The Brushless motor DC (BLDC)

It is widely used in applications including appliances, automotive, aerospace, consumer, medical, automated industrial equipment and instrumentation. The BLDC motor is electrically commutated by power switches instead of brushes. Compared with a brushed DC motor or an induction motor, the BLDC motor has many advantages like :
 Higher efficiency and reliability
 Lower acoustic noise
 Smaller and lighter
 Greater dynamic response
 Better speed versus torque characteristics
 Higher speed range
 Longer life Operation BLDC theory Motor operation is based on the attraction or repulsion between magnetic poles. Using the three-phase motor shown in Figure 9, the process starts when current flows through one of the three stator windings and generates a magnetic pole that attracts the closest permanent magnet of the opposite pole. The rotor will move if the current shifts to an adjacent winding. Sequentially charging each winding will cause the rotor to follow in a rotating field. The torque in this example depends on the current amplitude and the number of turns on the stator windings, the strength and the size of the permanent magnets, the air gap between the rotor and the windings, and the length of the rotating arm.