I just got an old grinder from Craigslist, and I'm tinkering with the idea of adding some form of peed control. The way the motor is wired is that the motor itself has three leads into it, one each of the leads coming from the power cord, and the third is coming from a capacitor that's also fed from the power.... if I'm understanding correctly that means that this is an induction motor correct? what are my choices to add a speed control?