Complete List of Electrical Connector Parts

Electrical connectors join two or more conductors together in a continuous and electrically conductive path. Regardless of their means of connection, application, or function, all electrical connectors have one objective: to provide a path of electrical conduction between the conductors being joined.

Connector Terminology and Anatomy

Gender- The gender of a connector designates if it plugs in or is plugged into. Connectors that plug in are designated as plugs, or ‘male.’ Connectors that have things plugged into them are jack connectors and designated as ‘female.’

Polarity/Keying- Most connectors can only be connected in one orientation. This trait is known as polarity. Connectors that have some means of preventing them from being wrongly connected have been ‘polarized,’ or ‘keyed.’

Contact- The contacts are the metal parts that touch each other in the connection, forming an electrical connection. Contacts can be soiled or oxidized and require occasional cleaning or replacement.

Pitch- The distance between the center of one contact and the center of the next. Families of contacts may look similar, but differ in pitch, requiring you to be careful when purchasing mating connectors to ensure the pitch is correct.

Mating cycles- Connecting and disconnecting connectors wears them out, giving them a lifespan referred to as mating cycles. A USB connector may have a lifespan of tens of thousands of mating cycles, while a board to board connector inside consumer electronics may have a lifespan of only tens of mating cycles.

Mount- Refers to several different things; how a connector is mounted in use, (panel mount, free-hanging, board mount) what the angle of the connector is relative to its attachment (straight or right angle) or how it is mechanically attached (solder tab, surface mount, through hole).

Strain relief- When a connector mounts to a board cable, the electrical connections tend to be somewhat fragile. Strain relief is usually provided to transfer any forces acting on that connector to a more mechanically sound object.

Connector shell- The housing of the main connector.

Pins and Sockets- Plug and socket connectors are made up of a male plug (with pin contacts) and female socket (with socket contacts) of matching shape and number of pins/sockets.

USB Connectors

USB (Universal Serial Bus) is a common interface that allows for communication between devices and a hose controller, such as a personal computer. USBs are used to connect various different devices, like keyboards, mice, printers, scanners, and media devices. USB connectors come is two different types, host and peripheral. In the USB standard, there is a difference between the two. However, all USB connectors share certain traits.

• Polarization: A USB connector can only be inserted one way.
• Four contacts: All USB connectors have at least four contacts. Some have five, and USB 3.0 may have even more.
• USB connectors are shielded, such that a metal shell that is not part of the electrical circuit is provided.
• Robust power connection: Power pins need to connect before data pins, to avoid trying to power the device over data lines. USB connectors are designed with this in mind.
• Molded strain relief: USB cables have plastic over-molding at the connector to prevent strain on the cable that could damage the connections.

USB Types

• USB-A: A standard connector type, comes in male plug and female socket. The female socket is typically found on computers, entertainment hubs, or any device that will have peripherals plugged into it. Peripherals have male plug connectors on them.
• USB-B: Another standard for peripheral devices, USB-B is bulkier, but more robust, and typically used in applications where size is not an issue.
• USB Mini: The first attempt to reduce the size of USB connections for devices like MP3 players and cellphones. However, USB Mini has a poor mating cycle lifetime.
• USB Micro: Released in 2007, meant to replace USB Mini as the connection-type for handheld devices. Like other USB connections, it has a male plug on cables and female socket on devices.
• USB-C: The newest design of USB connector, featuring a 24-contact pin design and a rotationally symmetrical connector.

Audio Connectors

Audio connectors are electrical connectors, that, as their name implies, transmit audio signals from one destination to another. The two most common designs are phono or “phone” type connectors and RCA connectors.

• “Phone” Type Connectors

                Phono connectors come in three sizes, ¼” (6.35mm), ⅛” (3.5mm), and 2.5mm. ¼” tip-sleeve (TS) jack connectors are used in audio and music, such as on electric guitars and amplifiers. ⅛ ” tip-ring-sleeve jacks (TRS) are common as the connector for headphones or audio input signals on MP3 players and computers. Texas Instruments graphing calculators include a 2.5mm tip-ring-ring-sleeve (TRRS) connector for a serial programming connector. Tip-sleeve connector types are not designed to carry power, and the lack of shielding makes the bad at carrying high-speed data.

• RCA Connectors

                RCA connectors have been used in home stereos for decades, ever since they were introduced in the 1940s for phonographs. Consisting of multiple connectors designated red, yellow, and white by their plastic shells, RCA connectors have been supplanted by HDMI in the audio-visual realm, but their ubiquity means they will not be obsolete for some time.

HDMI Connectors

HDMI (High Definition Multimedia Interface) is an audio/video interface that transmits both video and audio data. HDMI connectors come in male plugs and female sockets, with a 19-pin design arranged in two rows. HDMI connectors are used in Blu-ray and DVD players, digital cameras, personal computers, and video game consoles.

D-Sub

First introduced by Cannon in 1952, a D-Sub connector contains two or more parallel rows of pins or sockets (depending on the gender of the connector) surrounded by a D-shaped metal shield that provides mechanical support, ensures orientation, and screens against electromagnetic interference.

Fiber Optic

An alternative to the metal wires that other connectors use, fiber optic cables use flexible and transparent fibers made from silica or plastic slightly thicker than human hair. These fibers transmit light from one end to the other and can transmit data over longer distances and at higher bandwidths than electrical cables.

Power

Many connectors carry power as well as data, but some are specifically used to provide power to connected devices. These connectors come in several subtypes.

• Barrel connector: Barrel connectors are found on low-cost consumer electronics that plug into wall power via bulky AC wall adapters.
• Molex connector: Used by computer hard drives, optical drives, and other internal peripherals. Molex connectors can carry up to 11 amps per pin and are good for devices with high power requirements. They are also unique in that the female connector is technically on the cable, with the male connector inside a plastic shell that the cable plugs into.
• IEC connector: A generalized component name for a particular item, in this case PC power supplies. Like Molex connectors, IEC connector\s have their female connectors on the cable, and male connectors on the device.

MIL-SPEC

MIL-SPEC refers specifically to electrical and fiber-optic connectors used by the United States Department of Defense and various armed forces. Originally developed in the 1930s for the demands of military service, MIL-SPEC connectors consist of male plugs and female sockets like other connectors, but are designed and manufactured to endure harsh environment conditions and the shock and disruption that can be caused in battle (for example, 100 g’s worth of shock with no electrical discontinuity).