| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a power supply change arrangement which can achieve stabilization of an output of a selected external power supply as well as homogenization of this output and prevent a reverse current between the external power supplies when changed in the case of using one of a plurality of the external power supplies selected. <P>SOLUTION: The arrangement includes power supply change circuits 11 to 13, and a control circuit 14, with the power supply change circuits 11 to 13 in a manner as selectively taking out one of each output of an AC adapter 31 of the external power supply, an USB power supply 32 and each output of a battery 33. The power supply change circuit 11 is the circuit for selectively taking out output voltage of the AC adapter 31, to be provided with an input terminal 15, a common output terminal 16, a regulator 17 attaining stabilization of the self output voltage with output voltage of the AC adapter 31 serving as the input voltage, and a P type MOS transistor M11 for executing on/off control of an output of this regulator 17. <P>COPYRIGHT: (C)2009,JPO&INPIT |
