What factors of the input signal determine the direction the motor shaft will turn?

The factors that determine the direction the motor shaft will turn are phase and polarity. In electric motors, particularly in alternating current (AC) motors and stepper motors, the phase of the input signal is crucial because it defines the timing of the electrical cycle that interacts with the motor's magnetic field. When the phases are aligned properly, the motor can turn in a specific direction.

Polarity is also essential, especially in direct current (DC) motors. The direction of the magnetic field created by the input current determines the direction the motor will rotate. By reversing the polarity of the voltage applied to the motor, the magnetic field also reverses, causing the motor shaft to turn in the opposite direction.

Understanding these two concepts is vital as they directly correlate with how the input signal affects motor operation. Keeping the focus on phase and polarity allows for accurate control over the rotational direction, which is fundamental in various applications involving electric motors.