LED power supply

A LED power supply comprises a circulating current transformer, an EMI filter circuit, a rectification circuit, a boost circuit and a PFC control circuit, wherein an input terminal of the transformer is connected with power grid and the transformer is used to reduce and transform an input voltage and then output from an output terminal; the input terminal of the EMI filter circuit is connected with the output terminal of the circulating current transformer; the EMI filter circuit is used to filter an interference of a high frequency pulse of the external power grid to a power supply and the interference of the power supply to the external power grid; the input terminal of the rectification circuit is connected with the output terminal of the EMI filter circuit; the rectification circuit is used to commutate an input alternating current into a pulsating direct current and then output the current from the output terminal; the input terminal of the boost circuit is connected with the output terminal of the recti