Wireless power transfer via electrodynamic coupling
First Claim
1. A wireless power transfer system, comprising:
- a transmitter generating a time-varying external magnetic field; and
a receiver generating electrical power under an influence of the external magnetic field by electromechanical conversion, wherein the receiver comprises;
a magnet that oscillates via electrodynamic coupling under the influence of the external magnetic field, andan electromechanical conversion element coupled to the magnet, wherein the electromechanical conversion element comprises a variable capacitor comprising plates, wherein the magnet is connected to a plate of the variable capacitor and the oscillating movement of the magnet causes a time-varying capacitance change in the variable capacitor thereby generating the electrical power.
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Accused Products
Abstract
Wireless power transmission (WPT) systems are provided. According to an embodiment, the WPT system uses one or more power transmitting coils and a receiver for electromagnetically coupled wireless power transfer. The electrodynamic receiver can be in the form of an electrodynamic transducer where a magnet is allowed to oscillate near a receiving coil to induce a voltage in the receiving coil, a piezoelectric transducer where the magnet causes a vibrating structure with a piezoelectric layer to move, an electrostatic transducer where movement of the magnet causes a capacitor plate to move, or a combination thereof. An alternating magnetic field from the transmitting coil(s) excites the magnet in the receiver into mechanical resonance. The vibrating magnet then functions similar to an energy harvester to induce voltage/current on an internal coil, piezoelectric material, or variable capacitor. Embodiments utilize magnetic coupling and electromechanical resonance for safe, spatially distributed, low-frequency power delivery to portable devices.
40 Citations
17 Claims
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1. A wireless power transfer system, comprising:
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a transmitter generating a time-varying external magnetic field; and a receiver generating electrical power under an influence of the external magnetic field by electromechanical conversion, wherein the receiver comprises; a magnet that oscillates via electrodynamic coupling under the influence of the external magnetic field, and an electromechanical conversion element coupled to the magnet, wherein the electromechanical conversion element comprises a variable capacitor comprising plates, wherein the magnet is connected to a plate of the variable capacitor and the oscillating movement of the magnet causes a time-varying capacitance change in the variable capacitor thereby generating the electrical power. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method of wireless power transfer, comprising:
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generating and transmitting a time-varying magnetic field at a first frequency using a first transmitter; and generating a time-varying voltage in a receiver by allowing a magnet of the receiver to move due to an influence of a magnetic force generated by the magnetic field from the transmitter, the movement of the magnet influencing an electromechanical conversion element in the receiver, wherein the electromechanical conversion element comprises a variable capacitor, wherein the magnet is connected to a plate of the variable capacitor and movement of the magnet causes a time-varying capacitance change in the variable capacitor that generates the time-varying voltage. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14)
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15. A receiver of a wireless power transfer system, the receiver generating power under an influence of a time-varying external magnetic field by electromechanical conversion, wherein the receiver comprises:
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a magnet attached to an end of a mechanical flexure, the magnet oscillating via electrodynamic coupling under the influence of the time-varying external magnetic field, and an electromechanical conversion element coupled to the magnet, wherein the electromechanical conversion element comprises a variable capacitor, wherein the magnet is connected to a plate of the variable capacitor and the oscillating movement of the magnet causes a time-varying capacitance change in the variable capacitor thereby generating the power. - View Dependent Claims (16, 17)
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Specification