Whenever a current carrying conductor is placed inside a magnetic field, there will be mechanical force experienced by that conductor. Hence for constructing a DC motor. it is essential to establish a magnetic field. The magnetic field is obviously established by means of magnet.  When permanent magnet is used to create magnetic field in a DC motor, the motor is referred as permanent magnet DC motor or PMDC motor.

As it is indicated in name of permanent magnet DC motor, the field poles of this motor are essentially made of permanent magnets(commonly neodymium magnets). A PMDC motor mainly consists of two parts. A stator and an armature. Here the stator which is a steel cylinder. The magnets are mounted in the inner periphery of this cylinder. The permanent magnets are mounted in such a way that the N – pole and S – pole of each magnet are alternatively faced towards armature. That means, if N – pole of one magnet is faced towards armature then S – pole of very next magnet is faced towards armature.