Next we move to a unit with its motor connected to a generator. What we see is striking. The meters showed an input to the stator electromagnets of approximately 1.8 volts and 150mA input, and from the generator, 9.144 volts and 192mA output. 1.8 x 0.15 x 2 = 540mW input and 9.144 x 0.192 = 1.755W out.
Sorry, no. That's known as an "overunity device", which is more popularly called a "perpetual motion machine". If we believe the meters, 1.2W is magically coming from somewhere. That means extra energy is being supplied on a continous basis. "Energy can neither be created nor destroyed." So either he's mistaken or he's lying. Anyone can rig up meters to show anything.
"Back EMF" is not fiction. What's fiction is that it can be used in this way. If you want to use back EMF as an energy source (which is simply what a generator is), then the energy needs to have been put there by something else spinning the flywheel/rotor. So the energy path goes:-
Chemical energy -> Battery terminals -> electrical energy -> Motor -> kinetic energy (spinning rotor) -> Generator -> electrical energy -> Load
where "Load" will be wherever the generator puts the electricity it generates. At no point is extra energy added, so any energy reaching the load has come from the battery (via a very indirect route).
I Googled a bit more about Minato. An explanation from Chris Drake:-
All Minato's power calculations appear to be wrong (apparently it's a common mistake many scientists make); you can't measure input power using a multimeter when the current drain isn't constant. You can see his workshop in his videos - all his calculations are done using common multimeters and a desktop calculator.
Minato motors use an optical sensor to "switch on" the "stator" (electromagnet) for a fraction of each RPM, so he'd need an oscilloscope and some funky math to figure out how much current the motors are really sucking up (or a stopwatch; and wait for the driving battery to go dead, then estimate based on the battery capacity).
So in other words, Minato's input power figure is incorrect, which explains the mismatch in power readings.
As an aside, I also note that Minato's claim dates from 1997, and that there are no more articles anywhere beyond that first link (there's just a zillion copies of it). Had this worked, it would *definitely* be in production now, and he'd be shouting loudly about it, as would his sponsors. Note that this is Japan, so there's no oil industry to pander to - the Japanese would kill for independence from oil suppliers (and literally did in WWII) so no lack of support there, and the article claims that Nippon Denso were making the motors. But no news of it, no nothing, just fade into the "oops we screwed up" oblivion of every other perpetual motion machine.