For a college project I'm trying to make a set of legs that move with the user. The idea is to use the voltage that is made from a small motor when the output shaft is moved, pass that through an op-amp, and then use that to power the motion of the legs. This means that when the user lifts there legs it will power as long as they are doing so and then when they lower it will do the same.
The problem I have is that I can't figure out a way to the voltage high enough to power a decent size motor so I have altered the resistor values as much as I can and figure I need VCC and VDD is there a way of creating VCC and VDD from a battery (In my op-amp practical I used power supply which was attached to the mains) I want to make it as portable as possible. Am I out of my league here or there something I am missing