| 摘要 |
PURPOSE: A power supply unit and a method for supplying power are provided to efficiently reduce power consumption by changing the feedback sensitivity by turning off a second switch when an additional first switch is off for a standby off mode. CONSTITUTION: A transformer(22) changes a primary voltage by using the magnetic induction action and supplies the changed voltage to a secondary side. A microcomputer(27) outputs a multi control signal when the mode of a system is changed into a stead state or standby state off mode. A first switching unit(S1) turns on/off the output of the voltage supplied to a secondary side according to the control signal of the microcomputer. A second switch unit(S2) reduces the output voltage of the secondary side which is switched off according to the control signal of the microcomputer and uses the distribution resistance in the standby state off mode. A feedback circuit unit(25) feeds back the driving state of the secondary side of the transformer to the primary side according to the on/off of the first and second switch units. |
