Design of a Constant Current LED Driver Based on Primary Side Control

The design of a 6 W constant current light emitting diode driver based on flyback with primary side control technology is proposed,eliminating the opto-isolated feedback and secondary regulation circuits required in traditional designs.Then the realization principle of constant voltage and constant current is analyzed,and the element pa-rameters of the circuit are introduced.The constant current accuracy of the circuit in 85～264 V AC input voltage are 4.3% and 2.9% separately with rated load and light load.The experimental results show that the circuit has the advantages of simple structure,high constant current precision and good stability.