With the progress of science and technology, lighting tools and methods are constantly changing, the user for the lighting apparatus show illuminance, uniformity, color rendering and energy efficiency standards increasingly high demand, at this stage, the most watched the bright younger generation when a LED lighting is lighting.
However LED in lighting market application still has some problems, including LED consistency, life testing, especially the power supply and drive system specification problem remains to be solved. In the LED driver power supply requirements include high efficiency, high power factor, high control precision, high reliability, safety isolation, in line with EMI standards, small volume, low cost. Notably, the new energy star standards proposed for more than 5W of LED lighting products, called power factor index ( PFC ) must be greater than 0.7, so in order to further achieve the purpose of energy saving.
High power conversion efficiency for the pursuit of goals
It learns from that super efficient LED lighting topological structure in recent years popular, the industry is mainly hopes to at a relatively low power level ( < 50W ) provided more than 90% efficiency, and such high efficiency will need a new topology to reach, such as resonant half bridge topology structure to replace the flyback topological structure, so it can give full play to the zero voltage switching ( ZVS ) advantage.
From the applied power levels, AC-DC LED power supply general lighting applications include low power, medium power and power of different types. Low power applications are usually in the range of 1 to 12W switching power supply; medium power covers 8 to 40W switching power supply range; high power applications is often higher than that of 40W switching power supply. Overall, LED lighting drive power industry is facing a major challenge is the LED driver should challenge higher conversion efficiency, especially in driving high power LED is even more so, because all not as light output power as heat dissipation, power conversion efficiency is too low, will affect the LED energy-saving effect.
