diplomsko delo
Jan Žagar (Author), Marko Jankovec (Mentor)

Abstract

V diplomskem delu je opisan razvoj nove revizije napajalnika za mobilni zaslon, predstavljeni so problemi, do katerih je prišlo, in tudi način reševanja le teh. Nova revizija je posodobitev obstoječega napajalnika za mobilni zaslon. Posodobljen napajalnik bo uporabljen za napajanje celotne elektronike v mobilnem zaslonu. Napajanje lahko priključimo na zunanji napajalnik ali neposredno na izhodni napajalni priključek računalnikov, ki jih podjetje Dewesoft izdeluje za aplikacije na terenih. Do nove revizije napajalnika je prišlo zaradi pojava, za uporabnika precej motečih, vodoravnih premikajočih se črt. Problem smo reševali na prvotni verziji napajalnika, ker smo želeli ugotoviti, kaj je temeljni vzrok za pojav premikajočih se črt. Pri tem smo si pomagali s shemo napajalnika, na kateri smo opazili sklenjen vhodni in izhodni kontakt filtra. Izveden filter ni opravljal funkcije filtriranja sofaznih motenj. Predvidevali smo, da so vzrok lahko sofazne motnje, ki jih sicer s sofazno dušilko zmanjšujemo. Zato smo se odločili izdelati nov filter. S pomočjo simulacijskega orodja LTspice smo opravili simulacijo novega filtra, s katerim smo določili tudi vrednosti elementov. Po zamenjavi filtra je še vedno prihajalo do premikajočih se črt. Pozornost smo kasneje usmerili v masne zanke. Po eliminaciji ene od njih se je na zaslonu pojavila čista slika. Nato smo opravili imunske teste, ki sprva niso bili uspešno opravljeni, zato smo naredili nekaj izboljšav. Med oklopom in ohišjem smo dodali RC člen ter zopet izvedli imunske teste. Po opravljenih testih smo narejene popravke na obstoječem napajalniku izvedli v shemi, nato pa narisali tiskano vezje.

Keywords

elektromagnetna združljivost;napetostni regulatorji;zaščitni ukrepi;mobilni zasloni;tiskana vezja;simulacija LTspice;visokošolski strokovni študij;Aplikativna elektrotehnika;diplomske naloge;

Data

Language: Slovenian
Year of publishing:
Typology: 2.11 - Undergraduate Thesis
Organization: UL FE - Faculty of Electrical Engineering
Publisher: [J. Žagar]
UDC: 621.3(043.2)
COBISS: 122164483 Link will open in a new window
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Downloads: 6
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Other data

Secondary language: English
Secondary title: Revision of the power supply to achieve electromagnetic compatibility
Secondary abstract: The thesis describes the development of the new revision of the power supply for the portable display, presents the problems with electromagnetic interferences and suggested solutions. The new revision is an update of the existing power supply for portable display. The updated power supply will be used to power all of the electronics inside the portable display. The power supply can be connected to an external DC power adapter or directly to the output power connector of a computer manufactured by Dewesoft for field applications. The need for a new revision of the power supply arose due to the distrubances, that appeared as horizontal moving lines on the screen. Because we wanted to research the cause of the distrubances, we tried to upgrade the existing power supply to solve the issue. The search for the problem started right at the power supply schematic, where our attention was brought to the short circuit between input and output contacts of the filter. The absence of the filter suggested that the common mode noise might be worth pursuing. Therefore, we designed a new filter and determined the component values with the help of the simulation tool LTspice. However, even though the filter was replaced with the new one, the problem still persisted. Therefore we focused to the ground loops and after ground loop elimination a clean image appeared on the screen. We performed immunity tests which were not initially successfull. We added an RC circuit between the shield and housing which improved the immunity to a satisfactory level. Finally, we applied all the modifications into a new revision of the power supply.
Secondary keywords: electromagnetic compatibility;voltage regulators;safety precautions;portable display;printed circuit board;LTspice simulation;
Type (COBISS): Bachelor thesis/paper
Study programme: 1000315
Embargo end date (OpenAIRE): 1970-01-01
Thesis comment: Univ. v Ljubljani, Fak. za elektrotehniko
Pages: XXIV, 57 str.
ID: 16469473