A High Precision Constant Current Source Applied in LED Driver

2011 ◽  
Author(s):  
Hongtao Mu ◽  
Li Geng ◽  
Jun Liu
Keyword(s):  
High Precision ◽  
Current Source ◽  
Constant Current ◽  
Led Driver ◽  
Constant Current Source

Development of a Multi-Function Virtual Instrument Based on a Constant Current Source

2013 ◽  
Vol 385-386 ◽  
pp. 492-495
Author(s):  
Dong Bing Dai ◽  
Ya Jun Wang ◽  
Ye Ping Sun ◽  
Zheng Guang Liu
Keyword(s):  
Data Acquisition ◽  
High Precision ◽  
High Power ◽  
Virtual Instrument ◽  
Current Source ◽  
High Accuracy ◽  
Constant Current ◽  
Constant Current Source ◽  
Data Acquisition Card ◽  
Further Development

Virtual instrument is a result of the computer combined with some instrument hardware, working for the instrumentation applications, it is one trend of the instrumentation development .This paper presents a design of a high-power and high-precision constant current source, studied three different electrical testing technologies based on constant current source and propose the principle of integrated the three electrical test technologies on a virtual instrument platform. A multi-function virtual instrument system based on LabView language, USB data acquisition card and a constant current source has been developed. This system has a high accuracy, high integration and a thecapability of further development etc..

The Design of High-Precision Temperature Measurement System Based on C8051F350 and PT100

2013 ◽  
Vol 423-426 ◽  
pp. 2559-2562 ◽  
Author(s):  
Long Liu ◽  
Yun Cui Zhang ◽  
Shen Hua ◽  
Jun Xiao ◽  
Li Jia Huang
Keyword(s):  
Temperature Measurement ◽  
High Precision ◽  
Measurement System ◽  
Current Source ◽  
Constant Current ◽  
Constant Current Source ◽  
Interface Circuit ◽  
Software Algorithms ◽  
Precision Temperature ◽  
Temperature Measurement System

This article describes the design of High-Precision Temperature Measurement System based on C8051F350 and PT100. The system consists of the control circuit, temperature sensors, signal amplification circuit, field bus interface circuit. The system adopts constant current source method and a differential measurement circuit. A 24-bit A/D built in the CPU is used to sample the data and Non-linear compensation by software algorithms for it. The design improves the accuracy of the temperature measurement system.

Research of High Precision DC Constant Current Source

2013 ◽  
Vol 340 ◽  
pp. 933-936
Author(s):  
Dan Su ◽  
Zhi Hong Zhang ◽  
Jin Ping Zhao
Keyword(s):  
High Precision ◽  
Rocket Engine ◽  
Current Source ◽  
Engine Performance ◽  
Performance Testing ◽  
Constant Current ◽  
Output Current ◽  
Constant Current Source ◽  
New Type ◽  
Model Rocket Engine

In this paper, we designed a new type of high precision 1 μA constant current source after deeply studying the high precision precise dc constant current source. Compared with the traditional constant current source, in this paper we adopted complex amplifier added with floating power supply outside to design high precision dc constant current source which is for China's space use , its output current is 1 μA, resolution is 0.1 nA, accuracy is 0.5. This high precise dc constant current source is mainly used for new model rocket engine performance testing in aerospace, but also can be widely applied in different fields in need of precision measurement.

Design of Constant Current Source Based on Pulse Width Modulation

2013 ◽  
Vol 645 ◽  
pp. 418-421
Author(s):  
Li Hui Sun ◽  
Shu Jing Wang ◽  
Wei Chen
Keyword(s):  
High Precision ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Current Source ◽  
Constant Current ◽  
Output Current ◽  
Constant Current Source ◽  
Current Output ◽  
High Conversion Efficiency ◽  
Working Principle

Design of the constant current source based on pulse width modulation, and its working principle are discussed. The design can adjust the output current through pulse width modulation (PWM), and realize micro regulation by feedback output which stabilizes current output. The constant current source has some advantages of high precision, stable work, high conversion efficiency.

Adjustable Multi-Light Wireless Remote Control System Designed LED Light

2014 ◽  
Vol 543-547 ◽  
pp. 1250-1253
Author(s):  
Hong He ◽  
Feng Ling Zhang ◽  
Zhi Hong Zhang
Keyword(s):  
Remote Control ◽  
Smart Home ◽  
Current Source ◽  
Constant Current ◽  
Led Driver ◽  
Constant Current Source ◽  
Current Output ◽  
The People ◽  
Indoor Wireless ◽  
Lighting Systems

With the development of LED technology, the actual demand of the people for the smart home lighting, this paper designed a multiple lamps for indoor wireless remote control dimmable LED lighting systems. LED driver is using two levels of drive structure, and driver power supply adopts double-road current output, and the size of the output current of each constant current source is flexible to adjust by remote control. Wireless remote control part control multiple lamps by using 4 * 4 keyboard, which realizes intelligent management of LED interior lighting in the smart home.

Design of Low Power Lighting LED Driver with Multiplex Divided Constant Current Source

2013 ◽  
Vol 380-384 ◽  
pp. 3204-3208
Author(s):  
Fei Yu ◽  
Zhao Jie
Keyword(s):  
Low Power ◽  
Heat Dissipation ◽  
Low Cost ◽  
Current Source ◽  
Constant Current ◽  
Voltage Source ◽  
Led Driver ◽  
Constant Current Source ◽  
Good Efficiency ◽  
Driver Circuit

Low power lighting LED has the advantages of low cost and good heat dissipation. But the current driver for this kind of LED does not have a good efficiency. In this paper a new kind of LED driver circuit was designed. By using current mirror and PWM technique, the circuit has good efficiency. By simulation with PSPICE, we can prove that the circuit has can divide current equally and has a good performance while the voltage source has some jitters.

scholarly journals Illumination Adaptation in a Multi-Wavelength Opto-Electronic Patch Sensor

Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4734 ◽  
Author(s):  
Liangwen Yan ◽  
Yue Yu ◽  
Sijung Hu ◽  
David Mulvaney ◽  
Panagiotis Blanos ◽  
...  
Keyword(s):  
Rapid Determination ◽  
Current Source ◽  
Constant Current ◽  
Blood Oxygen Saturation ◽  
Led Driver ◽  
Constant Current Source ◽  
Light Emitting ◽  
Multi Wavelength ◽  
The Individual ◽  
Microcontroller Unit

In capturing high-quality photoplethysmographic signals, it is crucial to ensure that appropriate illumination intensities are used. The purpose of the study was to deliver controlled illumination intensities for a multi-wavelength opto-electronic patch sensor that has four separate arrays each consisting of four light-emitting diodes (LEDs), the wavelength of the light generated by each array being different. The study achieved the following: (1) a linear constant current source LED driver incorporating series negative feedback using an integrated operational amplifier circuit; (2) the fitting of a linear regression equation to provide rapid determination of the LEDs driver voltage; and (3) an algorithm for the automatic adjustment of the output voltage to ensure suitable LED illumination. The data from a single centrally-located photo detector, which is capable of capturing all four channels of back-light in a time-multiplexed manner, were used to monitor heart rate and blood oxygen saturation. This paper provides circuitry for driving the LEDs and describes an adaptive algorithm implemented on a microcontroller unit that monitors the quality of the photo detector signals received in order to control each of the individual currents being supplied to the LED arrays. The study demonstrated that the operation of the new circuitry in its ability to adapt LED illumination to the strength of the signal received and the performance of the adaptive system was compared with that of a non-adaptive approach.

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