This is a test of the brushless ESC I built for my 1/10-scale RC car. It uses sinusoidal AC commutation and field-oriented control, which dynamically adjusts the timing of the motor to optimize torque. As an extension of this control method, it can also run at other operating points that sacrifice torque for more speed. It does this by using some current to fight the permanent magnets, reducing back EMF and allowing the motor to spin faster at a given supply voltage. This is called field weakening.