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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Asynchronous sampling wattmeter.

Jones, Philip William, Carleton University. Dissertation. Engineering, Electrical. January 1992 (has links)
Thesis (M. Eng.)--Carleton University, 1992. / Also available in electronic format on the Internet.
2

Úspory energie při modernizaci PC sítě / Reduction in the Consumption of Electrical Energy during Computer Network

Doležal, Michal January 2010 (has links)
This Master’s thesis deals with the analysis problem during of electrical energy. On the basis of findings, the work includes analysis of the costs on electrical energy.
3

The Digital Multifunction Power Measuring System

Shoemaker, Ralph Warren 13 May 1974 (has links)
The Digital Multifunction Power Measuring System is the outgrowth of a project involving the design of a prototype precision Digital Watt Transducer for the Bonneville Power Administration (BPA). A prototype Digital Watt Transducer was built and tested since no other device of the desired accuracy was connnercially available. Upon partial completion of the project, another Watt Transducer did become available which was essentially identical to our development. Since we could not economically compete with the manufacturer of these Watt Transducers, our project was stopped. Over a period of several months we thought about other ways to apply the experience gained from the Watt Transducer project, and came upon the idea of designing a precision multifunction power meter to help simplify the calibration of Watt and VAR transducers in the Instrumentation and Standards Laboratory, and possibly replace approximately five less accurate analog meters presently used by our Meter-Relay Craftsmen in their field testing. Since no similar meter was available, and since possible revenues lost to inaccurate measurement could justify the development costs of such a meter, we were given authorization to design and build it. This instrument is the Digital Multifunction Power Measuring System which measures the following electrical parameters to approximately plus or minus one-tenth of one percent or better accuracy: True RMS AC Volts in two ranges; True RMS AC Amps in six ranges; Watts in twelve ranges; VARs in twelve ranges; Phase Angle between Volts and Amps in all ranges; DC Volts in three ranges. This instrument has been completed, tested, and calibrated to its design accuracies and is presently being demonstrated within the BPA system to make its availability known to those personnel who might have need for such an instrument.
4

Jednofázový síťový wattmetr / Single-phase wattmeter

Kolouch, Petr January 2019 (has links)
This diploma thesis deals with wattmeters. The introduction is devoted to approach the issue. Subsequently, the principle of sensing of circumferential quantities, sampling theory and basic theory is explained. The next chapter discusses Arduino development kits. The practical part deals with the design of the circuit diagram and the printed circuit board. Further described is designed software. The final part tests the parameters of the designed power meter.
5

Contribution au développement des méthodes de contrôle de fabrication industrielle des BAP / Contribution to the development of methods of control for the manufacturing of the SCC

Ngo, Hai Thong 13 December 2016 (has links)
Les bétons autoplaçants (BAP) constituent une nouvelle génération de béton avec un fort potentiel d’utilisation compte-tenu de la facilité de leur mise en œuvre dans les chantiers de construction. Leur production révèle cependant plus de difficultés par rapport à celle des bétons ordinaires, principalement liée à leur caractère très sensible à la variation de composition. En particulier, la variation du dosage en eau influe fortement sur la régularité de la fabrication des BAP. Cette variation est à l'origine de la connaissance insuffisante de l'eau apportée par les granulats. D'autre part, la formulation des BAP prévoit l'utilisation d'un volume élevé d'éléments fins ainsi que d'une forte proportion en adjuvants dans la composition de ces bétons. Cela conduit à des temps de malaxage plus longs que ceux des bétons ordinaires, diminue la productivité et augmente le coût de production. Le travail présenté dans ce mémoire vise à proposer des méthodes de contrôle pour améliorer la régularité et la productivité des BAP dans les centrales à béton prêt à l'emploi.Dans un premier temps, l'outil traditionnel du contrôle en ligne de l'humidité du béton - le wattmètre a été calibré suivant une procédure de simplifiée et réalisable en centrale à béton. En utilisant cette méthode de calibration, la stabilisation de la puissance consommée par le malaxeur, en milieu industriel, est validée comme un indicateur fiable de la teneur en eau des BAP. En parallèle, un critère objectif de stabilisation de la puissance a été proposé afin de définir quantitativement le temps de stabilisation de la puissance. Ce dernier est considéré comme un temps de malaxage suffisant pour décider la fin du malaxage en vue d’une augmentation de la productivité.Dans un second temps, nous avons étudié, à l'échelle de laboratoire, l'influence du temps de malaxage sur l'ouvrabilité d'une formule de BAP dont les gâchées sont différenciées seulement par leur dosage en eau. Cette étape a permis de montrer que le temps de stabilisation de la puissance de malaxage est comparable et proportionnel au temps nécessaire pour obtenir l'ouvrabilité optimale du BAP.Enfin, nous avons traité un cas particulier des BAP fluides dans une plage de dosage en eau élevé sur laquelle la méthode traditionnelle de mesure d'humidité par le wattmètre devient insuffisamment sensible. Une nouvelle exploitation du signal wattmétrique a été proposée en construisant un modèle de lissage des courbes de puissance. La validation expérimentale sur un malaxeur de laboratoire permet de montrer qu'il est possible d'améliorer la sensibilité du wattmètre à l'aide du paramètre "temps caractéristique" tiré du modèle. / Self-compacting concrete (SCC) is a new generation of concrete with a great potential thank to their ease of placement in construction sites. However, as compared to ordinary concrete, it is more difficult to produce SCC; sensitivity to the variation of the composition dosage often gets cited. In particular, changes in concrete water content strongly influence the SCC production regularity. The primary source of uncertainty in concrete water content stems from poor knowledge of aggregate moisture. On the other hand, the use of a high amount of fines together with a high dosage of superplasticizer results in a long mixing time of SCC, which decreases productivity and increases the cost of production. The aim of this work is then to propose methods to improve the SCC production regularity and productivity.At first, the traditional online mixer measurement - wattmeter was calibrated through use of a simple calibration procedure in a concrete plant. By using this calibration method, the stabilization of mixing power is confirmed as a reliable online indication of SCC water content in an industrial environment. In parallel, a stabilisation criterion of power curves was proposed to quantitatively define the stabilization time. This time is considered as a sufficient mixing time to stop mixing for an increase in productivity.Secondly, we studied at the laboratory scale, the influence of the mixing time on the workability of a SCC mix design with batches in which only the water content was varied. The result has shown that the stabilization time is comparable and proportional to the time required to obtain the optimum workability of SCC.Finally, we treated a case of SCC mixtures over a range of high water content in which the traditional processing of mixing power is not able to distinguish the water proportioning difference from water over dosage in SCC. A new wattmeter signal processing was proposed through using a mathematical model to fit the power consumption curve of the mixer. The experimental validation in a laboratory mixer can show that it is possible to improve the precision of wattmeter thanks to the use of the parameter "characteristic time" from the model
6

Návrh a realizace wattmetru s komunikací v síti IoT / Design and realization of the power meter with IoT connectivity

Zagrapan, Ivan January 2017 (has links)
This thesis deals with designing and creating working prototype of IoT Wattmeter with option to switching relay. This device can be control remotely with option to read measured values. To reach my goals, I am using open-source designing board, different sensors and modules. I tis possible to communicate with device through Wi-Fi module ESP 8266 and to test LPWAN network I am using SIGFOX, module. To measure current, it´s used simple Hall-effect sensor and all available information’s are displayed on OLED display. To switch the circuit off or on solid state relay was used. In theoretical part of the work, I am trying to explain working principles of every module and source code, which I am using to control these modules. In practical part I created scheme, using CADSoft EAGLE and created functional wattmeter. Whole work is programmed in C++ language using Arduino IDE.

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