| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an AC-DC conversion circuit which has less number of parts and small current consumption. <P>SOLUTION: This AC-DC conversion circuit 1 comprises a rectifier circuit including diodes 11-14, smoothing and voltage doubler electrolytic capacitors 17, 18 connected in series between output terminals T13, T14, balancing and voltage-dividing resistors 19, 20, a balancing resistor element 16, and a switch 15, which connects the resistor element 16 to the capacitor 17 in parallel in a full-wave rectification mode and connects an input terminal T12 to a node N17 between the capacitors 17, 18 in a double voltage mode. Since the resistor elements 19, 20 function as balancing resistors and voltage dividing resistors, the number of parts can be reduced. Furthermore, since the resistor element 16 is separated from the capacitor 17 in the double voltage mode, current consumption can be reduced. <P>COPYRIGHT: (C)2009,JPO&INPIT |
