The brushless motor construction is the same as the permanent magnet synchronous motor. However, a single brushless motor is not a complete power system, and the brushless basically must be controlled by a brushless controller, that is, an ESC to achieve continuous operation. What really determines its performance is the brushless electronic governor (that is, the ESC). Generally, there are two kinds of driving currents for brushless motors, one is square wave and the other is sine wave. Sometimes the former is called a DC brushless motor, and the latter is called an AC servo motor, which is exactly a type of AC servo motor.