Research On The Remove Flicker Technology Of LED Flexible Filament Lamp

The LED flexible filament lamp has a shape that resembles an incandescent lamp,deeply loved by lighting designers at home and abroad,and is popular in the LED lighting market.Compared with traditional LED light,flexible filament lamps have higher plasticity,more uniform light,with traditional bulb interfaces compatibility.According to the design requirements,the power supply is hidden in lamp holder such as E27,and the volume is severely limited,making the power supply structure more compact.However,the power of LED flexible filament lamps varies is uneven,which causes the flicker problem of lamps to become increasingly prominent.This paper focuses on the flicker problem of flexible filament lamps,and studies two techniques to remove flicker.One is a two-stage fly-back power supply technology to obtain a low-ripple and high-efficiency power;the other is the long afterglow phosphors to remove LED flicker.The output ripple of the power supply causes the LED light flicker.So the paper adopts a two-stage fly-back power supply technology.The front stage of the power supply uses fly-back technology,and the latter stage uses a linear controller to filter the power supply ripple.The power supply ripple rate is about 3%and flicker has dropped from 10%to 2.1%.After that,the power firstly uses the long afterglow phosphor Sr₄Al₁₄O₂₅:Eu²⁺,under the multi-phosphor system,greatly reducing the flicker of the LED light from 95.2%to 45.8%.The LED light also have the advantages of high color rendering index and high luminous efficiency.We use spectral fitting and phosphor aging tests to explore the energy transfer mechanism between phosphors in a multi-phosphor system.Finally,this paper uses Sr Al₂O₄:Eu²⁺,Dy³⁺as the same system as the Sr₄Al₁₄O₂₅:Eu²⁺to study remove flicker applied to flexible filaments lamp.The emission peak of Sr Al₂O₄:Eu²⁺,Dy³⁺is close to that of YAG phosphors,which reduces reabsorption phenomenon of phosphors.Finally,through the flicker test of the three color temperature Sr Al₂O₄:Eu²⁺,Dy³⁺in the flexible filament lamp,it was found that the increasing in the rate of the long afterglow phosphor,obviously removing the flicker from 13%to 4%.