Patent ID: 7550877

Claim:
A power control apparatus of an electronic apparatus powered by a battery device and connected to a second electronic apparatus via a cable, the power control apparatus comprising: a first switch that switches between first electric power of the battery device of the electronic apparatus and second electric power supplied from the second electronic apparatus via the cable, and supplying either the first electric power or the second electric power to a first power supply line connected to a CPU; a second switch that supplies the first electric power or the second electric power to a second power supply line connected to one or more components for the operation of the electronic apparatus; determining means for determining whether the second electric power supplied from the second electronic apparatus is less than or equal to a predetermined threshold value; controlling means for monitoring a power consumption of the CPU and for controlling the first switch based on a result of determination by the determining means and the power consumption of the CPU; and converting means for converting a power supply voltage into voltage of a constant level determined by a regulator and utilized by a power controller, a real-time clock and an interrupt controller, wherein each of the first switch and the second switch includes a first terminal that connects with the first electric power and a second terminal that connects with the second electric power, wherein when connection with the second electronic apparatus is detected, the second switch supplies the second electric power to the second power supply line, and wherein when connection with the second electronic apparatus is not detected, the second switch supplies the first electric power to the second power supply line.