Analysis and Design of a High Power Factor for LED Driver Circuit with Constant Current.

• Main Authors: Min-Sheng Chiou, 邱敏勝
• Other Authors: Ying-Pin Chang
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/46533402655706220531

碩士 === 南開科技大學 === 電機與資訊工程研究所 === 99 === In recent years, high-power light emitting diodes (LED) substantially improve the efficiency, and have easy to drive, environmentally friendly, long life and other features, gradually replaced the traditional lighting, a new generation of mainstream lighting. In this thesis presents the flyback converter circuit topology, the main structure is simple and suitable for low wattage of the circuit. In the single-stage circuits, contains an active power factor correction (APFC) of the constant current drive circuit can reduce power consumption and output constant voltage, power factor correction (PFC) circuit is used in conjunction with the driver of a switch, greatly simplifying the control circuit design for, it can be both cost and performance the only option for low power applications. The flyback converter operating in boundary conduction mode (BCM) frequency, the control method is simple, its switching frequency is not fixed, so no slope compensation and advantages of the current error compensator. Finally, a hardware circuit, the structure can achieve the constant current output and high power factor by the experimental result.