scholarly journals Design and Development of Temperature and Humidity Monitoring System

2019 ◽  
Author(s):  
R N Sonawane ◽  
A S Ghule ◽  
A P Bowlekar ◽  
A H Zakane
Keyword(s):  
Monitoring System ◽  
Printed Circuit Board ◽  
Liquid Crystal Display ◽  
Light Emitting Diode ◽  
Field Testing ◽  
Circuit Board ◽  
Light Emitting ◽  
Temperature And Humidity ◽  
Sd Card ◽  
Humidity Monitoring

The temperature and humidity monitoring system was developed using various components viz., Arduino Uno, DHT11 sensor, universal serial bus (USB) type B cable, adaptor, DC power jack, 9-V battery connector, 9-V DC battery, resistor, liquid-crystal display (LCD) screen, trimmer potentiometer, light-emitting diode (LED) bulbs, jumper wires, micro secure digital (SD) card module, printed circuit board (PCB), etc. The field testing of the developed temperature and humidity monitoring system was carried out at various locations of the college campus. It was observed that the system worked between the percent variation of 0–8.00% for temperature and 0–5.97% for humidity. The developed system showed the accuracy of ±2°C for temperature and ±4% for humidity. The total cost incurred for the development of temperature and humidity monitoring system along with all accessories was ₹1625.

Temperature and Humidity Dependent Reliability Analysis of RGB LED Chips

2006 ◽  
Author(s):  
Jun-Xian Fu ◽  
Shukri Souri ◽  
James S. Harris
Keyword(s):  
Reliability Analysis ◽  
Printed Circuit Board ◽  
Light Emitting Diode ◽  
Circuit Board ◽  
Light Emitting ◽  
Printed Circuit ◽  
Root Cause ◽  
Micro Cracks ◽  
Temperature And Humidity

Abstract Temperature and humidity dependent reliability analysis was performed based on a case study involving an indicator printed-circuit board with surface-mounted multiple-die red, green and blue light-emitting diode chips. Reported intermittent failures were investigated and the root cause was attributed to a non-optimized reflow process that resulted in micro-cracks and delaminations within the molding resin of the chips.

PENGARUH DIMENSI GEOMETRIK LAMPU LED TERHADAP PERSEPSI KECERAHAN

2013 ◽  
Vol 3 (2) ◽  
pp. 41
Author(s):  
Andrea Marisi ◽  
Revantino Revantino
Keyword(s):  
Solid State ◽  
Printed Circuit Board ◽  
Light Emitting Diode ◽  
Circuit Board ◽  
Solid State Lighting ◽  
Light Emitting ◽  
Printed Circuit ◽  
Surface Mounting

Perkembangan teknologi di bidang Solid State Lighting selama dekade terakhir membuat diversifikasi penggunaan Light Emitting Diode untuk pelayanan pencahayaan umum. Balai Besar Bahan dan Barang Teknik sejak tahun 2011 telah melakukan penelitian dan pengembangan lampu LED berbasis Surface Mounting Device (SMD) 5050. Pada perancangan Printed Circuit Board (PCB) untuk memasangkan LED-smd tersebut, dilakukan analisis dimensi geometrik yang optimal sehingga dapat memancarkan cahaya ke segala arah dan memberikan persepsi kecerahan yang lebih baik. Untuk perancangan PCB tersebut, dipilih 2 (dua) model berbentuk silinder dengan memperhatikan rasio antara tinggi dan diameter alas. Dari pendekatan sumber titik dan perhitungan eksitansi luminus, diperoleh bahwa model dengan rasio ≈ 1 menghasilkan persepsi lebih cerah terhadap visual manusia.Kata kunci : dimensi geometrik, pendekatan sumber titik, eksitansi luminus, persepsi kecerahan

Chip-On-ACB (Anodized Circuit Board) Package for High Power Light-Emitting Diode

2006 ◽  
Vol 3 (2) ◽  
pp. 67-72
Author(s):  
Kyuho Shin ◽  
Suho Shin ◽  
Soon Cheol Kweon ◽  
Kihwan Kwon ◽  
Seogmoon Choi ◽  
...  
Keyword(s):  
Dielectric Layer ◽  
Heat Dissipation ◽  
Printed Circuit Board ◽  
Light Emitting Diode ◽  
Circuit Board ◽  
Electric Signal ◽  
Anodized Aluminum ◽  
Metal Base ◽  
Light Emitting ◽  
Aluminum Oxide Layer

A new light-emitting diode (LED) package module based on anodized circuit board (ACB) is developed in this study. ACB represents the selectively anodized aluminum board, in which the aluminum oxide layer, formed by anodizing process, serves as a dielectric layer and the electric signal lines are formed on it. LED chips can be directly attached to the metal pads on the aluminum core of ACB, which acts as p-electrode and at the same time easily spreads out the heat generated from the chips. The use of ACB in LED packaging has the benefit that ACB provides an excellent heat dissipation path from junction to board. This characteristic cannot be obtained from metal-core printed circuit board (MC-PCB), because it inevitably has a dielectric layer for electrical insulation of signal lines from metal base, which acts as a blocking layer in the heat path. By using the thermal transient method, the thermal resistance of the LED package (from junction to board) is measured to be about 4 °C/W. Also, we have performed the simulation of heat conduction, of which the results agree well with the experimental results. This chip-on-ACB LED package module has a potential application as a back light unit for display panel.

scholarly journals Machine vision based in-process light-emitting diode chip mounting system

2018 ◽  
Vol 51 (7-8) ◽  
pp. 293-303 ◽  
Author(s):  
Chao-Ching Ho ◽  
You-Min Chen ◽  
Po-Chieh Li
Keyword(s):  
Machine Vision ◽  
Printed Circuit Board ◽  
Vision System ◽  
Light Emitting Diode ◽  
Circuit Board ◽  
Robot Arm ◽  
Light Emitting ◽  
Printed Circuit ◽  
Delta Robot ◽  
A Charge

Background: In this study, a machine vision–based method was developed for automated in-process light-emitting diode chip mounting lines with position uncertainty. In order to place the tiny light-emitting diode chips on the pattern of a printed circuit board, a highly accurate mounting process is achieved with online feedback of the visual assistance. Methods: The system consists of a charge-coupled device camera, a six-axis robot arm, and a delta robot. The lighting system is a critical point for the in-process machine vision problem. Hence, designing the optimal lighting solution is one of the most difficult parts of a machine vision system, and several lighting techniques and experiments are examined in this study. In order to commence the mounting process, the light-emitting diode chip targets inside the camera field were identified and used to guide the delta robot to the grabbing zone based on the calibrated homography transformation. Efforts have been focused on the field of machine vision–based feature extraction of the chip pins and the holes on the printed circuit board. The correspondence of each other is determined by the position of the chip pins and the printed circuit board circuit pattern. The image acquisition is achieved directly online in real time. The image analysis algorithm must be sufficiently fast to follow the production rate. In order to compensate for the uncertainty of the light-emitting diode chip mounting process, a visual feedback strategy in conjunction with an uncertainty compensation strategy is employed. Results: Finally, the light-emitting diode chip was automatically grabbed and accurately placed at the desired positions. Conclusion: On-line and off-line experiments were conducted to investigate the performance of the vision system with respect to detecting and mounting light-emitting diode chips.

Maker Chemistry: Exploring Redox Reactions in Introductory Laboratory through Light-Emitting Diode Printed Circuit Board Fabrication

2019 ◽  
Vol 97 (2) ◽  
pp. 490-496
Author(s):  
Scott L. Wallen ◽  
Jaspreet Dhau ◽  
Robert Green ◽  
Laura B. Wemple ◽  
Troy Kelly ◽  
...  
Keyword(s):  
Redox Reactions ◽  
Printed Circuit Board ◽  
Light Emitting Diode ◽  
Circuit Board ◽  
Light Emitting ◽  
Printed Circuit

Thermal Investigation and Placement Design of High-Brightness LED Array Package on PCB for Uniform Illuminance

2011 ◽  
Vol 133 (1) ◽  
Author(s):  
K. C. Yung ◽  
H. Liem ◽  
H. S. Choy ◽  
W. K. Lun
Keyword(s):  
Surface Temperature ◽  
Printed Circuit Board ◽  
Cfd Simulation ◽  
Light Emitting Diode ◽  
Circuit Board ◽  
Heat Transfer Analysis ◽  
Significant Drop ◽  
High Brightness ◽  
Light Emitting ◽  
Led Array

This paper reports the thermal performance of a high-brightness light-emitting diode (LED) array package with a novel placement method on a printed circuit board (PCB). The precise heat transfer analysis and modeling using computational fluid dynamics (CFD) were performed according to the practical working conditions of the LED array. Emphasis was placed upon investigating how the temperature of the surface of LEDs changed in accordance with different placement methods. A significant drop in the surface temperature of the LEDs was found when the triangular and arithmetic spacing placement methods were used; hence, the overall heat dissipating capability of the LED array to the PCB was improved. By optimizing the placement design, the average surface temperature of the LED array achieved a decrease of about 20%, from 120°C to 100°C. The illuminance level of each placement design was measured and compared. Both CFD simulation and experimental results are provided to demonstrate the efficacy of the proposed approach for LED array thermal management.

Items Searching in Factory Warehouse Using Arduino Module

2019 ◽  
Vol 1 (1) ◽  
pp. 1-14
Author(s):  
Tan Liong Ching ◽  
Nureize Binti Arbaiy
Keyword(s):  
Inventory Management ◽  
Liquid Crystal Display ◽  
Light Emitting Diode ◽  
Storage System ◽  
Voice Recognition ◽  
Inventory System ◽  
Search Process ◽  
Light Emitting ◽  
Recognition Function ◽  
Light Function

The smart store system (F3 Storage System) provides an inventory system function, and is supported by voice recognition for items searching purpose in the warehouse. This system is aimed to improve effectiveness in item searching process for the warehouse management. An inventory system structures is employed in this system to enable items management. Voice recognition facility helps the worker to search item in an effective way. Worker can use voice recognition function to search the item in the warehouse, and searched information of the item will be displayed in the liquid crystal display (LCD) screen. Meanwhile, the location of the item will be physically indicated by the light emitting diode (LED) light function. The developed system also contains a barcode system to enhance the process of scheduling warehouse activity. Such facilities will enhance the capabilities of existing inventory management systems in warehouses. Prototyping model is used to assist project development. Arduino technology is used to enable integrated hardware and software to read data or input. With Arduino technology, traditional search items by using text and search functionality are enhanced to allow speech functionality. This functionality makes the search process faster and more efficient.

scholarly journals Compact Modelling of Electrical, Optical and Thermal Properties of Multi-Colour Power LEDs Operating on a Common PCB

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1286
Author(s):  
Krzysztof Górecki ◽  
Przemysław Ptak
Keyword(s):  
Integrated Circuits ◽  
Optical Model ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Junction Temperature ◽  
Optical Parameters ◽  
Spice Simulation ◽  
Light Emitting ◽  
Proposed Model ◽  
Good Agreement

This paper concerns the problem of modelling electrical, thermal and optical properties of multi-colour power light-emitting diodes (LEDs) situated on a common PCB (Printed Circuit Board). A new form of electro-thermo-optical model of such power LEDs is proposed in the form of a subcircuit for SPICE (Simulation Program with Integrated Circuits Emphasis). With the use of this model, the currents and voltages of the considered devices, their junction temperature and selected radiometric parameters can be calculated, taking into account self-heating phenomena in each LED and mutual thermal couplings between each pair of the considered devices. The form of the formulated model is described, and a manner of parameter estimation is also proposed. The correctness and usefulness of the proposed model are verified experimentally for six power LEDs emitting light of different colours and mounted on an experimental PCB prepared by the producer of the investigated devices. Verification was performed for the investigated diodes operating alone and together. Good agreement between the results of measurements and computations was obtained. It was also proved that the main thermal and optical parameters of the investigated LEDs depend on a dominant wavelength of the emitted light.

Manufacture and Evaluation of Light Emitting Diode Package Substrate Using Flexible Printed Circuit Board

2015 ◽  
Vol 15 (10) ◽  
pp. 7578-7581
Author(s):  
Jung-Kab Park ◽  
Jin-Ha Shin ◽  
Mun-Gi Jung ◽  
Tomabechi Shigehisa ◽  
Hwa-Sun Park ◽  
...  
Keyword(s):  
Thermal Resistance ◽  
Light Emitting Diode ◽  
Thermal Conductance ◽  
Polyimide Film ◽  
Luminous Efficiency ◽  
Circuit Board ◽  
Light Sources ◽  
Thermal Shock Test ◽  
Light Emitting ◽  
Au Electrode

Unlike other light sources such as fluorescent lamps and incandescent bulbs, light-emitting diodes (LED) convert 70∼80% of energy into heat. If the heat produced an LED chip is not effectively released, its luminous efficiency and lifespan are reduced. Therefore, as a method effectively release heat, an LED PKG substrate containing a heat-releasing material with excellent thermal conductance was fabricated, and its thermal resistance and luminous efficiency were analyzed. In this experiment, a thin polyimide film with excellent ductility was used to fabricate the LED PKG substrate. A 35-μm-thick Cu foil with excellent thermal conductance was subjected to high temperature and pressure and attached to both sides of the polyimide film. By electroplating Ag or Au, which has excellent thermal conductance, for us as the electrode and heat-releasing material, LED PKG substrate was fabricated with a thickness of approximately 170 μm. (−40 °C → RT → 120 °C). The results revealed that the LED PKG substrate having a Ag electrode with excellent thermal conductance had an excellent thermal resistance of approximately 4.2 °C/W (Au electrode: 5.6 °C/W). The luminous flux after 100 cycles in the thermal shock test was reduced by approximately 0.09% (Au electrode: 2.77%), indicating that the LED PKG substrate had excellent thermal resistance without any mechanical and material defects in a rapid-temperature-changing environment. The advantages and excellent thermal resistance can be exploited in cellular phones and LCD panels, and heat-releasing problems in thin panels be solved.

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