Abstract: A wireless power transmission system and a method for increasing a coupling efficiency by adjusting a resonant frequency are provided. A device of the wireless power transmission system includes a resonator configured to transmit a wireless power, and a communication unit configured to receive information from another device. The device further includes a controller configured to determine a power transmission efficiency based on the information, and adjust a resonant frequency of the device, a resonant frequency of a relay device, and a resonant frequency of the other device, if the power transmission efficiency is less than or equal to a predetermined reference efficiency.

Abstract: A power transmitting unit (PTU) transmits a power wirelessly based on a location of a power receiving unit (PRU). The PTU determines whether the PRU is located within a charging area of the PTU based on frequency information corresponding to an inflection point detected on a curve of electrical characteristics of a resonator of the PTU.

Abstract: A wireless power transmitter includes a source resonator configured to wirelessly transmit power via magnetic coupling with a target resonator; and an impedance adjusting unit configured to adjust an impedance of the source resonator using a plurality of impedance-matching bars located in the source resonator.

Abstract: An overvoltage protecting unit and an overcurrent protecting unit protect a power device from an overvoltage and an overcurrent using a comparator having hysteresis. An overtemperature protecting unit protects the power device from an overtemperature using a thermistor having a resistance that changes as a temperature of the thermistor changes.

Abstract: An electronic device for charging a battery is provided. The electronic device includes a first path configured to receive a first power of a first voltage from an adapter, a second path configured to receive a second power of a second voltage from the adapter, a charger, connected to the first path, configured to receive the first power, adjust at least one of a voltage or a current of the first power, and provide the adjusted first power to the battery; and a processor configured to control to connect the second path to the battery during fast charging to directly connect the battery to the adapter.

Abstract: A wireless power transmission system and a method for increasing a coupling efficiency by adjusting a resonant frequency are provided. A device of the wireless power transmission system includes a resonator configured to transmit a wireless power, and a communication unit configured to receive information from another device. The device further includes a controller configured to determine a power transmission efficiency based on the information, and adjust a resonant frequency of the device, a resonant frequency of a relay device, and a resonant frequency of the other device, if the power transmission efficiency is less than or equal to a predetermined reference efficiency.

Abstract: A resonance power transmission system for controlling a supply voltage of a power converter based on power transmission efficiency is provided. According to an aspect, a resonance power transmitter configured to transmit resonance power to one or more resonance power receivers may include: a voltage controller configured to receive an input signal and to output voltage of a predetermined level; a source controller configured to control a signal level of the DC voltage based the number of resonance power receivers.

Abstract: An interference control method of a power transmitting unit (PTU) includes determining whether the PTU is in an interference environment in which interference by a neighbor PTU occurs, and controlling a communication parameter of either one or both of the neighbor PTU and a power receiving unit (PRU) in response to a result of the determining being that the PTU is in the interference environment.

Abstract: A method of synchronization control of a power transmitting unit (PTU) includes network-connecting a PTU to a PTU operating in a slave mode by setting an operation mode of the PTU to a master mode, and transmitting a signal to a power receiving unit (PRU) by controlling either one or both of a communication time and a communication frequency of the PTU operating in the slave mode.

Abstract: Provided are a method and apparatus for detecting an efficiency of a wireless power transmission. An output power of a source device may be adjusted based on current that is flowing in a power converter of the source device. The efficiency of wireless power transmission may be calculated based on the adjusted output power, and an amount of power used by a target device.

Abstract: An apparatus that transmits and receives wireless power, includes a controller configured to determine whether the apparatus is to operate in a power reception mode or a power transmission mode based on a capacity of a battery of the apparatus, and a capacity of a battery of another apparatus. The apparatus further includes a resonator configured to receive power from the other apparatus in response to the apparatus being determined to operate in the power reception mode, and transmit power to the other apparatus in response to the apparatus being determined to operate in the power transmission mode.

Abstract: The present disclosure enables materials of a triboelectric charging member to exhibit a characteristic of increased surface charge density, thereby improving output of a triboelectric generating device. Accordingly, the present disclosure provides a triboelectric generating device showing improved output without increasing a size of the triboelectric generating device or without increasing amounts of materials required for the triboelectric generating device.

Abstract: An apparatus and a method for charge control are provided. The apparatus for charge control may include an integrated direct current-to-direct current (DC/DC) converter configured to step up an output voltage level of a load to be greater than or equal to a supply voltage level set in a power amplifier, and the power amplifier configured to convert a direct current (DC) voltage stepped up by the integrated DC/DC converter into an alternating current (AC) voltage based on a resonant frequency, and to amplify the converted AC voltage. The apparatus for charge control may include a rectification unit configured to convert an AC power received wirelessly into a DC power; and a DC/DC converter configured to step down a voltage level of the DC power to a voltage level required by a load in the receiving mode.

Abstract: A resonator has an increased isolation for stable wireless power transmission. A material that reduces resonance coupling may be disposed in a space between each of a plurality of resonators and a resonator adjacent to each of the plurality of resonators. A material that reduces resonance coupling may be disposed on a plane opposite to a direction in which a resonator resonates. Power at an operating frequency set to be equal to or within a predetermined range of a frequency corresponding to a resonant mode may be injected into a plurality of transmission resonators.

Abstract: A resonance power transmission system for controlling a supply voltage of a power converter based on power transmission efficiency is provided. According to an aspect, a resonance power transmitter configured to transmit resonance power to one or more resonance power receivers may include: a voltage controller configured to receive an input signal and to output voltage of a predetermined level; a source controller configured to control a signal level of the DC voltage based the number of resonance power receivers.

Abstract: An apparatus and method of using near field communication (NFC) and wireless power transmission (WPT) are provided. A power receiving apparatus includes a resonator configured to receive a power and to output the power. The power receiving apparatus further includes a near field communication (NFC) receiver configured to perform wireless communication using the power output by the resonator. The power receiving apparatus further includes a wireless power transmission (WPT) receiver configured to supply a voltage using the power output by the resonator. The power receiving apparatus further includes a connecting unit configured to selectively connect the resonator to either the NFC receiver or the WPT receiver. The power receiving apparatus further includes a mode selector configured to control the connecting unit to selectively connect the resonator to either the NFC receiver or the WPT receiver based on the power output by the resonator.

Abstract: A wireless power receiving device and a wireless power transmission apparatus are provided. The wireless power receiver may include a resonator configured to emit an electromagnetic field, a blocker configured to surround a portion of an exterior of the resonator, and a spacer disposed between the resonator and the blocker.

Abstract: An interference control method of a power transmitting unit (PTU) includes determining whether the PTU is in an interference environment in which interference by a neighbor PTU occurs, and controlling a communication parameter of either one or both of the neighbor PTU and a power receiving unit (PRU) in response to a result of the determining being that the PTU is in the interference environment.

Abstract: A wireless power transmission system, and a method for controlling wireless power transmission and wireless power reception are provided. According to an aspect, a method for controlling a wireless power transmission may include: detecting a plurality of target devices used to wirelessly receive power; selecting a source resonating unit from among a plurality of source resonating units, based on the amount of power to be transmitted to one or more of the plurality of target devices, a coupling factor associated with one or more of the plurality of target devices, or both; and wirelessly transmitting power to a target device using the selected source resonating unit.

Abstract: A wireless power transmission apparatus includes a plurality of transmission (TX) resonators configured to resonate with at least one reception (RX) resonator, and wirelessly transmit power to the at least one RX resonator; and a frequency controller configured to control the input frequency so that power is stably supplied to the at least one RX resonator.