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The inverter for arc-welding
Vaculík, Josef ; Klíma, Bohumil (referee) ; Červinka, Dalibor (advisor)
This diplom thesis theoretically deals about principle of pulse welding current source. Work explains operation principle of the single acting transmit converter used in realized construction and mention the others examples of converters types. Goal of the work is design individual parts of source : input filter, pulse transformer, output inductor and power semiconductors components. Thesis also contains description of the regulation circuitry of the converter, auxiliary power supply and pre-driver for power transistors. If everything will be all right prototype of the source will be assembled and measured. Results will be compared with theoretical assumptions.
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Resistance saw
Kalčík, Petr ; Minárik, Vladimír (referee) ; Procházka, Petr (advisor)
This work is focused on the design and construction of component parts of resistance saw. Mechanical parts consist of a movable bracket and a taut cutting wire of Constantan. Electrical parts are designed to supply and control temperature of the cutting wire. The current intensity in the cutting wire is compared with the required current intensity. The difference of these two measurements is fed into a PI - controller. The next part is a PWM generator which generates the square wave signal. The pulse ratio of this signal is proportional to the required temperature of the cutting wire. This signal switches a switching converter that consists of a power transistor P-MOSFET IRF5210 and a diode MBR20100CT. Choking coil with a ferrite E core and with the cutting wire is connected to the output of the converter.
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Influence of skin effect, proximity effect and air gap on winding losses of HF inductors and transformers
Pitner, Tomáš ; Cipín, Radoslav (referee) ; Martiš, Jan (advisor)
The bachelor's thesis deals with power losses in the windings of high-frequency inductors and transformers. A detailed mathematical and qualitative analysis of the skin effect, proximity effect and leakage flux of air gap is performed, supplemented with the results of computer simulations using the finite element method. The thesis introduces analytical and numerical methods for calculating power losses in the windings of inductors and transformers and describes suitable measurement methods, which are further used in the thesis. For selected geometries of inductors and transformers, AC resistances of their windings are calculated using FEM and the results are compared with measurements on constructed prototypes. The winding geometries are also compared between each other.
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Reactive Power Compensation of The Industrial Consumer
Hanzelka, Jiří ; Holoubek, Jiří (referee) ; Toman, Petr (advisor)
This thesis is focused on reactive power compensation and it suggests new conceptions for industrial customers. The first part describes the basics of compensation, location and ways of compensation. In conclusion of this part it is a good example of parallel reactive power compensation. The second part deals with the design of reactive power compensation specifically for raw water pumping station. Compensation was solved both on a low voltage level and on the high voltage level. For drawings were used program EPLAN Electric P8.
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Measurement of meteorological variables
Škorpík, Daniel ; Harabiš, Vratislav (referee) ; Chmelař, Milan (advisor)
This bachelor thesis discusses about the basic meteorological variables, especially temperature and airflow. These magnitudes are measured using an anemometer which uses resistive sensors, namely, two thermistors of NTC type that described technology, operations, methods of scanning, sensor placement and implementation of such a device. After that was designed block diagram and circuit diagram. The meter is realized, than we describe the individual components and then is calibrated and tested. In conclusion, it is evaluated for use in medicine.
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Electronic ballast for sodium lamp
Eliáš, Jaroslav ; Vorel, Pavel (referee) ; Huták, Petr (advisor)
The aim is to get acquainted with the way the management and regulation of sodium lamps. This knowledge is then applied to design your own gear. The introductory section describes the basic characteristics of discharge light sources. Their behavior was verified by measuring and findings were used to create diagrams, mainly the control circuit. Theoretical design is developed by individual functional parts of the inverter.
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The reactive power compensation of the industrial consumer
Doseděl, Tomáš ; Martinák, Rostislav (referee) ; Toman, Petr (advisor)
This thesis is about reactive-power compensation used in real practise. In theoretical part, basic principles of reactive-power compensation are stated. Also, charges for breaching power factor and overview of individual compensation components are dealth with. Practical part is about the design of a low voltage compensator for industrial customer.Compensator uses central compensation with gradual switching.
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Step down convertor
Koutný, Martin ; Kadlec, Josef (referee) ; Cipín, Radoslav (advisor)
Thesis deals with the evaluation of the solutions and the design of the DC voltage converters. The first describes the different types of converters, which subsequently choose types of resources for the construction. In other chapters of the work devoted to the design of schemes, selected types of sources and selection of circuits and components therefor, for the manufacture, including calculations cooling performance parts. The last chapter is devoted to the description of the structure and measurement of the produced sources. The measurements are primarily deals with the verification of the specified parameters.
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Reactive power compensation of electrothermal devices
Tomeš, Martin ; Paar, Martin (referee) ; Lázničková, Ilona (advisor)
The work deals with reactive-power compensation (power factor correction = PFC) in practice. The theoretical part describes the basic concepts of power factor correction, reasons for the PFC, and the ways of the PFC, eventually a sanction for a breach of rated power factor. Attention is given to basic partition of the PFC and compensation devices which are capacitors and detuning reactors. The practical part is focused on the PFC analysis for a concrete customer where the central compensation is projected. The practical part is also focused on a detuned power factor correction which is often used by reason of increases in number of nonlinear loads nowadays.
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