Binding post

A binding post is a connector commonly used on electronic test equipment to terminate (attach) a single wire or test lead. They are also found on loudspeakers and audio amplifiers as well as other electrical equipment. A binding post is a connector commonly used on electronic test equipment to terminate (attach) a single wire or test lead. They are also found on loudspeakers and audio amplifiers as well as other electrical equipment. A binding post contains a central threaded metal rod and a cap that screws down on that rod. Binding posts slowly evolved from 19th century general purpose fasteners into 20th century electrical binding posts. Examples of binding posts used during 19th century are telegraph key and blasting machine devices. Caps are commonly insulated with plastic and color-coded: red commonly means an active or positive terminal; black indicates an inactive (reference or return) or negative terminal; and green indicates an earth (ground) terminal. Caps during the 19th century were typically bare metal until synthetic plastic, such as Bakelite, became available in early 20th century. During the late 1940s, General Radio created a new binding post that had a jack in a cap. Today it is commonly known as a 'five-way' or 'universal' binding post, which allows many types of connection methods: Even so-called isolated binding posts are typically not sufficiently isolated to protect users from coming into contact with their metal parts carrying voltage. As such they are not suitable to be used for carrying dangerous voltages (cf. extra-low voltage). On several types of equipment it has been becoming common to no longer use the traditional binding posts, but safety banana jacks. The universal property of binding posts is lost here, since safety banana jacks can only be used with traditional and safety banana plugs.