Electric motor drives krishnan pdf motor from a 3. The coils, arranged radially, are made from copper wire coated with blue insulation. The grey ring inside its cup is a permanent magnet. The advantages of a brushless motor over brushed motors are high power to weight ratio, high speed, and electronic control.
1980s thanks to better permanent magnet materials. If the magnetic field of the poles remained the same, this would cause a reversal of the torque on the rotor each half-turn, and so the average torque would be zero and the rotor wouldn’t turn. This reverses the direction of the magnetic field as the rotor turns, so the torque on the rotor is always in the same direction. It consists of a rotating cylinder divided into multiple metal contact segments on the rotor.