LED lighting is a new type of light source that has developed rapidly in recent years, and its many good features make it more and more widely used. The unidirectional conduction characteristics of LEDs make people generally think that they should be driven by DC. However, when the DC constant voltage and current limiting devices ensure better current limiting characteristics, their own power consumption is very large, so the efficiency of the system is greatly improved. reduce. Only by driving the LED with a higher frequency AC, and using an inductor or capacitor with low power consumption when presenting a large impedance to limit the current, can the current limiting characteristics of the LED drive circuit and its own power consumption be ideal.