Energy Channeling LED Driver Technology to Achieve Flicker-Free Operation With True Single Stage Power Factor Correction

A conventional single stage ac-dc LED driver usually produces significant twice-line-frequency ripple current when a high power factor is achieved. The ripple current causes a lighting flicker of the LEDs. In this paper, an energy channeling ripple cancellation LED driver is proposed. It achieves true single stage power conversion, maintains a high power factor while significantly removing the twice-line-frequency ripple current - flicker free LED driving. An 8.5 W, 50 V/0.17 A Buck-Boost experimental prototype has been built to verify the proposed method.