Research And Implementation Of Programme Controlled High Precision LED Driver Source Based On LABVIEW

LED(Light Emitting Diode), whose features are small size, longevity, low drive voltage, reaction speed, anti-shock good, less power consumption, low fever, and high color purity, etc., has widely been used in all the aspects of production and life. LED appears as the main stream of lighting industry in the next times, enjoying tremendous popularity in the world. LED's optical, electrical and color integrated performance parameters are its major technical indicators; the accurate and fast measurement of LED's optical, electrical and color integrated performance is of great importance to its research, production, and quality. LED's multi-parameter testing equipment can test and filtrate its optical performance and electrical properties, and requires LED's current drive circuit to have features of high-precision and high-stability.This paper designs a high-precision program control LED drive source,according to the high-precision and high-stability requirements. The design core is to use closed loop feedback principle to stabilize output current. The paper compares output current test data with current set value, links work environment temperature test data, uses PC as program controller, Labview virtual equipment software as development platform, and control program to complete output current and work environment temperature collection, calculation, analysis, display, etc. by combining general computer with hardware circuit. The combination of circuit with software control can completely raise the performance of high-precision and high-stability power supply, ensure control high-precision, and better raise high-precision stability drive source intelligent degree. The operation is simple and friendly interface.This LED driver source has the features of set accuracy, output current stability, control high-precision, etc. The circuit system is composed of the two parts:①voltage control current source circuit;②PC software control system. The former is the core of drive source circuit and the key functions of current regulator and restraining ripple current; the latter is the functions of setting drive source output, improving current regulator precision and stability, eliminating small current output nonlinear, etc.This essay intends to introduce the main functions and targets of high-precision and high-stability drive source, analyze the various elements of affecting drive source stability, state the different plans of drive source circuit process, and discuss a feasibility plan for LED's multi-parameter testing equipment LED constant current source driving device, and design process and experiment results.