This document discusses permanent magnet brushless DC motors (BLDCM). It begins by explaining that BLDCMs are generated by inverting the stator and rotor of a PM DC motor, and are fed by a rectangular AC waveform. This has the advantage of removing brushes and their associated problems, while allowing for larger torque production. The document goes on to classify motors and discuss brushed motors, BLDCM workings, applications, advantages like higher efficiency, and disadvantages like higher cost compared to brushed motors.