Power Factor Correction With Passive Elements
Original Publication Date: 1987-Oct-01
Included in the Prior Art Database: 2005-Feb-02
A parallel resonant circuit is combined with a normal passive bridge and filter capacitor of the input section of a switching power supply. The resultant circuit improves the power factor of the power supply, and greatly reduces the peak current at the AC input. A number of different circuits are being used to do power factor correction and input current wave shaping on the input of switching power supplies. Some of the most effective circuits are those that use a boost converter on the input. The disadvantage with the boost converter method is that the circuit uses both active and passive components and requires switching transistors to perform the boost function.