Rotation speed raising device for permanent magnetic motor

The rotation speed raising device for permanent magnetic motor includes several magnetic sensors set inside the permanent magnetic motor to sense the magnetic pole conversion of the permanent magnetsin the rotor. One of the magnetic sensors makes the stator and the permanent magnetic rotor produce armature reaction with relatively strong armature air gap magnetic flux density, while the others make the motor controlled in the effect similar to weak magnetic control resulting in weak armature air gap magnetic flux density, lowered torque constant KT of the motor and increased rotation speed of the rotor. The said device makes it possible to design motor in relatively high torque constant Kt and when high rotation speed is required, the magnetic sensing selection circuit is made to output signal to produce effect similar to weak magnetic control.