Phone connector (audio)
The phone connector is cylindrical in shape, with a grooved tip to retain it. In its original audio configuration, it typically has two, three, four or, occasionally, five contacts. Modern phone connectors are available in three standard sizes. In the UK, the terms jack plug and jack socket are commonly used for the respective male and female phone connectors.
About Phone connector (audio) in brief
The phone connector was invented for use in telephone switchboards in the 19th century and is still widely used. The phone connector is cylindrical in shape, with a grooved tip to retain it. In its original audio configuration, it typically has two, three, four or, occasionally, five contacts. Modern phone connectors are available in three standard sizes. The 3. 5 mm or miniature size was originally designed in the 1950s as two-conductor connectors for earpieces on transistor radios, and remains a standard still used today. In the UK, the terms jack plug and jack socket are commonly used for the respective male and female phone connectors. The terms phone plug and phone jack are sometimes used to refer to different genders of phone connectors, but are also sometimes used for RJ11 and older telephone plugs and the corresponding jacks that connect wired telephones to wall outlets. It is not to be confused with the similar terms phono plug and phono jack, which refer to RCA connectors common in consumer hi-fi and audiovisual equipment. The current form of the switchboard-plug was patented prior to 1902, when Henry P. Clausen received a patent on an improved design. Several modern designs have descended from those earlier versions: U.S. military versions of the Western Electric plugs were initially specified in Amendment No. 1, MIL-P-642, and included: The 0.5-inch miniature phone jacks.
The 2 5mm or sub-mini sizes were often used on similarly popularized small portable electronics. There is also an EIA standard for 0. 5-pronged connector with both 3 and 2. 5mm miniature sizes. They often appeared next to a 3 5mm microphone jack on early record-offers and used on the microphone control switch-off on portable tape recorders; such machines provided a two-off jack for a remote control on the record player. This roughly half-sized version of the original, popular Sony EFM-117J radio is still used in portable Walkman radios today. It became very popular with Walkman applications in 1979, as unlike earlier transistor radios these devices had no speaker of their own; the usual way to listen to them was to plug in headphones to the speaker. The original 1⁄4 inch version descends from as early as 1877, when the first-ever telephone switchboard was installed at 109 Court Street in Boston in a building owned by Charles Williams, Jr. ; or 1878, when an early commercial manual telephone exchange in New Haven, Connecticut created by George W. Coy. In February 1884, C. E. Scribner was issued US Patent 293,198 for a \”jack-knife\” connector that is the origin of calling the receptacle a ‘jack’”. In the US, a stationary electrical connector is called a jack. By 1950, the two main plug designs were: The 2.5mm sub- mini connector has a diameter of 3.5 mm.