| 摘要 |
PROBLEM TO BE SOLVED: To provide a power source controller which can reduce the electric power consumed by a system at the time of turning off the power supply to the system. SOLUTION: A power source controller is provided with a first switching transistor Tr1 which is controlled by a power supply turning-off signal 10 from a microcomputer 2 and supplied with electric power from a system power source 6 through a first resistor R1 for power supply, a second switching transistor Tr2 which is controlled by the transistor Tr1 and supplied with electric power from an external power source 5 through a second resistor R2 for power supply, and a third switching transistor Tr3 which is controlled by a power supply turning-on signal 11 outputted from a clock IC3 and supplied with electric power by means of the second resistor R2. Therefore, the power consumption of a system can be reduced, because no route is required for making an electric current to flow at the time of turning off the power supply to the system. |
