J

jack (connector) A connecting device into which a plug can be inserted to make circuit connections.

jacket (component) A rubber or synthetic covering applied over the primary insulation, braids, shields, cable components, or over the cable itself.

jackscrew (connector/accessory) A mechanical fastening device (one or two per connector) used to draw mating connectors together and to separate them. Includes a threaded screw on one connector that engages a threaded bushing on the mating connector.

JAN specification (abbreviation) Joint Army-Navy specification.

Jones block (general) Jones is the name of the originator of barrier blocks. The term "Jones block" is sometimes erroneously used to describe terminal strips and barrier blocks in general.

jumper (printed circuit) A direct electrical connection, which is not a portion of the conductive pattern, between two points on a printed circuit.

Jumper Cable - A short flat cable interconnecting two wiring boards or devices.