Hi Rakesh,

"Brushless DC motors" are in real AC motors with a chip inside, e.g. the fan motor in your PC. This chip can have a pin to control the speed, e.g. depending from a temperature sensor.

To build the function of those chips separate, you must look on control applications for AC motors, e.g. stepper, synchron or asynchron motors.

Asynchron motors are very effective and cheap, but not easy to control. Thus, why specialized DSP used. And the algorithm are secret of the motor company, since they must be adapted to the motor characteristics.

Stepper motors are expensive and only for less power, but easy to control. I think, there are already million postings about stepper motors on this forum.


Peter