Public broadcasting system is widely used in daily life, especially in enterprises, schools, government agencies and other departments. However, it seems that the public broadcasting system, careful analysis, there is still a lot of knowledge. The first thing we need to do is to make clear the public broadcasting system, and analyze its characteristics. In order to achieve targeted, improve their knowledge at the same time, can also for their purchase and use to provide a lot of reference. At present, the public broadcasting system can be divided into the following categories according to the transmission mode.

Constant pressure broadcasting system

Constant pressure broadcasting system refers to the front using the constant pressure broadcast amplifier audio audio power amplifier by wire transfer to the loudspeaker broadcast system. As the most basic structure of such systems: the audio power amplifier and speaker -. Depending on the functional requirements, the main control device can be added at the front end. Main control machine's main function is to control audio input / output, peripheral equipment (such as power amplifier) power management, line output area zoning management. I used Nanjing million Kay's MP3 music player and constant pressure area broadcast host feeling pretty good. Of course, this type of partition must be based on the physical partition of the line.

Its main features: high transmission stability, low failure rate, simple structure, easy maintenance.

Two, FM broadcasting system

FM broadcasting system refers to the front audio source modulated by the modulator for RF signal is transmitted to the loudspeaker, and demodulation for audio signals in the local power amplification of the public broadcasting system. According to the different transmission carrier can also be divided into cable FM radio system and radio FM radio system.

The basic structure of this kind of broadcasting system for audio modulator demodulator: - - - - loudspeaker amplifier. According to the functional requirements of different sources may also increase the modulator and the peripheral equipment and a plurality of main control computer, on the basis of. The working pattern of the FM radio host computer will control the modulation signal into the RF signal and modulation of single or multiple different frequency audio frequency signal by mixer and a rear transmission to each a separate speaker points, in each a separate speaker point counter modulation control signal and an audio signal of control command (this is work and choose the way in which the sound source), source selection after the power amplifier output. I use the Nanjing wankai control host which is the audio modulation and data command modulation integrated into a host, principle and I said similar.

The main characteristics of the multi program source can realize single cable or wireless transmission, and realize the control of point to point. Equipment is simple, easy to maintain, the function is also extremely powerful suitable for all kinds of places under the use of. But the transmission line to consider the attenuation of radio frequency signal amplification and other issues (familiar with the CATV is very simple).

Three, network broadcasting system

Network broadcast system refers to a broadcast system that carries out the transmission of audio and control signals through a LAN or WAN. Its structure is: control software (or integrated control software and computer functions of the radio host computer) - Internet - network radio terminal. The basic function of network broadcasting terminal according to the front-end control commands and analysis myself this address whether the response action, select a channel audio power amplifier to a loudspeaker. With the popularization and development of network technology, existing network broadcast using TCP / IP protocol but also to achieve the two-way intercom, remote paging and other functions.

The characteristics of this type of broadcasting system: line, making full use of the resource of IP network; multi program source to point of real-time playback; two-way intercom, remote paging.

This article mainly explains the definition, the structure and the main characteristics of the three kinds of public broadcasting system, we hope to choose and use the public broadcasting system to help.