| 摘要 |
PROBLEM TO BE SOLVED: To reduce the power consumption on a load side by reducing the internal losses of power source sections in steps by detecting supplied power by means of a power detecting circuit and controlling the number of used power source sections in accordance with the detected value of the supplied power. SOLUTION: A power detecting circuit 1 outputs a signal which discriminates the number of used power source sections in accordance with the power consumption on a load side. A power source section control circuit 2 controls the number of used power source sections upon inputting the discriminating signal. In this case, only a first power source section 3 is used when the power consumption is smaller than a certain value or a second power source section 4 is also used in addition to the section 3 when the power consumption is larger than the certain value. Therefore, the power consumption on the load side can be reduced. |
