Quasi-Active Power Factor Correction Circuit for HB LED Driver

High brightness light emitting diodes (HB LEDs) are likely to be used for general lighting applications due to their high efficiency and longer life. The paper presents a quasi-active power factor corrector (PFC) for driving a string of HB LEDs. The single-stage PFC circuit has a high efficiency, and it does not increase the voltage/current stress on the active switch used in the switching converter due to PFC. The circuit has two operating modes based on the input voltage level and its features, like power factor correction and power balance, are explained. The experimental results obtained on a prototype converter along with waveforms are presented.