| 摘要 |
PURPOSE:To prevent the over-charge of a storage battery provided as the back-up of a solar battery with a simple circuit arrangement. CONSTITUTION:This is provided with a storage battery 15 for storing an electric power from a solar battery 11, a charging voltage detection circuit 16 for detecting the terminal voltage of the storage battery 15 and a switching element 12 and a switching control circuit 13 for switching the connection of solar battery elements constituting the solar battery according to a difference in voltage between the maximum allowable voltage of the storage battery 15 and its charging voltage, thereby preventing the over-charge of the storage battery 15. |
