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High resolution ammeter
Honek, Marek ; Roubal, Zdeněk (referee) ; Steinbauer, Miloslav (advisor)
A transmission electron microscope is a device operating on a similar principle as an optical microscope. The fact that electrons wavelength is much shorter than the wavelength of photons is used to obtain huge magnifications. Glass lenses commonly used in the optical microscope are therefore replaced by magnetic coils in the electron microscopes. A magnetic field is directly proportional to the current passing through these coils. It is important to the current supplied to the coils to be as stable as possible to achieve high resolution. The goal of this thesis is to analyze usable current measurement methods and to design a current stable measuring device with a resolution of 1 ppm.
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Control system for temperature stabilization
Malý, Pavel ; Běťák, Petr (referee) ; Kadlec, Jaroslav (advisor)
This bachelor´s thesis is engaged in problems, programming and proposal of Control system for temperature stabilization of any system. Main condition is using the Peltier´s component and microcontroller. Principle consists in setting of temperatures by user controls and operating of Peltier´s component thought MOSFET semiconductors. This MOSFET´s are designed to an H-bridge. We regulate power of Peltier´s component by the H-bridge. Main part of the circuit is microcontroller from ATMEL. This is called ATmega16. It’s programmed by ISP (In System Programming) property of microcontroller, which is necessary for programming of microcontrollers in applications. All measured and controlled values will be showed on the LCD display and should by supply by the 5V power source.
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High resolution ammeter
Honek, Marek ; Roubal, Zdeněk (referee) ; Steinbauer, Miloslav (advisor)
A transmission electron microscope is a device operating on a similar principle as an optical microscope. The fact that electrons wavelength is much shorter than the wavelength of photons is used to obtain huge magnifications. Glass lenses commonly used in the optical microscope are therefore replaced by magnetic coils in the electron microscopes. A magnetic field is directly proportional to the current passing through these coils. It is important to the current supplied to the coils to be as stable as possible to achieve high resolution. The goal of this thesis is to analyze usable current measurement methods and to design a current stable measuring device with a resolution of 1 ppm.
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Control system for temperature stabilization
Malý, Pavel ; Běťák, Petr (referee) ; Kadlec, Jaroslav (advisor)
This bachelor´s thesis is engaged in problems, programming and proposal of Control system for temperature stabilization of any system. Main condition is using the Peltier´s component and microcontroller. Principle consists in setting of temperatures by user controls and operating of Peltier´s component thought MOSFET semiconductors. This MOSFET´s are designed to an H-bridge. We regulate power of Peltier´s component by the H-bridge. Main part of the circuit is microcontroller from ATMEL. This is called ATmega16. It’s programmed by ISP (In System Programming) property of microcontroller, which is necessary for programming of microcontrollers in applications. All measured and controlled values will be showed on the LCD display and should by supply by the 5V power source.
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Temperature stabilization of semiconductor lasers for direct measurement of index of refraction of air
Matoušek, Vít
Laser interferometers are even more precise distance measurement devices with resolution in nanometer or sub-nanometer region. If interferometric measurements are carried out under atmospheric conditions (usual situation in industry), they measure optical path length of an unknown distance instead of its true geometrical value. It is caused by an index of refraction of air that introduces a multiplicative constant to measured results. If we want to obtain correct values, the knowledge of the index of refraction is necessary. Generally, the index of refraction can be measured by two ways: indirectly or directly. The first of them is based on parametric analysis of atmospheric properties as: relative humidity, pressure, temperature, concentration of CO.sub.2./sub. etc. Values of these parameters are processed then by Edlen formulas with 10.sup.-7./sup. order [1]. The direct methods are more precise then Edlen formulas (more than 10.sup.-7./sup.) but their practical implementation is more difficult. Devices that directly measure the index of refraction are called refractometers.
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