Development Of High Performance LED Drive And Control Systems

With the development of society and economy, the energy issue has become a focus of society. As the product of conservation-oriented society, LED play its irreplaceable advantages in lighting industry.LED has many advantages of high efficiency, energy conservation, environment protection, long life and difficult to damage. The special low voltage and direct-current drive for LED have to design a suitable driver power. Switching power has advantages of high efficiency and small size, so it becomes the first choice of LED driver power.Add dimming to LED lighting not only confirms the theme of energy conservation.The dimming driving system is mainly to provide lighting solutions for LED ceiling in this design. In order to achieve good dimming effect, PWM dimming is selected after comparing with three dimmings. According to the requirements of dimming scheme and output parameters, the control circuit and the drive circuit are designed respectively in two parts of system. The control circuit section complete the output that adjustable duty ratio of the PWM signal. Drive power complete several functions, reduce electromagnetic interference, power factor correction, constant current step-down and so on. STC12C5620 micro controller is the core of Control circuit, combined with infrared remote control technology, through software programming and analysis of infrared commands to achieve step-changes of the PWM signal, thus adjust the output current smoothly. PT4107 is the main chip of drive power, it receives the PWM signal and transforms the control time of MOSFET to change the average value of the output current.The sampling resistor sample the output current, and compare with the chip reference voltage, thereby adjusting the PWM control so that make the current more stable.After final debugging and testing, the system performance fulfils the initial design requirements, and achieve from 0% to 100% of the Promise dimming. Driving power is stable, and completes many performance indicators, achieve the volume of product requirements, and laid the foundation for the next development.