Patent ID: 6222746
Filing Date: 2001-04-24
Classification: H02M,Y02B

Abstract:
A power supply device for supplying power to an electronic apparatus, comprising:a rectifier circuit for converting an input alternating current voltage to a direct current voltage;a boost circuit for boosting said direct current voltage to a prescribed voltage level;a power factor correction circuit for correcting a power factor of an output voltage of said boost circuit according to a feedback voltage derived from an output of said boost circuit; anda power factor correction disable circuit for providing a switch drive control off signal to said power factor correction circuit, said switch drive control off signal for disabling a switching operation of said power factor correction circuit in a power saving mode, said switching operation for correcting said power factor, whereby power consumption is prevented for said switching operation of said power factor correction circuit in said power saving mode, said power factor correction disable circuit comprising:a feedback circuit for feeding back a part of said output voltage of said boost circuit as said feedback voltage to said power factor correction circuit;a power saving mode detector for detecting said power saving mode depending on a level of said feedback voltage;a comparator for generating an active control signal when an output voltage of said power saving mode detector is lower than a prescribed reference voltage; anda drive circuit controller for generating said switch drive control off signal upon receiving said active control signal.