Best Practices for the Selection of Rugged Connectors

Ensuring that data, signals, or power flows between different components in a system requires connectors that link essential equipment with each other. For example, connectors route a microphone’s output to an amplifier. Similarly, linking power supplies to radar and other communication systems, and sensors to data processors to relay analog or digital signals, are just two of the many ways connectors find uses in everyday operations.

Connector technology continues to evolve along with the use cases for these essential parts. Although the military is expected to continue to be one of the biggest markets for connectors in the future, demand is not restricted to this sector alone. Globally, the rugged connector market is forecast to grow at a steady clip of 3.5% compounded annual growth until 2030, according to market research from Lucintel.

Advances in connector technology

Connector technology has a storied history, starting with a circular connector commissioned for the Douglas DC-1 aircraft in the 1930s. James Cannon of ITT Cannon developed the product. Since then, connector technology—and the wide ranges in which these products are available—has evolved to meet industry demand. Tracking these new advances in connector technology gives a peek into the many industrial use cases for connectors.

Made for high temperatures

Military operations in extreme climate conditions or space missions require connectors that can not only take severe cold and heat, but also withstand rapid cycling between two dramatically different temperature states. Advances in connector technology have enabled material composition that tolerates such conditions without compromising performance.

Lightweight materials

Weight has always mattered in aerospace applications, where every ounce affects aerodynamics and fuel requirements. Now, the topic is under renewed research as connectors find use in autonomous driving systems, electronic vehicles (EVs), robotics, and industrial automation. Large loads and battery life are incompatible, which means connectors are being made with lightweight composites to meet engineering and design constraints.

Modular designs

Infrastructure needs change frequently, and today’s solutions can become obsolete by tomorrow. In such cases, an entire rip-and-replace approach to components is wasteful and expensive. Modular connectors address this problem by delivering the ability to swap parts out selectively. Users can also mix and match configurations for greater flexibility to meet custom needs.

Miniaturization of components

The adoption of sensors in a variety of use cases, including automotive systems, is driving the need for connectors in a wider range of sizes. Miniaturization will help design engineers develop compact circuitry that can fit into tighter spaces, which is becoming necessary in a variety of applications from the military to aerospace and beyond.

The rise of rugged connectors

The growth in the demand for rugged connector technology likely coincides with the rise of connected machines in the industry. Industrial IoT necessitates data collection from sensors that might have to withstand a variety of severe conditions.

While it is easy to imagine that data centers are the hubs for computing and real-time information, data-driven decisions underpin most modern-day operations. The military, railways, aerospace, oil and gas, agriculture, factory automation, and robotics all depend on real-time data—field operational and environmental conditions are far from ideal. Equipment might have to tolerate extreme temperatures, dirt, and windstorms without losing signal integrity and speed. All hardware equipment—down to the connectors used for communications, networking, data, and power transmission in the field—needs to be ruggedized.

Exacting specifications for rugged connectors

Not all rugged connectors are the same; a variety of operating conditions dictates connector characteristics. A few best practices before choosing a connector include:

• The end-use application: It is important to consider whether the connector will be used in medical settings—in which case it might have to withstand sterilization—in a military war zone, or underwater. ITT Cannon’s CA/5015 connectors, for example, are rugged interconnects designed for the most demanding applications. Originally developed for commercial aviation, these connectors are now widely used in the military, transportation, industrial, and heavy equipment sectors.
• Weight of final system: Weight can affect the performance of a connector simply by increasing pressure on the ends and causing wear and tear. Weight also matters for battery-powered systems like robots or semi-autonomous machines, as the power needed to lug extra weight can shorten battery life. Weight also determines the material of the shell casing for the connectors. Housings made of lightweight aluminum decreases the final weight.
• Cybersecurity and the need for stealth: Military operations especially call for systems that can avoid detection by the enemy. This requires specialty shielding techniques in rugged connectors. Full-metal backshells preserve electronic signals and prevent electromagnetic interference. ITT Cannon’s CA/5015 series offers an extensive range of backshells with connections using individual wires or jacket cables in shielded or unshielded versions.
• Connector shape: Connectors come in a variety of shapes, including circular, rectangular, blade, or modular, to name just a few. The circular connectors are the most common variation to transmit power, signal, or data. It is easier to align pins during mating, and the circular design provides compact sealing. Circular connectors have many pins or contacts arranged in a specific grid pattern to accommodate the various kinds of connections needed, such as power or data.

Kinds of locking systems

Once the connector links two systems, it needs to be locked into place so the connection does not come loose and affect the transmission of power, data, or signal quality. The most common locking systems include a screw-like threaded coupling mechanism to hold connections firmly in place, and push-pull where connections lock together when pushed and release when pulled. Connectors like the TBF10SL-4PS-B from ITT Cannon (Figure 1) have a bayonet mechanism, which has pins and grooves that lock into place with a twist.

Of these, the threaded coupling mechanism offers superior vibration resistance, which is especially useful in aerospace and military applications.

Figure 1: ITT Cannon's TBF10SL-4PS-B rugged circular connector uses a bayonet locking mechanism. (Image Source: ITT Cannon, LLC)

Mating cycles

A mating cycle is the process by which the plug and receptacle connect and disconnect. Repeated plugging and unplugging of equipment can cause wear and tear on leads in the connector. As a result, connectors are rated by the number of mating cycles they can withstand. A reliable unit can handle hundreds of such couplings without significant damage.

Ingress protection

The International Electrotechnical Commission (IEC) instituted a series of ratings to gauge the effectiveness with which electrical equipment can ward off hazards like dirt and water. These ratings are especially important in military operations where equipment must function in severe conditions like dust and hailstorms, and where performance is tested routinely. Repeated exposure to abrading sand or water can corrode electronic leads, lead to poor signal transmission, and create barriers that prevent strong connections. Extreme environments typically demand connectors have a rating of IP68 or higher.

These stipulations and a host of others are ones that military specification (MIL-SPEC) connectors pass. Circular connectors typically embrace MIL-SPEC standards like MIL-DT-5015, which the ITT Cannon’s CA/5015 connectors meet (Figure 2). These circular connectors function well across a wide range of temperature conditions from -55°C to +200°C.

Figure 2: ITT Cannon's CA/5015 connectors are rugged and versatile solutions for demanding environments (Image Source: ITT Cannon, LLC)

ITT Cannon’s CA/5015 connectors are ideal for defense, rail, aerospace, and industrial applications, as well as factory automation and robotics. The series offers five different polarizations through which users can ensure that the components are mated in the right orientation to prevent damaging circuits. The connectors come in a variety of plating options: cadmium, TinZinc (J plating), ZincNickelBlueGen, ZincCobaltBlack, and nickel compositions. The connectors also comply with RoHS (Restriction of Hazardous Substances), a European Union regulation that oversees the use of certain hazardous materials in electrical and electronic equipment.

Conclusion

The vital functioning of electronic and electrical equipment in severe environments is becoming increasingly necessary across various sectors, including discrete manufacturing, oil and gas plants, solar and wind technologies, and industrial operations such as mining. Given that many of today’s industrial and military operations run on real-time data, computing hardware and sensors need frontline-tested equipment to support a robust field infrastructure. Rugged connectors such as the CA/5015 Connector Series from ITT Cannon play a key role in carrying out this mission of data-driven operations in all sectors.