1、 Overview

The public address system includes background music, 

business broadcast and emergency broadcast. Under normal circumstances, it is used as the media of background music to show the perfection of hardware in commercial buildings and beautify the public environment and business broadcasting of the building, such as commodity information broadcasting. In special cases, the public broadcasting system can be used as an emergency broadcast medium. Through the control and switching equipment of the broadcasting center, the public broadcasting system can be used as an emergency broadcast medium Each broadcasting area carries out emergency broadcast calls, guides personnel evacuation, and cooperates with fire alarm system, anti-theft alarm system and security monitoring system to form a set of complete, three-dimensional, audio-visual function of commercial building fire prevention and security facilities.

2、 Technical solutions
1. Background music system
The system provides nine channels of sound source, four channels of local broadcasting, two channels of card and three channels of CD player, which can be selected by program control function.
Use the partition selector to control the on / off of any partition broadcast.
The microphone can broadcast business and business information to the whole building or any partition.
When using the background music, the power input to the speaker is 3W, and 6W when the service is wide.
2. Fire emergency broadcast
The system adopts professional fire emergency broadcasting equipment, which can be connected with the fire protection system. After receiving the alarm signal from the fire protection system, it can automatically broadcast fire emergency to the fire floor and adjacent layers, or manually command with the attached microphone.
When the normal background music broadcast is carried out, once the business broadcast or fire emergency broadcast is needed, the system will automatically cut off the background music for business or fire emergency broadcast, instead of using the outdated scene forced cut mode.
The output power input to the loudspeaker is 6W.
The connection of all loudspeakers is directly connected from the machine room, which is convenient and fast, and is conducive to the daily maintenance in the future.
3、 Main configuration and functions of the system
1. Sound source equipment
A FM receiver: it can receive FM stereo radio programs from Liaoning and Shenyang.
Three disc CD player: playing high fidelity music from CD records.
Double deck, player: play prefabricated recording or music.
Microphone: broadcast commercial unified information, such as business broadcast.
2. Control equipment
Central controller: the host of broadcasting and public address management system.
Expansion chassis: used for expansion of central controller control unit.
Extender: with it, more power amplifiers can be connected to the central controller. When an amplifier fails, it will automatically switch to the standby machine.
Call station: it is used for manual control, forced switching and zone selective broadcasting.
3. Transmission equipment
Sound source equipment as described above
Preamplifier: amplify audio signal to meet the input signal requirements of power amplifier.
Power amplifier: the audio signal is amplified to meet the system output power requirements.
4. Layout of public address system
Public address sound system is set up in public corridors, shopping malls, entertainment places and underground parking lots.
4、 Equipment selection
The design scheme adopts Philips sm30 audio broadcasting management system, which is an intelligent system controlled by a microprocessor. LCD display and various function keys, menu operation, modular structure, and plug-in board assembly bring flexibility and convenience. It can be said that it is the first choice system in the finalized broadcasting products, which can be divided into 36 independent broadcast partitions at most.
1. Sm-30 central controller
The model is LBB 1280 / 40
Central processing unit of SM 30 public address management system
It can accept 10 application modules
There are 50 different time reports and alarm signals
L desktop and rack mounted
This control center is the host of sm30 public address management system. It includes: the main microprocessor of the system installed in the cabinet and the slots of 10 additional application modules. There are LCD display, various function keys and power switch on the front panel of the case. The sm30 has no amplifier and must be used with one or more sq 45 amplifiers.
The built-in signal generator card can generate 50 different chimes and alarm signals, including those according to NATO STANAG standard. Because of the use of software controlled e-eprom (programmable read only memory), there is no need to add battery backup memory to the circuit board.
2. Sm-30 Application module
2.1 microphone input module, model lbb1282 / 00, features:
L is the interface between two balanced microphones and the sm-30 host
L user selects microphone / line input and removes bass
L provides phantom power for connected microphones with LED status indicator
Each lbb1282 microphone input module provides an interface between two symmetrical microphones and the sm-30 control center. The center can accommodate up to three lbb1282 or lbb1283 modules.
The module is equipped with phantom power supply. On the microphone, there is an LED system status display, which flashes when playing the bell signal and stably when playing the speech.
The microphone with remote control contact and wiring can be triggered remotely by the module. The module can be selected by the user for voice or line input. In the noisy environment can choose to cut off the bass is particularly good.
2.2 call station input module, model lbb1283 / 00
Provide input ports for 2 call stations
Each input has independent volume control
The sm-30 can accept up to 3 lbb1283 modules. The maximum distance of the call station is 1000m. Two pairs of shielded wires (for audio and power supply) and two pairs of ordinary twisted wires (for control and data transmission) are provided.
2.3 control input module, model lbb1284 / 00, features:
8 remote control switches can be connected to sm30
Plug in module
Optical disconnector

Each module can connect up to 8 remote control switches to the control center, and the center can accommodate up to 6 LBB 1284 / 00 modules, that is, a total of 48 remote control switches. The switches have light insulation treatment inside.

Lbb4157 / 00 IC card encoder
Lbb9094 / 10 portable microphone
Lbb9568 / 30 call station keyboard
Lbb9568 / 36 call station keyboard
Lbb9600 / 20 portable microphone
Lbc2900 / 15 portable microphone DIN
Ple-wp3s2z-eu conference equipment

Sales telephone (same number of wechat): 13428785305 QQ: 2461903042