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Copper Connectors Overview

Jun 6, 2025

Overview

This lecture covers common types of copper connectors used in networking, telecommunications, and computer systems, describing their features, uses, and key differences.

RJ11 and RJ45 Connectors

  • RJ11 is a 6-position, 2-conductor connector (6P2C) mainly for analog phones and DSL connections.
  • RJ14 is similar to RJ11 but uses four conductors.
  • RJ45 is an 8-position, 8-conductor connector used for Ethernet and other network connections.
  • RJ45 is larger than RJ11, which can lead to accidental mismatching when plugging in cables.

F Connector and Coaxial Cables

  • F connectors are used for cable TV and cable modem connections.
  • F connectors have a threaded design for secure attachment and a single copper core for signal transmission.
  • Cable modems using F connectors follow the DOCSIS standard.

Punchdown Blocks and UTP Cables

  • Punchdown blocks are used for quickly terminating many twisted pair wires in large installations.
  • A punchdown tool pushes wires into metal contacts that pierce insulation for electrical connection.

USB Connectors

  • USB 1.1/2.0 use standard A (rectangular) plugs for computers and B (square) plugs for peripherals.
  • Mini B and Micro B connectors are used for smaller devices.
  • USB 3.0 has differently shaped B and Micro B plugs but similar A plug.
  • USB-C is the new universal connector type, supporting multiple protocols (USB, Thunderbolt, HDMI).

Molex Connectors

  • Molex (also called AMP Mate-n-Lock) is a 4-pin connector for internal computer power (fans, drives).
  • Supplies both 12V and 5V power and connects via friction.

Lightning Connectors

  • Apple’s proprietary Lightning connector, used for iPhones and iPads, can be inserted in either orientation.
  • Industry is moving towards USB-C, but some devices still use Lightning.

DB9 and Serial Connectivity

  • DB9 connectors are 9-pin serial interfaces, using the RS232 standard for communication.
  • Still used for connecting to networking equipment console ports for configuration.

Key Terms & Definitions

  • RJ11 — 6-position, 2-conductor modular telephone connector.
  • RJ45 — 8-position, 8-conductor modular connector for Ethernet.
  • F Connector — Threaded coaxial cable connector for TV and cable modems.
  • Punchdown block — Hardware that terminates and organizes multiple twisted-pair cables.
  • USB (Universal Serial Bus) — Standard for connecting peripherals to computers.
  • USB-C — Reversible, versatile connector supporting various protocols and power.
  • Molex connector — 4-pin power connector for internal PC components.
  • Lightning connector — Apple-specific reversible connector for mobile devices.
  • DB9 — 9-pin serial connector, often used for device configuration ports.
  • RS232 — Serial communication standard used by DB9.

Action Items / Next Steps

  • Review connector images and practice identifying RJ11, RJ45, USB, F, and Molex connectors.
  • Read textbook section on copper connectors for deeper understanding.
  • Prepare to identify connectors and their uses in lab exercises.

Full transcript