Unmanned Systems Technology 024 | Wingcopter 178 l 5G focus l UUVs insight l CES report l Stromkind KAT l Intelligent Energy fuel cell l Earthsense TerraSentia l Connectors focus l Advanced Engineering report

contacts in the insulator, such as a ‘crimp and poke’ style of contact. That means their contacts and wires are crimped at the factories and permanently epoxied in place, giving a highly secure connection but no end-user termination capability. That has its advantages though, in that the connector is environmentally sealed without needing the added bulk and weight of a separate backshell. It also means not having to rely on a mechanical feature to keep the contact and wire from being pulled out by shock or load stresses. The stranded wire will therefore typically break without the contact being pulled from the connector, making repairs far easier. Many suppliers also offer connector savers – adapters that fit between the plug and receptacle to absorb the stresses of repeated mating cycles – for the micro-D and nano-D standards. The 83513 standard requires a minimum of 500 mating cycles, while the 32139 standard specifies a minimum of 200. By using a connector saver between the plug and receptacle, the housings and gold finishes on the contacts can be preserved, avoiding the need for costly repairs or replacements of those parts after repeated mating cycles. Connector savers could be particularly useful for industrial or tactical-grade UASs that have been developed over more than half-a-dozen iterations and hundreds of hours of test flights. Such development, as well as tests by the end-user before professional use, could mean needing mating cycles that exceed the maximum number dictated by the standards. Instead, a connector saver could be fitted, which would count as one mating cycle, and then run as many tests, mating and un-mating, as many times as required. The developer could then remove the connector saver for the final test, with only two mating cycles having been conducted by the time UAV testing is complete. PCB connectors Where the robustness of MIL-DTL-32139 runs in excess of that needed by a vehicle’s, subsystem’s or payload’s PCB, a range of micro-strip connectors are available for processor card edge-to- cable connections along circuit board peripheries. These micro (or nano) strip connectors often have a 1.27 mm pitch, much like the nano-D, but can be wider than the standard if saving on manufacturing cost is more desirable than minimising contact spacing. The pitch can also be thinner, with cost savings on materials or latching mechanisms. JST-standard connectors are widely used in multi-rotor systems and other small unmanned vehicles. Originally developed by the Japan Solderless Terminal Manufacturing Company, they consist of single pin row connectors, mostly shrouded in plastic housings and with pitches running mainly from 1 to 2.5 mm.