Downlight

the application of time-division multiplexing method implements an output of each branch  LED Downlight  current independent regulator to improve drive reliability ; Because this method uses only one magnetic components to achieve constant two-way stream output , thereby reducing the cost of the driver ; converter operating in DCM, fixed-frequency , fixed duty cycle , a high power factor . Finally, simulation and experimental results validate the correctness and effectiveness .

1 Introduction

Today , LED has been widely used in LCD backlighting, automotive , traffic lights and general lighting. According to IEC 61000-3-2 C class regulations , the need for greater than 25W of LED general lighting driver for power factor correction (Power Factor Correction, PFC), so low-cost power factor correction schemes become the focus of research.

LED Strip 

AC / DC converter in the common active Power Factor Correction (Active PowerFactor Correction, APFC) circuit is a two PFC circuit , before a circuit is used for power factor correction circuit is used after a DC / DC converter . Since there are two cascaded power level , this kind of circuit size and cost is usually higher, therefore , there has been another APFC topology , the topology of the PFC circuit and the type of DC / DC converters integrated together, they share an active power switch , a single-stage AC / DC converter , thus reducing costs , this APFC circuit is now widely used in ballast, charger. GU10