At present, if the more and more commonly used LED lighting fixtures use constant DC power supply, it is theoretically possible to achieve constant lighting without flicker. But in fact, due to the lack of industry standards and fierce and disorderly market competition, the market is flooded with low-quality LED lights, especially indoor low-power LED lights, which also has stroboscopic problems. In order to obtain a pure constant current source, the LED drive power supply is the key to ensure that the LED lighting does not flicker. At present, the LED power supply can fully meet the requirement of no flicker. There are roughly two methods:
First, increase the output electrolytic capacitor: This method can theoretically absorb part of the AC ripple, but related experiments have shown that when the ripple is controlled within a certain range (10%), it is difficult to further reduce it, unless the electrolysis is increased. The cost of capacitors cannot be completely eliminated otherwise.
Second, adopt a two-level solution: that is, on the basis of the existing isolated power supply, adding a first-level DC power supply can completely eliminate the influence of AC ripple, and the electrical parameters will also meet the certification standards. However, the cost of the program has increased to a certain extent, and it is necessary to add more power management chips and some peripheral circuits.