DC motor

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A DC motor is an electric motor that runs on direct current (DC) electricity.

Contents 1 Brushed 2 Synchronous 3 Brushless 4 Uncommutated 5 External links 6 References

[edit] Brushed

The brushed DC motor generates torque directly from DC power supplied to the motor by using internal commutation, stationary permanent magnets, and rotating electrical magnets. Advantages of a brushed DC motor include low initial cost, high reliability, and simple control of motor speed. Disadvantages are high maintenance and low life-span for high intensity uses. Maintenance involves regularly replacing the brushes and springs which carry the electric current, as well as cleaning or replacing the commutator. These components are necessary for transferring electrical power from outside the motor to the spinning wire windings of the rotor inside the motor.

[edit] Synchronous

Synchronous DC motors, such as the brushless DC motor and the stepper motor, require external commutation to generate torque. They lock up if driven directly by DC power.

[edit] Brushless

Brushless DC motors use a rotating permanent magnet in the rotor, and stationary electrical magnets on the motor housing. A motor controller converts DC to AC. This design is simpler than that of brushed motors because it eliminates the complication of transferring power from outside the motor to the spinning rotor. Advantages of brushless motors include long life span, little or no maintenance, and high efficiency. Disadvantages include high initial cost, and more complicated motor speed controllers.

[edit] Uncommutated

Other types of DC motors require no commutation.

• the homopolar motor

• the ball bearing motor

[edit] External links

• DC Motor - Interactive Java Tutorial National High Magnetic Field Laboratory
• DC Motor Control & Interfacing - Build DC motor control and interfacing circuit to control the speed and direction. Included simulation model.

[edit] References

v • d • e Electric motors Broad Motor Categories Synchronous motor • AC motor • DC motor Conventional Electric Motors Induction • Brushed DC • Brushless DC • Stepper • Linear • Unipolar • Reluctance Novel Electric Motors Ball bearing • Homopolar • Piezoelectric • Ultrasonic • Electrostatic Motor Controllers Adjustable-speed drive • Amplidyne • Direct Torque Control • Direct on line starter • Electronic speed control • Metadyne • Motor controller • Variable-frequency drive • Ward Leonard control See also Barlow's Wheel • Nanomotor • Traction motor • Lynch motor • Mendocino motor • Repulsion motor • Inchworm motor • Booster (electric power) • Brush (electric)