scholarly journals Selected Problems of Power MOSFETs Thermal Parameters Measurements

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8353
Author(s):  
Krzysztof Górecki ◽  
Krzysztof Posobkiewicz
Keyword(s):  
Measurement Error ◽  
Measurement Methods ◽  
Thermal Parameters ◽  
Contact Method ◽  
Electrical Method ◽  
Power Mosfets ◽  
Measurement Results ◽  
Additional Influence ◽  
Transient Thermal ◽  
Selection Of

In the paper, selected problems that are related to the measurements of thermal parameters of power MOSFETs that are placed on a common heat sink are analysed. The application of the indirect electrical method, the contact method, and the optical method in measuring self and mutual transient thermal impedances of these transistors is presented. The circuits that are required to perform measurements are presented and described. The errors of measurements are assessed for each of the considered methods. In the case of the indirect electrical method, an additional influence of the selection of a thermo-sensitive parameter and the function approximating thermometric characteristics on the measurement error are taken into consideration. The measurement results of the thermal parameters of the investigated transistors that were obtained using the considered measurement methods in various supply conditions are presented and discussed.

scholarly journals Modification of Digital Oil Pressure Measurement Equipment using Bluetooth Technology

2019 ◽  
Vol 13 (2) ◽  
pp. 103
Author(s):  
Rasma Rasma ◽  
Thomas Junaedi ◽  
Hendro Purwono ◽  
Riki Effendi
Keyword(s):  
Pressure Gauge ◽  
Measurement Methods ◽  
Hydraulic Pressure ◽  
Work Process ◽  
Diagnostic Instruments ◽  
Digital Pressure ◽  
Wide Range ◽  
Measurement Results ◽  
The Right ◽  
Selection Of

PT United Tractors Tbk Jakarta workshop held a lot of Machine Inspection Programs for Komatsu units. During the implementation of the Machine Inspection Program (PPM) the machine inspection program is one part of the maintenance that is carried out periodically to obtain accurate data on the condition of the equipment at the time by carrying out checks and adjustments using measurement methods and diagnostic instruments The use of a pressure gauge is still using manual and has a measurement distance that is still limited, if workers or mechanics are not equipped with sufficient knowledge then the pressure gauge will have the potential for error in use and the selection of a pressure gauge is not appropriate to the pressure gauge directly connected to the hydraulic pressure through the hose then the work process ppm is not enough 1 manpower. Therefore it is necessary to modify a digital pressure gauge that has a wide range of scales, in addition a wireless connection is needed to enable the operation of the unit and measurements are made 1 manpower and Bluetooth is one of the right choices in addition to the reach can be met in an application not too difficult so that readings measurement results can be connected directly via mobile.

scholarly journals Comparison of Properties for Selected Experimental Set-Ups Dedicated to Measuring Thermal Parameters of Power LEDs

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3240
Author(s):  
Krzysztof Górecki ◽  
Przemysław Ptak ◽  
Marcin Janicki ◽  
Małgorzata Napieralska
Keyword(s):  
Optical Power ◽  
Measurement Procedure ◽  
Thermal Parameters ◽  
Measurement Results ◽  
Set Up ◽  
Transient Thermal

This article compares properties of two measurement set-ups dedicated to determining thermal parameters of power LEDs. The standard T3Ster set-up and the custom set-up developed in Gdynia Maritime University are considered. Both set-ups are described and the used measurement procedure is presented. The manner of measurement of optical power of the tested LEDs is also described. The method of measuring transfer transient thermal impedances between thermally coupled power LEDs using both set-ups is proposed. The measurement results of the mentioned parameters obtained with these set-ups for selected power LEDs are compared and discussed. Certain properties of software operating with both the considered measuring set-ups are also analyzed.

Numerical and Experimental Investigations of the Transient Thermal Behavior of a Steam By-Pass Valve at Steam Temperatures Beyond 700 °C

2015 ◽  
Vol 7 (1) ◽  
Author(s):  
Anis Haj Ayed ◽  
Martin Kemper ◽  
Karsten Kusterer ◽  
Hailu Tadesse ◽  
Manfred Wirsum ◽  
...  
Keyword(s):  
Thermal Behavior ◽  
Power Plants ◽  
Numerical Approach ◽  
Life Assessment ◽  
Experimental Investigations ◽  
Steam Power ◽  
Steam Power Plants ◽  
Cyclic Operation ◽  
Measurement Results ◽  
Transient Thermal

Increasing the efficiency of steam power plants is important to reduce their CO2 emissions and can be achieved by increasing steam temperatures beyond 700 °C. Within the present study, the thermal behavior of a steam by-pass valve subject to cyclic operation with 700 °C steam is investigated experimentally and numerically. An innovative numerical approach was applied to predict the valve’s thermal behavior during cyclic operation, which is essential for fatigue life assessment of such a component. Validation of the applied numerical approach has shown good agreement with measurement results, indicating the potential of its application for the valve design process.

scholarly journals Measurements and Computations of Internal Temperatures of the IGBT and the Diode Situated in the Common Case

Electronics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 210
Author(s):  
Paweł Górecki ◽  
Krzysztof Górecki
Keyword(s):  
Thermal Properties ◽  
Measurement Error ◽  
Thermal Model ◽  
Bipolar Transistor ◽  
Internal Temperature ◽  
Self Heating ◽  
Factors Influencing ◽  
Proposed Model ◽  
The Common ◽  
Transient Thermal

This article proposes effective methods of measurements and computations of internal temperature of the dies of the Insulted Gate Bipolar Transistor (IGBT) and the diode mounted in the common case. The nonlinear compact thermal model of the considered device is proposed. This model takes into account both self-heating phenomena in both dies and mutual thermal couplings between them. In the proposed model, the influence of the device internal temperature on self and transfer thermal resistances is taken into account. Methods of measurements of each self and transfer transient thermal impedances occurring in this model are described and factors influencing the measurement error of these methods are analysed. Some results illustrating thermal properties of the investigated devices including the IGBT and the antiparallel diode in the common case are shown and discussed. Computations illustrating the usefulness of the proposed compact thermal model are presented and compared to the results of measurements. It is proved that differences between internal temperature of both dies included in the TO-247 case can exceed even 15 K.

Determination of the limits of stable combustion at high supersonic flow velocities in a channel

2010 ◽  
Vol 3 (2) ◽  
pp. 47-60
Author(s):  
Alexey V. Starov
Keyword(s):  
Paper Analysis ◽  
Measurement Methods ◽  
Experimental Results ◽  
Physical Parameters ◽  
Supersonic Speed ◽  
Combustion Limits ◽  
Criterial Description ◽  
Selection Of ◽  
Good Agreement

In this paper, analysis of existing methods application of criterial description of ignition conditions and combustion break-out for summarizing of experimental results is carried out. Experimental results are obtained at investigations of hydrogen combustion in combustor with high supersonic speed of airflow. For these conditions selection of several criterions was substantiated and they have a good agreement with new experimental results. At the same time complexity of determination of experimental physical parameters, which are included in criterions, do not allow confidently to apply them for prediction of steady-state combustion limits. Therefore further accumulation of experimental data and development of measurement methods are necessary for accurate criterions obtaining.

scholarly journals Latency and Cybersickness: Impact, Causes, and Measures. A Review

2020 ◽  
Vol 1 ◽  
Author(s):  
Jan-Philipp Stauffert ◽  
Florian Niebling ◽  
Marc Erich Latoschik
Keyword(s):  
Review Article ◽  
Measurement Methods ◽  
Low Latency ◽  
Interactive Graphics ◽  
Counter Measures ◽  
Systems Research ◽  
Sound Experiment ◽  
Measurement Results ◽  
Research Findings ◽  
Good Measurement

Latency is a key characteristic inherent to any computer system. Motion-to-Photon (MTP) latency describes the time between the movement of a tracked object and its corresponding movement rendered and depicted by computer-generated images on a graphical output screen. High MTP latency can cause a loss of performance in interactive graphics applications and, even worse, can provoke cybersickness in Virtual Reality (VR) applications. Here, cybersickness can degrade VR experiences or may render the experiences completely unusable. It can confound research findings of an otherwise sound experiment. Latency as a contributing factor to cybersickness needs to be properly understood. Its effects need to be analyzed, its sources need to be identified, good measurement methods need to be developed, and proper counter measures need to be developed in order to reduce potentially harmful impacts of latency on the usability and safety of VR systems. Research shows that latency can exhibit intricate timing patterns with various spiking and periodic behavior. These timing behaviors may vary, yet most are found to provoke cybersickness. Overall, latency can differ drastically between different systems interfering with generalization of measurement results. This review article describes the causes and effects of latency with regard to cybersickness. We report on different existing approaches to measure and report latency. Hence, the article provides readers with the knowledge to understand and report latency for their own applications, evaluations, and experiments. It should also help to measure, identify, and finally control and counteract latency and hence gain confidence into the soundness of empirical data collected by VR exposures. Low latency increases the usability and safety of VR systems.

Updating the ANSI Standard on Measurement of Exhaust Emissions

1994 ◽  
Author(s):  
J. M. Vaught
Keyword(s):  
Gas Turbine ◽  
Exhaust Emissions ◽  
Measurement Methods ◽  
National Standards ◽  
Turbine Engines ◽  
Measurement Technology ◽  
Gas Turbine Engines ◽  
Regulatory Requirements ◽  
Industrial Gas Turbine ◽  
Selection Of

The American National Standards Institute (ANSI) required that the source testing Standard on Measurement of Exhaust Emissions from Stationary Gas Turbine Engines, B133.9, be brought up to date with today’s regulatory requirements and best measurement technology. The criteria for the design of the Standard along with its content and format are discussed. The selection of measurement methods for gaseous components, smoke, and particulates emitted by present day emission controlled industrial gas turbine engines is presented.

Identification of thermal parameters of a building envelope based on the cooling process of a building object

2019 ◽  
Vol 43 (6) ◽  
pp. 503-527 ◽  
Author(s):  
Iwona Pokorska-Silva ◽  
Artur Nowoświat ◽  
Lidia Fedorowicz
Keyword(s):  
Thermal Conductivity ◽  
Regression Model ◽  
Multiple Regression ◽  
Analytical Model ◽  
Multiple Regression Model ◽  
Building Envelope ◽  
Thermal Parameters ◽  
Cooling Process ◽  
Building Envelopes ◽  
Measurement Results

Thermal properties of building envelopes are often described using thermal conductivity or thermal resistance. And the opposite task involves the identification of thermal parameters of building envelopes based on the measurements of their cooling process. In this article, the authors proposed a method of identifying thermal parameters of a building envelope based on cooling measurements, using a multiple regression model for this purpose. To satisfy the research objectives, two basic experiments were carried out. The first experiment was performed in laboratory conditions. The research model was a cube of the dimensions of 1.1 m × 1.1 m × 1.1 m. The second experiment was carried out in semi-real conditions, and the used model was a small house of the dimensions of 6.0 m × 4.15 m × 5.2 m. The measurement results were also used to calibrate numerical models made in the ESP-r program. The research studies have demonstrated that the model can be used to identify thermal parameters of a building envelope. Based on the measurements and simulations, the cooling equations of the object were determined and the 95% confidence interval for the heat retention index was estimated. On that basis, using the multiple regression model, such parameters of the model as density, specific heat, and thermal conductivity were estimated. It turned out that using the Gauss–Newton approximation, we obtained the correlation of the measurement results and the analytical model with the correlation coefficient of 0.9971 (for the laboratory scale). And the multiple regression improved not only the correlation between the measurement and the analytical model, but it also allowed to obtain “almost identical” results. Similarly, promising results were obtained for the semi-real scale.

The Research and Realization of Capacitive Current on Line Measurement Based on DSP

2012 ◽  
Vol 195-196 ◽  
pp. 195-199
Author(s):  
Jian Wen Wang ◽  
Zheng Feng Wang ◽  
Peng Li
Keyword(s):  
Measurement Error ◽  
Real Time ◽  
Measurement Methods ◽  
Current Measurement ◽  
Capacitive Current ◽  
Line Measurement ◽  
On Line ◽  
Capacitance Current ◽  
Signal Method

In the paper, it proceeds in-depth research and analysis to the existing capacitance current measurement methods, and the infuse signal method is chosen to achieve capacitance current accurate measurement on this basis. The method has the advantage of measurement error small, real-time good and safe reliable.

scholarly journals Calibration of Mangerud'S Boundaries

Radiocarbon ◽  
2010 ◽  
Vol 52 (4) ◽  
pp. 1639-1644 ◽  
Author(s):  
Adam Walanus ◽  
Dorota Nalepka
Keyword(s):  
Measurement Error ◽  
Calibration Procedure ◽  
Radiocarbon Age ◽  
Measurement Results ◽  
Standard Calibration ◽  
Typical Measurement ◽  
Natural Situation

The “calibration” of arbitrarily defined (in some sense, “conventional”) ages, given in conventional radiocarbon years BP, is now becoming necessary because the term “radiocarbon age” is used less often in archaeological and Quaternary practice. The standard calibration procedure is inappropriate here because Mangerud's boundaries are not measurement results. Thus, another approach to the problem is proposed in order to model the natural situation of many, uniformly distributed, dated samples, which should be similarly divided by the original and “calibrated” boundary. However, the result depends on the value of the typical measurement error and is not unequivocal.

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