Product Focus: Connectors

The design philosophy of ARINC’s connector working groups until recently has trended toward new generation connectors designed specifically for high-throughput in-flight entertainment (IFE) applications. The economic realities of commercial aviation, however, drive continued interest within the ARINC groups to standardize older, but already proven and less expensive connectors for IFE applications, even if their performance isn’t up to the capabilities of the latest IFE systems from Panasonic Avionics, Thales, Rockwell Collins and others.

That’s created a bit of a push-pull between different factions participating in the working groups. On one side are the interests of manufacturers supplying legacy connectors, whose voices are increasingly holding sway. Stakeholders who want more emphasis on connectors with next generation throughput capability represent the other side.

"There is not a consensus that some legacy products are entirely problematic," said Jay Sandidge, district sales manager with Positronic Industries, of Springfield, Mo., and a member of the Connector Working Group in ARINC’s Cabin Systems Committee. Sandidge spoke of a growing call to use legacy connectors even though they are not the best choice from a performance aspect for IFE systems demanding lots of bandwidth.

"There are a lot of people in the same room competing for the same piece of business, so you have to weigh people’s opinions against that fact," he said.

Another ARINC connector committee is working to develop a common way of characterizing connectors regardless of form factor. That’s because the industry is using a variety of different connector types for what would be called "non-traditional applications," or those for which they weren’t originally designed. An example would be a connector of moderate throughput that is being asked to carry the signals of top-end IFE technology.

The newer connectors are a better technical fit with modern-day IFE systems, but older-generation connectors remain popular because they are proven and cost less. With additional shielding to prevent interference, the tried and true copper wires running through these connectors can be pushed to gigabit transmission speeds. And since older and newer connectors are being produced in quantity, the different manufacturers are equally represented on standards-setting bodies such as those within ARINC.

"Regardless of whether you’re trying to make older connectors work or introducing new generation connectors you need a common method of characterizing them," said Larry Patterson, principal technical designer, Airplane System Laboratories, with Boeing Commercial Airplanes.

Patterson is a member of a number of ARINC working groups and leads its Ethernet test standardization efforts, which are helping develop design standards for gigabit Ethernet connectors destined for IFE and other applications requiring high bandwidth.

"I would say that we’re still sorting out (the definition of) high-throughput connectors," Patterson said. In the case of connector applications "where there is a lot of volume involved," he said, "the interest is in using products that are out there that are lower-cost. Keeping cost low is most important even when new connectors are introduced."

The people working on gigabit Ethernet standards development at ARINC are also looking at connectors and cables that combine high-speed data transmission with other signals like power currents. The goal there is to create a manufacturing and performance standard for connectors that maintain adequate isolation between whatever two (or more) channels are being carried.

The technical questions of the connector business remain the same as in the past, namely, how do you make connectors smaller, with better contact and higher throughput? "All of those would be on everybody’s list, though probably in different priorities," said Sandidge. "My opinion is that bandwidth concern has been a primary driving force."

Positronic Industries introduced a contact system called "PosiBand" this past summer that addresses some of those criteria, and Sandidge said it is "the most important product release from Positronic in years."

"PosiBand is essentially an alternative design to the traditional split tine design that you find on most mil-spec female contacts," he explained. "It doesn’t split the mating barrel so you don’t end up with two fingers that can open. It is one solid piece of metal all around."

PosiBand contacts separate the mechanical and electrical function of the contact system, and a spring clip provides more stable mechanical function and resistance to vibration and corrosion in aerospace environments. Positronic said greater contact interface is achieved without increased insertion force.

"The advantages are that mechanically it is more robust," Sandidge said. "There is increased surface engagement and the product doesn’t have to be annealed, which could be one of the biggest advantages, because that’s another manufacturing step, which increases costs and adds inspection criteria."

Sandidge said the PosiBand concept can be used in D-sub connectors and rectangular connectors, as well as new IFE connectors "because the design is all about the female contact… it doesn’t matter what the housing is."

More Throughput

Like Sandidge, Kerry Stuckart, product manager for coax cables, connectors and equipment trays at Emteq, New Berlin, Wis., believes that bandwidth is the defining factor in connector development today.

"We’re using so much of the electronic bandwidth that signals are starting to interfere with themselves," she said.

That’s partially due to the use of prior-generation connectors for present-day IFE applications, and because development of aerospace-grade IFE connectors lags behind those developed for retail electronics, like HDMI connectors for high-definition TV, for instance. The fact that a variety of connector companies are supplying both legacy and now-generation products means that "we’re seeing a lot more competition in connectors for the IFE market," said Stuckart.

Even connector suppliers that don’t currently compete in the aerospace market plan to do so in the near term. An example is Yokowa America Corp., the U.S. subsidiary of a Japanese company that bills itself as the world’s largest spring pin connector manufacturer.

Naoki Kawata, managing director of Yokowa America, and Tommy Tsubokawa, sales manager for its west coast division, in an interview said they intended to compete in the aerospace connector market in the next couple years.

"Price is what’s most important for connectors in other industries, but in the case of aviation quality is key," said Tsubokawa. "We’re working to miniaturize connector size while creating flexibility tailored to customer needs."

One way they’re doing that in a connector designed for non-aerospace communications is through development of hybrid module connectors. The use of metal injection molding facilitates the manufacture of more complex designs such as one Yokowa developed that combines a spring-loaded pogo connector and a leaf (metal plate) connector in a single connection. Tsubokawa said that product isn’t necessarily one that would have aerospace applicability, except for the design philosophy of doing more with less and in a small space.

Emteq has noticed a marked increase in hits on its Web site, which Tony Forst, applications engineer for coax cable and connectors, attributes to the constant hunt for connectors that are lower in weight, cost less and/or have better performance.

"We see a lot more engineers researching new technology," said Forst. "Ninety percent of the hits on our Web site are engineers looking for new products and trying to find what’s out there."

Forst said he’s noticed that younger engineers, those fairly new to the industry, spend more time searching for new technologies, as opposed to engineers more established in their jobs who might be more willing to "use what’s always been in the drawings."

If they’re engineers working on a business jet, performance is likely their number one criteria, because of the "home entertainment center in the sky" nature of cabin furnishings. In that category, silver contacts trump zinc, and gold contacts trump silver. If they’re working in commercial aviation, price is the defining element. "The airframers have seen their production slashed, and are shifting their focus to weight reduction programs," said Stuckart. "They might be willing to pay more than in the past to save weight.

The commercial airline industry wants weight reduction, and the connector industry is responding with an evolving product list.

"Today we tend to produce a lot of products that take weight out of the aircraft," said Sandidge. "To do that, you use one metal instead of another, such as aluminum versus zinc, which gives you weight savings out of the gate but with something that is mechanically identical."

Positronic Industries is getting more requests for connectors that can hold more signal pins without the shell becoming larger, or for 22 gauge wire instead of 20 gauge, but with the same performance and reliability, Sandidge said.

Emteq is seeing a demand from the military for self-locking connectors as a replacement for connectors with safety wire (which keeps a pair of threaded connectors from loosening over time). The company is providing these type of connectors in quantity for the C-130 Avionics Modernization Program, the long-running upgrade program managed by Boeing.

Avionics Magazine’s Product Focus is a monthly feature that examines some of the latest trends in different market segments of the avionics industry. It does not represent a comprehensive survey of all companies and products in these markets.

Market Moves

Following are some recent developments announced by connector manufacturers.

* Sabritec, of Irvine, Calif., in December released a series of High Power Connectors and Contacts for the aerospace market. The company said the connectors (left) utilize Hyperboloid contact technology, and provide high current ratings with smaller contacts for the same power, thus saving overall weight and space. Other features of the series include low coupling force; shock and vibration resistance; operability in harsh environments; reduced contact resistance; increased power handling capability; and improved low-rate of wear and high coupling durability, the company said.

* Arrow Electronics, based in Melville, N.Y., announced plans in November to acquire A.E. Petsche, a wire and cable manufacturer based in Arlington, Texas. Financial terms of the acquisition were not disclosed. Arrow Electronics said the deal was designed to expand its footprint in the aerospace and defense markets.
"This strategic transaction will add to the breadth of Arrow’s customer base and increase our staff of highly experienced sales professionals, while allowing for a variety of cross-selling opportunities with our existing business as well as other emerging markets," said Peter T. Kong, president of Arrow Global Components.

* ITT Interconnect Solutions in June released a hermetically sealed connector with a lightweight aluminum shell for low-pressure water immersion or fording applications. The connector is suited for military and aerospace applications, including integrated avionics, communication and navigation equipment, displays and instrumentation, data processing equipment, electronic warfare systems, radar and sensors, weapon controls and targeting systems, electronic countermeasures, radio and telecommunications devices and battery packs.

* Positronic Industries, Springfield, Mo., expanded its power connector line, adding the Scorpion series. The line is modular, allowing customers to configure a power connector for their individual requirements. Power options include 60 amperes size 8, 40 amperes size 12, and 30 amperes size 16 contacts, with contact resistance values as low as 0.001 ohms. Size 22 signal contacts are also available.

* Omnetics Connector Corp., based in Minneapolis, in November said its design, production and quality assurance systems were certified to the ISO 9001:2000, AS9100 Revision B, International Quality System Standard. ISO9001:2000 combines three standards of 9001, 9002 and 9003 into one and focuses specifically on design and development procedures. The company’s quality system was audited and certified by Smithers Quality Assessments Inc., an independent registrar accredited by both the Dutch Council for Accreditation and the American National Accreditation Body.