Electrical connector
In addition to the classes mentioned above, connectors are characterised by their pinout, method of connection, materials, size, contact resistance, insulation, mechanical durability, ingress protection, lifetime (number of cycles), and ease of use.
It is usually desirable for a connector to be easy to identify visually, rapid to assemble, inexpensive, and require only simple tooling.
In some cases an equipment manufacturer might choose a connector specifically because it is not compatible with those from other sources, allowing control of what may be connected.
No single connector has all the ideal properties for every application; the proliferation of types is a result of the diverse yet specific requirements of manufacturers.
Properties important to conductor materials are contact resistance, conductivity, mechanical strength, formability, and resilience.
For example, copper alloys have favorable mechanical properties for electrodes, but are hard to solder and prone to corrosion.
[7]: 15 Connector bodies for high-temperature use, such as thermocouples or associated with large incandescent lamps, may be made of fired ceramic material.
Insecure mounting of connectors (primarily chassis-mounted) can contribute significantly to the risk of failure, especially when subjected to extreme shock or vibration.
[11] Fretting (so-called dynamic corrosion) is a common failure mode in electrical connectors that have not been specifically designed to prevent it, especially in those that are frequently mated and de-mated.
The M12 connector, specified in IEC 61076-2-101, is a circular electrical plug/receptacle pair with 12mm OD mating threads, used in NMEA 2000, DeviceNet, IO-Link, some kinds of Industrial Ethernet, etc.
[18] In some cases, this backshell provides a hermetic seal, or some degree of ingress protection, through the use of grommets, O-rings, or potting.
Depending on application requirements, housings with locking mechanisms may be tested under various environmental simulations that include physical shock and vibration, water spray, dust, etc.
[24] To deliver ensured signal stability in extreme environments, traditional pin and socket design may become inadequate.
The internal wires that form the hyperboloid structure are usually anchored at each end by bending the tip into a groove or notch in the housing.
[25] They are also significantly more expensive than traditional pin and socket contacts, which has limited their uptake since their invention in the 1920s by Wilhelm Harold Frederick.
During the following decades, the connectors steadily gained popularity, and are still used for medical, industrial, military, aerospace, and rail applications (particularly trains in Europe).
[28] Pogo pin or spring loaded connectors are commonly used in consumer and industrial products, where mechanical resilience and ease of use are priorities.
Because they rely on spring pressure, not friction, they can be more durable and less damaging than traditional pin and socket design, leading to their use in in-circuit testing.
They have a high number of contact points, which provides a more electrically reliable connection than traditional pin and socket connectors.
When working with multi-pin connectors, it is helpful to have a pinout diagram to identify the wire or circuit node connected to each pin.
[6]: 56 These connectors includes mating with both male and female aspects, involving complementary paired identical parts each containing both protrusions and indentations.
The movable (less fixed) connector is classified as a plug (denoted P),[37] designed to attach to a wire, cable or removable electrical assembly.
Soldered joints in connectors are robust and reliable if executed correctly, but are usually slower to make than crimped connections.
To make these connections reliably on a production line, special tools accurately control the forces applied during assembly.
Power conductors carrying more than a few amperes are more reliably terminated with other means, though "hot tap" press-on connectors find some use in automotive applications for additions to existing wiring.
Binding posts are a single-wire connection method, where stripped wire is screwed or clamped to a metal electrode.
They can be used to join multiple conductors,[43] to connect wires to a printed circuit board, or to terminate a cable into a plug or socket.
Some disadvantages are that connecting wires is more difficult than simply plugging in a cable, and screw terminals are generally not very well protected from contact with persons or foreign conducting materials.
One type of terminal block accepts wires that are prepared only by stripping a short length of insulation from the end.
Electrical contact is made by the flat surface of the ring or spade, while mechanically they are attached by passing a screw or bolt through them.
