Wireless power feeder, wireless power transmission system, and table and table lamp using the same
First Claim
1. A wireless power feeder for feeding power by wireless from a feeding coil to a receiving coil, comprising:
- a power transmission control circuit that feeds AC power to the feeding coil;
a feeding coil circuit that includes the feeding coil and a capacitor and resonates at the resonance frequency of the receiving coil; and
a phase detection circuit that detects a phase difference between the voltage phase and current phase of the AC power, whereinthe power transmission control circuit adjusts the drive frequency of the AC power such that the phase difference is reduced so as to make the drive frequency track the resonance frequency, andin the phase difference detection circuit, a detected phase value of both or one of the voltage and current phases can be changed intentionally.
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Accused Products
Abstract
Power is fed from a feeding coil L2 to a receiving coil L3 by magnetic resonance. A VCO alternately turns ON/OFF switching transistors Q1 and Q2 at a drive frequency fo, whereby AC current is fed to the feeding coil L2, and then the AC current is fed from the feeding coil L2 to the receiving coil L3. A phase detection circuit detects a phase difference between the current phase and voltage phase, and the VCO adjusts the drive frequency fo such that the phase difference becomes zero. In a current phase detection circuit and a voltage phase detection circuit, detection values of the current and voltage phases can be changed, respectively and intentionally.
29 Citations
9 Claims
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1. A wireless power feeder for feeding power by wireless from a feeding coil to a receiving coil, comprising:
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a power transmission control circuit that feeds AC power to the feeding coil; a feeding coil circuit that includes the feeding coil and a capacitor and resonates at the resonance frequency of the receiving coil; and a phase detection circuit that detects a phase difference between the voltage phase and current phase of the AC power, wherein the power transmission control circuit adjusts the drive frequency of the AC power such that the phase difference is reduced so as to make the drive frequency track the resonance frequency, and in the phase difference detection circuit, a detected phase value of both or one of the voltage and current phases can be changed intentionally. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification