This 12 volt, 3-phase generator is one of my latest projects.
The client needed to power high-intensity LED spotlights and other airborne equipment in model airplane drones that are being used for air reconnaissance in wildlife conservation. Typical mission duration can be up to 6 hours long, thus in-flight charging is a necessity.
The shaft of the generator is turned via a timing belt by the same 60cc petrol engine that powers the aircraft.
The generator had to be mounted in close proximity to the engine, therefore temperature was an important design concern. Potential heat-related problems were averted by using a Scorpion motor, because it employs magnets with a temperature rating of 200°C.
The 150 Watt, 12 volt generator is based on a Scorpion S-3020 brushless motor kit. The stator was wound so that charging voltage is obtained at just above idle speed.