Research of Weak Signal Processing Circuit Based on Non-Dispersive Infrared Automobile Exhaust Sensor

2013 ◽  
Vol 336-338 ◽  
pp. 163-167
Author(s):  
Jun Xie ◽  
Yi Long Zhang ◽  
Yue Feng Yuan
Keyword(s):  
Light Source ◽  
Infrared Detection ◽  
Weak Signal ◽  
Gas Concentration ◽  
Automobile Exhaust ◽  
Detection Technology ◽  
Thermopile Sensor ◽  
Gas Chamber ◽  
Modulated Light ◽  
Processing Circuit

Based on the analysis of infrared detection technology and Lambert-Beer law a new kind of quad-channel non-dispersive infrared (NDIR) gas concentration analyzer is designed by applying the modulated IR light source and a quad thermopile sensor into automobile exhaust gases concentration detection. The emphasis is paid on the analysis of modulated light source, gas chamber, sensor and the acquisition and processing circuit of the signal. The result of simulation and analysis of the designed circuit proved the feasibility of the design.

scholarly journals Submillimeter Crack Detection Technology of Eggs Based on Improved Light Source

2021 ◽  
Vol 697 (1) ◽  
pp. 012018
Author(s):  
Haokang Chen ◽  
Jia Ma ◽  
Qiangjian Zhuang ◽  
Shuaitongze Zhao ◽  
Yuanliang Xie
Keyword(s):  
Light Source ◽  
Crack Detection ◽  
Detection Technology

Optical Fiber CO Concentration Measurement Prism of the Gas Chamber Variable Optical Path Automatic Adjustment System Research

2011 ◽  
Vol 109 ◽  
pp. 237-243
Author(s):  
Hong Xiu Zhu ◽  
Hao Zheng ◽  
Hong Bo Zhang ◽  
Xin Wang ◽  
Bo Xi Yang ◽  
...  
Keyword(s):  
Absorption Spectrum ◽  
Optical Fiber ◽  
Light Sensitivity ◽  
Concentration Measurement ◽  
Harmonic Detection ◽  
Feedback Type ◽  
Detection Technology ◽  
Co Concentration ◽  
Adjustment System ◽  
Gas Chamber

According to the absorption spectrum, combined with CO distribution feedback type laser diode (DFB-LD) light source, we selected R a center for 1567.3 nm as the wavelength of the absorption spectrum line. Comprehensively using of prism of gas chamber and harmonic detection technology, we constructed the optical fiber CO concentration measurement system. Through the stepping motor regulation height, it changes indoor prism gas effective absorption process, adjusts the light sensitivity system.

Phantom array and stroboscopic effects of a time-modulated moving light source during saccadic eye movement

2017 ◽  
Vol 50 (5) ◽  
pp. 772-786 ◽  
Author(s):  
C-S Lee ◽  
J-H Lee ◽  
H Pak ◽  
SW Park ◽  
D-W Song
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Light Source ◽  
Light Emitting Diode ◽  
Saccadic Eye Movements ◽  
Movement Speed ◽  
Light Sources ◽  
Saccadic Eye Movement ◽  
Modulated Light ◽  
Source Motion

This paper evaluates the detectability of the phantom array and stroboscopic effects during light source motion, eye movement and their combination, using time modulated light-emitting diode light sources. It is well known that the phantom array can be observed when time-modulated light sources are observed during saccadic eye movements. We investigated whether light source motion can cause similar effects when the subject has fixed eyes. In addition, we estimated the detectability threshold frequency for the combination of stroboscopic effect and the phantom array, which is named the stroboscopic-phantom array effect, during two eye movements in opposite directions under one directional rotating light source with variable speed. Our results indicate that one of the most important factors for the stroboscopic-phantom array effect is eye movement speed relative to the speed of the light source. Therefore, time-modulated moving light sources induce a stroboscopic effect in subjects with fixed eyes that is similar to the stroboscopic-phantom array effect observed during saccadic eye movement. Our findings are likely to be useful for predicting the stroboscopic effect and the stroboscopic-phantom array effect during the fast motion of time-modulated LED light sources, like multi-functional rear lamps, in automotive lighting applications.

Effects of the photogenerated excess carriers on the thermal and elastic properties of n-type silicon excited with a modulated light source: Theoretical analysis

2019 ◽  
Vol 126 (18) ◽  
pp. 185102 ◽  
Author(s):  
D. K. Markushev ◽  
D. D. Markushev ◽  
S. Aleksić ◽  
D. S. Pantić ◽  
S. Galović ◽  
...  
Keyword(s):  
Theoretical Analysis ◽  
Light Source ◽  
Elastic Properties ◽  
Type Silicon ◽  
Modulated Light

Pulse-modulated light source for psychometric and vision experiments

1987 ◽  
Vol 19 (3) ◽  
pp. 203-207 ◽  
Author(s):  
C.N. Scholfield ◽  
M. Murdock
Keyword(s):  
Light Source ◽  
Modulated Light

Design of Amplifying Circuit for Receiving Weak Signal for Laser Fuze

2013 ◽  
Vol 300-301 ◽  
pp. 1012-1017
Author(s):  
Bing Ting Zha ◽  
He Zhang ◽  
Jun Hong Wang ◽  
Jing Guo
Keyword(s):  
Small Volume ◽  
Avalanche Photodiode ◽  
High Gain ◽  
Low Noise ◽  
Weak Signal ◽  
Echo Signal ◽  
Long Distance ◽  
Detection Range ◽  
Simulation And Experiment ◽  
Processing Circuit

The echo signal received by laser fuze was very weak when the detection range increased. In order to expand the operating range of fuze, the reception capacity of fuze for weak signal should be improved. According to the requirements of long-range laser fuze receiving system as small volume, low-power, low-noise, high-gain, the amplifying circuit of the receiving system was analyzed and designed. To improve the ability of laser fuze for detecting weak signal, the high-sensitive, low-noise, inner-gain avalanche photodiode (APD) was used as a photodetector in the system, and the low-noise preamplifier and voltage amplifying circuit was designed. The noise and frequency response of the amplifying circuit was researched and analyzed by simulation and experiment. The results show that the design is effective and feasible, which can meet the requirements of processing circuit as receiving weak signal from long-distance.

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