One stage flyback-type power factor correction converter for LED driver

An isolated power factor correction converter for power light emitting diode (LED) is presented. The converter is constructed with single-stage by employing flyback topology, and the high power factor is accomplished through controlling the PFC circuit operates on the boundary between continuous and discontinuous current mode. The principle and design method of the converter is presented. A 180~.250V input, 70W constant current switch mode power supply with proposed method is designed, and experimental results show that the system has advantages of little bulk, high efficiency (87%), and high power factor (0.97).