Method for controling output volatge of power supply apparatus for multi-output, power supply apparatus for multi-output, and image forming apparatus having it

摘要

A multi-output power supply device includes a first power switch (10), a first switch controller (12) that controls the first power switch (10), a transformer (14) that transforms a power supplied from the first power switch (10), first through Nth output circuits (16,18) connected to a secondary side of the transformer (14), where N is a positive integer greater than 1, a second power switch (20) that switches the power output from one of the first through Nth output circuits (16,18), a second switch controller (22) that controls the second power switch (20), a feedback circuit (28) that feeds back output voltages of the first through Nth output circuits (16,18), and a feedback compensation circuit (100) that performs a switching operation complementarily with the second power switch (20) to compensate for a resistance of the feedback circuit (28). Accordingly, when power output to one of the output circuits is blocked, the multi-output power supply device can stably control the power output to the other output circuits.