Long-life LED Drive Circuit Design

LED (Light Emitting Diode) has been extensively used as light source in our society.Its advantages include energy saving, high efficiency, long life and etc. Nonetheless, thelong-life LED drive circuit is still absent now. Traditional LED drive circuit useelectrolytic capacitors for filtering, which only have a small lifespan. In this paper, along-life LED drive circuit is designed and trial-manufactured as follows:First, an approach of switching power associated with linear power is employed. Highenergy conversion efficiency is achieved by switching power, and linear power is used tosuppress the ripple in output. Long-life film capacitor is also equipped to prolong thelifespan of drive power.Second, the appropriate circuit topology is selected according to the investigation ofseveral different switching power circuits.Third, the ripple compensation circuit is designed based on the principle of ripplecompensation and the factors which affect the ripple in circuit output.Fourth, the circuit topology is designed and all the parameters are calculated. Thesimulation software is applied to test the novel circuit topology and the control method.At last, the prototype of LED drive circuit is trial-manufactured. Aseries ofperformance testing is conducted.The testing results indicate that the inaccuracy of voltage deviation is less than1%,load regulation rate is less than5%, output efficiency is over85%, PF value is higher than90%, and the line voltage adjustment rate is less than2%. The good performance andlong-life of this circuit is verified by all the evidence above.