| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a switching power supply device that is hardly broken down, has low power consumption during the standby mode, and can significantly reduce the reset time from the standby mode to the normal mode. <P>SOLUTION: A switching power supply device comprises: a first power supply circuit 6 that has the normal operation mode and the standby mode and drives a first load 10; and a second power supply circuit 7 that does not have the standby mode and drives a second load 11. The first power supply circuit 6 is connected to a commercial power supply via a series circuit composed of a first rectifier circuit 2 and a power-factor improvement circuit 4 connected to a rush-current prevention circuit 3, and the second power supply circuit 7 is connected to the commercial power supply via a second rectifier circuit 70. The switching power supply device further comprises power supply control circuits 8 and 9 that turn on or off an auxiliary power supply VCC obtained by rectifying a current at a primary-side circuit 76-P3 of the second power supply circuit 7. The power supply control circuits 8 and 9 turn off the auxiliary power supply VCC in the standby mode, so that the power-factor improvement circuit 4 and a PWM control circuit 63 of the first power supply circuit 6 stop the operation, thereby stopping the power supply to the first load 10. <P>COPYRIGHT: (C)2013,JPO&INPIT |
