Expansion of the Junction Temperature Measurement via the Internal Gate Resistance to a wide range of Power Semiconductors

Nowadays, signal lights are made using light-emitting diode arrays (LEDs). These devices are extremely energy efficient and have a very long lifetime. Unfortunately, especially for yellow/amber LEDs, the intensity of the light is closely related to the junction temperature. This makes it difficult to design signal lights to be used in naval, road, railway, and aeronautical sectors, capable of fully respecting national and international regulations. Furthermore, the limitations prescribed by the standards must be respected in a wide range of temperature variations. In other words, in the signaling apparatuses, a system that varies the light intensity emitted according to the operating temperature is useful/necessary. In this paper, we propose a simple and effective solution. In order to adjust the intensity of the light emitted by the LEDs, we use an LED identical to those used to emit light as a temperature sensor. The proposed system was created and tested in the laboratory. As the same device as the ones to be controlled is used as the temperature sensor, the system is very stable and easy to set up.

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Apply IOT technology to practice a pandemic prevention body temperature measurement system: A case study of response measures for COVID-19

International Journal of Distributed Sensor Networks ◽

10.1177/15501477211018126 ◽

2021 ◽

Vol 17 (5) ◽

pp. 155014772110181

Author(s):

Wei-Ling Lin ◽

Chun-Hung Hsieh ◽

Tung-Shou Chen ◽

Jeanne Chen ◽

Jian-Le Lee ◽

...

Keyword(s):

Body Temperature ◽

Temperature Measurement ◽

Measurement System ◽

Disease Surveillance ◽

Disease Surveillance System ◽

Temperature Detection ◽

Wide Range ◽

Body Temperature Measurement ◽

Analysis System ◽

Temperature Measurement System

Today, the most serious threat to global health is the continuous outbreak of respiratory diseases, which is called Coronavirus Disease 2019 (COVID-19). The outbreak of COVID-19 has brought severe challenges to public health and has attracted great attention from the research and medical communities. Most patients infected with COVID-19 will have fever. Therefore, the monitoring of body temperature has become one of the most important basis for pandemic prevention and testing. Among them, the measurement of body temperature is the most direct through the Forehead Thermometer, but the measurement speed is relatively slow. The cost of fast-checking body temperature measurement equipment, such as infrared body temperature detection and face recognition temperature machine, is too high, and it is difficult to build Disease Surveillance System (DSS). To solve the above-mentioned problems, the Intelligent pandemic prevention Temperature Measurement System (ITMS) and Pandemic Prevention situation Analysis System (PPAS) are proposed in this study. ITMS is used to detect body temperature. However, PPAS uses big data analysis techniques to prevent pandemics. In this study, the campus field is used as an example, in which ITMS and PPAS are used. In the research, Proof of Concept (PoC), Proof of Service (PoS), and Proof of Business (PoB) were carried out for the use of ITMS and PPAS in the campus area. From the verification, it can be seen that ITMS and PPAS can be successfully used in campus fields and are widely recognized by users. Through the verification of this research, it can be determined that ITMS and PPAS are indeed feasible and capable of dissemination. The ITMS and PPAS are expected to give full play to their functions during the spread of pandemics. All in all, the results of this research will provide a wide range of applied thinking for people who are committed to the development of science and technology.

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A wide‐range superconductor thermal sensor for low‐temperature measurement

Review of Scientific Instruments ◽

10.1063/1.1142214 ◽

1991 ◽

Vol 62 (11) ◽

pp. 2792-2794 ◽

Cited By ~ 3

Author(s):

M. V. S. Lakshmi ◽

K. Ramkumar ◽

M. Satyam

Keyword(s):

Low Temperature ◽

Temperature Measurement ◽

Thermal Sensor ◽

Wide Range

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Direct Liquid Cooling of High Flux LED Systems: Hot Spot Abatement

Volume 2: Thermal Management; Data Centers and Energy Efficient Electronic Systems ◽

10.1115/ipack2013-73031 ◽

2013 ◽

Cited By ~ 1

Author(s):

Enes Tamdogan ◽

Mehmet Arik ◽

M. Baris Dogruoz

Keyword(s):

Hot Spots ◽

Hot Spot ◽

Heat Removal ◽

Heat Fluxes ◽

Light Extraction ◽

Junction Temperature ◽

System Level ◽

Design Parameters ◽

Liquid Cooling ◽

Wide Range

With the recent advances in wide band gap device technology, solid-state lighting (SSL) has become favorable for many lighting applications due to energy savings, long life, green nature for environment, and exceptional color performance. Light emitting diodes (LED) as SSL devices have recently offered unique advantages for a wide range of commercial and residential applications. However, LED operation is strictly limited by temperature as its preferred chip junction temperature is below 100 °C. This is very similar to advanced electronics components with continuously increasing heat fluxes due to the expanding microprocessor power dissipation coupled with reduction in feature sizes. While in some of the applications standard cooling techniques cannot achieve an effective cooling performance due to physical limitations or poor heat transfer capabilities, development of novel cooling techniques is necessary. The emergence of LED hot spots has also turned attention to the cooling with dielectric liquids intimately in contact with the heat and photon dissipating surfaces, where elevated LED temperatures will adversely affect light extraction and reliability. In the interest of highly effective heat removal from LEDs with direct liquid cooling, the current paper starts with explaining the increasing thermal problems in electronics and also in lighting technologies followed by a brief overview of the state of the art for liquid cooling technologies. Then, attention will be turned into thermal consideration of approximately a 60W replacement LED light engine. A conjugate CFD model is deployed to determine local hot spots and to optimize the thermal resistance by varying multiple design parameters, boundary conditions, and the type of fluid. Detailed system level simulations also point out possible abatement techniques for local hot spots while keeping light extraction at maximum.

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