[Audio Network Information]
At present, it is very common to design and install a background music system in a newly built or renovated building or public entertainment place. As an emergency alarm broadcasting system in a fire emergency, it is based on the "Fire Automatic Alarm System Design Specification". (GB50116-98) must be considered for installation. These two systems have similar functions. In order to save money and maximize the use of devices with the same functions, more and more designs have combined these two systems to make them compatible. However, the premise of compatibility of such devices is that it is necessary to ensure that the two systems can "switch" the signals in case of emergency, so that the emergency alarm broadcast is in an absolute priority state.
First, several situations that need to be switched <br> In actual use, some newly built buildings are basically multi-purpose, both shopping malls and entertainment, as well as offices and guest rooms. There is a part of the rental. In this way, the background music system of the entire building is in the process of playing, and different areas contain the insertion and playback of many other signals. The insertion of such signals includes
(1) While playing background music normally, it should have the function of temporarily broadcasting people to find people and advertising advertisements. It is in the form of a broadcast that interrupts or superimposes its background music.
(2) Insertion of unattended work schedules. The work schedule (bell, music or other sound effects) is inserted into the relevant position in the order of the time.
The insertion of such a signal is the "insertion" of the signal in the background music system, and the "switching" referred to herein refers to the switching of the background music and the emergency alarm broadcast in case of emergency, in which the emergency alarm broadcast is broadcasted. It is absolutely priority, that is, when the system receives the emergency fire signal, regardless of the condition of the background music, the system will switch to the emergency alarm broadcast state, thus completing the task of "switching".
"Switching" includes the following ways
1 Full cut <br> When there is an emergency in any area of ​​the building, the system shall implement an emergency alarm broadcast to the accident floor and adjacent floors in accordance with the requirements of the “Design Specificationâ€. At this time, the other floors do not make an emergency broadcast, but stop playing normal background music and are in a mute state. This "switching" mode is called "full cut" in the form of simultaneously switching the background music and the low level signal of the emergency alarm broadcast source with the signal before the corresponding alarm floor amplifier. In this way, there are two sets of signal sources in the device, and other intermediate devices such as power amplifiers and speakers are “compatibleâ€, but the signal input terminal of the power amplifier needs to have a priority port input.
2 Switching between related floors <br> The difference between this method and the “full cut†method is that in case of emergency, the emergency alarm broadcast only broadcasts broadcasts to the accident floor and adjacent floors, while other floors do not require special requirements. In the case of broadcasting, background music is played as usual. In this way, the main equipment (including signal source, preamplifier, power amplifier) ​​basically has two sets, namely: a set of background music, a set of emergency alarm broadcast, in which the speakers in the system are shared. However, relatively speaking, emergency alarm broadcasting equipment is rarely used, and the constant voltage power amplifier therein can satisfy the broadcasting power of 3-4 layers. The principle of "switching" in this way is to link the accident layer and the adjacent layer through the control module of the fire-fighting equipment, so that the emergency alarm broadcasting device is activated, and the emergency alarm broadcast is performed to the relevant floor.
In addition, when the system is designed, install a power amplifier on each floor (this method is suitable for each floor area is large, the number of installed speakers meets the power of the power amplifier), in this case, It can meet the "compatibility" mode in which the main equipment is shared, and can also play background music on the floor that does not require emergency alarm broadcasting. The switching principle is as follows: the fire protection device linkages the control module of the relevant floor, so that the signal of the emergency alarm broadcast is switched to the input end of the power amplifier of the relevant floor (using the priority input socket or the long open contact with the relay), thereby completing the "switching" "work.
Second, the form of switching
1. Switching method of electronic priority line <br> It is convenient to switch by using this device with priority jack. Especially in places where the floor is not high and the function is simple, switching between background music and emergency alarm broadcasting is a very common switching method. This device with priority socket function is available in most professional public address devices. Due to different equipment design ideas of domestic and foreign manufacturers, some priority ports are designed on the preamplifier, and some are designed to be used in the final stage of the power amplifier or combined amplifier signal input terminal, and some manufacturers have specially designed different signal priorities. The output selector has four independent signal channels, each of which is output in a priority order of 1-4 depending on the emergency, so that various types of signal insertion and switching functions can be solved. However, if the form of signal insertion is many and the requirements for switching are complicated, simply switching with the priority port can not meet the requirements.
2, switch type strong switching method <br> This method is to use the relay's normally open, normally closed contact to achieve switching. Generally speaking, the background music signal is transmitted via the normally closed contact of the relay, and when the emergency alarm broadcast is required, the relay operates after receiving the command, and the normally open contact is connected to the emergency alarm broadcast. This way is any kind of switching method is inseparable. In order to meet the switching mode in different situations, the complicated project adopts the method of sharing the above two switching modes to complete the complex "switching" requirement.
3. Manual switching <br> The manual switching function is indispensable in every system. Manual switching refers to manual switching when it is necessary to broadcast to other floors or areas during the specified automatic switching.
Third, the choice of system switching equipment <br> The system "switching" is inseparable from the "switching" command, and the "switching" command is undoubtedly from the fire control equipment, currently there are two options on the switching device, one is The background music system equipment is equipped with a set of emergency alarm broadcast control equipment, and its working principle is shown in Fig. 1.
As soon as the emergency alarm device receives the emergency signal of the accident floor transmitted by the fire-fighting equipment, the adjacent layer (ie +/- layer) is activated by the matrix to activate the relay of the corresponding floor, so that the emergency alarm signal is alarmed according to the adjacent layer. The principle will play out the emergency alarm signal.
The other is to make full use of the control module of the linkage control system of the fire control device to perform the switching. The control module is an execution device of the linkage control of the fire control device bus system. When the fire alarm is in a logical control relationship, the external control device is activated or deactivated by the action of the relay contact in the module. The control module thus realizes the signal switching between the accident floor and the adjacent layer, which is convenient and economical.
In the fire control system, basically, each floor is used as a partition, and the corresponding control module is installed in each partition. As an emergency alarm broadcast, the start of the control layer of the accident layer and the adjacent layer is controlled by fire control. Equipment to complete. By adopting this method, the emergency alarm control device matched in the background music device can be omitted, and the switching of the background music and the alarm broadcast can be completed.
Fourth, the control device in the switching process <br> In the background music and emergency alarm broadcast switching process, the key problem is to control the work of the corresponding equipment. Whether it is an emergency alarm switching device that is mated with background music or a module that uses a fire control device, the devices to be controlled include:
(1) In the power supply part, when the background music system is at night or on holidays, the power system of the device automatically turns on the power that has been turned off and supplies power to the system after receiving the fire control signal, so that the system is in working state.
(2) Issue a linkage command to the emergency alarm broadcast source to enable it to transmit an emergency alarm broadcast signal to the system.
(3) Switch the signal channels of the accident floor and adjacent floors.
In the process of system design, the choice of “switching†mode of background music and emergency alarm broadcast signal should first be considered from the function and requirements of the building or building, and it should be chosen with the idea of ​​reliability, simplicity and low investment. Scientific attitude.
At present, it is very common to design and install a background music system in a newly built or renovated building or public entertainment place. As an emergency alarm broadcasting system in a fire emergency, it is based on the "Fire Automatic Alarm System Design Specification". (GB50116-98) must be considered for installation. These two systems have similar functions. In order to save money and maximize the use of devices with the same functions, more and more designs have combined these two systems to make them compatible. However, the premise of compatibility of such devices is that it is necessary to ensure that the two systems can "switch" the signals in case of emergency, so that the emergency alarm broadcast is in an absolute priority state.
First, several situations that need to be switched <br> In actual use, some newly built buildings are basically multi-purpose, both shopping malls and entertainment, as well as offices and guest rooms. There is a part of the rental. In this way, the background music system of the entire building is in the process of playing, and different areas contain the insertion and playback of many other signals. The insertion of such signals includes
(1) While playing background music normally, it should have the function of temporarily broadcasting people to find people and advertising advertisements. It is in the form of a broadcast that interrupts or superimposes its background music.
(2) Insertion of unattended work schedules. The work schedule (bell, music or other sound effects) is inserted into the relevant position in the order of the time.
The insertion of such a signal is the "insertion" of the signal in the background music system, and the "switching" referred to herein refers to the switching of the background music and the emergency alarm broadcast in case of emergency, in which the emergency alarm broadcast is broadcasted. It is absolutely priority, that is, when the system receives the emergency fire signal, regardless of the condition of the background music, the system will switch to the emergency alarm broadcast state, thus completing the task of "switching".
"Switching" includes the following ways
1 Full cut <br> When there is an emergency in any area of ​​the building, the system shall implement an emergency alarm broadcast to the accident floor and adjacent floors in accordance with the requirements of the “Design Specificationâ€. At this time, the other floors do not make an emergency broadcast, but stop playing normal background music and are in a mute state. This "switching" mode is called "full cut" in the form of simultaneously switching the background music and the low level signal of the emergency alarm broadcast source with the signal before the corresponding alarm floor amplifier. In this way, there are two sets of signal sources in the device, and other intermediate devices such as power amplifiers and speakers are “compatibleâ€, but the signal input terminal of the power amplifier needs to have a priority port input.
2 Switching between related floors <br> The difference between this method and the “full cut†method is that in case of emergency, the emergency alarm broadcast only broadcasts broadcasts to the accident floor and adjacent floors, while other floors do not require special requirements. In the case of broadcasting, background music is played as usual. In this way, the main equipment (including signal source, preamplifier, power amplifier) ​​basically has two sets, namely: a set of background music, a set of emergency alarm broadcast, in which the speakers in the system are shared. However, relatively speaking, emergency alarm broadcasting equipment is rarely used, and the constant voltage power amplifier therein can satisfy the broadcasting power of 3-4 layers. The principle of "switching" in this way is to link the accident layer and the adjacent layer through the control module of the fire-fighting equipment, so that the emergency alarm broadcasting device is activated, and the emergency alarm broadcast is performed to the relevant floor.
In addition, when the system is designed, install a power amplifier on each floor (this method is suitable for each floor area is large, the number of installed speakers meets the power of the power amplifier), in this case, It can meet the "compatibility" mode in which the main equipment is shared, and can also play background music on the floor that does not require emergency alarm broadcasting. The switching principle is as follows: the fire protection device linkages the control module of the relevant floor, so that the signal of the emergency alarm broadcast is switched to the input end of the power amplifier of the relevant floor (using the priority input socket or the long open contact with the relay), thereby completing the "switching" "work.
Second, the form of switching
1. Switching method of electronic priority line <br> It is convenient to switch by using this device with priority jack. Especially in places where the floor is not high and the function is simple, switching between background music and emergency alarm broadcasting is a very common switching method. This device with priority socket function is available in most professional public address devices. Due to different equipment design ideas of domestic and foreign manufacturers, some priority ports are designed on the preamplifier, and some are designed to be used in the final stage of the power amplifier or combined amplifier signal input terminal, and some manufacturers have specially designed different signal priorities. The output selector has four independent signal channels, each of which is output in a priority order of 1-4 depending on the emergency, so that various types of signal insertion and switching functions can be solved. However, if the form of signal insertion is many and the requirements for switching are complicated, simply switching with the priority port can not meet the requirements.
2, switch type strong switching method <br> This method is to use the relay's normally open, normally closed contact to achieve switching. Generally speaking, the background music signal is transmitted via the normally closed contact of the relay, and when the emergency alarm broadcast is required, the relay operates after receiving the command, and the normally open contact is connected to the emergency alarm broadcast. This way is any kind of switching method is inseparable. In order to meet the switching mode in different situations, the complicated project adopts the method of sharing the above two switching modes to complete the complex "switching" requirement.
3. Manual switching <br> The manual switching function is indispensable in every system. Manual switching refers to manual switching when it is necessary to broadcast to other floors or areas during the specified automatic switching.
Third, the choice of system switching equipment <br> The system "switching" is inseparable from the "switching" command, and the "switching" command is undoubtedly from the fire control equipment, currently there are two options on the switching device, one is The background music system equipment is equipped with a set of emergency alarm broadcast control equipment, and its working principle is shown in Fig. 1.
As soon as the emergency alarm device receives the emergency signal of the accident floor transmitted by the fire-fighting equipment, the adjacent layer (ie +/- layer) is activated by the matrix to activate the relay of the corresponding floor, so that the emergency alarm signal is alarmed according to the adjacent layer. The principle will play out the emergency alarm signal.
The other is to make full use of the control module of the linkage control system of the fire control device to perform the switching. The control module is an execution device of the linkage control of the fire control device bus system. When the fire alarm is in a logical control relationship, the external control device is activated or deactivated by the action of the relay contact in the module. The control module thus realizes the signal switching between the accident floor and the adjacent layer, which is convenient and economical.
In the fire control system, basically, each floor is used as a partition, and the corresponding control module is installed in each partition. As an emergency alarm broadcast, the start of the control layer of the accident layer and the adjacent layer is controlled by fire control. Equipment to complete. By adopting this method, the emergency alarm control device matched in the background music device can be omitted, and the switching of the background music and the alarm broadcast can be completed.
Fourth, the control device in the switching process <br> In the background music and emergency alarm broadcast switching process, the key problem is to control the work of the corresponding equipment. Whether it is an emergency alarm switching device that is mated with background music or a module that uses a fire control device, the devices to be controlled include:
(1) In the power supply part, when the background music system is at night or on holidays, the power system of the device automatically turns on the power that has been turned off and supplies power to the system after receiving the fire control signal, so that the system is in working state.
(2) Issue a linkage command to the emergency alarm broadcast source to enable it to transmit an emergency alarm broadcast signal to the system.
(3) Switch the signal channels of the accident floor and adjacent floors.
In the process of system design, the choice of “switching†mode of background music and emergency alarm broadcast signal should first be considered from the function and requirements of the building or building, and it should be chosen with the idea of ​​reliability, simplicity and low investment. Scientific attitude.
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