In any military setting—be it wearable technology on a soldier or within machines—one of the most desirable attributes is a compact, lightweight and rugged design. That’s the case with connectors used in military equipment, and so these devices just keep getting smaller and smaller and lighter and lighter.
Most designs, like those of ODU-USA, evolved out of traditional push-pull connectors. And because they are often designed with a soldier in mind, they must be easy to connect and disconnect as well as light and small to carry around, said Brendan Dempsey, business development manager, ODU.
These miniature designs must be secure in mission-critical applications, such as radios, handheld and rugged computers, tablets, UAVs (unmanned aerial vehicle), and AUVs (autonomous underwater vehicles). The low-power connectors, rated at 40 A or lower can transfer power and also run HDMI, Ethernet and other network systems.
For vehicles, these connectors can be as small as 1½ in., while in devices used by soldiers, most circular connectors can be as small as about ½ in., said Dempsey. Connectors on vehicles usually lock to prevent accidental unmating during vibrations, while those on wearable devices are designed to easily break away in case of emergency.
As for standards connectors in military settings must meet, IP68 is probably the most common. This allows the connector to be submerged water without leaking. In addition, some connectors are rated to IP69K for high-pressure steam and water applications. This is used on devices that might encounter contamination and must go through intense cleaning processes.
And although both rectangular and circular designs are available for military applications, circular designs are more common because they are usually more compact. Mating cycles on all designs can range anywhere from 500 to 100,000, depending on the type of application.
One trend that started in Europe that companies like ODU are following is the move to certify to the RoHS (Reduction of Hazardous Substances) standard, said Dempsey. For example, ODU has eliminated toxic chemicals like cadmium, lead and mercury, making its product line 100% RoHS compliant.
In keeping with the notion that these connectors may be used on devices worn or carried by humans, they also must be non-reflective and offer high EMI shielding.
Another difference in ODU products from other connector manufacturers is the use of plastic in the connector caps and covers. Most connectors come with metal caps, which can make a lot of rattling noise when not closed. To eliminate the noise, Dempsey said, a lot of soldiers will cut the cap off, thus exposing the connector to environmental damage. By switching to rubber or plastic, the noise is no longer an issue. This solution is an example of looking at how a product is meant to be used and how it is actually used, said Dempsey. “We want to make a product that people want to use,” he said.