The Design And Implementation Of Public Address System In The Railway Station And Subway Station

As the development of economy and the progress of science and technology, our country’s public broadcasting industry has entered into a period of rapid growth; the technical level and comprehensive strength has greatly improved. With the development of technology and the changing of customers demand patterns, the broadcasting system products tend towards diversification and standardization.PA, an abbreviation of Public radio system, as a branch of audio technology application is widely used in every related fields. Typically, PA has three main functions:public broadcasting, background music playing and emergency broadcast. And now PA combines the three functions into one system, sharing a set of power amplifier and speaker equipment, has become the general broadcasting system.This paper firstly introduced the background of the broadcast system, the current development situation of broadcast system, the classification and components of the system, and then made a detailed analysis of the public radio system, basing on the actual demand. This detailed analysis includes audio equipment, systems module, transmission lines and speaker system. Plus, the preamp study design and commissioning. This system mainly include:audio output devices, prerecorded voice equipment, preamp, power amplifiers, individual function module, transmission lines, the speaker system and management control terminals etc. This system can achieve parallel radio with multiple sources, multiple channels, and multiple loading areas, i.e. all kinds of source can be transmit by different radio audio channels to different load areas play different radio content. This system supports the daily operations according to customers’needs.People can use the radio equipment for public radio; voice broadcast and paging business play, or make instructions at work space. If there is a fire or any other emergencies, the broadcast system can be an emergency radio, used to guide the evacuation.This article provides the instructive working method with working process for the public radio system designers, targeting to improve the working efficiency of the technicians. I participate in the design work of a metro broadcast system project, and responsible for the preamp hardware design.