This paper is designed for voice transmission system based on laser torch. In this system, it has two parts; transmitting section and receiving section. The transmitting section mainly comprises with condenser microphone, IC 741, BC 548, BD 139 and laser torch. The receiving section composes with L14f1 photo transistor, LM 386 and Loud speaker. If there is any obstruction in the path of the laser beam, no sound will be heard from the receiver. The gain of the op-amp can be controlled with the help of 1 mega ohm pot meter variable resistor. The AF output from the amplifier is coupled to the base of transistor BD 139, which in turn, modulates the laser beam. The receiver circuit uses NPN photo transistor as the light sensor that is followed by two stage transistor preamplifier and LM 386 based audio power amplifier. The receiver does not need any complicated alignment. The photo transistor is kept towards the remote transmitter’s laser point and the volume control is adjusted for a clear sound.
laser beam, op-amp, amplifier, transistor, gain
International Journal of Trend in Scientific Research and Development - IJTSRD having
online ISSN 2456-6470. IJTSRD is a leading Open Access, Peer-Reviewed International
Journal which provides rapid publication of your research articles and aims to promote
the theory and practice along with knowledge sharing between researchers, developers,
engineers, students, and practitioners working in and around the world in many areas
like Sciences, Technology, Innovation, Engineering, Agriculture, Management and
many more and it is recommended by all Universities, review articles and short communications
in all subjects. IJTSRD running an International Journal who are proving quality
publication of peer reviewed and refereed international journals from diverse fields
that emphasizes new research, development and their applications. IJTSRD provides
an online access to exchange your research work, technical notes & surveying results
among professionals throughout the world in e-journals. IJTSRD is a fastest growing
and dynamic professional organization. The aim of this organization is to provide
access not only to world class research resources, but through its professionals
aim to bring in a significant transformation in the real of open access journals
and online publishing.