By Bill Neukomm, Vice President, Sales and Marketing, Harwin Inc. -- Size, weight, performance, cost. Those are the key determining factors that influence the choice of interconnect system.
In an ideal world a connector would be invisible electrically, take up no space, be weightless and cost nothing. Aircraft applications make even greater demands. Connectors must guarantee the integrity of signal at all times and ensure power flows uninterrupted, yet the application is far from benign, and devices must withstand great forces of shock and vibration. Extremes of temperature may be experienced.
Whilst commercial aircraft do not have to undergo the horrors and associated physical stresses that face their military counterparts, they are entrusted to carry hundreds of passengers, so the choice of components used is no less critical – simply: failure is not an option.
As well as the vital systems that keep an aeroplane in the air and in communication with air traffic control, commercial aircraft are increasingly equipped to enhance the passenger experience through a range of sophisticated entertainment systems. Whilst not ‘mission critical’ if the in-flight movie system fails air travellers may well be tempted to switch to another carrier, and the most likely place for a fault to occur is with the interconnection system.
All these factors combine with the result that manufacturers of commercial aircraft systems are requiring innovative interconnect systems, such as Datamate from Harwin.
Harwin is a manufacturer of standard interconnect components with an enviable reputation for high quality and customer service. Its high reliability Datamate range, a 2mm pitch cable to cable, cable to board and board to board connector family, has been specified for use in harsh operating conditions many times, featuring on the Robonaut 2 NASA space robotics program, missile guidance and roadside bomb detection systems, UAVs, auto sport telemetry systems, dialysis and patient monitoring equipment. Datamate's patented contact design features a stamped, four-fingered, gold-plated beryllium copper clip with highly stressed contact beams. The clips reside in the female half of the connector clasping round pins tightly, ensuring the integrity of electrical connection even under severe conditions.
Now Harwin has extended Datamate to include miniature, lightweight mixed technology versions. Mix-Tek Datamate range offers a multitude of configurations for signal, power and/or coax, effectively allowing the customer to configure their own Datamate connector, specific to their application, by mixing and matching the required signal, power and/or coax contacts up to a maximum of 50 low frequency contacts or 12 special (coax and power) contacts. Miniature Mix-Tek connectors feature power contacts rated for use at up to 20 amps – particularly suited to commercial aircraft designs based on an ’everything always on’ that necessitate interconnect systems with a high current carrying capability. Datamate’s signal contacts are rated at up to 3 amps; coax contacts are rated at 50 ohms.
Connectors are optionally available with quick-mate 101lok or jackscrew terminations for added security in applications which require extra contact security. They are available in Male PC Tail, Female Crimp, Male Crimp and Female PC Tail options. Moldings are polarized and have a UL94V-0 rating. Mix-Tek connectors comply with the international standards including MIL-C-55302 and CECC 75101-008.
Addressing signal speed, Harwin has just submitted Datamate for independent testing which confirmed that the connector family performs well enough at high speed to make it suitable for many USB 2.0 designs - although marginally outside the spec. These results open up a whole new range of markets for Datamate – and potentially for USB 2.0. Whereas previously if designers had wanted a hi-rel USB 2.0 connection they would have needed to tool special fixtures or housings and maybe select a custom connector, now (in most instances) they can use the appropriate Datamate device – potentially even running power, fibre optic or coax signals through the same device – while guaranteeing secure data transmission in the most extreme of operating conditions.
In a further development, Harwin has developed single-piece, machined metal backshells for the Datamate range to provide electrical screening against RFI and EMI interference. Datamate S-Tek is industry’s lowest cost, shielded hi-rel connector, and its launch means that Datamate, well-proven in harsh environments, can now be considered for I/O applications as well as PCB-mount designs. Manufactured in aluminum alloy and nickel plated for electrical performance and corrosion resistance, when used in conjunction with the relevant J-Tek Datamate connectors and metal braid, Datamate S-Tek backshells ensure full 360 degree electrical shielding. Designed to attach to a wide variety of standard metallic braids using industry standard tools, the backshells enable the shield braid to be connected through the backshell to the PCB ground plane.
Available in female cable-to-PCB-mount and female cable-to-panel-mount configurations in a range of sizes including 6,10,14,20 and 26 positions, the backshells also provide excellent design flexibility. Delivering 55/125/56 (-55 to +125degC, 56 day damp heat steady state) performance levels the new backshells are mechanically strong and easily assembled using industry standard tooling. The Datamate J-Tek connectors also feature jackscrews for added mating security. This combination of screening, security and performance means that Datamate S-Tek connectors and backshells will suit many applications in the aeronautical market where electrical noise is, or may be, present.
Another trend prevalent in the commercial aircraft world today is the requirement to make retrofits/upgrades and through life of aircraft. It is sure that if you design an aircraft now and continue building the same aircraft structure for the next 20 years the electrical power demands on that aircraft will grow as new technologies are introduced. To avoid costly redesigns, designers often look for ‘retrofittable’ or modular solutions. Datamate plays well in this scenario. Harwin is a long established company which has been manufacturing products for the aerospace industry for more than 50 years.
Although product families such as Datamate are continuously being updated, the company does not make older parts obsolete and it guarantees the availability of products. It is able to make this commitment as it retains all manufacturing processes in house – design, moulding, stamping, turning, plating, tool making etc – and is therefore not at the mercy of third-party suppliers like other companies who have chosen to outsource. Datamate itself is modular in concept and the Mix-Tek version can be custom configured to suit changing demands.
When considering the needs of commercial aircraft, we should not forget UAVs, which have developed out of the military field and into applications such as agriculture and traffic monitoring. These will also require smaller, lighter high performance, high reliability connectors, and as well as being widely used in many passenger aircraft, Datamate connectors are to be found on a growing number of UAVs used in commercial applications.
BILL NEUKOMM is Vice President of Sales and Marketing at Harwin Inc.
