Sean-bumble-bee
Core User of DJI
Flight distance : 15997 ft
United Kingdom
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Maybe it is American vs British but to me a "resistor", large or small, is part of an electrical circuit that opposes the passage of an electrical current via "resistance", measured in Ohms. Motor windings, by design, have very little resistance, small fractions of an Ohm.
Most of a running motor's opposition to the passage of current through its windings comes from a "back emf" induced in the windings by the rotating magnetic field that surrounds those windings.
When the motor is running well below its desgined speed, which includes stalled/stopped, the back emf is greatly reduced and the current 'soars'.
With regards the action of a bird on a motor, unless the bird is actually grasping the motor's rotor or is pressing down on the propeller blades etc. then it opposes the rotation of the motor by blocking the rotation of its prop.
Try this with a not powered on drone, put your finger inside the area swept by the prop blades and then turn the motor by hand. I bet you find that your finger at some point stops the rotation of one blade by blocking the rotation of it and that blade will come up against a stop of some sort, with my mini 1 & 2 the impeded blade comes up against the hub of the other blade, At that point the motor can no longer turn.
Something similar happens with mavic 2 style props. In fact with an in flight Mavic 2 the stopping of the motor causes the not blocked blade to whip around and smack into the trailing edge of the blocked blade and the not blocked blade takes a chunk out of the trailing edge if the blocked blade.
Unfortunately we probably can not check the motor rpms of a Mini 4 pro as their DATs are, from memory, encrypted but I am reasonably confident that the bird would have stopped the 'offending' motor rather than significantly slowed it but left it turning at avery much reduced rate.
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