What is a permanent magnet DC motor?

A permanent magnet DC motor is characterized by its use of permanent magnets in the rotor to create the magnetic field necessary for operation. This design provides several advantages, such as reduced size and weight compared to motors that rely on electromagnetic coils, as well as improved efficiency in delivering power. The permanent magnets maintain a constant magnetic field, which allows the motor to operate effectively with direct current (DC) power sources.

This motor type is widely used in various applications due to its simplicity and the reliability of its construction. The permanent magnetic setup does not require additional energizing coils, which simplifies design and control mechanisms.

In contrast, a motor that operates on alternating current is not relevant to this definition, as it refers specifically to AC motors. A motor with a variable resistor might be associated with speed control mechanisms in certain types of motors but does not define a permanent magnet DC motor itself. Finally, while permanent magnet DC motors can be designed for high torque applications, this feature is not exclusive to them and does not define the essence of what a permanent magnet DC motor is. Therefore, the defining characteristic remains that it utilizes permanent magnets for its magnetic field.