| 摘要 |
A power supply device for supplying electric power to a portable electronic device includes a rechargeable battery supplying electric power to the portable electronic device, a circuitry assembly connected to the battery, and a solar cell connected to the circuitry assembly. The solar cell transforms light irradiating thereon into electric power. The circuitry assembly detects the voltage of the battery, and charges the battery with the electric power generated by the solar cell when the voltage of the battery is lower than a predetermined value. |
