| 摘要 |
<P>PROBLEM TO BE SOLVED: To effectively accumulate the electromotive force that occurs at a speaker. <P>SOLUTION: An electric conversion device 10 includes a selecting switch 31 capable of switching between a first connection state in which an electric power can be supplied to an information terminal 13 from a speaker 11 and a second connection state in which a sound signal can be transmitted to the speaker 11 from the information terminal 13, an impedance conversion circuit 33 which is connected to the speaker 11 in the first connection state and performs impedance-conversion with an AC electromotive force outputted from the speaker 11, for outputting an AC power of the voltage higher than the AC electromotive force, a rectification circuit 34 which is connected to at least the information terminal 13 in the first connection state and rectifies the AC power outputted from the impedance conversion circuit 33 to a DC power, and a first smoothing capacitor 36. The impedance conversion circuit 33 converts the AC electromotive force outputted from the speaker 11 to an AC power of the voltage higher than the rising voltage of the rectification circuit 34. <P>COPYRIGHT: (C)2012,JPO&INPIT |
