| 摘要 |
A saturating-inductor (112) or transformer (114) is used to shape input current flowing into an alternating current (AC) to direct current (DC) power supply (100) to correct the power factor for the supply. If a saturable inductor (112) is used, it is connected to feed current into the power supply (100) and a capacitor (113) is connected across the input of the power supply. The capacitor precharges the saturable inductor to a point just short of saturation during a preliminary portion of each sinusoidal half cycle of the input AC power. For steady state operation, this is the point at which current will start to flow into the AC to DC power supply and the inductor will saturate. Since the inductance falls in accordance with the permeance curve characteristic of material used to construct the inductor, the current will continue to flow at the same or an increasing level despite the declining voltage level of the AC input power. |
