Video Cables (DVI, HDMI)
1. Video Cables Overview
Video cable is a special cable used to transmit video signals, usually composed of a conductor, insulation layer, shielding layer, and outer sheath. Depending on the purpose, it may contain a single-core coaxial structure (such as the SYV series) or a multi-core composite design (such as a composite cable with integrated power supply and signal transmission). Its core function is to ensure that the video signal remains clear and stable during transmission and reduce electromagnetic interference.
2. What are the Types of Video Cables?
1) Classification by Interface Type
VGA: used for analog video transmission and connecting old display devices.
HDMI: supports high-definition digital signals and audio synchronous transmission, divided into standard HDMI (Type A) and Mini-HDMI (Type C).
DVI: divided into DVI-D (pure digital) and DVI-I (digital + analog), supporting single/dual link transmission.
DisplayPort: similar to HDMI, but more commonly used for computer monitors.
BNC/RCA: BNC is mostly used in professional monitoring equipment, and RCA (lotus head) is common in consumer-grade devices.
2) Classification by Cable Structure
Coaxial Cable: Such as SYV50-3, it adopts a multi-layer structure of copper core + insulation layer + aluminum foil shielding + braided mesh, with an impedance of 75Ω, suitable for long-distance high-definition signal transmission.
Composite Cable: Integrates video cable and power cable to simplify wiring complexity.
3. What are the Structure and Materials of Video Cables?
1) Coaxial Cable:
Inner Conductor: Copper core (single core or multi-strand twisted), the diameter affects the transmission performance (such as 75-3, 75-5, and other specifications).
Shielding Layer: Aluminum foil + copper mesh braiding, double shielding enhances anti-interference ability.
Sheath: PVC or PU material, providing wear-resistant and anti-bending protection.
2) Composite Cable: The power cable is integrated in parallel on the basis of the video cable, and the integrated design is realized through the common mold extrusion process.
4. What are the Technical Parameters of Video Cables?
1) Transmission Distance:
VGA: conventional 45 meters, up to 200 meters after expansion.
DVI: 15 meters for digital signal and only 5 meters for analog signal.
Coaxial Cable (such as SYV75-5): up to 300 meters.
2) Signal Quality: A high-stranded shielding layer can reduce signal attenuation, and bandwidth performance determines the supported resolution (such as SYV50-3 supports ultra-high definition).
5. Where are Video Cables Used?
Security Monitoring: A coaxial cable is used to connect the camera to the control center to ensure the stability of real-time images.
Broadcasting and Television: HDMI and DisplayPort are used for the interconnection of high-definition audio and video equipment.
Industry and Intelligent Systems: composite cables support multi-signal synchronous transmission in the fields of intelligent transportation, medical treatment, etc.
6. Manufacturing Process and Quality Requirements of Video Cables
Connector Process: BNC/RCA adopts crimping or welding, and aviation head connectors are widely used due to their high reliability and plug-in life.
Testing Standards: electrical performance tests (such as impedance matching, and signal attenuation) and mechanical strength tests (such as bending more than 100,000 times) are required.