Miniaturni polnilnik za pametne telefone

MEDAK, MARIN (author), Kamnik, Roman (mentor)

Vse več ljudi vedno več časa nameni uporabi pametnih telefonov. Razvoj tehnologije je šel v zadnjih desetih letih bliskovito naprej, baterije, ki napajajo pametne telefone, pa tega ne dohajajo. V diplomskem delu sta predstavljena razvoj in evalvacija miniaturnega polnilnika za pametne telefone, opisana je njegova komercializacija. Polnilnik je načrtovan s fokusom na priročnosti. Kadar polnilnik ni v uporabi, se zloži in nosi kot obesek za ključe. S svojo majhnostjo zagotavlja, da ga imajo uporabniki lahko ves čas s seboj. Polnilnik napajajo štiri AA-baterije, ki so enake in dostopne po vsem svetu. Razvili smo popolnoma nov produkt. V polnilnik smo vgradili konektor, zato uporabnik ne potrebuje dodatnega polnilnega kabla, ampak lahko pametni telefon preprosto priključi na polnilnik. Minimalen volumen smo dosegli z odstranitvijo dela, v katerega se zaprejo baterije, in uporabo močnih magnetov, ki držijo baterije med obema polovicama polnilnika. Električni del polnilnika smo zgradili okoli napetostnega regulatorja. Ta skrbi, da je ne glede na vhodno napetost, ki jo zagotavljajo štiri AA-baterije, na izhodu polnilnika 5 V, tj. toliko, kot je priporočena napetost za polnjenje pametnih telefonov. Izmerili smo karakteristiko uporabljenih baterij in polnilnika v treh načinih. Najprej smo izmerili karakteristiko praznjenja petih različnih tipov baterij. To smo naredili tako, da smo štiri baterije določenega tipa vsakič priključil na fiksni upor ter merili električno napetost in električni tok skozi upor. Nato smo izmerili delovanje polnilnika z napajanjem prek različnih tipov baterij; kot breme smo uporabili enak fiksni upor, merili smo vhodno in izhodno napetost ter vhodni in izhodni tok polnilnika. Na koncu smo delovanje polnilnika evalvirali tudi s preizkušanjem polnjenja telefona iPhone 6 s petimi različnimi seti AA-baterij. Pri uporabi naprave za polnjenje telefona iPhone 6 smo merili vhodne in izhodne napetosti polnilnika ter iz pridobljenih podatkov izračunali moč, energijo in izkoristek polnilnika pri uporabi različnih vrst baterij. Ugotovili smo, da obstaja velika razlika med alkalnimi baterijami, tudi med tistimi, ki spadajo v isti cenovni razred. Rezultati so pokazali, da ima iPhone 6 diskretne tokovne nivoje, s katerimi se polni, in da med polnjenjem sam spreminja notranjo upornost in s tem tok polnjenja ter da se polni tudi pri veliko manjši napetosti, kot je zapisana v tehnični dokumentaciji. V zadnjem delu diplomskega dela smo opisali potek razvoja komercialnega polnilnika, različne faze razvoja, izzive, ki smo jih morali rešiti, in na koncu tudi napake, ki so po našem mnenju privedle do tega, da projekt ni uspel.

• Language: Slovenian
• Keywords: polnilnik, pametni telefon, napetostni regulator
• Work type: Undergraduate thesis
• Organization: FE - Faculty of Electrical Engineering
• Year: 2016
• PID: 20.500.12556/RUL-84475
• Publication date in RUL: 25.08.2016

Secondary language

• Language: English
• Title: Miniature charger for smartphones

Abstract

Smartphone usage and sales have been surging for the last ten years. Smart mobile phones are getting more and more entangled in our daily life and have seen a big improvement in the last decade. Unfortunately, their batteries haven’t followed the fast innovation pace and are trailing behind. The thesis addresses the development and evaluation of a small smartphone charger and the commercialization of the product. The charger has been developed with a focus towards portability and usability. When the charger is not in use, it can pack down to a very small size and be used as a keyring. This feature enables users to have it always with them and use it whenever it’s necessary. The charger is powered by 4 AA batteries which are a standard size and available all around the world. We invented and developed a completely new product. The charger has a build in connector, which means that users don’t need an additional cable to charge their phones. The volume of the charger was minimized by removing the battery compartment. To do that, we used strong magnets, which hold the batteries on the contacts when the charger is in use. When it’s a keyring, the same magnets hold the two parts together. The electrical circuit was built around a voltage regulator, which provides 5 V output for the whole range of voltage inputs, that 4 AA batteries are able to provide. Pomeril sem karakteristiko uporabljenih baterij ter polnilnika v treh načinih. Najprej sem izmeril karakteristiko praznjenja petih različnih tipov baterij. To sem naredil tako, da sem vsakič štiri baterije priključil na fiksni upor ter meril električno napetost in električni tok skozi upor. Nato sem izmeril delovanje polnilnika z napajanjem različnih tipov baterij in kot breme uporabil enak fiksni upor ter meril vhodno in izhodno napetost ter vhodni in izhodni tok polnilnika I measured the characteristics of different types of batteries and the charger in three modes. First I measured the discharge characteristics of 5 sets of 4 AA batteries by connecting them to a fixed resistor and measuring the voltage and electrical current on it. Next I measured the characteristics of the charger by using 5 different sets of AA batteries to power the charger and using a fixed resistor as load and measuring the input and output voltage and electrical current. At the end I evaluated the charger by testing it with five different sets of brands and types of AA batteries charging an iPhone 6 and measuring the input and output voltage and electrical current. I calculated the power, energy and efficiency of the charger with different sets of batteries. Results show a big difference in provided electrical energy from alkaline batteries, even from those in the same price range. I also found out that the iPhone 6 changes its internal resistance during charging and has discreet levels of electrical current it charges with. The minimum voltage that I measured when the phone was still charging, was much lower than that written in the technical manuals. In the last part of the thesis I wrote about the commercialization of the charger, different steps in the development, challenges that we had to solve and mistakes that we made that culminated in the failure of the project.

• Keywords: smartphone, charger, voltage regulator