| 摘要 |
PURPOSE: A power supply circuit is provided to maintain a power factor compensation portion equal to or lower than a normal voltage by detecting an operating state of a main transmission. CONSTITUTION: A rectification portion(1) rectifies AC power. A power factor compensation portion(2) compensates a power factor of an output voltage of the rectification portion(1). An output portion(3) transfers the outputs of the power factor compensation portion(2) to two different paths. A main transmission(6) converts the output voltage of the output portion(3). An operating state detection portion(10) senses an operating state of the main transmission(6) and outputs a control signal according to a sensed result. A power transistor(7) is used for applying the output voltage of the main transmission(6) to a load(9) according to a control signal of a control portion(8). A detection portion(4) changes the output voltage of the output portion(3) according to a control signal of the operating state detection portion(10). A power factor control portion(5) controls the power factor compensation portion(2). |
