Design Of High Power Factor Intelligent Dimmer LED Driver Based On Single Chip Microcomputer

LED products are widely used in the lighting field, and the excellent performance of the LED driver is the premise of producing excellent LED lighting lamps. With the improvement of living standards, the lighting function of LED products can not meet the needs of the people. Intelligent control technology has some advantages of energy saving, adjustable light, and special lighting effect, it will gradually replace the traditional lighting control technology. A high power factor intelligent control LED driver which had a WiFi communication system based on Android platform and a RF remote contol system was designed in this dissertation.The intelligent LED driver was composed by AC-DC converter module, DC-DC converter module and intelligent control module. Firstly, the boundary conduction mode(BCM) boost two stage active power factor correction(APFC) technology and quasi resonant(QR) current mode flyback converter technology were combined in the AC-DC converter to improve the value of PF and efficiency, AC input voltage could be converted to a stable DC voltage as the required voltage for the DC-DC module. The working principle of two kinds of technology and the design of the external circuit were described in detail. Secondly, the regulator IC was used in the DC-DC converter to provide the required voltage for the intelligent control module. At the same time, the dimming chip and the PWM dimming signal were combined in this converter to achieve dimming function. Lastly, the STM32F103 was adopted into the intelligent control module to output PWM signal, and the internal program and PID control algorithm were set in it to achieve temperature control and LCD display function. Moreover, two kinds of control system were used in the intelligent control module. The remote control’s switch timing function and diamming function were achieved by RF wireless communication technology, the design idea of the control system and the flow chart of each function were illustrated in this dissertation. The intelligent control also could be realized by the Android mobile interface using WiFi wireless communication technology, the selection process of WiFi module, the design of Android UI interface and the Socket communication including Client and Server were introduced in detail in this dissertation.After the test results of each module reached design standards, the prototype was assembled and debugged. It finally obtained the performance parameters as follows: the output voltage was 30V, the output current was 1A, the efficiency was up to 0.86, the PF was greater than 0.97, the standby loss was less than 0.3W, the output voltage ripple factor was less than 1%, and the THD was equal to 5.1%. In addition, it achieved some intelligent control functions of temperature control, LCD display, timer switch and dimming. The test results showed that the performance of the system achieved the design target, the output was stable, the process of dimming had no flicker, and the performance was good.