The main difference between a general-purpose DC motor and a permanent magnet DC (PMDC) motor is the stator construction. A PMDC stator is made of permanent magnets, whereas a DC motor features electromagnet. The former does not need separate field excitation whereas an ordinary DC motor stator comes with field windings to provide excitation to the electromagnet. A PMDC motor is also more efficient when compared to a DC motor due to the absence of field windings and the resulting copper loss.