| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an electronic device with a simple circuit structure capable of handling various problems such as back-flow prevention in a charging input section, overvoltage input, connection among a plurality of charging power supply sources and breakage of a charging control circuit. <P>SOLUTION: Priority is previously determined among input contacts 1 to 3 connected to chargers. When a plurality of chargers are concurrently connected to the input contacts, a high-priority charging input 1 detection 52 inhibits an AND gate 54 and an AND gate 57, turns off transistors 14, 15 and inhibits charging from lower-priority chargers. Under abnormal conditions, any detection among the overvoltage 1 detection 53, the overvoltage 2 detection 56 and the overvoltage 3 detection 59 of the respective input contacts, or the overcharging detection 62 of a battery voltage 32a inhibits all AND gates 51, 54, 57, turns off transistors 13 to 15 and inhibits charging from all chargers. The transistors 13 to 15 with a small voltage drop prevent back-flow. <P>COPYRIGHT: (C)2008,JPO&INPIT |
