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V diplomski nalogi je predstavljeno delovanje prenapetostne zaščite v nizkonapetostnem omrežju. Opisani so vzroki in posledice, ki nastopijo ob prenapetostih, pa tudi posamezni prenapetostni odvodniki. Prav tako je predstavljen standard SIST EN 62305-4, ki opisuje zaščito za električne in elektronske naprave v zgradbah pred udari strel. Na koncu sta še dva primera izračunov induciranih napetosti v zankah električnih inštalacij in tokov, ki stečejo ob udaru strele. The dissertation introduces the operation of overvoltage protection in a low voltage network. The causes and consequences of overvoltages as well as individual overvoltage arresters are described. The standard SIST EN 62305-4 is also presented, which describes the protection for electrical and electronic devices in buildings against impact. Finally, there are two other examples of the calculation of induced voltages in loops of electrical installations, as well as of currents that flow when lightning strikes.

Projekt je posvečen analizi obnašanja različnih vrst fotovoltaičnih modulov, v danem primeru monokristalnih in polikristalnih modulov proizvajalca Bisol. Razložen bo fotoelektrični pojav in tudi predstavljene karakteristike fotovoltaičnih modulov. Opisana bo programska oprema, kot tudi naprave uporabljene za meritve karakteristik modulov. Najpomembnejši del bo analiza rezultatov meritev in obnašanje različnih modulov v dveh različnih časovnih obdobjih. The project is dedicated to the analysis of the behavior of different types of photovoltaic modules, in my case monocrystalline and polycrystalline modules produced by Bisol. It will be explained the photoelectric phenomenon and presented the characteristics of photovoltaic modules. Later, I will describe the software, as well as devices used for measuring the characteristics of the modules. The most important part will be the analysis of the measurement results and the behavior of two different modules in two different periods of time.

Diplomska naloga na kratko opiše zgodovino, delovanje in lastnosti svetlečih diod. Predstavljena je problematika povišane temperature svetlečih diod, zakaj jo je potrebno spremljati in jo s primernim hlajenjem obdržati v priporočenem območju. Opisanih je nekaj metod merjenja temperature p-n spoja, podrobneje pa je predstavljen standard EIA/JEDEC JESD51-1, ki določa izvajanje merjenja temperature p-n spoja z uporabo dveh tokov v prevodni smeri. Uporablja se za meritve temperature polprevodnih elementov, med katere spadajo tudi diode. V eksperimentalnem delu naloge je na osnovi standarda EIA/JEDEC JESD51-1 prikazano izvajanje meritev temperature p-n spoja petih testnih svetlečih diod. Meritve temperature na vseh petih diodah so izvedene pri sobni temperaturi, ena svetleča dioda pa je merjena tudi pri povišanih temperaturah okolice. Metoda merjenja temperature p-n spoja s pomočjo prevodne napetosti je uporabna, saj daje primerljive rezultate pri vseh petih meritvah na sobni temperaturi in tudi pri meritvah pri zvišanih temperaturah okolice. Slabost metode je njena zamudnost. Svetleče diode se med seboj razlikujejo v svoji U-I karakteristiki in spremembi napetosti na p-n spoju ob spremembi temperature. Zaradi tega je potrebno pri vsaki merjeni svetleči diodi najprej izmeriti karakteristiko odvisnosti napetosti od temperature (faktor K). The following thesis includes a short description of the history, working principle and characteristics of light-emitting diodes. Presented are the problems of elevated temperature of light-emitting diodes, the importance of tracking the temperature and keeping the light-emitting diodes at the recommended temperatures by means of adequate cooling. Described in the thesis are some methods of temperature measurements of the p-n junction, with a detailed description of the EIA/JEDEC JESD51-1 standard, which determines the method for performing temperature measurements of the p-n junction by using two electric currents in forward direction. It is used for temperature measurements of semiconductor devices, including diodes. In the experimental part of the thesis, performing temperature measurements of the p-n junction of five test light-emitting diodes is presented on the basis of the EIA/JEDEC JESD51-5 standard. The temperature measurements of all five diodes are performed at a room temperature of the environment additionally, the temperature measurement is performed at elevated temperature of the environment for one diode. The method of temperature measurement of the p-n junction by means of voltage drop is being attested as useful as it gives comparable results with all five measurements at a room temperature, as well as with elevated temperature of the environment. The disadvantage of this method is that it is time-consuming. Light-emitting diodes differ in U-I characteristic and in change of voltage on the p-n junction that is a result of a change of temperature. Therefore, characteristic dependence of the voltage on the temperature (K factor) needs to be measured at every light-emitting diode.

Diplomsko delo je zasnovano na merjenju toka in napetosti električnega kolesa ter izračunu njegove moči in energije. Izmerjene vrednosti so prikazane na različne načine: najprej na android napravi, na kateri je predstavljena zgolj številska vrednost meritev. Za grafični prikaz meritev pa sta uporabljna TFT LCD-zaslon, priključen na Arduino, ter program Processing, ki je namenjen prav grafični upodobitvi meritev na osebnem računalniku. Na tržišču imamo na razpolago najrazličnejše pripomočke in metode za merjenje napetosti in toka. Zagotovo med cenejše spada uporaba že kar dobro razvitega in razširjenega orodja Arduino. Le-ta obstaja v najrazličnejših velikostih, odvisno od načina uporabe ter od zahtevnosti projekta. Arduino ploščice imajo namreč različno število vhodov, izhodov in celo internetni priključek. Za merjenje toka je skupaj z Arduino ploščico najenostavneje uporabiti senzor ACS 712, ki deluje na principu Hallovega efekta in obstaja v treh različnih velikostih toka. Merjeno napetost je treba prilagoditi na velikost vhodne napetosti merilnega člena, in sicer z napetostnim delilnikom, sestavljenim iz dveh uporov. Eden izmed ciljev je tudi vse izmerjene vrednosti, ki smo jih izmerili z Arduinom in jih poslali preko bluetooth komunikacije, prikazati na android telefonu. Tudi na tem področju je možno uporabiti najrazličnejša programska orodja: od profesionalnih do bolj laičnih. V nalogi sta uporabljena precej razširjen MIT app inventor ter S2-terminal, ki sta namenjena predvsem začetnikom. Meritve so prikazane tudi v obliki grafa na LCD-zaslonu. This work is based on measuring the current and voltage of an electric bicycle and calculating its power and energy. One of our goals is to show results in different ways. The numerical value of the measurements will be showed on the smart phone. Both the TFT LCD screen connected to Arduino an the Processing program that can be used on a personal computer will be used for a graphical presentation. There are a lot of different accessories and methods on the market for measuring current and voltage. But the cheapest and the most widespread device is definitely Arduino. It is available in different sizes, depending on our needs and complexity of our project. These devices offer different numbers of analog and digital inputs and outputs and even an internet connection. The easiest way of current measuring is the use of ACS 712 sensor, working on principle of the Hall effectand available in three different sizes. The results have to be adapted to the size of the input current measurement with the voltage divider, made up of two resistors. Our goal is also to send the data from Arduino to an android device using bluetooth. There are a lot of different ways, both professional and laic, to do this. In this project we used the easiest way to display data on the phone by using the MIT App Inventor and the S2 terminal, both of them totally free of charge and designed for beginners. The measurements are also going to be displayed on the LCD display.

U poglavlju 2. ovog rada opisan je i dokumentiran postupak projektiranja naponski kontroliranog oscilatora s negativnim otporom u 180 nm tehnologiji tranzistora s horizontalnim tokom struje. Opisana je fizikalna slika rada oscilatora s negativnim otporom. Navedene su glavne karakteristike VCO-a te opisan utjecaj parametara titrajnog kruga i tranzistora. VCO je projektiran u dvije različite izvedbe obzirom na izvedbu titrajnog kruga te dvije izvedbe s različitim brojem HCBT-a u diferencijalnom paru s titrajnim krugom na čipu. Oscilator je simuliran pomoću programskog alata “ADS”, a layout je izrađen pomoću programskog alata “Cadence”. U poglavlju 3. dokumentirana je analiza mixera projektiranog u 180 nm tehnologiji tranzistora s horizontalnim tokom struje. Analiza je provedena u dva dijela – simulacijski pomoću programskog alata “ADS” i fizički na čipu pomoću laboratorijske mjerne opreme i programskog alata “Labview”. U simulacijskom dijelu ispitan je i objašnjen utjecaj parametara HCBT-a Re i Nk na linearnost (IIP3) i pojačanje (CG) mixera. U mjerenjima na čipu ispitan je utjecaj statičkih radnih točaka HCBT-a na IIP3 i CG mixera. In Chapter 2. of this work designing a VCO with a negative resistance in 180 nm transistor technology with horizontal flow of current is described and documented. Oscillator with negative resistance working operation is described. Main characteristics of the VCO's are listed and influence of a resonant circuit’s parameters are described. VCO is designed in two different versions depending of location of the resonant circuit, and two versions with different numbers of HCBT’s in a differential pair with a resonant circuit on a chip. The oscillator is simulated using the software tool "ADS" and the layout was designed using the software tool "Cadence". In Chapter 3 analysis of mixer designed in 180 nm transistor technology with horizontal flow of current is documented. There was two separated parts of analysis – a simulation part using the software tool "ADS" and on-chip laboratory measurement using laboratory equipment and software tool "Labview". In the simulation section influence of HCBT parameters Re and Nk on linearity (IIP3) and conversiongain (CG) was examined and explained. In the on–chip measurements influence of static working point of HCBT’s on IIP3 and CG of mixer are examined and explained.