Characteristics of BLDC Motors:

The torque speed characteristics of BLDC motor is same as that of a DC shunt motor as shown in fig. The speed decreases linearly from no load speed Noas we increase the load on the motor.

Advantages of BLDC motors:

1) No maintenance is required as there is no requirement of brushes and commutators

2) Low inertia due to low friction

3) Quick acceleration and reacceleration

4) Higher maximum speed due to low friction

5) High efficiency more than 75 %

6) Speed control over a wide range of speeds

7) Reliable operation

8) Long life

9) Low RF interference with neighbouring circuits

10) Speed and position can be controlled accurately.

Disadvantages of BLDC motors:

1) They are more expensive than commutator and brush motor

2) Complex construction

3) Need complex electronic controllers

Applications of BLDC motors:

1) Computer peripheral equipment's

2) Sprindle drives in hard disk drives in computers

3) Turn table drives in record players

4) Instrumentation and control systems

5) Electric power steering

6) Air conditioners

7) Biomedical instruments

8) In aerospace.