Good to know: What is the jack plug?

31.10.2018

The jack plug is something that all of us have probably used at some point. In its most common form, it is used for connecting headphones, for example. In today’s article, we explain what else you can do with it and what different designs there are.

The history of the handle

The jack plug, as we know it today, evolved from the plugs that were used at the end of the 20th century. 19. and beginning 20th century were used in manual telephone exchanges. This makes the evolutionary line of jack plugs one of the oldest in plug technology.

The typical area of application for the jack plug is the transmission of audio and video signals. In the past, it was also common to use the jack plug to supply power to small electronic devices. However, this is no longer used due to the increased risk of short circuits.

Design of the jack plug

In its simplest form, the plug consists of an elongated shaft and a spherical, rounded tip, which is separated by an insulating ring.

The jack plug has two main shapes, which differ in their shaft diameter: the plug with a diameter of 3.5 mm and the plug with a diameter of 6.3 mm. The mini jack with a diameter of 3.5 mm is usually found on portable devices such as smartphones or sound cards. The post connector has a diameter of 6.35 mm and is used in almost all devices in the music industry. There are also various other plugs with diameters of 2.5 mm, 4.4 mm, 5.2 mm and 7.1 mm, for example. However, these are rarely found and do not play a major role.

Special applications of the jack plug

In addition to the different shaft diameters, the jack plugs also differ in the number of poles. These include the mono plug with two poles, the three-pole stereo plug and the mono plug with balanced connection and three poles.

A special feature is the four-pole stereo plug with additional function. A total of four contacts are available with this plug. This stereo plug is used for connecting headsets, but also for transmitting multi-channel sound, audio, video and USB signals.