| 摘要 |
PROBLEM TO BE SOLVED: To stably supply electric power to a main load by avoiding overload conditions and provide reduction in the size and cost of the device as a whole. SOLUTION: A fuse 2 is inserted in an output line supplying the output of AC/DC converter 1 to a DC-DC converter 5. There are provided a current control circuit 3, serving as a means for producing a control signal and a FET 4 serving as a separating means. In the current control circuit 3, voltages generated at both ends of the fuse 2 are detected respectively and a difference between the voltages is determined and amplified. If the amplified voltage, corresponding to the current flowing through the fuse 2, is equal to or larger than a prescribed threshold voltage as compared with a prescribed threshold voltage, it is determined as an overcurrent condition and for example, a low level control signal S1 is produced. The overload condition is avoided and stable electric power is supplied to a main load by supplying a control signal S1 to the gate of the FET 4, by separating a battery 6 from the output line. |
