Low Cost Voice Communication Device Design Using Ordinary Laser Torch and LDR Available in Bangladesh Md. Kayesar Ahmmed EEE Department, Green Land Builders Limited, Dhaka, Bangladesh Email: maks_eee_cuet@yahoo.com Anmona Shabnam Pranti Faculty, Department of Electrical and Electronics Engineering, IUBAT—International University of Business Agriculture and Technology, Dhaka, Bangladesh Email: anmona.s.p@iubat.edu Arif Md. Shahed Iqubal Faculty, Department of Mechanical Engineering, IUBAT—International University of Business Agriculture and Technology, Dhaka, Bangladesh Email: iqubal.shahed@iubat.edu Abstract — As living in the society, communication is the most important activity of human being. All most for every purpose we are communicating with each others. Different modes of communication are used and voice communication is one of those categories. From the beginning of technological advancement, many processes have been used for the voice communication purpose and among those, Laser Voice Transmission Process is much more useful because of wireless connectivity and free from disadvantage of radio frequency transmission. Long distance high cost Laser voice transmission system is not economic for the purpose of ordinary communication. This paper deals with the designing of a very low cost voice transmission system which is perfect for information transmission of general conversation in Bangladesh, using an ordinary available LDR and Laser torch of cost BDT 727. This is almost 86% cheaper than the lowest cost voice transmission system available in this country. Index Terms — laser torch, voice transmission, low cost design I. INTRODUCTION From the beginning of human living, before the invention of language, communication was the biggest challenge. Human being had always the necessity for communication throughout the history. Initially, communication was done through signals, voice or primitive forms of writing. As time has changed, the necessity of communication through distances was grown Manuscript received May 14, 2013; revised October 24, 2013 to pass information from one place to another. Different ways to exchange information over long distances like pigeons and smoke signals have been adopted in every stages of civilization advancement, some of them have sustained and some has vanished. All these methods were the pioneer of today’s modern technological long- distance communication system. This system involves transmission and reception of a large amount of information in a short period of time. Gradually through the technological development, man has invented different procedure of communication with each other. Now communication has entered in our daily life in many ways like telephone, radio, televisions, cell phone, computer and Internet, in our office and home. Different modes of communication can provide rapid connection from every corner of the globe and even out of the globe (aircrafts, rockets and satellites in space). Along with the wire communication system like telephone, two ways wireless communication system like mobile, internet have become popular now a day. As Laser is stimulated radiation, problem of interference occurs in electromagnetic wave is eliminated, it can be a good substitution of present day communication systems [1], [2]. The laser based voice communication system currently available in market is expensive, $614 [3], in respect to our country’s general people income. The people of our country generally use cell phone now days to communicate with each other for general purpose and sometimes spent hours and money (as call tariff) to talk with next door neighbor, specially young generation. A simple device can be made with minimum cost by cheap electronics parts and Laser torch available in Bangladesh 223 International Journal of Electronics and Electrical Engineering Vol. 1, No. 4, December, 2013 ©2013 Engineering and Technology Publishing doi: 10.12720/ijeee.1.4.223-229