When it comes to reliable system operation, choosing the right connector is key.
The right connector can make your system smaller, lighter, and easier for the user to handle. It's not a place to take shortcuts, as the right connector system can help avoid the high price of recalls, repairs, and lost customers. Conducting adequate research on the connectors and cables must be done at the beginning of a systems design process to produce the optimal design. Follow these 10 steps to research the ideal connector early in the design phase and you can positively impact the design, usability, and cost structure of your entire device.
Defining the electrical voltage and current requirements each contact will carry is the first step to selecting the ideal connectors for your device. You have to ensure that you not only have the right number of contacts, but that the contacts can carry the power demands of your application. The size of the contact and the wire dictate the contact's current-carrying capability. Contact spacing, insulation materials, and the geometry of the insulator used to isolate the contacts dictates the voltage rating.
To ensure that you design in the proper connector, it's important to dig deep and understand how a manufacturer specifies their connectors' current ratings and operating voltages. Their test data should reference a test standard, informing you exactly how their testing was conducted. Not everyone uses the same testing criteria, so ensure that you understand how these specifications were derived. When you are reviewing current ratings, take note of the "temperature rise" spec, which indicates how much heat will be dissipated at a specific current value. You should also confirm that the contact will support the conductor size that you've selected. A non-compatible conductor could cause overheating issues, leading to premature connector failure (see table A).
After you identify the electrical requirements, determine whether other functions can or should be added to your connector. Hybrid connectors are usually custom-designed, but if you have the time to work with a manufacturer to develop a specific hybrid connector to exactly meet your needs, it can be worth the effort. The results will provide the end user with fewer connections and cables to manage. Try to source a single connector that can carry more than one of the following: power, signal, coax, fiber, liquid, and/or gas. The most common types of hybrid connector are the all-electrical versions that offer several larger pins for power and a high-density group of smaller pins for signals. The industry is moving to smaller, denser, and often more rugged multi-use connectors, and this approach could lead you to a device that's easier to use and more cost efficient.
Termination types have a direct effect on the assembly process and the ability to seal a connector. Connectors with solder contacts are typically easier to seal against moisture ingress, while crimp contacts may offer better field reparability. There's a trade-off between the two, so the final decision on which termination type to use is often made after discussions with your manufacturing and design groups. It's important to know exactly how and where the connector will be used, and whether field reparability is a requirement, as this decision has a significant impact on the assembly equipment and processes used in manufacturing.
If the connectors will be used in harsh operating environments, check the manufacturer's IP (Ingress Protection) rating for sealing to dust and water at various depths and operating time frames. Make sure you understand the end-use environment for your connectors, and then compare that scenario with the details behind the manufacturer's IP rating (more information about IP ratings can be found here). Most of the IP designations have specific conditions, but the IP68 rating may be defined differently by each manufacturer.