Method and system for prevention of motor reversal

A power tool comprising:

• a housing;
• a brushless DC motor housed inside the housing, the motor comprising a rotor, a stator, and at least one sensor positioned to sense a state of the rotational position of the rotor inside the stator;
• a power supply;
• an input unit actuated by a user comprising a variable-speed actuator;
• and
• a control unit configured to control commutation of the motor through a plurality of power switches coupled to the power supply, the control unit receiving a current sensor state from the sensor and a user-selected speed from the variable-speed actuator, the control unit further configured to determine whether the motor has reversed direction using the user-selected speed and the current sensor state and to disable commutation of the motor if the motor has reversed direction until a proper current sensor state is received from the sensor.