A Novel Primary-Side Regulation Scheme for Single-Stage High-Power-Factor AC-DC LED Driving Circuit

This paper integrates a novel primary-side regulation (PSR) scheme with a single-stage high-power-factor (PF) ac-dc light-emitting-diode (LED) driving circuit. The driving circuit is based on the combination of a buck-boost PF corrector and a flyback converter. The component amount, cost, and size can be significantly reduced by replacing the secondary-side regulation with the PSR. In this way, not only high performance but also low cost and small system size can be achieved. Above 0.97 PF and 82% efficiency are obtained from a 12-W (60 W replaced) LED bulb driver prototype.