So what is an ESC? Well, electronic speed controllers are used to control brushless motors, in thisc ase the motor has a triple phase input. To control this input, the ESC must apply a special sequence of LOWs and HIGHs signals in a predefined order. It has to conmutate very fast and by taht rotate the rotor of the motor. In this tutorial we will see how to control the rotation, the speed, detect the BEMF and by that know when to make the switch to the next step of the sequence. So this is a sensorless brushless motor speed controller since it uses no sensor to detect the rotor position. We will learn: