Audio connectors are used to affix cables to other audio equipment, providing electronic signal transference and grounding protection. Applications for audio connectors can be general purpose, telephone, or microphone. Most audio connectors are for commercial purposes, but some may conform to military specifications.

Video connectors are electrical connectors used for carrying analog or digital data and video signals. They can be used on the end of a cable, as part of an electronics device, or with another device with a video input or output. Some video connectors carry video with a radio frequency (RF) signal and a coax, while others may use a multiconductor cable. Other types of video connectors may also carry audio in addition to video. 

Types of Audio and Video Connectors

Audio Connectors may be plugs, jacks, or combinations, and may have an integral switch.

• Plug type audio connectors are a plug, or male, connector that includes pins that can be inserted into a socket. 
• Jack type audio connectors are a jack, or female, connector that consists of sockets that are aligned to mesh with a pin-type connector. 
• Combination plug and jack connectors are also available. 

System signals for audio connectors can be mono or stereo. 

• Mono, or monophonic, describes a system where all the audio signals are mixed together and routed through a single audio channel. 
• Stereophonic sound systems have two independent audio signal channels.  

Common analog video connectors include:

• Composite video connectors
• S-video connectors
• Component video connectors
• Video graphics array (VGA) video connectors

Composite analog video connectors often consist of one wire that branches with RGA plugs. They are often color-coded red, white, and yellow — with yellow marking the video input. S-video connectors are an improvement over composite connectors, as they send luminance and chrominance as two separate signals. S-video connectors are limited to 480i resolution, also known as standard definition. 

Other analog video connectors include component video and VGA array. Component video connectors also feature RGA plugs. However, component video connectors transmit images in three separate signals (Y, B-Y, R-Y). These video connectors also support progressive scanning, which displays lines of video in order as an interlaced signal provides the odd numbered lines before going back to display the even numbered lines. VGA video connectors are more widely used with computers than televisions and has been the standard since it was designed by IBM in 1988. 

As technology continues to become more digital, a number of digital video connectors are also used. Unlike the wave signal of analog, digital video is sent as a series of 1s and 0s to protect against quality loss. This binary signal makes digital video much easier to distribute to televisions and computers. Common digital video connectors include digital video interface (DVI), and high definition multimedia interface (HDMI). 

Other digital video connectors include DVI and HDMI connectors. DVI connectors were created to replace VGA as the industry switched from analog to digital. These hybrid connectors are commonly used for PC graphics cards and liquid crystal display (LCD) monitors. HDMI connectors are similar to DVI connectors, but with the added benefit of transmitting audio also. HDMI connectors support any television or PC video format, including standard and high definition video and up to eight channels of compressed or uncompressed digital audio. Other types of analog and digital video connectors may also be available.

Specifications

Important parameters for audio and video connectors include conductors and maximum diameter or side dimension. 

• Conductors are the number of conductive elements in a connector that mate with a corresponding element to provide an electrical path. 
• Maximum outer diameter or maximum side dimension of connector does not include dimension of flanges, if applicable.
• Housing materials for audio connectors can be plastic or metal. 
  • Some audio connectors have no housings; they are open frame.
• Mounting options include right angle, panel or flange mount, threaded housing, strain relief, DIN mount, PCB mount, and BNC. 

Contact platings for audio and video connectors can be nickel, gold, or silver. 

Plated contacts are used for a more reliable connection, but do not have to be plated. 

Connections

Terminal connections for audio and video connectors include crimp sleeve and solder cup. 

• Crimp sleeve terminals have electrical connections made using a wire crimp.
• Mechanical compression during the crimping process causes a functional union between the conductor and crimp barrel. 
• In solder cup terminals, the electrical connections are conditionally detachable, and are made by soldering. Connections may be soldered directly, or through use of a solder cup, hollow cylinder, eyelet, or hook.

More information on types of connectors can be found here.

Standards

Audio connectors must adhere to standards to ensure proper design and functionality.

BS 7947—Gives guidance on identification and application of connectors and definitive electrical and mechanical standards, such as IEC 60130 where these exist. To be read in conjunction with BS 6840-11:1994.

IEC 61076-3-112—These connectors are designed based on IEEE standard 1394a-2000 and applicable for high performance serial bus used for consumer audio/video equipment. These connectors consist of fixed and free connectors having four contacts.

MIL—DTL—55116—This specification covers waterproof, polarized, five and six contact electrical connectors (plugs and receptacles) for use in audio frequency circuits at 60 volts maximum potential and 0.5 amperes maximum current.

Video connectors must adhere to standards to ensure proper design and functionality.

IHS Video Standards

NFPA NEC Expert Video

Image Credit: API Technologies