Define a brushed DC motor and its simple construction.
1 Answer
A brushed DC motor is a type of electric motor that converts electrical energy into mechanical energy using direct current (DC). It is one of the most common types of motors used in various applications due to its simplicity, cost-effectiveness, and ease of control. Despite its wide use, its popularity has decreased in recent years due to the advent of more efficient and reliable alternatives, such as brushless DC motors.
Here's a brief explanation of the construction and functioning of a brushed DC motor:
Construction:
Armature: The armature is the central rotating component of the motor. It consists of a coil of wire wound around a soft iron core, often referred to as the rotor.
Commutator: The commutator is a split metal ring attached to the armature shaft. It acts as a mechanical rectifier, converting the alternating current induced in the armature coil into direct current.
Brushes: The brushes are conductive carbon blocks or springs that press against the commutator. They provide electrical connections between the external power supply and the rotating armature.
Field Magnets: The stationary part of the motor contains the field magnets, which produce a magnetic field. These magnets can be permanent magnets or electromagnets.
Functioning:
When a direct current is supplied to the motor, it flows through the brushes and into the armature coil.
As the current passes through the coil, it creates a magnetic field around the armature.
The magnetic field interacts with the stationary magnetic field produced by the field magnets, causing a torque that rotates the armature.
As the armature rotates, the commutator ensures that the current direction in the armature coil changes at the right moment, keeping the motor's motion continuous and in the same direction.
One of the major downsides of brushed DC motors is the wear and tear caused by the brushes and commutator. The friction between the brushes and the commutator leads to brush wear, limiting the motor's lifespan and requiring periodic maintenance. In comparison, brushless DC motors eliminate these issues by using electronic commutation instead of physical brushes.
Despite their drawbacks, brushed DC motors still find applications in smaller devices, toys, appliances, and certain automotive systems due to their simplicity and cost-effectiveness.
Here's a brief explanation of the construction and functioning of a brushed DC motor:
Construction:
Armature: The armature is the central rotating component of the motor. It consists of a coil of wire wound around a soft iron core, often referred to as the rotor.
Commutator: The commutator is a split metal ring attached to the armature shaft. It acts as a mechanical rectifier, converting the alternating current induced in the armature coil into direct current.
Brushes: The brushes are conductive carbon blocks or springs that press against the commutator. They provide electrical connections between the external power supply and the rotating armature.
Field Magnets: The stationary part of the motor contains the field magnets, which produce a magnetic field. These magnets can be permanent magnets or electromagnets.
Functioning:
When a direct current is supplied to the motor, it flows through the brushes and into the armature coil.
As the current passes through the coil, it creates a magnetic field around the armature.
The magnetic field interacts with the stationary magnetic field produced by the field magnets, causing a torque that rotates the armature.
As the armature rotates, the commutator ensures that the current direction in the armature coil changes at the right moment, keeping the motor's motion continuous and in the same direction.
One of the major downsides of brushed DC motors is the wear and tear caused by the brushes and commutator. The friction between the brushes and the commutator leads to brush wear, limiting the motor's lifespan and requiring periodic maintenance. In comparison, brushless DC motors eliminate these issues by using electronic commutation instead of physical brushes.
Despite their drawbacks, brushed DC motors still find applications in smaller devices, toys, appliances, and certain automotive systems due to their simplicity and cost-effectiveness.