| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a portable apparatus which can be driven stably for a long time. <P>SOLUTION: Respective circuits of a digital camera 10 are operated by power generated from a fuel cell 30. Electric energy generated by the cell 30 is stored in a buffer 72 via a converter 70, and further stored in a buffer 76 via a converter 74. The converter 74 has a function of cutting off the buffer 72 and the buffer 76. If a charging level of the buffer 76 reaches a predetermined level V2 or lower, the buffer 76 is charged by electric energy charged in the buffer 72. If a large load is generated, the converter 74 cuts off the buffer 72 and the buffer 76 so as to prevent a current from reversely flowing from the buffer 76 to the buffer 72. <P>COPYRIGHT: (C)2004,JPO |
