Design Of DC 12V 30W High-power LED Drive Array With High-efficiency And Single Dimmer

LED (Light Emitting Diode) lighting becomes more and more popular in factory, infrastructure and homes as a new lighting for its remarkable characters such as longevity, energy conservation, high efficiently lightening, quickly responsibility, various colors, convenient regulation. It can be expected that LED lighting will replace incandescent and halogen bulbs in general illumination in the near future, which makes that it is necessary to design a high power LED driver. Now many LED driver factories adopt constant voltage driver which cannot make sure LED'current in parallel are the same, and this easily causes LED semi-conductor IC burned out. So it is practical and academic to do research for high power LED driver.First, in the paper we introduce LED development history and application status at home and abroad, as well as the broad prospects of LED. Second, we introduce the basic principles of LED's light-emitting, and show necessary of adopting constant current drivers. At last, we analysis LED driver application status, and make a comparison of advantages and disadvantages of common LED driver topologies.In the paper, the LED driver of multiple constant current sources supplied by a single voltage source supply is proposed, one LED circuit is supplied by one constant current, and lightning of every constant current circuit is regulated by a dimmer driver. The whole circuit is designed; constant voltage circuit, constant current circuit and dimmer driver circuit are designed and simulated; the key Parameters of the synthetic circuit are verified and the results of simulation meet the function requirement.First, in the Constant voltage source Maxim's MAX668 is adopted as boost topology of the controller, considering it's simple and high efficient. MAX668 as backward boost topology of the controller takes RCD clamp and non-source non-loss snubber circuit which is suitable for multi-outputs and isolation. UCC2897A is adopted as forward boost topology circuit of the controller in which zero-voltage soft switching is applied. The key parts of high frequency transformer of forward boost topology driver are designed, and how to design key parameter in the circuit is listed.Second, Maxim's MAX16803 and SI-EN's SN3350 are respectively used as the constant current sources; when loading the PWM input, single dimming is achieved and constant current output is attained. By comparison of the results of the constant current sources, the most efficient constant current source is SN3350, with efficient 95%. At last, the multi-resonant self-excited oscillator consisted by NE555 can generate a fixed frequency and produce adjustable duty cycle PWM output to achieve single light-dimmer.The LED driver of multiple constant current sources has broad development, which will be the main stream in the future.