【 Weak current College 】 on background music and emergency broadcasting switch---Power By 【 China power house network 】

On the background music and emergency broadcasting switch
Currently, new or rebuilding of buildings or places of public entertainment, design and installation of background music system, it should be said that it is very common, but as fire emergencies emergency alarm broadcast system, is the basis for the automatic fire alarm system design code (GB50116-98) will need to consider the installation. These two systems function similar to that in order to save costs, maximize the use of the same features of the device, an increasing number of design of the system, enabling it to a compatible implementation. However, this device compatibility if you must guarantee that the two systems in case of emergency, to signal the "switch" to make emergency alert broadcasts are absolute priority status.
First, you need to switch a
In actual use, some of the new buildings are basically multi-purpose, shopping, entertainment, Office, guest rooms have their own Office on the one hand, there are also part of the rent. This will make the whole building's background music system during playback, the different regions also contains many other signals into play, this signal insertion including
(1) normal play background music at the same time, should have temporary broadcast to find people, advertising insert functionality. Its form is to interrupt or overlay the background music of broadcasting.
⑵ unattended and rest time of insertion. According to the established order provide the location to insert schedule (bells, music or other sound effects).
This signal into the background music system signal "insert", but this article is about the "switch", refers to the encounter emergency situations the background music and emergency alarm radio switch, switch in emergency alarm radio is an absolute priority, the system received an emergency fire signal, regardless of background music in what circumstances, the system will switch to the emergency alarm broadcast status in order to complete the task of the "switch".
"Switch" consists of the following ways.
① total
When building these regional emergencies, according to the "design standard" requirements, the system should be accidents floors and the adjacent floor emergency alarm broadcast. At this point, the other floors are not as emergency alarm broadcast, but stop playing normal background music that is in the mute the sound. This way the "switch" is called "complete" in the form of the background music and emergency alarm broadcast signal source of low level signal and the corresponding alarm floor amplifier the signal at the switch before. This way the signal source device has a total of two sets, power amplifiers, speakers and other intermediate devices are "compatible", but power amplifier of signal input required input with priority estuary.
② related floor switch
In this way and "complete" means the difference lies in the fact that, in case of emergency, emergency alert broadcasts only to accidents floors and the adjacent floor switch broadcasting, while other floors in do not need special requirements for broadcasting, as usual play background music. This way the main equipment (including the signal source, preamplifier and power amplifier) basically there are two, namely: a set of background music, emergency alarm, radio, a set of the system's speakers are common. But relatively emergency alarm broadcast equipment is very small, constant pressure-type power amplifier, as long as it meets 3-4 layers of broadcasting power. This way the "toggle" the principle of which is through the fire-fighting equipment of control module linkage accidents floors as well as the adjacent layer so that it will start the emergency alarm broadcast equipment, switching and related emergency alarm broadcast floors.
In addition to system design, each floor of the installation of a power amplifier (this way fit each storey area is large, the number of speakers installed conforms to the power amplifier corresponding power), in this case, you can meet the main devices sharing a set of "compatibility" mode, you can implement not need emergency alarm broadcast floor still play background music. How to: switch it through fire linkage related floor control module for emergency alarm broadcast signal switch to related floor power amplifier input (using priority delivery man Jack or relays long open contacts), thus fulfilling the "switch".
Second, in the form of switching
1. electronic priority circuit switching method
This is a device priority phone jacks for switching is very convenient. Especially in the floor is not high, features simple sites, but for background music and emergency alarm radio switch, the switch is very common. Such a device priority Jack, in the vast majority of professional public broadcasting equipment are. As a result of domestic and foreign manufacturers of the equipment design ideas, have priority of design in the preamplifier, there is the design in the last stage of power amplifier or merge-amplifier of signal transmission and human side, there are manufacturers designed a signal priority different output selector, this device has four independent signal channels and each channel under the emergency, press 1-4 priorities output so you can solve a variety of signal Plug and switch features work. However if the signal insertion form many and switch requirements complex, simple switch with priority mouth is meeting the requirements.
2. switching of strong switch method this method is the use of relay normally open, normally closed contacts for switching. Generally speaking background music signal through the normally closed contact relay transmission and emergency alarm radio, after receiving the instruction of relay, normally open contact access emergency alarm broadcast. This is a toggle are inseparable. In order to meet the different circumstances of toggle, complex projects are both toggle common method to complete the complex requirements of the "switch".
3. manual switching
Manual switching function is a system are indispensable manual switch is required when you want to automatically switch to other floors or areas should also be broadcast, the implementation of a manual selection switch.
III. system switching equipment selection
System of "switching" from the "switch" directives, and directives of the "switch" is from fire control equipment, switching equipmentThere are two options, one is the background music system equipment yourself with a set of emergency alarm radio control equipment, it works as in Figure 1.
This set of emergency alarm device as long as they receive the fire-fighting equipment transferred accidents floors of emergency signal, after matrix for joint and several adjacent layer (i.e. +/-layer) activate the floor of the relay, the emergency alarm signal in accordance with the principle of adjacent layers alarm will play out emergency alarm signal.
Another way is to take full advantage of fire control equipment of linkage control system control module to switch to. The control module is fire control equipment bus system linkage control of device, when the fire alarm is the logical control relationship within the module's relay contact action to start external control device on or off. This control module for accidents floors and adjacent layer signal switch, in this way is very easy and very affordable.
The fire control system, basically at each floor as a partition, and each partition to install the appropriate control module, as emergency alarm, radio
Accidents floors and adjacent layer control module startup by fire control equipment. This approach eliminates background music devices with emergency alarm control unit, as this can complete the background music and alarm broadcast switch.
4. switching process control equipment
In the background music and emergency alarm radio switch, the key issue is the control of the device. Whether using background music himself with emergency alarm switching equipment, or fire control equipment switch module, they want to control the device include:
(1) the power, when the background music system at night or on holidays, the device's power supply system in fire control signal, the auto will have the power to open and close to the system, so that the system is operational.
(2) emergency and alarm broadcast signal source issue joint directive to enable them to provide emergency alert system to transmit radio signals.
(3) switch accidents floors and the adjacent floor of the signal path.
During the system design process, select the background music and emergency alarm broadcast signal "switch" mode, first from the building or buildings function and asked to consider, in a reliable, simple, less investment ideas to choose, is a scientific attitude.