National Repository of Grey Literature 25 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Single-phase DC/AC converter with output parameters 230 V / 50 Hz / 100 VA
Smolák, Martin ; Martiš, Jan (referee) ; Vorel, Pavel (advisor)
This master‘s thesis focuses on optimization of power and control circuits of an inverter, which was developed at UVEE. The principle of function and circuit implementation of a single-phase inventer, various calculations (design of an LC filter, DC link capacitor, semiconductor elements and heat sink) are described in the thesis. A design of fast overcurrent protections, oscillator and saw signal generator is included. Furthermore, a printed circuit board was designed which was optimized by thermal simulation in the Workbench Ansys. Subsequently, the printed circuit board was mounted, debugged and verification measurements were performed on it. At the end of the thesis there is a documentation for the implemented equipment.
Wireless power transfer 20 kW
Tománek, Radek ; Vorel, Pavel (referee) ; Martiš, Jan (advisor)
This thesis deals with the design of wireless power transfer at a distance of 600 mm dimensioned to 20 kW. The transfer is provided by inductive coupling of resonant circuits with 800 mm diameter coils. It contains a description of the design and calculations of individual parts, stating specific values. It also includes description and schematics of control circuits.
Switching benchtop power supply 0-30 V, 0-5 A
Galia, Jan ; Pazdera, Ivo (referee) ; Martiš, Jan (advisor)
This thesis deals with the design and construction of switching mode power supply for lab application. Convertor is based on the forward topology with adjustable output voltage regulation from 0 to 30V and with maximal output current 5A. Antoher features of this power supply is adjustable current limiting function which can be set from 0 to 5A. For closed loop control was chose analogue cascade regulation.The contol part consists of operation amplifire TL072 and SG3525 contorl circuit.
Switching charger for car batteries 14.4V/6A
Gábel, Marián ; Huták, Petr (referee) ; Martiš, Jan (advisor)
This bachelor's thesis deals with issue of design of a switching charger for car batteries using a fly-back converter. The fly-back converter and its functions are theoretically described in the first chapter, which also explains use of a modification of a circuit. The modification is used because of its increased efficiency compared to the ordinary loss solutions of a relieving circuit. Subsequently, in next chapter the thesis focuses on design of a power section of the circuit, which involves calculations of the circuit’s elements. Subsequently, the MOSFET transistor control design is performed using the UC3844 integrated circuit. The charger was constructed according to design and its proper functionality was verified by measurements.
Efficiency Improvement and Optimization of High Power Switching Converters
Martiš, Jan ; Dudrik,, Jaroslav (referee) ; Peroutka,, Zdeněk (referee) ; Vorel, Pavel (advisor)
This thesis focuses on optimization and increasing the efficiency of high-power DC/DC switching converters with transformer (switching power supplies). The work focuses mainly on using converters with flyback topology for high power, even though it is a common belief that this type of converter is not suitable for high power. This topology was selected because of potentially better achievable parameters, especially the efficiency, in comparison to a commonly used forward converter – in a flyback converter, losses are produced only in one magnetic component (transformer) in contrast to two components (transformer and inductor) in the forward converter. Compared to resonant and quasi-resonant converters, the flyback converter is easily controllable in the whole output voltage and current range. To make the flyback converter favorable for a high-power use, some innovative circuit modifications were made and modern semiconductor and passive components were used. Theoretical part of the work deals with efficiency optimization of the flyback converter, based on analytical solution. Operating parameters of the converter – switching frequency and parameters of the transformer (flux density and numbers of turns) are commonly only guessed or chosen from experience. The objective of this part is a mathematically exact determination of these parameters to achieve lowest total losses of the converter for given input parameters. In a certain case, it was possible to obtain the final solution analytically, in other cases the final solution step had to be done with a help of software. A prototype of a 12-kW switching power supply with a flyback converter was constructed to validate the proposed solutions and methods. The power supply fits into a space of only 33x33x16 cm. Modern semiconductors based on the silicon-carbide (SiC) technology (MOS-FET transistors and diodes) were used. After bringing the converter to a full-power operation, an efficiency of 96.8 % of the DC/DC converter was measured. High efficiency was obtained for a wide range of output parameters. A certain comparison with a forward converter with the same output parameters is done in the work. Not only from an efficiency point of view, the flyback converter seems very perspective.
DC/DC converter 24 V / 320 V / 60 W for a back-up supply source with a galvanic separation
Dvořák, Petr ; Martiš, Jan (referee) ; Vorel, Pavel (advisor)
This bachelor‘s thesis deals with the design, dimensioning and realization of a DC/DC 24 V / 320 V converter with a output power of 60 W. In the first part there is a short description of the linear stabilizer and then the switching sources with their dismemberment. Based on that chapter, was selected the flyback converter. The second part deals with components design and description of the control circuit. At the end, the construction of the converter with the verification measurement records is shown.
Experimental electromagnetic acceleration device with more stages
Kovařík, Martin ; Červinka, Dalibor (referee) ; Martiš, Jan (advisor)
This master thesis deals with design and realization of multistage electromagnetic accelerating device (gun) and possibilities to increase its effectivity. This work contains a simulation of a magnetic circuit and designs of each components, inclusive of control circuits. Reached effectivity will be measured by appropriate methods.
Soldering gun with Li-Ion battery supply
Bartoš, Miroslav ; Vorel, Pavel (referee) ; Martiš, Jan (advisor)
This master‘s thesis deals with the design of battery powered soldering iron. The soldering iron will be placed in the plastic box from a conventional transformer soldering iron. First, we need to find the parameters of the original transformer soldering iron. Then design a synchronous step-down converter, driver of converter, BMS circuits, and component placement in a plastic box. The battery-powered soldering iron was successfully revived and tested, the final parameters of the converter are: voltage 0.4 V at 80 A current. The total power on the soldering wire is 32 W. Technically, this is a very interesting alternative to the classic version of the soldering iron, which can be used for assembly or repairs in poorly accessible locations.
Portable source for induction heating
Nevřela, Tomáš ; Martiš, Jan (referee) ; Knobloch, Jan (advisor)
The aim of this work is to realize and test a prototype portable source for induction heating of small parts. The project contains a theoretical basis of resonant circuits and induction heating. The device design is based on simulation results from the FEMM program, with which a focussing coil for induction heating has been designed. The parts of the thesis are the realization of the designed device, its putting into operation and the programming of the control.
Proposal for Marketing Tools of Specific Company
Floriánová, Aneta ; Martiš, Jan (referee) ; Mráček, Pavel (advisor)
The bachelor thesis is focused on analysis of Marketing mix at the company MSD, spol. s. r. o. which is engaged in the sale and servicing of office equipment, printing and copying services also. I will analyse current marketing situation of the commpany and on the basis of longterm observations, I will suggest marketing arrangements that will lead to the acquisition of potential new customers and a consequent improvement in profits of the company.

National Repository of Grey Literature : 25 records found   1 - 10nextend  jump to record:
See also: similar author names
2 MARTIŠ, Jiří
1 Martiš, J.
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