Power applications can be divided into two categories, strong and weak, according to the strength of power transmission. Electricity for buildings and buildings generally refers to the exchange of strong electricity at 220V 50Hz and above. Mainly provide people with electricity and energy, and convert electrical energy into other energy sources, such as air-conditioning power, lighting power, power power, etc. There are two main types of weak electricity in smart buildings. One is the country's specified safe voltage level and control voltage and other low-voltage electrical energy, which is divided into AC and DC, below AC 36V, below DC 24V, such as 24V DC control power supply, or emergency Lighting backup power. The other type is information sources that contain information such as voice, images, and data, such as telephone, television, and computer information.
Introduction
People are accustomed to the weak electricity technology as weak electricity technology. It can be seen that the basic meaning of the weak technology of intelligent buildings is still weak current technology in the original sense. However, with the rapid development of modern high-tech weak electronics, the application of weak current technology in smart buildings is becoming more and more widespread. Such as intelligent fire control systems, monitoring systems, computer networks, building automation, smart broadcasts and so on. The degree of application of weak current technology determines the degree of intelligence in smart buildings.
Commonly used weak systems for buildings mainly include the following types:
(1) The telephone communication system realizes the communication function of the telephone (including the three types of facsimile machines and video telephones), the star topology, and the use of three types (or more) of unshielded twisted pairs, and the frequency of the transmission signal is within the audio range.
(2) The computer LAN system is the network foundation for office automation and various data transmission; star topology; using five types (or more) of unshielded twisted pair, the transmission of digital signals, the transmission rate of up to 100Mb / s or more.
(3) The music/broadcast system plays music through loudspeakers installed in the field (such as shopping malls, stations, restaurants, rooms, corridors, etc.), and can broadcast to the site through a microphone; multiple bus structures; transmission is output by the power amplifier The constant-pressure (eg, 120V/120Ω) audio signal is used to drive the live speaker, and the transmission line uses a copper-core insulated wire.
(4) The cable television signal distribution system evenly distributes cable television signals to all user points in the building; it uses splitters and distributors to allocate signals. In order to reduce signal distortion and attenuation, the signal quality of each user point is up to the specifications. Requirements, the wiring is a tree structure, and different with the form of the building and the distribution of user points; using 75Ω RF coaxial cable, transmission of multiple RF signals.
(5) The security monitoring system monitors and anomalies alarms at various entrances and exits of buildings and alarms through abnormal cameras, anti-theft detectors, etc. installed on site; the transmission of video signals adopts a star structure and uses video coaxial Cable; control signal transmission adopts bus structure and uses copper core insulated cable.
(6) Fire alarm system This system consists of three parts: a fire alarm and fire linkage system, a fire radio system, and a fire alarm intercom system.
The fire alarm and fire linkage system monitors the on-site situation through fire detectors and manual alarm devices installed in various places in the building. When there is an alarm signal, according to the received signal, the linkage is made according to a preset program. Equipment to control the spread of fire, its signal transmission adopts multi-channel bus structure, but for the transmission of linkage control signals of important fire-fighting equipment (such as fire pump, spray pump, positive pressure fan, exhaust fan, etc.), sometimes star type Structure, signal transmission using copper core insulated cable (some products require the use of twisted pair).
The fire radio system is used to direct the on-site personnel to safely evacuate in the event of a fire. Multiple bus structures are used, and copper core insulated conductors are used for signal transmission (the system can be used with music/radio systems).
The fire alarm intercom system is used to direct firefighters at the scene to perform fire extinguishing work. Star-type and bus-type structures are used, and shielded cables are used for signal transmission.
(7) The entrance and exit control system uses computers, smart card door locks, card readers and other devices to set, monitor, control and record the status of each entrance and exit, to achieve unified management of entrances and exits of buildings, to ensure the safety of buildings, and their topological structure. Transmission media varies from product to product.
(8) The parking lot charge management system senses the entrance and exit of the vehicle through an induction coil installed under the entry and exit grounds, and realizes the charge and control of the opening and closing of the electric railing through a manual/semi-automatic/automatic charge management system. The system wiring is limited to the entrance and exit of the building yard. Each entrance and exit is controlled by a controller. The controller can work independently or can be networked with a superior management computer. The wiring structure and transmission medium vary from product to product.
(9) The building automation system passes various detection and execution devices connected to the site controller, and various environmental parameters inside and outside the building and various equipments in the building (such as air conditioning, water supply and drainage, lighting, power supply and distribution, elevators, etc. The working status of the system is tested, monitored and controlled, and each field controller is connected through a computer network to rationally allocate and manage resources and equipment within the building to achieve comfort, convenience, economy, and reliability. So far, there are no international standards for building automation systems, and the communication protocols used by different manufacturers' products are different. The topology and transmission media of the field bus and control bus are also different. The following will briefly introduce Lon Works technology and BA Cnet technology that are currently accepted and adopted by the international community.
In addition, there are video conference systems, screen display systems, sound reinforcement systems, patrol systems, building intercom systems, and three-meter (water, electricity, gas) automatic meter reading systems. Buildings with different functions need different weak current systems.
Introduction
People are accustomed to the weak electricity technology as weak electricity technology. It can be seen that the basic meaning of the weak technology of intelligent buildings is still weak current technology in the original sense. However, with the rapid development of modern high-tech weak electronics, the application of weak current technology in smart buildings is becoming more and more widespread. Such as intelligent fire control systems, monitoring systems, computer networks, building automation, smart broadcasts and so on. The degree of application of weak current technology determines the degree of intelligence in smart buildings.
Commonly used weak systems for buildings mainly include the following types:
(1) The telephone communication system realizes the communication function of the telephone (including the three types of facsimile machines and video telephones), the star topology, and the use of three types (or more) of unshielded twisted pairs, and the frequency of the transmission signal is within the audio range.
(2) The computer LAN system is the network foundation for office automation and various data transmission; star topology; using five types (or more) of unshielded twisted pair, the transmission of digital signals, the transmission rate of up to 100Mb / s or more.
(3) The music/broadcast system plays music through loudspeakers installed in the field (such as shopping malls, stations, restaurants, rooms, corridors, etc.), and can broadcast to the site through a microphone; multiple bus structures; transmission is output by the power amplifier The constant-pressure (eg, 120V/120Ω) audio signal is used to drive the live speaker, and the transmission line uses a copper-core insulated wire.
(4) The cable television signal distribution system evenly distributes cable television signals to all user points in the building; it uses splitters and distributors to allocate signals. In order to reduce signal distortion and attenuation, the signal quality of each user point is up to the specifications. Requirements, the wiring is a tree structure, and different with the form of the building and the distribution of user points; using 75Ω RF coaxial cable, transmission of multiple RF signals.
(5) The security monitoring system monitors and anomalies alarms at various entrances and exits of buildings and alarms through abnormal cameras, anti-theft detectors, etc. installed on site; the transmission of video signals adopts a star structure and uses video coaxial Cable; control signal transmission adopts bus structure and uses copper core insulated cable.
(6) Fire alarm system This system consists of three parts: a fire alarm and fire linkage system, a fire radio system, and a fire alarm intercom system.
The fire alarm and fire linkage system monitors the on-site situation through fire detectors and manual alarm devices installed in various places in the building. When there is an alarm signal, according to the received signal, the linkage is made according to a preset program. Equipment to control the spread of fire, its signal transmission adopts multi-channel bus structure, but for the transmission of linkage control signals of important fire-fighting equipment (such as fire pump, spray pump, positive pressure fan, exhaust fan, etc.), sometimes star type Structure, signal transmission using copper core insulated cable (some products require the use of twisted pair).
The fire radio system is used to direct the on-site personnel to safely evacuate in the event of a fire. Multiple bus structures are used, and copper core insulated conductors are used for signal transmission (the system can be used with music/radio systems).
The fire alarm intercom system is used to direct firefighters at the scene to perform fire extinguishing work. Star-type and bus-type structures are used, and shielded cables are used for signal transmission.
(7) The entrance and exit control system uses computers, smart card door locks, card readers and other devices to set, monitor, control and record the status of each entrance and exit, to achieve unified management of entrances and exits of buildings, to ensure the safety of buildings, and their topological structure. Transmission media varies from product to product.
(8) The parking lot charge management system senses the entrance and exit of the vehicle through an induction coil installed under the entry and exit grounds, and realizes the charge and control of the opening and closing of the electric railing through a manual/semi-automatic/automatic charge management system. The system wiring is limited to the entrance and exit of the building yard. Each entrance and exit is controlled by a controller. The controller can work independently or can be networked with a superior management computer. The wiring structure and transmission medium vary from product to product.
(9) The building automation system passes various detection and execution devices connected to the site controller, and various environmental parameters inside and outside the building and various equipments in the building (such as air conditioning, water supply and drainage, lighting, power supply and distribution, elevators, etc. The working status of the system is tested, monitored and controlled, and each field controller is connected through a computer network to rationally allocate and manage resources and equipment within the building to achieve comfort, convenience, economy, and reliability. So far, there are no international standards for building automation systems, and the communication protocols used by different manufacturers' products are different. The topology and transmission media of the field bus and control bus are also different. The following will briefly introduce Lon Works technology and BA Cnet technology that are currently accepted and adopted by the international community.
In addition, there are video conference systems, screen display systems, sound reinforcement systems, patrol systems, building intercom systems, and three-meter (water, electricity, gas) automatic meter reading systems. Buildings with different functions need different weak current systems.
Stevia Rebaudioside M
JINING USP INTERNATIONAL CO.,LTD. , https://www.uspintl.com