Most quadcopters are powered by brushless motors. These have major advantages over brushed motors: less friction, less noise, and no brushes that need replacement. However, these advantages come at a cost — while brushed motors can be powered by a simple direct current, brushless motors require some sort of complicated, changing AC current. No idea how that works. Fortunately for us, we can just use an electronic speed controller. An ESC accepts a DC voltage, and takes care of running a bru...
