In an embodiment, a wireless power transmitter includes: a master transmitter resonant tank configured to wirelessly transmit power to a receiver resonant tank; a master transmitter driver configured to drive the master transmitter resonant tank; a slave transmitter resonant tank; a slave transmitter driver configured to drive the slave transmitter resonant tank; and a controller configured to adjust an impedance seen by the master transmitter resonant tank by controlling the slave transmitter driver, where controlling the slave transmitter driver includes adjusting a phase angle between a slave transmitter current flowing through the slave transmitter resonant tank and a master transmitter current flowing through the master transmitter resonant tank or adjusting a slave supply voltage of the slave transmitter driver.

Provided is a wireless power supply system employing a magnetic resonance technique in which high-frequency power is wirelessly supplied from a power transmission device that includes a power transmission coil to a power reception device that includes a power reception coil that is at least magnetically coupled with the power transmission coil. The wireless power supply system includes a relay coil that is coupled with the power transmission coil and the power reception coil using at least a magnetic field, and a relay circuit that is connected to the relay coil and forms a resonant circuit together with the relay coil. When k1 represents a coupling coefficient between the power transmission coil and the power reception coil and k2 represents a coupling coefficient between the power transmission coil and the relay coil, a relationship k1≥k2 holds true.

Provided is a wireless power supply system employing a magnetic resonance technique in which high-frequency power is wirelessly supplied from a power transmission device that includes a power transmission coil to a power reception device that includes a power reception coil that is at least magnetically coupled with the power transmission coil. The wireless power supply system includes a relay coil that is coupled with the power transmission coil and the power reception coil using at least a magnetic field, and a relay circuit that is connected to the relay coil and forms a resonant circuit together with the relay coil. When k1 represents a coupling coefficient between the power transmission coil and the power reception coil and k2 represents a coupling coefficient between the power transmission coil and the relay coil, a relationship k1≥k2 holds true.

In an embodiment, a sub-surface wireless charger includes a transmitter coil and a controller. The controller is configured to generate a protective pulse having a first energy, determine a characteristic of the transmitter coil based on the generated protective pulse, determine whether it is safe to begin wireless charging based on the determined characteristic, and when the controller determines that it is safe to begin wireless charging, generate an operating pulse having a second energy, where the second energy is higher than the first energy.

In an embodiment, a sub-surface wireless charger includes a transmitter coil and a controller. The controller is configured to generate a protective pulse having a first energy, determine a characteristic of the transmitter coil based on the generated protective pulse, determine whether it is safe to begin wireless charging based on the determined characteristic, and when the controller determines that it is safe to begin wireless charging, generate an operating pulse having a second energy, where the second energy is higher than the first energy.

A vehicle power system includes a coil that, in a first operational mode, receives power wirelessly from an external source, a first battery connected to the coil to receive power transferred from the coil while the coil is in the first operational mode, a second battery that receives power from the first battery, and a switch that switches the coil between the first operational mode and a second operational mode in which the coil receives power from the second battery and wirelessly transfers power from the second battery to an electrical load in the vehicle.

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.

An example operation includes one or more of determining, by a transport, an energy transfer condition exists along a route, routing, by the transport, to a location on the route based on the energy transfer condition exceeding an energy transfer value and based on one or more traffic conditions, aligning, by the transport, a position of the transport at the location to wirelessly receive an energy transfer, and receiving, by the transport, the energy transfer while the transport is in motion.

An example operation includes one or more of determining, by a transport, an energy transfer condition exists along a route, routing, by the transport, to a location on the route based on the energy transfer condition exceeding an energy transfer value and based on one or more traffic conditions, aligning, by the transport, a position of the transport at the location to wirelessly receive an energy transfer, and receiving, by the transport, the energy transfer while the transport is in motion.