The Research And Development Of 60W White LED Intelligent Driver

LED is gradually replacing the traditional lighting, because of its high efficiency, long life, energy saving, environmental friendly and other advantages. Dimming can highlight the energy-saving advantages of LED, currently there are two main diming method:analog dimming and PWM diming. Analog diming is simple and easy to implement, but it changs the magnitude of the current while diming, resulting in poor color stability. PWM dimming change the duty cycle not the current amplitude, so it has good color stability, and has been widely used. White LED mainly using blue LED chip excite yellow phosphor to produce white light, it is easy to produce color temperature drift along with increased operating time and mutative operating temperature. Studies have shown that the amplitude of the drive current can affect the color temperature drift. The paper funded by the Guangdong Science and Technology Program--2012A080304012. This paper research and design an intelligent drive which can simultaneously achieve PWM and PAM adjustment, it not only can realize LED dimming, but also can suppress the color temperature drift.Paper firstly describes the implementation of white LED, and the effects of existing dimming to the the brightness and color temperature of the white LED; Then briefly intoduced the common lighting communications protocol; And gives the overall design according to design requirements, and specifically designed hardware circuitry and software. Finally, built the experiment platform and test the LED intelligent drive.The hardware design of LED intelligent drive is divided into the drive circuit design and control circuit design, Drive circuit uses a single-stage PFC flyback structure based on NCL30001, which can simultaneously achieve PFC and DC/DC conversion. The control circuit based on STC12C5A60S2 consist of DALI communication circuit, Zig Bee communication circuit and infrared communication circuit, and adjust the duty cycle and amplitude of driving current by two control signals, i.e. PWM and PAM adjustment. The software design of LED intelligent drive includes main program design and each communication interface subprogram design.Finally, we test the LED intelligent drive design, test results show that LED intelligent drive can simultaneously achieve PWM and PAM regulator of drive current, and achieve LED dimming by wire and wireless ways. Drive have a good performance in real-time, accuracy, reliability, etc.