| 摘要 |
<P>PROBLEM TO BE SOLVED: To supply power from a normal power supply to a clock, properly maintain the clock time accuracy of the clock used for a clock time management if the normal power supply is replaced with a battery when the normal power supply is interrupted, and extend a lifetime of the battery. <P>SOLUTION: An apparatus supplies power from the AC power supply to a clock circuit 14, and replaces the AC power supply with the battery 16 when the AC power supply is interrupted. A clock time controlling block 15 configures a clock time of the clock circuit based on information on a standard clock time from a NTP server 22. If the information on the standard clock time can not be obtained, a battery lifetime monitoring circuit 17 is connected to the battery, and monitors the lifetime. If the information on the standard clock time can be obtained, the battery lifetime monitoring circuit 17 is disconnected from the battery, and the battery is inhibited from being wasted by monitoring the lifetime while the clock time accuracy is properly maintained. <P>COPYRIGHT: (C)2008,JPO&INPIT |
