Manually turning a brushed DC electric motor will produce readable AC and DC voltages, already. The thing here is phase
and frequency. Using a rectifier reverse biased, even if you could rely on back leakage being enough for your purposes (a bit of a "bull let loose in a fine crystal shop" approach), it does not guarantee appropriate phase on the AC (most likely you will not get away from the motor rpm), so it is pointless, I think, to do that. The chief purpose of an inverter is to establish dependable
frequency, and you need an oscillator for that. If you are knowledgeable enough with transistors, you can make your own by making it saturate and breakdown repeatedly, but again, a second best approach. Also, you don't get something for nothing; you can up or down the final output voltages easily enough with dissimilar wound transformer coils, but at the end of the day the amp/hour capacity of the generation cannot be exceeded (safely), and that's down to the "generation potential" of the original motor, at a given rpm.
Experts will be able to correct me, please; I am only at hobby level electronics, myself.
It is an interesting little demo, particularly like the use of the last magnet as a starter/sustainer. Don't get the French, so I am missing a lot, no doubt. However, it is not all that innovative.
Read this.
