Electrical Connectors Part Types and Components List - Page 2

Connectors refer to plugs and receptacles that join electrical wiring; they also serve as disconnect points to enable maintenance and repair of the system or an individual cable and/or wire. The components are used to fasten electrical circuits together and maintain conductive paths within IT systems, powerplant systems, voltage regulators, peripheral connections, power inputs, etc.; they are used in practically every industry. This mechanical device integrates an outer sleeve, inner sleeve, and mating pin/s or receptacle/s. Connectors are sorted by their features (gender); “Male” connectors have a center pin feature and contacts, while “Female” connectors are fitted to receive the contacts and pin/s. Connectors are crimped- or soldered-on to the ends of wiring or cable, and can be constructed of a multitude of materials depending on application. They are vulnerable to degradation and corrosion from environmental conditions including vibration, moisture exposure, chemical exposure, pressurization cycles, etc. This category does not describe connectors that are directly relevant to fiber-optic cabling and connection, and accessories.

Connector Identification
Electrical connectors are essential across all industries that utilize electrical wiring; therefore, there is a vast selection of wiring and connector types. Connectors are categorized based on wire size, contact pitch, polarity, voltage type, shielding, etc. In addition, connectors are labeled with letters and numbers to identify its type. The most common identification system (AN) identifies connectors by standard, plug type, class, size, contact arrangement number, contact style, and insert rotation. Wire type can also indicate the necessary connectors and can be found stamped on the conduit and/or at termination points.

Standards
Connectors are held to specific standards set by industry organizations and global governing bodies. Criteria for electrical connectors is set by the following codifications: National Electrical Safety Code (NESC), Canadian/Mexican/National Electric Code (ANCE NMX), American National Standards Institute (ANSI), Council on Large Electrical Systems (CIGRE), Canadian Standards Association & CSA International (CSA Group), Institute of Electrical Electronics Engineers (IEEE), the National Electrical Manufacturers (NEMA), and others.

Associated standards set by the above organizations include but are not limited to:

Military Grade Connectors

Most electrical connectors used for aerospace military and defense applications are set to meet Army/Navy (AN) standards specified by the US military. There are five basic types of Army/Navy (AN) connectors used on aircraft: Class A, Class B, Class C, Class D, and Class K. Class A-D connectors are made of aluminum while Class K is made of steel. Class A is a general-purpose, one-piece back shell connector. A class B back shell is separated into two parts along its length and is used where soldered connectors are readily accessible. Class C describes  pressurized connectors. This type family has inserts that are not removable. They are used on walls or bulkheads of pressurized equipment. Class D connectors are moisture and vibration resistant and integrate a sealing grommet in the back shell. Lastly, Class K connectors are fireproof, and are usually greater in length than other connectors.

Common Connector Types

DC connectors

This type of connector facilitates direct current. They are the most prevalent type of connector, and a variety of DC connectors exist. Connectors for this type of current are commonly utilized for LED lighting, electrical panels, computer systems, XLR connections, and USB connections.      

AC Connectors

AC connectors join electrical wiring that operate using an alternating current supply. AC Connectors are categorized by voltage, phases, and application. The most common types of AC connectors include straight-blade style and twist lock style AC connectors. Prevalent uses for AC connectors and AC wiring include computer monitors, battery packs, vehicle charging cables, etc.

Barrel Connectors

Barrel connectors are power supply connectors. “Male” connectors are referred to as plugs and “Female” connectors are referred to as jacks. There are three main different types of barrel connectors: PCB mount, cable mount, and panel mount.

Molex Connectors

This type of connector is used to carry high current and can be used to supply and connect multiple system circuits. These types of connectors are integrated with hard drives and optical drives.

USB-A

USB-A refers to a “female” receptacle connector type that is prevalently integrated on computers, hubs, HUDs, etc. The mating connector is commonly found on IT accessory components or USB cables; they can also be found mounted on USB memory sticks.

USB-B

USB-B connectors are considered durable and inexpensive. They form easily detachable connections integrated with peripheral devices i.e. Arduino boards. These components are most commonly seen in a board mount or panel mount configuration.

USB-Mini

This connection, like USB-B, is commonly seen on peripheral devices. Its small size enables it to be utilized in external hard drives, cellphones, etc.

USB-Micro

USB-Micro’s are often integrated in cameras, cell phones, charge points, small computers, and the like. They are utilized in USB-OTG conditions and can operate as peripheral connectors or host connectors.       

HDMI Connectors

HDMI connectors are primarily used for digital audio/video data transmission.

RCA Connectors

RCA connectors transmit electric video and audio signals.

SMA Connectors

This type of connector is most commonly used in systems that require connection with an external antenna; they are therefore typically referred to as SMA RF connectors.

RP-SMA connectors are also frequently used for the same application. These connectors can be found integrated with systems utilizing the following technology: Cell, GPS, Bluetooth, etc.

Contact Shape & Assemblies

Contact shapes include circular, rectangular, and coaxial, and can act as splices or terminals. Connector assemblies commonly include the following components to provide contact retention: bolts, nuts, flat washers, lock washers, Belleville washers, belts, etc.

Materials

The materials used to construct electrical connectors greatly depends on the application. Connectors are particularly vulnerable to galvanic corrosion, tension degradation, and damage from moisture. Graphite, copper, aluminum, silicon bronze, galvanized stainless steel, plastic composites, and oxide inhibitors are all common materials used in the build of a connector.

Pins

Contact pins are typically made of bronze that has been coated and dipped in sulfide. Pins are coated in sulfide to protect them from chemicals present in the atmosphere, making them more durable and resistant to corrosion.

Conduits

A conduit is a tube or coating that protects electric wiring and is used in various industries to protect wires and cables. There are four main varieties of conduit: metallic, nonmetallic, rigid, and flexible form.

Aerospace Electrical Connectors

Aircraft connectors need to meet two crucial parameters: they need to be durable despite multiple environmental stressors and provide ease of installation and replacement.  Most connectors used on an aircraft are designed to meet AN standards in order to ensure airworthiness. Electrical connectors are integral to multiple aircraft avionic platforms: IFE systems, flight control systems, glass cockpit systems, sensors, etc.

Commonly utilized aerospace connectors include D-sub type connectors, data bus connectors, coaxial connectors, triaxial connectors, and others.