Motor

A motor comprising:

• a shaft;
• a yoke coupled to the shaft;
• a stator disposed between the shaft and the yoke;
• a first magnet and a second magnet disposed in the yoke;
• and
• a circuit board including a first Hall sensor disposed to correspond to the first magnet, a second Hall sensor disposed to correspond to the second magnet, and a controller,
• wherein the second magnet includes a plurality of divided magnets and an index magnet, and
• the controller generates an index signal at a second time point delayed from a first time point at which a pulse due to the index magnet is detected among pulses of a pulse width modulation (PWM) signal detected by the second Hall sensor, compares a second time point which is input in advance based on a constant speed condition of the motor and a detected second time point to obtain a first error, compares a duty value, which is input in advance based on the constant speed condition of the motor, of a PWM signal and a duty value of a detected PWM signal to obtain a second error, and controls a speed of the motor on basis of the first error and the second error.