NON-CONTACT POWER TRANSMISSION APPARATUS AND POWER TRANSMISSION METHOD USING A NON-CONTACT POWER TRANSMISSION APPARATUS

Disclosed is a non-contact power transmission apparatus provided with an AC power source and a resonant system. The resonant system has a primary coil that is connected with the AC power source, a primary-side resonance coil, a secondary-side resonance coil, a secondary coil and a load that is connected with the secondary coil. In addition, the non-contact power transmission apparatus is provided with a state detection unit and a variable-impedance circuit. The state detection unit detects the state of the resonant system. The variable-impedance circuit is constructed so as to adjust its own impedance in accordance with the state of the resonant system detected by the state detection unit, in such a way that the input impedance and the output impedance at the resonant frequency of the resonant system are matching.