A contactless power feeding device that supplies electric power to a power receiving device without contact includes: a power transmitting circuit that transmits alternating-current power; and a power transmitting resonator including a power transmitting coil. The input impedance of the power transmitting resonator is set low in a facing state in which a power receiving coil included in the power receiving device faces the power transmitting coil, and the input impedance of the power transmitting resonator is set high in a non-facing state in which the power receiving coil does not face the power transmitting coil.

In a dynamic wireless power transfer system, a power transmission coil is provided in a road. A power transmission circuit supplies electric power to the power transmission coil. A power reception coil is provided in a vehicle. A power reception circuit is connected to the power reception coil. A relay circuit is provided in a tire of the vehicle. The relay circuit includes at least two relay coils that are connected in series. The relay circuit transfers electric power from the power transmission coil to the power reception coil by one relay coil of the two relay coils opposing the power transmission coil and the other relay coil opposing the power reception coil. A resonance frequency of the relay circuit is a frequency that is within a fixed range that is centered on an applied frequency of an alternating-current voltage that is applied to the power transmission coil.

A low power transmitter includes a low frequency feedback loop, a high frequency switching element embedded within the low frequency feedback loop, and a mixer electrically communicating with the low frequency feedback loop and the high frequency switching element. The low frequency feedback loop employs either a voltage mode interface or a current mode interface. The high frequency switching element includes a first transistor, a second transistor, and a pair of inductive elements. Alternatively, the high frequency switching element includes a single transistor and a single inductive element.

Transmitter or receiver resonant circuit for carrying out contactless power transmission via resonant inductive coupling to a receiver or transmitter resonant circuit, comprising a first capacitance and a first winding, the first winding comprising an inductance and a first resistance, the transmitter resonant circuit comprising a second capacitance of value C2′ and a second winding, the second winding comprising a second inductance of value L2′ and a second resistance of value R2′, the transmitter resonant circuit having a natural angular frequency u>2 such that w2=1/V(L2′×C2′) and a natural frequency f2 such that f2=w2/(2π), characterized in that the value of the second inductance varies in a predetermined manner.

Eyewear and receptacles for housing such eyewear include components of a wireless power transfer system. The eyewear includes a receiver system for receiving power from a transmission system associated with the receptacle(s). The receiver system includes at least one receiver antenna, for receiving wireless power from the transmission system, and a repeater antenna for repeating the wireless power signal to the receiver antenna. The receiver antenna is positioned proximate to a first arm of the eyewear and the repeater is positioned proximate to a second arm of the eyewear. Positioning of the receiver and repeater antennas allows for positional freedom of the eyewear and/or the arms of the eyewear, when mechanically received by the receptacle.

A modular wireless power transfer system includes a first wireless transmission system and one or more secondary wireless transmission systems. The first wireless transmission system is configured to receive input power from an input power source, generate AC wireless signals, and couple with one or more other antennas. Each of the one or more secondary wireless transmission systems includes a secondary transmission antenna, the secondary transmission antenna configured to couple with one or more of another secondary transmission antenna, the first transmission antenna, one or more receiver antennas, or combinations thereof. The one or more secondary wireless transmission systems are configured to receive the AC wireless signals from one or more of the first wireless transmission system, another secondary wireless transmission system, or combinations thereof and repeat the AC wireless signals to one or more of the secondary transmission antennas, the one or more receiver antennas, or combinations thereof.

A battery case has first and second coils on opposing sides of a battery and has switching circuitry that is coupled between the first and second coils. The battery case has a battery that provides supplemental battery power wirelessly to a wireless power receiving device via the second coil when the switching circuitry is in an open state. The case can also receive power wirelessly with the first coil from a wireless charging mat when the switching circuitry is in the open state. In a closed state, the switching circuitry shorts the first and second coils together so that current flowing through the first coil flows through the second coil in series and so that wireless power from the wireless charging mat that is received with the first coil is transmitted wirelessly to the wireless power receiving device using the second coil.

Provided is a wireless power transceiver including a magnetic body, a solenoid coil wound with respect to the magnetic body, and a dual coil spaced downwardly from the solenoid coil and wound with respect to the magnetic body on opposite sides of the solenoid coil, the dual coil being wound in directions opposite to each other.

A battery case has first and second coils on opposing sides of a battery and has switching circuitry that is coupled between the first and second coils. The battery case has a battery that provides supplemental battery power wirelessly to a wireless power receiving device via the second coil when the switching circuitry is in an open state. The case can also receive power wirelessly with the first coil from a wireless charging mat when the switching circuitry is in the open state. In a closed state, the switching circuitry shorts the first and second coils together so that current flowing through the first coil flows through the second coil in series and so that wireless power from the wireless charging mat that is received with the first coil is transmitted wirelessly to the wireless power receiving device using the second coil.

A wireless transmission system includes a transmitter antenna configured to transmit AC wireless signals to the at least one antenna, the AC wireless signals including wireless power signals and wireless data signals, the transmitter antenna including a source coil and an internal repeater coil. The system further includes at least one sensor configured to detect electrical information associated with the electrical characteristics of the AC wireless signals at one of the source coil or the internal repeater coil. A demodulation circuit is configured to receive the electrical information from the at least one sensor at the internal repeater coil, detect a change in the electrical information, (iii) determine if the change in the electrical information meets or exceeds one of a rise threshold or a fall threshold, if the change exceeds one of the rise threshold or the fall threshold, generate an alert, and output a plurality of data alerts.