Design And Construction Of A 100W Public Address System

This work is titled design and construction of a public address system with ac and battery power source. A public address system (PA system) is an electronic sound amplification and distribution system with a microphone, amplifier and loudspeakers, used to allow a person to address a large public, for example for announcements of movements at large and noisy air and rail terminals.
The term is also used for systems which may additionally have a mixing console, and amplifiers and loudspeakers suitable for music as well as speech, used to reinforce a sound source, such as recorded music or a person giving a speech or distributing the sound throughout a venue or building.
Public addressing system is often used in small venues such as school auditoriums, churches, and small bars. PA systems with many speakers are widely used to make announcements in public, institutional and commercial buildings and locations. Intercom systems, installed in many buildings, have microphones in many rooms allowing the occupants to respond to announcements.
This system was built using some major electronics components such as transistor, resistor, capacitors, and an aluminum heatsink was used to protect the power transistors from overheating.
This Public Addressing Systems have a potential for audio feedback, which occurs when sound from the speakers is picked up by the microphone and is then re-amplified and sent through the speakers again. That makes it to sounds like a loud high-pitched squeal or screech, and can occur when the volume of the system is turned up too high.