—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 singlestage
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.