Design and luminescence characteristics of LED controllable burst circuit for jaundice detectors

ZHANG Zhongwei; YANG Haikun; LIN Shujie; LIU Zeyu

doi:10.16186/j.cnki.1673-9787.2024030036

Abstract：Objectives The jaundice detector is a precision optoelectronic detection instrument used for mea-suring jaundice severity in newborns.For the jaundice detector,the light source luminous intensity is a key factor that determining the signal-to-noise ratio and measurement accuracy of the photoelectric detection sig-nal.To develop a miniature jaundice detector with high signal-to-noise ratio and measurement accuracy by using LED light sources,related technical research on the LED controllable burst driving circuit and lumi-nous characteristics was conducted with the aim of designing and developing LED light source driver cir-cuits that with controllable and high luminous signal intensity.Methods Firstly,the application circuit and circuit timing driver program that used for LED controllable burst flash were designed based on the LED light source pulse strobe circuit that realized by introducing Circuit control devices such as silicon con-trolled rectifier(SCR)and P-type MOSFETs and combining MCU control chip in the traditional avalanche transistor pulse circuit.Then,by changing the technical characteristic parameters such as discharge capaci-tance and driving voltage in the flash circuit,the parameter optimization experiments for the luminous char-acteristics of LED light sources were conducted under different discharge capacitance values and driving voltage conditions.Results The research results show that under the conditions of a discharge capacitance of 100 μF for the avalanche transistor in the burst flashing circuit,a discharge capacitance of 330 μF for driving the LED emission,and a circuit driving voltage of 18 V,the peak intensity of the LED light source emission signal could exceed 12 times that of normal constant voltage drive at 12 V.Conclusions The con-trollable burst flashing circuit,which was designed for LED light sources,significantly enhanced the in-stantaneous luminous intensity of LED.This achievement will offer robust technical support for the develop-ment of jaundice detectors with high photoelectric signal intensity and signal-to-noise ratio.