Autumn and Winter Check-in Challenge Wire and cable1. Power cord
The power cord is the wire that transmits the current, and the general current transmission method is point-to-point transmissionThe structure of the power cord is not very complicated, and its structure is composed of an outer sheath, an inner sheath, and a conductor.
1：rvv
The full name is copper core polyvinyl chloride insulated polyvinyl chloride sheathed flexible cable. The RVV line has a round appearance, a large number of cores, and there are twists between the two cores. R stands for flexible wire and the letter V stands for insulating polyvinyl chloride (PVC). The main purpose of RVV cable: used in electrical appliances, instruments, electronic equipment and automation devices and other power lines, control lines and signal transmission lines that do not need to be shielded.
Commonly used RVV cable models are:rvv2*0.5,rvv2*0.75,rvv2*1.0，rvv3*0.5, rvv3*0.75,rvv3*1.0 example: rvv2*25 - 2 means 2 cores, 25 represents the cross-sectional area of a wire core (in units).
2：rvvp
The full name is copper core polyvinyl chloride insulated polyvinyl chloride shielded flexible cable. It is suitable for communication, audio, broadcasting, audio system, anti-theft alarm system, intelligent automation system, automatic meter reading system, fire protection system and other anti-interference line connection, efficient and safe transmission data cable. The letter R stands for flexible wire, the letter V stands for insulating polyvinyl chloride (PVC), and the letter P stands for shielding. RVVP can be used specifically for control lines in monitoring systems, access control systems, building video intercom systems, and building control systems.
The difference between RVVP and RVV wire
r denotes flexible wire and cable;
v The first V stands for polyvinyl chloride (PVC) insulation;
v The second V denotes the polyvinyl chloride (PVC) sheath;
p denotes shielded wires and cables;
RVVP stands for PVC insulated PVC sheathed shielded wire and cable;
RVV stands for PVC insulated PVC sheathed flexible wire.
1. The structure is different.
RVV wires and cables are two or more RV wires with a sheath. RVVP is a kind of soft conductor PVC insulated wire, with a shield and PVC sheath.
2. Different uses.
RVV is suitable for control signal transmission lines, electrical equipment, instruments, automation equipment, security and anti-theft alarm systems, high-rise building intercom systems, household lighting connection lines, etc.
RVVP is suitable for communication, audio, broadcasting, audio system, burglar alarm system, intelligent automation system, automatic meter reading system, fire protection system and other anti-interference line connection, efficient and safe transmission data cable.
3. **Different.
The advantage of RVVP is that it minimizes the impact of external signal interference, which is higher than that of RVV wires.
4. Different colors.
RVV is available in black and white, and RVVP is only available in black.
3：rvsp
RVSP is an ordinary shielded copper conductor polyvinyl chloride insulated stranded wire. It is used in those occasions where the signal transmitted is very demanding, and the effect is better than that of the RVS series in shielding external interference, and the cost is also higher than that of the RVS.
RVVSP is a copper conductor PVC insulated shielded PVC sheathed stranded flexible cable. It is suitable for semi-industrial environments and industrial environments, industrial and mining enterprises, medical buildings, and when the transmission bandwidth is greater than 500MHz, it may need to support 25G, 5G, 10GBASE-T, etc., or when high shielding interference signals are required.
4 bv
This is a copper single core wire, often referred to as a hard wire for power supply, lighting, ordinary sockets, air conditioning sockets.
Advantages: strong tensile strength, strong corrosion resistance, weak fatigue resistance, high rejection rate. Disadvantages: Inconvenient crimping.
5 bvr
The single-core wire formed by twisting multiple strands of copper wire, compared with the BV wire, it is called a flexible wire, which is a special wire in the electrical cabinet, and most people call it a secondary wire. BVR wires are mainly flexible wires made of copper core PVC insulation, and are often used in occasions where soft wiring is required for fixing wiring. For example, when the home improvement wiring is fixed, you can see its figure, in order to facilitate a better distinction in the installation, the general BVR wire can be divided into seven colors, namely red, yellow, green, blue, black, white, yellow-green (ground wire). Since BVR is a soft structure, most of its applications are in soft environments.
6 rvb
RVB is commonly known as parallel wire RVB flat soft wire. RVB is a two-core flat copper core polyethylene insulated flexible wire, flat flexible wire without sheath structure, often used as an internal installation wire RVB has two components, and there is no outer sheath RVB is a flat parallel wire without sheath, usually known as red and black wire. It is mainly used in household appliances, small power tools, instrumentation, broadcasting and electric lighting lines, etc.
7rvvb
RVVB is a copper-core PVC insulated and sheathed flat power cord, which is suitable for home appliances, lighting fixtures, security monitoring cables, etc. The purpose of RVVB and RVB is the same, the difference is that RVB is a flat unsheathed flexible wire, while RVVB is a flat sheathed flexible wire, so RVVB has an extra layer of sheath than RVB.
8rvs
RVS wire is also called "twisted multi-strand soft wire", also known as "flower wire", at present, this kind of wire is mostly used in fireproof and fire-fighting equipment, so it is also called "fire-fighting wire".The main material of this wire is copper core polyvinyl chloride. The letter "R" means soft wire, the letter "V" means polyvinyl chloride, which means its material, and the letter "S" means "twisted pair"!
RVS wires are generally used in alternating current, but they are also common in direct current. When used for alternating current, the system voltage shall not exceed the rated voltage of the cable;When used for direct current, the system voltage must not exceed 15 times. In both DC and AC circuits, GB T8734 should be followed3-2012 standard. It is a cable wound from two copper insulated wires, which is widely used in the field of home appliances and fire protection.
According to the color of the RVS line, there is also a standard access method: its double white core is used for connecting the lamp head, its red and blue core is used for fire protection and alarm, the most important red and white core is generally connected to the radio and ** line, and the red and black core is only used for connecting the broadcast line.
9 wdz-byj、wdz-ryj、wdz-yjv
A low-smoke halogen-free cable is a type of cable that does not produce toxic fumes and corrosive gases when burned. These cables typically use halogen-free polymers such as cross-linked polyethylene (XLPE) as insulation and halogen-free flame retardants such as magnesium oxide or magnesium hydroxide as flame retardants. Therefore, LSZH cables have excellent environmental performance and efficient flame retardant performance.
What kind of cable is a low-smoke halogen-free power cable?As the name suggests: low smoke, i.e. reduces the production of harmful objects when burning;Halogen is a toxic gas for the human body, and halogen-free is the release of no toxic gas, usually for the cable when it encounters fire.
Low-smoke halogen-free power cables can also be called environmentally friendly cables, and most of the low-smoke halogen-free cables are used in hospitals and places with strict requirements for environmental sanitation.
Second, the ** line
* wire is used to transmit ** signal, is used to transmit ** baseband analog signal is a kind of coaxial cable. **The wire generally has two impedances of 75 ohms and 50 ohms, and can also be divided into -3, -5, -7, -9 and other models according to the coarse subdivision.
*Common sense of cable purchase.
We should choose the best coaxial cable required according to the site environment and transmission distance, for example: the transmission distance is far away can choose to use optical cable transmission.
* Coaxial cable in the process of transmitting ** signal will be due to the material and specification of the cable, the distance of the transmission distance, environmental interference and other factors lead to the signal attenuation in the transmission process, the transmission distance of the 64 series is 150m, the transmission distance of the 96 series is 300m, the transmission distance of the 128 series is 380 meters, and the transmission distance of the 144 series is 500 meters.
When we use the best coaxial cable, we must use the best coaxial cable that meets the relevant national standards and regulations.
*The line is divided into two types: SYV and SYWV according to the different materials.
1 syv
Refers to the coaxial cable insulated by solid polyethylene, and the national standard code is RF cable - also known as "** cable". Generally, the ** line refers to TV cable, which can also be used as a cable for surveillance cameras in the field of security.
Below are the parameters of the General Line.
75 represents the impedance, and the 3 and 5 in the back represent its insulation outer diameter (3mm 5mm).
SYV medium S--- coaxial RF cable, Y--- polyethylene, V --- polyvinyl chloride.
SYV75-3 transmission works well within 300 meters.
SYV75-5 transmission works better at up to 800 meters.
75-3 Transmission distance 100 meters.
75-5 transmission distance 300 meters.
75-7 transmission distance 500--800 meters.
75-9 transmission distance 1000---1500 meters.
75-12 transmission distance 2000---3500 meters.
2 sywv
The full name of SYWV is polyethylene physical foam insulated coaxial cable, which is usually used for satellite TV transmission, cable TV transmission, long-distance video intercom system special cable, suitable for radio frequency propagation. The characteristic impedance of the SYWV is also 75 ohms and the core diameter is 10mm, the insulation layer is 80% nitrogen bubbles and 20% polyethylene filling.
Main Differences Between SYV and SYWV:
The main difference between SYV and SYWV is that the physical properties of the insulation layer and the diameter of the core are different, resulting in different transmission attenuation of the two cables. Generally speaking, the transmission attenuation of SYWV is smaller than that of SYV, and the transmission distance is longer than that of SYV.
There are many specifications of SYV and SYWV, the common ones are SYV75-3, SYV75-5, SYWV75-5, SYWV75-7, etc., where 75 represents the impedance of 75 ohms, and the following number represents the thickness of the wire. The thicker the wire, the longer the transmission distance.
3vga
VGA is an analog signal** line that is most commonly used in the connection of a computer to a monitor. The full name of VGA is Video Graphics Array.
The VGA cable consists of 15 pins and is divided into three rows and five columns. Each row represents the red, green, and blue color signals, and each column represents horizontal synchronization, vertical synchronization, ground and other functions. With these pins, the computer's graphic signal can be converted into an analog signal that can be recognized by the monitor.
The advantage of the VGA cable is that it is compatible and is supported by almost all computers and monitors. The disadvantage is that the signal quality is affected by interference and loss, and the resolution and refresh rate are limited.
4 rg
RG RG is a physically expanded polyethylene insulated access network cable that is commonly used for the transmission of data, analog signals, etc. in a vulnerability** image transmission or a hybrid fiber coaxial cable network (HFC network). RG stands for Radio Guide or Radio Grade.
RG can be divided into two basic types according to their application: baseband coaxial cable and broadband coaxial cable. Baseband coaxial cable is used in computer networks and other occasions, and its shielding layer is made of copper mesh, with a characteristic impedance of 50 ohms (such as RG-8, RG-58, etc.). Broadband coaxial cables are used in television systems, for example, and their shielding layer is usually stamped with aluminum, with a characteristic impedance of 75 ohms (such as RG-59, etc.).
There are many specifications of RG, the common ones are RG-6, RG-8, RG-11, RG-58, RG-59, RG-62, etc., where the number after RG indicates different structures and performance. Generally speaking, the larger the number, the thicker the wire diameter, the farther the transmission distance, and the smaller the attenuation.
* line is the abbreviation of audio cable (audio cable) and ** line (video cable) in home audio, also called audio ** line. It is mainly used for audio equipment, home film and television equipment audio and signal connection.
*The wire usually consists of three coaxial cables, which are red, white, and yellow. Red and white represent the audio signal for the left and right channels, and yellow represents the composite signal. Through these cables, the audio and signal of devices such as VCD can be transmitted to devices such as TVs or amplifiers.
* The advantage of the line is that it is simple and easy to use, and the cost is low. The disadvantage is that the signal quality is average, and it cannot transmit high-definition ** signals.
6hdmi
HDMI is a high-definition video and audio transmission cable, not an optical fiber. Advantages: It can transmit high-definition images and audio at the same time, unlike VGA, which can only transmit SD images, and cannot transmit audio signals at the same time.
HDMI cable is a connection cable used to transmit high-definition multi-*** signals, and it is a special cable for audio-visual equipment and TV to choose high-definition multi-*** transmission rate. The Chinese name of HDMI cable is copper core. Another feature of HDMI cables is: a dedicated cable with high definition and multiple transmission rates. HDMI cables deliver high-quality uncompressed HD** and multi-channel audio data at speeds up to 5Gbps. At the same time, there is no need to perform digital-to-analog or analog-to-digital conversion before signal transmission, which can ensure the highest quality audio and video signal transmission. Another feature of HDMI cable is: a dedicated cable with high definition and multi** transmission rate.
Three, network cable, network cable, optical fiber.
1 network cable
Also known as twisted pair. Because the network cable is composed of two pairs of twisted four pairs of twisted pairs and a plastic outer jacket. Therefore, the network cable is also known as a twisted pair. The network cable is mainly used for channel link connection of no more than 100 meters between terminal equipment and access layer switches.
Divided by performance
Network cables are classified according to the ISO IEC 11801 standard, and commonly used network cables can be divided into Category 5 cables, Category 5 cables, Category 6 cables, Category 6 cables, and Category 7 twisted pair cables.
Category 5 lines:It has been replaced by Category 5e cable for data transmission, with a maximum transmission rate of 100Mbps, mainly used in 10BASE-T and 100BASE-T local area networks.
Superclass line:It has the characteristics of small crosstalk and low attenuation, which is higher than that of the five types of linesNear-end crosstalk power andand has a higher attenuation crosstalk ratio, smaller time delay difference, the performance has been greatly improved compared with the Category 5 line, and the maximum transmission rate is 1000Mbps data transmission, which is the lowest entry threshold in quasi-Gigabit Ethernet.
Category 6 lines:Compared with Category 5e, Category 6 improves the performance of crosstalk and return loss, and the transmission performance is much higher than that of Category 5e, making it most suitable for Gigabit Ethernet applications.
CAT6e Line:The Category 6 cable is an upgraded version of the Category 6 cable, which is mainly used in 10 Gigabit Ethernet, with a transmission frequency of 500MHz and a maximum transmission rate of 10Gbps, which has been greatly improved in terms of external crosstalk.
Category 7 lines:The starting point of Category 7 cable is shielded twisted pair, with a transmission frequency of at least 600MHz and a transmission rate of up to 10Gbps, which is used for 10 Gigabit Ethernet.
There are also two main connection methods: straight-through cables and crossover cables.
a) Both ends of the water lens of the straight-through cable follow the 568A or 568B standard, each set of wires of the twisted pair is one-to-one corresponding at both ends, and the same color is consistent in the corresponding slots of the water crystal heads at both ends. It is mainly used in the uplink port of the switch (or hub) to connect the ordinary port of the switch (or hub) or the common port of the switch to connect the computer network card.
b) One end of the crystal head of the crossover cable follows 568A, and the other end adopts the 568B standard, that is, the A crystal head corresponds to the B crystal head, and the A crystal head corresponds to the B crystal head, which is mainly used in the switch (or hub) ordinary port to connect to the switch (or hub) ordinary port or network card connection card.
2 fibers
Optical fiber is a soft, slender solid glass medium, which is mainly composed of three parts: coating, core and cladding, and is a light conduction tool that uses the principle of total reflection of light in glass or plastic fiber. The conduction loss of light in optical fibers is much lower than that of electricity in wires, and optical fibers are used for information transmission over long distances.
There are two main categories of optical fibers:
Single-mode fiber: Generally, optical fiber patch cords are indicated in yellow, and connectors and protective sleeves are blueThe transmission distance is long. Single-mode optical fiber optical fiber only transmits a mode of light wave, with small dispersion and large bandwidth, and is generally suitable for long-distance transmission within 100km.
Multi-mode fiber: Generally, fiber patch cords are represented by orange, some are gray, and the connector and protective sleeve are beige or blackThe transmission distance is shorter. Multimode optical fiber can transmit multiple modes of light source, which will produce light dispersion, and the transmission distance is short, generally within 2km.
Fourth, elevator cable:
It is made of coaxial cable (generally SYV-75-3 + TVVB 2X10、 syv-75-4 + tvvb 2x1.0) Combined, other models can be customized if needed. There are reinforced steel wire and nylon rope inside, and fiber tissue, and the outer sheath is made of super soft PVC material, which effectively increases tensile strength and flexibility. It has the characteristics of long service life, stable transmission model and high definition. It is mainly used for TV monitoring wires that walk with elevators, including ** wires, power cords, and steel wires.
1tvvb
TVVB flat cable is a special elevator cable with high flame retardancy, excellent mechanical properties, heat resistance, heat aging resistance, heating deformation resistance, low temperature characteristics (flexibility at low temperatures), and electrical insulation. Its structural composition comprises a cable conductor, an insulating layer covering the conductor, a low-dielectric layer arranged on the outer side of the insulating layer, and a shielding layer arranged on the outer side of the low-dielectric layer. The following is an introduction to the advantages of TVVB flat cables.
2. Elevator composite cable
A composite cable is a composite of two or more cables of the same or different types, usually consisting of a signal cable and one or more power cables. Composite cables are usually used in situations where power and signal need to be transmitted at the same time, such as surveillance cameras, televisions, stereos, and other equipment. Usually, the outer layer of the composite thread is covered with a protective holster.
The signal line of the composite cable generally uses coaxial cable and twisted pair cable, and the power line adopts parallel cable and round cable. The shielding of signal lines can be done in different ways, such as copper wire screens, aluminum foil screens, etc. The power cord can also be composed of multiple strands to increase the conductive area, reduce the line loss, and improve the safety of the cable.
5. Audio cables.
Generally, it refers to the audio line, which is a shielded input and output balanced signal line, which is usually used to connect the audio pre-amp and the power amplifier, and the equalization line. It is used to transmit signals and is the carrier of signals. There are two very different ways of transmitting signals. The cable itself can transmit a signal, or the cable can transmit energy from an external signal source.
1 audio cable
An audio cable, or audio cable for short, is a wire used to transmit sound. The high-quality audio cable on the market is mainly made of gold-plated, silver, and copper oxide. It is generally used to transmit unamplified audio signals, such as computers, VCDs, and radio amplifiers. There is basically no need to consider the audio cables when wiring, because the audio source equipment and the amplifier are often placed together, and these cables are very short, and the post-configuration is sufficient.
The main specifications of the audio cable are: audio cable 2 012. Audio cable 71c, audio cable 2 03²
2** line
A wire is a telecommunications device that uses a wire (also known as a cable) to connect a phone with a telecommunications bureau or wireless access point, that is, it is used to establish a line to transmit voice, data and signals. Wires can be divided into wired lines and wireless lines, according to different transmissions, wired lines are mainly divided into ordinary wired lines, optical fiber lines, coaxial cables, etc.