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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.
271

The Development of a High-Performance Distributed Battery Management System for Large Lithium Ion Packs

Grasberger, Christopher B 01 June 2015 (has links) (PDF)
A high performance battery management system (BMS) for large capacity cells was designed, built, and tested in a cycle of three revisions. The BMS was designed for use in applications where the battery pack configuration is unknown: parallel, series, or any combination. Each of the cells is equipped with its own battery management system to allow a peer-to-peer mesh network to monitor the safety of the cell. The BMS attached to each cell also is equipped with a 25A DC/DC converter to perform active balancing between cells in a string. This converter can transfer charge to (or from) a cell of higher potential and a cell of lower potential at the same time. The balancing circuit has a peak efficiency of 85.3%. The system draws only 53mA while balancing at 25A helping to increase low current performance. The system draws just under 5mA over all while active. Each BMS is equipped with one current sensor, which can measure ±800A with a second ±120A current range. Additionally, the board is equipped with coulomb counting to provide a better understanding of each cell. While this design has many great features, lack of full software support makes many of the subsystems dependent on user interaction to use. As a result, the design is not fully complete. Additionally, last minute design changes on the final revision resulted in detrimental effects to the accuracy of many of the analog circuits including the current sensing features.
272

Design and Modeling of a Distributed Network for the DC House Project

Rotsios, Lauren N 01 June 2021 (has links) (PDF)
This thesis covers the design and simulation of a model for a distributed network of DC Houses in MATLAB Simulink. The model will allow for sharing of power between houses within the network. The developed model consists of five separate DC House branches with local power generation. Each branch consists of a PV MPPT charge controller subsystem, a resistive load, and a bidirectional buck-boost converter subsystem. The high voltage side of every bidirectional buck-boost converter is connected together through the transmission line at a single high voltage DC bus. The performance of the individual components of the model is verified before constructing the network. The power sharing capability of the network was evaluated by measuring the efficiency transmission at varying wire gauges, distances, and high-end voltages. Results of the study show that for the most part, higher transmission voltage resulted in higher efficiency. However, this was not the case at some configurations due to different methods of power sharing. Overall, the proposed design provides a viable model for a distributed network of DC Houses, which serves as a basis model for future designs of DC House network for different parameters such as capacity, size and price points.
273

Analysis of Error Propagation in Differential Satellite Based Positioning Systems

Krishnan, Vignesh January 2004 (has links)
No description available.
274

The development of a framework for and a model teaching-learning system in electronics technology for the elementary school /

Inaba, Lawrence Akio January 1971 (has links)
No description available.
275

Studie av konstruktion och implementering av CORDIC-algoritmer / Survey and Implementation of High-Speed CORDIC Algorithms

Hellberg, Rikard January 2004 (has links)
<p>Abstract CORDIC (Coordinate Rotation Digital Computer) is an iterative algorithm for the calculation of a two-dimensional vector in circular, linear or hyperbolic coordinate systems. This paper presents a survey of known CORDIC algorithms and architectures for the rotation and vectoring mode in the circular cordinate system. In addition an implementation of the differential CORDIC algorithm in VHDL has been done. The implementation is designed to keep the fast timing and throughput characteristic known for on-line redundant arithmetic.</p>
276

Elektriskt system för detektion vid ballistiskt prov

Kiuru, Tobias January 2004 (has links)
<p>The purpose of this thesis was to design an electrical system for use in a ballistic test at the Swedish National laboratory of forensic science (SKL). The detector unit would use four main parts: coilsystem, transmitter, reciever and indicator. The coilsystem would be based on a balanced system using three coils. One that creates a magneticfield and the other two will sense the differences when a metallobject is in the coilsystem. </p><p>This report starts out by investigating possible solutions for this specific task followed by a description of the physics that the metaldetector use. Then a description of the design of a scaled metaldetector model followed by testing and evalution. The results are then beeing used when the design and testing of the full scale detector. The possible solutions for the transmitter-, reciver- and indicator circuit are then beeing described and also simulated. Last in this report a evalution and suggestions of further improvments are presented.</p>
277

Konstruktion och byggnation av testfixtur för 10Gbit/s transpondermoduler / Construction and development of testfixture for 10Gb/s transponder modules

Behnam, Henry January 2002 (has links)
This thesis for the Master of Science degree was performed at Solectron Corporation in Norrköping. The background for the thesis was a need to develop and build two test fixtures to automatize testing and adjusting of transmitter modules (TX-fixture) and receiver modules (RX-fixture) which are head devices in DWDM-systems. The basic elements for the test fixtures are: Test board, switch board and DC/DC board. The main function of the test board is to handle communication between the transmitter and receiver modules and supply voltage to these modules. The test board was insufficient and modified with a microprocessor to handle the communication between the PC and the receiver module. There are two connectors (NexLev) on test board to connect the receiver and transmitter modules. The switchboard has been used in fixtures for testing and adjusting both the receiver and transmitter modules for data rate up to 2.5 Gbit/s. This board has been modified for use in new fixtures for data rate up to 10Gbit/s. Because the power consumption of the test module will be measured with the amperemeter in the power supply, the reference module and the test module cannot be supplied by the same power supply. Because of high cost and the fact that no current is measured it is unacceptable to use a power supply to feed the reference module. The solution is to build a DC/DC board. Because the NexLev connector has a durability of 30-40 times it was necessary to have a connector with higher durability. This connector is located between the test board and the test module. Without this connector the project will not be profitable for the company. Some parts in RX- and TX-fixture have been used in older versions of fixtures for data rate up to 2.5Gbit/s. These parts have been updated for the new test demands of the new fixtures.
278

Studie av konstruktion och implementering av CORDIC-algoritmer / Survey and Implementation of High-Speed CORDIC Algorithms

Hellberg, Rikard January 2004 (has links)
Abstract CORDIC (Coordinate Rotation Digital Computer) is an iterative algorithm for the calculation of a two-dimensional vector in circular, linear or hyperbolic coordinate systems. This paper presents a survey of known CORDIC algorithms and architectures for the rotation and vectoring mode in the circular cordinate system. In addition an implementation of the differential CORDIC algorithm in VHDL has been done. The implementation is designed to keep the fast timing and throughput characteristic known for on-line redundant arithmetic.
279

Elektriskt system för detektion vid ballistiskt prov

Kiuru, Tobias January 2004 (has links)
The purpose of this thesis was to design an electrical system for use in a ballistic test at the Swedish National laboratory of forensic science (SKL). The detector unit would use four main parts: coilsystem, transmitter, reciever and indicator. The coilsystem would be based on a balanced system using three coils. One that creates a magneticfield and the other two will sense the differences when a metallobject is in the coilsystem. This report starts out by investigating possible solutions for this specific task followed by a description of the physics that the metaldetector use. Then a description of the design of a scaled metaldetector model followed by testing and evalution. The results are then beeing used when the design and testing of the full scale detector. The possible solutions for the transmitter-, reciver- and indicator circuit are then beeing described and also simulated. Last in this report a evalution and suggestions of further improvments are presented.
280

Konstruktion och byggnation av testfixtur för 10Gbit/s transpondermoduler / Construction and development of testfixture for 10Gb/s transponder modules

Behnam, Henry January 2002 (has links)
<p>This thesis for the Master of Science degree was performed at Solectron Corporation in Norrköping. The background for the thesis was a need to develop and build two test fixtures to automatize testing and adjusting of transmitter modules (TX-fixture) and receiver modules (RX-fixture) which are head devices in DWDM-systems. The basic elements for the test fixtures are: Test board, switch board and DC/DC board. </p><p>The main function of the test board is to handle communication between the transmitter and receiver modules and supply voltage to these modules. The test board was insufficient and modified with a microprocessor to handle the communication between the PC and the receiver module. There are two connectors (NexLev) on test board to connect the receiver and transmitter modules. </p><p>The switchboard has been used in fixtures for testing and adjusting both the receiver and transmitter modules for data rate up to 2.5 Gbit/s. This board has been modified for use in new fixtures for data rate up to 10Gbit/s. </p><p>Because the power consumption of the test module will be measured with the amperemeter in the power supply, the reference module and the test module cannot be supplied by the same power supply. Because of high cost and the fact that no current is measured it is unacceptable to use a power supply to feed the reference module. The solution is to build a DC/DC board. </p><p>Because the NexLev connector has a durability of 30-40 times it was necessary to have a connector with higher durability. This connector is located between the test board and the test module. Without this connector the project will not be profitable for the company. </p><p>Some parts in RX- and TX-fixture have been used in older versions of fixtures for data rate up to 2.5Gbit/s. These parts have been updated for the new test demands of the new fixtures.</p>

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