Research On Intelligent LED Driver System Based On Fieldbus

The high-power white light LED is a new generation green light source. It can save energy and controlled easily. But it has to use special LED driver because of its non-linear load characteristics and sensitive temperature characteristics. Then a multi-channel LED drive system is designed based on CAN bus controller. The design is used in the intelligent vehicle system.This paper brings up the general structure of the LED driver. Firstly general intelligent control module is established. It can receive monitor instruction from the system and control multi-channel current power source to control series of LED current. The control purpose is to dimming separately. The design of intelligent control module is based on SOC microchip. It supports CAN2.0 communication protocol and RS485 bus standard. It can set work parameter setting and working state response. It can establish CAN identifier and support the execution freely. It makes the need of LED drive current and luminous intensity. It also makes the need of current, voltage and temperature of monitor driver. In order to the system test, the module can support USB interface. The interface can connect with PC. Moreover the paper designs two kinds of current power sources. The first module uses integrated circuit chip of especial switch power supply to build Buck-Boost circuit. The circuit is to establish wide range controlled current power source. The power source can be protected using the protect circuit of under voltage, over voltage, over current and over temperature. The second module uses the PWM generator to control the MOSFET switch. The module makes boost controlled current source and the gets a high work efficiency. The paper also illustrates the testing system of the driver and points out the design idea and implements point. The paper promotes the method of current closed-loop regulation and controlled equipment to the design of general switched current power source module.In order to test working situation of the driving system, the demo system of LED driver and testing system of LED is established in this paper. The demo system of LED driver can change the LED luminance using CAN bus. It can show the flexibility of automotive control. The testing system of LED can test the basic working characteristics of LED module. The test result shoes that the model machine has good practicability. It can be used in the vehicle lighting and automated in the whole system in the future.