WIRELESS POWER-RECEIVING DEVICE, WIRELESS POWER-SUPPLY DEVICE AND WIRELESS POWER-SUPPLY SYSTEM, AND AUTOMATIC-TUNING AUXILIARY CIRCUIT

摘要

An automatic-tuning auxiliary circuit (80) is coupled to a transmission antenna (20) in series. A first switch (SWc1) and a second switch (SWc2) are provided in series between a first terminal (81) and second terminal (82) of the automatic-tuning auxiliary circuit (80). A third switch (SWc3) and a fourth switch (SWc4) are also provided in series between said first terminal (81) and second terminal (82). A first auxiliary capacitor (C_A5) is provided between the point (N1) where the first switch (SWc1) connects to the second switch (SWc2) and the point (N2) where the third switch (SWc3) connects to the fourth switch (SWc4). A first control unit (40) operates the first through fourth switches (SWc1 to SWc4) at the frequency (f_TX) of a drive voltage (V_DRV) but with a phase difference (θ_TX) with respect thereto.