| 摘要 |
A wireless charging module includes: a power receiver (2) having a power receiving resonant circuit (4) composed of a power receiving coil and a resonant capacitor; and a rechargeable battery (5) to which output power of the power receiver is supplied. A rectification circuit (20) converts, to DC power, AC power generated in the power receiving resonant circuit through electromagnetic induction between a power transmitting coil of a power transmitter (1) and the power receiving coil, so as to charge the rechargeable battery. The wireless charging module further includes: a capacity detection circuit (24) for detecting a remaining capacity of the rechargeable battery; and a power reception controller (25) for controlling an operation of the capacity detection circuit. The power reception controller can operate the capacity detection circuit with switching between a high-accuracy measurement mode and a low-accuracy measurement mode, the high-accuracy measurement mode detecting the remaining capacity with high accuracy, and the low-accuracy measurement mode detecting the remaining capacity with accuracy lower than that of the high-accuracy measurement mode. The capacity detection circuit is operated in the high-accuracy measurement mode in charging of the rechargeable battery and the low-accuracy measurement mode in discharging of the rechargeable battery. Thus, the remaining capacity of the rechargeable battery can be detected effectively in a power saving manner. |
