The paper introduces the principle of LED drive power with the single-stage Power Factor Corrector(PFC). The structure principle of constant-voltage source AC/DC with single-stage PFC is analyzed and the solutions of the questions related to the constant-voltage source with single-stage PFC is given.It is a key part to design of constant-current

the principle and design step of constant-current drive chip BP2808 are given

meanwhile

the manual dimmable LED is added

the multi-resonant self-excited oscillator consisted by NE555 is used to generate a fixed frequency and produce 0.09%

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99.91% adjustable duty cycle pulse width modulation(PWM) output to adjust LED's light.The results show the design could achieve a wide range of adjustment duty cycle PWM pulse wave and it is satisfied with the requirements of the Power Factor Corrector

meanwhile

the high efficiency and low-cost is realized

the paper conform to the trend of the development of LED drive power.