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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

Bezdrátový přenos dat ze senzorů / Wireless transfer of the sensor data

Kičina, Andrej January 2008 (has links)
Thesys is focused on wireless transfer of the sensor data. It describes different wireless standards for potential use and realization of interface between sensor's data and their transfer. Crux of the matter is in detailed description of whole system with created utility programs. In the end it is summarized acquiered features of the realization.
2

Non-radiative resonant wireless energy transfer

2013 April 1900 (has links)
This thesis describes a theoretical and experimental investigation of wireless energy transfer between high-Q resonant radiofrequency (RF) oscillators. A model used by Kurs \emph{et al} \cite{Kurs_original} was recast in a form which enabled expression of the results in terms of measurable electrical quantities. This model was tested using circular resonant copper loop antennas at a frequency near 10 MHz. Accurate calculation of the mutual inductance between loops was required in order to predict the loop coupling parameters, and was carried out using a custom-written computer code. Two resonant loop antenna RF oscillators were first used to check that the model predictions were accurate in the two-oscillator case. Based on the success of these tests, the model was extended to the case of three oscillators in two different configurations, the first having two receiving oscillators, and the second having two transmitting oscillators. Model predictions for both configurations were experimentally tested over a range of coil separations and angular inclinations. These experimental tests confirmed the model's applicability in the three-oscillator regime, with significant deviations from the model only being observed when any pair of loops was in very close proximity (i.e. when the separation of loop centers was comparable to the loop diameter). This may have been be due to either nonlinear dielectric losses (due to large amplitude RF electric fields) spoiling the Quality factors Q of the loop antenna resonators, or to increased capacitive coupling between loops at short distances (not included in the current model), or both. Further investigation would be required to definitively establish the origin of the deviation from the model at short distances, but from an engineering point of view accurate modelling of the performance in the "close loop" regime is not critical since the primary purpose of wireless power transfer is to transmit power over a reasonable distance.
3

Bezdrátový pager / Wireless Messaging System

Musil, Tomáš January 2009 (has links)
The aim of thesis is a design of wireless pager, that can be used for short text messages transmission from the sender to a particular recipient. The report is sent from a computer via serial port. The application is based on microcontrollers, which provide data protection, evaluation and display data on the display of the receiver. The wireless transmission is effected via the RF modules, that are powered from batteries.
4

Bezdrátové měřicí zařízení pro soutěže v požárním sportu / Wireless Timer for Fire Sport Competitions

Holinka, Milan January 2012 (has links)
This thesis describes the design, development and realization of a wireless electronic timer for use in firesport. Specification of the final product is built with regard to versatility, ease of use and low acquisition costs. Commercial products have been compared as inspiration for this work. Requirements of the timer are based on the rules of firesport disciplines, where the timer can be used. It consists of a base station that can be accompanied for additional elements used to starting, splits capturing and stopping. An independent communication module has been created to ensure wireless connection. Libraries for comfort work with the module, support for USB bus and reliable protocol for wireless transmission have been implemented.

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