| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a power switching circuit which can switch power in simple constitution without causing power damage due to a backflow. <P>SOLUTION: The power switching circuit has a detection means 12 which detects the supply of a first power source, a comparison means 13 which compares the voltage of a second power source with the voltage of an output terminal, first and second switching means M1-1 and M1-2 which are connected in series between the first input terminal and the output terminal, a third switching means M2 which is provided between the second input terminal and the output terminal, and a control means 14 which turns on the first and second switching means M1-1 and M1-2 a first specified time after turning off the third switching means M2 when the detection means 13 detects the supply of the first power source and turns off the first and second switching means M1-1 and M1-2 when the detection means 13 detects the stop of supplying the first power source and turns on the third switching means M2 a second specified time after detecting the voltage of the output terminal having dropped under the voltage of the second power source by the comparison means 13. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
