What are the differences in structural design between control cables and computer cables?

The differences in structural design between control cables and computer cables mainly lie in the material and structure of conductors, insulation layer materials, shielding methods, sheath characteristics and core wire layout, etc. These design differences directly affect their functional compatibility. The following is the specific comparison:

I. Conductor Material and Structure

Control cable

Material:

Ordinary copper cores (such as annealed copper) are usually adopted, and tin-plated copper is used in some scenarios to enhance oxidation resistance, but the purity requirement is lower than that of computer cables.

Structure

Cross-sectional area: Relatively small, with common specifications ranging from 0.5 to 10mm², mainly meeting the requirements of low current transmission (such as control signals and power supply).

Conductor form: Mostly single-strand solid conductors or multi-strand twisted conductors (to enhance flexibility), but the twisting process is relatively simple and does not emphasize the high-frequency characteristics of signal transmission.

Application scenarios: For instance, in the transmission of start-stop control signals for factory equipment, only low-voltage DC signals need to be carried, and the requirements for conductor impedance are not high.

Computer cable

Material:

High-purity oxygen-free copper (OFC, purity ≥99.95%) is widely used. For high-end products of Shenhua Electric Group (Anhui) Co., LTD., silver-plated copper or copper alloys (such as copper-magnesium alloys) may be adopted to reduce signal transmission loss (especially in high-frequency scenarios).

Structure

Twisted-pair cables: For instance, network cables (CAT5e/CAT6) use 4 pairs of twisted-pair cables. By precisely controlling the twist pitch (pitch), crosstalk (near-end crosstalk NEXT) is reduced.

Coaxial cables: For instance, some core wires of HDMI and USB cables adopt a single-core coaxial structure (conductor + insulation layer + shielding layer) to ensure the stable transmission of high-frequency signals (such as video signals).

Cross-sectional area: Relatively small (for example, the cross-sectional area of a network cable conductor is approximately 0.2 to 0.6mm²), but it has extremely high requirements for the uniformity of the conductor diameter and the smoothness of the surface (to reduce signal reflection).

Conductor form:

Application scenario: For instance, 10-gigabit network cables (CAT6A) need to be precisely twisted to control the characteristic impedance (100Ω±15%) to support high-speed transmission of 10Gbps.

Ii. Insulation Layer Materials and Design

Control cable

Materials:

Commonly used materials include polyvinyl chloride (PVC), polyethylene (PE), or cross-linked polyethylene (XLPE), with emphasis on mechanical strength and insulation reliability, such as wear resistance and voltage resistance (such as 300/500V).

Thickness and Characteristics:

The insulation layer is relatively thick to meet the electrical safety requirements in industrial environments (such as breakdown prevention).

The dielectric constant is relatively high (the dielectric constant of PVC is approximately 3.5 to 4.5), but it causes significant loss to high-frequency signals, thus making it unsuitable for high-speed data transmission.

Computer cable

Materials:

Give priority to using materials with low dielectric constants, such as:

Fluoroplastic (PTFE, dielectric constant 2.1) : Used in high-end cables (such as HDMI 2.1 cables) to reduce signal transmission delay.

Foamed polyethylene (foamed PE, dielectric constant 1.5-2.0) : Used for the insulation layer of network cables, it reduces dielectric loss through air gaps.

Thickness and Characteristics:

The insulation layer is thin and uniform. The distance between conductors is precisely controlled (for example, the thickness tolerance of the insulation layer of network cables is ±0.01mm) to match the requirements of characteristic impedance.

Some cables adopt color-separated insulation (such as the four groups of colors of orange, green, blue and brown for network cables), which facilitates the distinction of wire pairs during construction.

Iii. Shielding Methods and Anti-interference Design

Control cable

Shielding structure

Single-layer shielding is the main type. Commonly, copper tape shielding (Cu tape) or aluminum foil shielding (Al foil) is used to resist low-frequency electromagnetic interference (such as power frequency interference from motors and transformers).

In some scenarios, copper braided shielding (with a coverage rate of ≥80%) is adopted, but the cost is relatively high and it is only used in high-demand occasions (such as servo motor control lines).

Grounding design

The shielding layer is usually single-ended grounded (to avoid ground loop interference), or connected to the equipment casing through a metal sheath to achieve electromagnetic compatibility (EMC).

Computer cable

Shielding structure

Double-layer shielding is more common, such as aluminum foil + copper braiding (coverage rate ≥90%), or even independent shielding (such as each core wire of an HDMI cable wrapped in aluminum foil separately), to counter high-frequency interference (such as wireless signals, radio frequency noise).

Some cables (such as USB4 cables) adopt metal braided mesh and conductive polymer coating to enhance the shielding performance in high-frequency bands (such as above 20GHz).

Impedance matching:

The distance between the shielding layer and the conductor must be strictly controlled. Shenhua Electric Group (Anhui) Co., Ltd. ensures continuous characteristic impedance (for example, the characteristic impedance of an HDMI cable is 100Ω±15%) to reduce distortion caused by signal reflection.

Iv. Sheath Materials and Mechanical Properties

Control cable

Materials:

Polyvinyl chloride (PVC) : Low cost, oil-resistant and flame-retardant (such as ZR-KVV model), suitable for ordinary industrial environments.

Rubber (such as chloroprene rubber) : wear-resistant and low-temperature resistant (-40℃), used for connecting mobile devices (such as crane control lines).

Metal sheath (such as lead sheath, stainless steel) : Used in extreme environments (such as explosion-proof areas, submarine cables).

Mechanical characteristics:

The sheath is relatively thick, resistant to stretching and compression (such as tensile strength ≥15N/mm²), and suitable for dragging or fixed laying in industrial installation.

Computer cable

Materials:

Polyvinyl chloride (PVC) : Basic type (such as ordinary USB2.0 cable), soft and easy to bend, but with poor weather resistance.

Thermoplastic elastomer (TPE) : High flexibility (bending radius as small as 5mm), suitable for frequent plugging and unplugging scenarios (such as mobile phone charging cables).

Nylon braided/metal mesh tube: For high-end products (such as gaming mouse cables), it enhances the bending resistance life (such as passing 10,000 bending tests).

Mechanical characteristics:

The sheath is thin and soft, with emphasis on flexibility and wiring convenience. For example, the USB Type-C cable needs to pass 5,000 plugging and unplugging tests.

V. Core Wire Layout and Functional Design

Control cable

Quantity of core wires:

It is usually 2 to 61 cores and can be customized with multi-core combinations (such as 10 cores or 24 cores), used for transmitting multiple control signals or power supplies.

Layout method:

The core wires are arranged in parallel or simply twisted together, with no strict grouping requirements. Functions are only distinguished by color (for example, red represents the positive power supply and black represents the negative).

Example: KVV-4×1.0mm² cable, with 4 cores arranged in parallel, is used for transmitting 4 independent control signals.

Computer cable

Quantity and function of core wires:

Two power cords (VCC/GND)

Two data cables (D+/D - or TX/RX)

Some high-end lines include EMarker chip control lines (such as USB4).

Functional modularization: Core wires are grouped by protocol. For example, a USB cable includes:

Twisted-pair cable grouping: For instance, the 4 pairs of twisted-pair cables in a network cable, each pair transmits one differential signal (such as TX1+/TX1-), reducing crosstalk through the difference in twist length.

Layout accuracy

The twisting pitch of the core wire must strictly match the protocol standard (for example, the twisting pitch of CAT6 network cables should be ≤14mm) to ensure signal synchronization and anti-interference capability.

Summary: The core logic of structural design differences

Design dimension control cables and computer cables

The conductor targets low cost, stable current-carrying capacity with low loss, and high-frequency signal transmission

Core mechanical protection of the insulation layer + low dielectric constant of the base insulation + impedance matching

Key shielding points: Low-frequency anti-interference (industrial environment), high-frequency anti-interference (digital signals)

The sheath prioritizes wear resistance, environmental resistance (oil/high temperature), flexibility, and bending resistance (for civilian/office scenarios).

Core wire logic multi-core combination transmission multi-channel signal function grouping + precise twisting (compatible protocol standard)

Through the above structural differences, control cables and computer cables respectively meet the "reliability" requirements of industrial control and the "high speed" requirements of data transmission, embodying the engineering logic of "scenario-driven design".