Situasi kecemasan boleh berlaku disebabkan berlakunya bencana alam atau apabila seseorang secara tiba-tiba tersesat di lokasi pedalaman. Dalam keadaan seperti ini, komunikasi memerlukan peranti mudah alih yang dapat berfungsi untuk menghubungi servis bantuan menyelamat. Namun begitu, dalam kebanyakan kes sumber elektrik akan terputus. Kebiasaannya, sumber tenaga alternatif berupaya memberikan kuasa kepada telefon mudah alih. Walau bagaimanapun sumber tenaga alternatif ini adakalanya terbatas yang menjejaskan ketersediaanya. Kajian ini bermatlamat untuk mengumpulkan beberapa sumber alternatif kepada satu unit yang boleh memberikan keupayaan kepada telefon mudah alih dengan penekanan diberikan kepada kecekapan sumber dinamo elektrik berengkol tangan. Tiga sumber kuasa digunakan iaitu kuasa manusia melalui dinamo elektrik, panel solar dan sepasang bateri boleh cas semula. Ujian dan analisa awal dilakukan dalam memilih dan memasang perkakasan. Sistem yang lengkap mempunyai suis manual bagi sumber tenaga tersebut iaitu regulasi dc-dc, susun atur elektronik pengecas bateri dan lampu suluh untuk pencahayaan. Kecekapan lebih baik sebanyak 87.5% dicapai bagi dinamo dengan sistem berupaya menghantar secara purata 400 mW semasa operasi. Purata 21 minit berlalu sebelum cas minima dihantar kepada telepon asas. Tempoh mengecas bagi telefon pintar sehingga ke aras yang ditentukan adalah masing-masing sebanyak 108 minit, 86 minit dan 72 minit bagi sumber solar, dinamo dan bateri. Unit yang dibangunkan ini berguna kepada manusia untuk dijadikan suatu alat yang boleh diharap dalam memberikan kuasa kepada telefon mudah alih bagi membolehkan mesej bantuan kecemasan dihantar.
Emergency situations may arise due to natural disaster occurrences or when chance takes one to a remote location. In settings like this, communication requires that mobile devices are powered on in the expectation of access to relief and rescue services. However, in many cases the electricity supply will be broke down. Usually, alternative energy sources provide the needed power to mobile phones in such circumstances. These alternative energy sources exhibit peculiar limitations that affect availability. This work was aimed at merging various alternative sources into a unit that will provide potential to a mobile phone with an emphasis on enhancing the efficiency of a hand-cranked electric dynamo source. Three power sources are employed which are active human power in the electric dynamo, solar panels and a pair of rechargeable batteries. Preliminary tests and analysis were conducted for hardware selection and assembly. The completed system contains a manual switch for the energy sources, a dc-dc regulation, battery charging electronic layout and a torchlight for illumination. An improved efficiency of 87.5% was achieved for the dynamo with the system able to deliver an average 0.4 W during operation. An average of 21 minutes elapsed before a minimum charge was delivered to a basic phone. The charging times for a smartphone to a determined level was found to be 108 minutes, 86 minutes and 72 minutes for the solar source, dynamo source and battery source, respectively. The developed unit is useful to people to keep it as a tool that they can rely on to power up their mobile phone in order to send emergency rescue message.
Multi source handphone charging system for communication during emergencies_ Affam Azuka_E3_2017_MFAR