US aircraft manufacturer Sonex has unveiled an electric powered, full size aircraft that has an uncanny resemblance to an R/C electric model. E-Flight's proof-of-concept prototype uses their flight proven Waiex airframe coupled with a purpose-built AeroConversions brushless DC cobalt motor, controller, and a highly efficient battery and charging system.
Initial top speeds will reach approximately 130mph, and endurance is expected to range between 25 - 45 minutes or longer, depending upon power usage.
The motor is the lightest, most powerful and efficient unit of its type ever produced. It is a 3-phase, 270volt, 200amp motor produced using elegantly designed CNC machined anodized aluminium and nickel-plated steel parts in combination with 'off the shelf' bearings, races, snap rings, magnets, etc. The prototype motor is slightly larger than a 35oz coffee can and weighs approximately 50 lbs.
The time and cost associated with acquiring a commercial ESC was deemed unacceptable so the research and development team, in cooperation with an electronics expert, began designing a proprietary AeroConversions electronic motor controller. The controller can commutate the motor in two different ways: using Hall Effect sensors to determine the magnet core's position in relation to the coils, or using the motor's back-EMF to sense rotor position, eliminating the need for Hall sensors.
Ten battery 'safe boxes' intended to contain 8 Li-Po battery packs per box and consolidate their charge/discharge and balancing wiring into two sets of multi-pin connectors were created by the design team. The Boxes accommodate natural cell expansion and contraction while safely securing each cell pack and facilitating cell cooling with 'cooling foam' padding.
Cooling is further aided by heat sink surfaces on each box that have cooling inlet air directed over them. Additionally, the boxes are designed to contain and safely direct fire or explosion within the box through a blow-hole in the box that will be connected to a small exhaust manifold!
Looks like a big model to us!
There's more information at www.sonexaircraft.com, see the video in our video gallery too.
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