Wire spring jacks vs standard jacks in aviation plugs

The jacks used in aviation plugs fall into two families: standard (general) jacks and wire spring jacks. The two differ in production process, and their performance differs accordingly.

How the wire spring jack is built

In a wire spring jack, a number of elastic, gold- or silver-plated wires are arranged along the straight busbars of a single-leaf reverse hyperboloid and form an angle with the straight busbars of the inner sleeve. When the pin is inserted into the hole, it is contacted by several independent spring wires, which form multiple independent current paths, and the wires deform elastically in both the radial and axial directions.

Reliability and contact resistance

Because the jack is made from multiple spring wires, even if a few wires break the spring hole can still form a useful current path. This gives high insertion and removal force, high reliability and small contact resistance. Contact resistance is not only small but also stable: when the pin is inserted, the elastic wires surround it tightly and make a multi-line contact, so one pair of pinholes behaves like several pairs of standard pins and holes in parallel. This greatly improves contact reliability while keeping plugging force small, wear of the contact parts low and plugging life long. In strongly oscillating, impact-loaded environments the electrical contact remains highly reliable. Typical applications include aerospace, medical equipment, electronic communications, intelligent equipment, automotive electronic testing and weapons systems.

The standard (general) jack

A standard jack is simpler in workmanship than a wire spring jack. Its contacts are plated with gold, silver, tin or nickel, and the diameter range is 0.5 mm to 20 mm. It is used mainly in military, medical and computer connectors, where it provides good contact and a dependable number of mating cycles, helping to ensure product quality and durability.