I enjoyed that video Chet, thanks.
I think this is definitely hysteresis and eddy current losses getting minimized when the coil is shorted. He uses an iron bolt, and that not only will suffer hysteresis losses from domain flipping, but also eddy current losses due to it's conduction properties. Toranorad at least used laminated steel, so he cut down on his eddy current losses but still has hysteresis losses, so that's why his speed up was not as pronounced as the guy in the video.
However,
I just read a comment on his video, and somebody was saying that toranorad has a higher RPM with the coil shorted, than WITH NO COIL AND IRON CORE PRESENT IN THE SETUP.
I like that, that's good thinking right there. Just remove the coil and core entirely from the system and see what the RPM is. Than place it there and the hysteresis losses and eddy current losses should slow it down, than when the coil is shorted, minimizing these losses by opposing changes in flux, the rotor should speed back up, but will it speed up faster than with no coil and core present?
If it does than this could be good news, and than we need to eliminate the other objections I had. The magnets field could be weakened and than the motor will draw more current and speed up, since the emf that opposes the input voltage drops with weaker B fields at a set RPM.
If this is ruled out as well, and the input current stays constant, meaning input power stays constant, than we might have something interesting here, very interesting.
EM
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