Yeah it is a three phase full wave bridge rectifer circuit. I had used a Mabuchi 550 brush motor years ago, but I can see using a brushless motor nowadays. But then the Mabuchi motors and the Johnson 12vdc motors are so cheap to buy now, that one could simply swap them out as the brushes wear out.

I can see simply using a engine speed governor like the helicopter guys use on their heli's for this. So one wouldn't have to design, build and program one on their own, unless they really want to.