A power transmitter (101) comprises a driver (201) generating a drive signal for a transmitter coil to generate a power transfer signal during a power transfer time interval and an electromagnetic test signal during a foreign object detection time interval. A set of balanced detection coils (207, 209) comprise two detection coils arranged such that signals induced in the two detection coils by an electromagnetic field generated by the transmitter coil compensate each other. A foreign object detector (205) is coupled to the detection coils and performs foreign object detection during the foreign object detection time interval. The foreign object detector (205) is arranged to detect a foreign object in response to a property of a signal from the detection coils meeting a foreign object detection criterion. A transformer (1101) has a primary winding and a secondary winding coupled in series with the set of balanced detection coils A compensation circuit (1103) is coupled to the primary winding and arranged to generate a compensation drive signal for the primary winding which offsets a combined voltage of the set of detection coils.

Discussed is a wireless charging device that changes a direction of a magnetic field generated by a transmission coil, through a repeater capable of rotating in a plane, and supports a user terminal in parallel with the repeater, to wirelessly transmit power in various directions and at various angles. The wireless charging device includes a power transmitting module including a plurality of transmission coils arranged side by side, therein, a terminal supporting module including a repeater therein and disposed at a slant with respect to an upper surface of the power transmitting module on the upper surface of the power transmitting module, a moving module to move the terminal supporting module along a direction in which the transmission coils are arranged, and a controller to supply a voltage to any one of the plurality of transmission coils depending on a position of the moving module.

An electronic device may include: a resonance circuit which comprises a battery, a coil and a capacitor, and receives power wirelessly; a rectifier which rectifies AC power, provided from the resonance circuit, to DC power; a DC/DC converter which converts and outputs the DC power provided from the rectifier; a charger which charges the battery by using the converted power provided from the DC/DC converter; a first OVP circuit which selectively connects the coil to the capacitor; a second OVP circuit which is connected in parallel to the first OVP circuit; a detection circuit which detects a rectified voltage; a control circuit; and a communication circuit, wherein the control circuit, on the basis that the detected rectified voltage is equal to or greater than a first threshold voltage, controls the first OVP circuit so as to be in an off state so that the coil is not connected to the capacitor, and on the basis that the detected rectified voltage is less than a second threshold voltage, controls the first OVP circuit so that the first OVP circuit is switched from the off state to an on state so that the coil is connected to the capacitor, wherein the second threshold voltage may be smaller than the first threshold voltage.

An electromagnetic wave shielding filter is configured in a magnetic field transmission scheme, not in a low pass filter or band pass filter scheme, and thus allows a desired signal to pass, while maintaining unintended electromagnetic waves shielded.

The present embodiment relates to an electromagnetic wave shielding filter for high-frequency communication, having a structure in which an elliptical ferrite magnetic core is formed inside the filter, a primary coil and a secondary coil are installed at both ends of the magnetic core, and then a shielding and penetration unit is formed of a shielding material on the elliptical magnetic field core, so that a signal from the primary coil is transmitted in the form of a magnetic field to the secondary coil, and the other unintended common-mode components are eliminated.

An electromagnetic wave shielding filter is configured in a magnetic field transmission scheme, not in a low pass filter or band pass filter scheme, and thus allows a desired signal to pass, while maintaining unintended electromagnetic waves shielded.

The present embodiment relates to an electromagnetic wave shielding filter for high-frequency communication, having a structure in which an elliptical ferrite magnetic core is formed inside the filter, a primary coil and a secondary coil are installed at both ends of the magnetic core, and then a shielding and penetration unit is formed of a shielding material on the elliptical magnetic field core, so that a signal from the primary coil is transmitted in the form of a magnetic field to the secondary coil, and the other unintended common-mode components are eliminated.

A wireless power receiver coil is attached to a landing gear of a drone. The wireless power receiver coil is closer to the drone when the landing gear is in a retracted position and farther away from the drone when the landing gear is in an extended position. A length of the wireless power receiver coil may be the same length when the landing gear is in the retracted position and in the extended position. The wireless power receiver coil may be in a first orientation when the landing gear is in the retracted position and the wireless power receiver coil may be in a different orientation when the landing gear is in the extended position. The wireless power receiver coil may have a first shape when the landing gear is in the retracted position and may have a second shape when the landing gear is in the extended position.

Disclosed is a system for recharging a selected power source wirelessly, such as through a power transmission. The power source may be positioned within a subject and be charged wirelessly through the subject, such as tissue of the subject. A thermal transfer system is provided to transfer or transport thermal energy from a first position to a second position, such as away from the subject.

An electronic device is disclosed. The electronic device discloses a plurality of wireless charging antennas, a plurality of shielding partition layers, at least some of the plurality of shielding partition layers disposed between the plurality of wireless charging antennas, a plurality of external device-receiving grooves formed through spaces defined between pairs of the shielding partition layers, and a processor electrically coupled to the plurality of wireless charging antennas. The processor is configured to: determine whether at least one external device is inserted into at least one of the plurality of external device-receiving grooves, and when the at least one external device is inserted into the at least one of the plurality of external device-receiving grooves, wirelessly transmit power through at least one wireless charging antenna corresponding to the at least one of the plurality of external device-receiving grooves into which the at least one external device is inserted.

An electronic device is disclosed. The electronic device discloses a plurality of wireless charging antennas, a plurality of shielding partition layers, at least some of the plurality of shielding partition layers disposed between the plurality of wireless charging antennas, a plurality of external device-receiving grooves formed through spaces defined between pairs of the shielding partition layers, and a processor electrically coupled to the plurality of wireless charging antennas. The processor is configured to: determine whether at least one external device is inserted into at least one of the plurality of external device-receiving grooves, and when the at least one external device is inserted into the at least one of the plurality of external device-receiving grooves, wirelessly transmit power through at least one wireless charging antenna corresponding to the at least one of the plurality of external device-receiving grooves into which the at least one external device is inserted.

There is described an electric power base (100) comprising: a casing (105), a wireless transmitter (110) of electric energy placed in the casing (105), and an interface surface (120) placed external to the casing (105), at said wireless transmitter (110), which is adapted to receive in contact a device (500) to be powered, characterized in that said interface surface (120) is made available by at least one microsuction body (125).