparatus includes: a resonance element having a specific resonance frequency and adapted to couple in a non-contacting relationship to a different resonance element through a resonance relationship; a rectification section configured to rectify ac current of the resonance frequency in response to energy received by the resonance element; and a switching section configured to cut off a supplying path of the ac current from the resonance element to the rectification section; the resonance element maintaining the coupling state through the resonance relationship to the different resonance element also when the supplying path of the ac current to the rectification section is blocked by the switching section.

A power receiving apparatus includes: a resonance element having a specific resonance frequency and adapted to couple in a non-contacting relationship to a different resonance element through a resonance relationship; a rectification section configured to rectify ac current of the resonance frequency in response to energy received by the resonance element; and a switching section configured to cut off a supplying path of the ac current from the resonance element to the rectification section; the resonance element maintaining the coupling state through the resonance relationship to the different resonance element also when the supplying path of the ac current to the rectification section is blocked by the switching section.

A carry case can house multiple removable electronic devices and facilitate wireless power or data communication among the devices. The case can include a primary coil for inductively receiving energy from a source device, and a secondary coil for inductively providing energy to a target device. The case can include a control circuit or a storage circuit coupled with the primary coil or the secondary coil. The control circuit can coordinate an inductive energy transfer among the source device, the target device, and the storage circuit using the primary or secondary coils.