A very low THD and high power factor primary side regulation LED driver

This paper introduces a new power factor correction scheme for a flyback converter with primary regulation technique, to ideally eliminate the distortion of the ac input current (practically a Total Harmonic Distortion (THD) lower than 5%). The effectiveness of the new control scheme is proved in a 35W driver with universal input range (90VAC~277VAC). Application target is Solid State Lighting (LED drivers).