日期：2019年11月07日 / 人气： / 来源：未知
The concept of strong current is that compared with weak current, there is generally no specific limit of voltage and current.
People's habits are divided into strong electricity (electricity) and weak electricity (information). , there are both connection and difference in general heavy current processing object is energy (electricity), its characteristic is high voltage, large current, large power, low frequency, the main concern is to reduce loss, improve efficiency, the processing of weak current object mainly is information, the information transmission and control, its characteristic is low voltage, small current, power, high frequency and the main consideration is the effect of information transmission problems, such as fidelity of information transmission, speed, breadth, and reliability. Generally speaking, the weak current project includes the television project, the communication project, the fire protection project, the security project, the image project and so on and serves for the above project the synthesis wiring project. Weak electricity is for strong electricity. Strong electric =(380/220), high voltage regardless.
In power system, 36 v called safe voltage, under voltage 3 kv voltages below, 3 kv voltage as high pressure, the line is called distribution circuit of the power supply to the user directly, such as user voltage of 380/220 v, is known as the low voltage power distribution line, is the family is decorated in the high voltage (because it is the highest voltage in the family use). Strong current generally means alternating current voltage in 24V above. Such as the electric light in the family, socket, voltage in 110V~220V. Domestic electric lighting lamps, electric water heater, heater, refrigerator, television, air conditioning, audio equipment and other electrical appliances are strong electric equipment.
The intelligent system consists of building equipment monitoring system, safety prevention system, communication network system, information network system, automatic fire alarm and fire linkage system, etc. It is an integrated system with the purpose of centralized monitoring, control and management. All sorts of data collect inside the home, control, management and communication control or the line such as network system, call intelligent line (namely the weak current that the family decorates in saying). Weak current is to point to direct current circuit commonly or audio, video line, network line, telephone line, dc voltage is in 24V commonly less than. The signal input of telephone, computer and TV set in household electrical appliances (cable TV line), audio equipment (output line) and other electrical appliances are weak current electrical equipment.
Weak current is to point to direct current circuit commonly or audio, video line, network line, telephone line, direct current voltage is in commonly 32V less than. The signal input of telephone, computer and TV in household appliances (cable TV line), audio equipment (output line) and other electrical appliances are weak current electrical equipment.
There are mainly two types of weak current in buildings: one is the safety voltage level stipulated by the state and the control of weak voltage and other low-voltage electric energy, which can be divided into ac and dc, such as 24V dc control power supply, or emergency lighting backup power supply. Another is the information source that contains information such as voice, image, data, etc., such as telephone, television, computer information.
The building weak current on narrow sense basically is to point to: security prevent (monitor, perimeter alarm, parking lot), fire protection (electrical part), floor control and network are integrated wiring and audio system.
Strong electricity and weak electricity from the concept, generally easy to distinguish, the main difference is the use of different. Strong electricity is used as a power source, weak electricity is used for information transmission. They differ roughly as follows:
Different ac frequency
The frequency of strong electricity is generally 50Hz(Hertz), called "power frequency", which means the frequency of industrial electricity: the frequency of weak electricity is often high frequency or ultra-high frequency, in KHz(KHz), MHz(MHz) meter.
Different transmission mode
Strong power is transmitted by transmission line, weak power transmission can be divided into wired and wireless. Radio transmits in electromagnetic waves.
Power, voltage and current are different
Strong voltage is generally more than 36V, weak voltage is generally less than 36V.
There are mainly two types of weak electricity in buildings: one is the state specified safety voltage level and control voltage and other low voltage electric energy, there are ac and dc points, such as 24V dc control power supply, or emergency lighting backup power supply. Another is the information source that contains information such as voice, image, data, etc., such as telephone, television, computer information.
Functions and applications
Electric power application can be divided into strong and weak electric power according to the strength of electric power transmission. Building and building complex electricity generally refers to ac 220V50Hz and above strong electricity. It mainly provides people with electric energy, which can be converted into other energy, such as air conditioning electricity, lighting electricity, power electricity and so on.
There are mainly two types of weak electricity in intelligent buildings, one is the safety voltage level and control voltage and other low voltage electric energy stipulated by the state, which can be divided into ac and dc, ac under 36V, dc under 24V, such as 24V dc control power supply, or emergency lighting backup power supply. Another is the information source that contains information such as voice, image, data, etc., such as telephone, television, computer information.
People are used to calling weak current technology weak current technology. It can be seen that the basic meaning of weak current technology of intelligent building is still weak current technology in the original sense. However, with the rapid development of modern weak current technology, the application of weak current technology in intelligent buildings is more and more extensive. Generally, weak current system engineering refers to the second class of applications.
Main include: 1, television signal engineering, such as television monitoring system, cable television. 2. Communication engineering, such as telephone. 3. Intelligent fire protection engineering. 4. Sound reinforcement and sound engineering, such as music broadcasting in the middle background of the community and music broadcasting in the background of the building. 5, integrated wiring project, mainly used for computer network. With the rapid development of computer technology, the software and hardware functions of the rapid and powerful, a variety of weak current system engineering and computer technology perfect combination, so that the previous classification is no longer as clear as before. The mutual integration of various projects is system integration.
Common weak current system working voltage includes: 24VAC, 16.5vac, 12VDC, sometimes 220VAC is also weak current system, for example, some by the camera working voltage is 220VAC, we can not put them into the strong current system. Weak current system is mainly aimed at buildings, including buildings, communities, airports, docks, railways, highways and so on.
Common weak current systems include: Closed-circuit television monitoring system, anti-theft alarm system, entrance guard system, electronic patrol system, parking management system, visual intercom, home intelligent system and security system, background music system, LED display system, plasma splicing screen area, DLP systems, systems, building automation systems, lightning protection and grounding system, paging intercom and professional intercom, weak current pipeline system, UPS uninterruptible power supply system, computer system, integrated wiring system, computer local area network (LAN) system, property management system, multi-functional conference room system, cable television system, satellite television system, satellite communication system, fire fighting System, telephone communication system, hotel management system, video vod system, human resource management system and so on.
Why are strong and weak currents separated
Distinguish between strong and weak electricity is because between strong and weak electricity can total slot, otherwise will interfere with the weak electricity information transmission, affect the use of TV, computer, telephone in the home, even may cause a fire.
Then, in the construction of strong and weak electricity, how to avoid the interference of weak electricity, and the specific points for attention in the line layout, mainly include the following five points:
Strong and weak electricity should be separated
In decorating, circuit wiring changes the most taboo thing, it is to receive all lines together. So in the construction of the transformation circuit, the national standard is: strong and weak electricity to separate wire, prohibit condominium total box, and the parallel distance between the strong and weak electricity line must not be less than 30cm. But consider actual situation (contemporary apartment did not accomplish the condition of 30cm above), exquisite a few decorate a company to be able to put apart 15 centimeters at least, assure put apart distance. This distance also ensures that strong current will not interfere with weak current.
Separate the weak wires
Different weak wire also can cause signal interference together, in order to avoid this kind of circumstance, the weak wire such as telephone line, network line, TV line must be worn separately when line operation, cannot share same tube.
Wiring in front and wiring in back
No matter be strong current or weak current, when wiring construction, should follow the rule that installs conduit to traverse again first, do so is to prevent to appear the phenomenon that cannot twitch, undertake maintenance to change a line conveniently later.
The same pipe line should not be too much
In the strong and weak electric circuit layout, the number of required tubes should be based on the number of conductors and change, in principle, a tube can not exceed four wires, must not have a wire to fill up the space inside the tube. The utilization rate that resembles general bend tube is between 40 and 50, linear tube can a few taller, it is advisable to be between 50 and 60.
Avoid breaking right Angle bend
In construction go through a line, encounter the circumstance that line needs turn, must not appear broken type turn right Angle, such likelihood can affect signal intensity, and cause the case that the wire cannot pass through, accordingly, had better use big bend, metal horn will pass the case that joins a wire.