Abstract: A DC motor includes a driver, a Hall rotor position detector, an electromagnet stator and a permanent magnet rotor. The driver includes a rotor position signal amplifier and a power amplifier. The rotor position detector includes six Hall sensing crystals and an induced magnet fixed to a motor shaft. A rotor pole position signal is detected by the Hall effect between the induced magnet and the Hall sensing crystals. Power is amplified by the power amplifier and supplied to a winding of an electromagnet stator, so that the pole of electromagnet stator keeps repelling and attracting the pole of the permanent magnet rotor to produce a multiplied torque according to the relative displacement to drive the generator by the multiplied torque and achieve the effects of outputting an electric power greater than the electric power provided for the operation of the motor, amplifying the electric power, and saving energy.