Question

How does a DC motor work?

Answer 1

A DC motor works based on the basic principle of electromagnetism. When an electric current passes through a conductor (like a wire), it creates a magnetic field around that conductor. This is the basic principle that powers most electric motors, including DC motors. Here’s a simplified explanation of how it works:

### Main Components:
1. **Armature (Rotor)**: This is the rotating part of the motor, usually made of copper wire wound into a coil.
2. **Stator**: This is the stationary part of the motor that creates a magnetic field. In a DC motor, the stator is usually a permanent magnet or another set of coils that generate a magnetic field.
3. **Commutator**: This is a switch that reverses the direction of current flow through the armature windings as it spins, ensuring the motor keeps rotating in one direction.
4. **Brushes**: These are in contact with the commutator and allow the electric current to flow from the power supply to the armature windings.

### How it Works:
1. **Magnetic Fields**: When you connect a DC motor to a power source (like a battery), an electric current flows through the brushes and into the armature coils. The armature, which is within the magnetic field created by the stator, now experiences a force due to the interaction of the current and the magnetic field. This is described by **Lorentz force law**: the current-carrying conductor in a magnetic field experiences a force.

2. **Rotation**: This force causes the armature to rotate. However, if the current kept flowing in the same direction through the armature, the motor would eventually stop because the force would oppose itself after half a turn. This is where the **commutator** comes in.

3. **Commutator Action**: The commutator is a mechanical switch that reverses the direction of the current in the armature windings every half turn. This ensures that the armature keeps rotating in the same direction.

4. **Continuous Motion**: The brushes continuously supply current to the armature through the commutator, and the armature keeps spinning. The interaction between the magnetic fields of the armature and stator generates rotational motion, powering the mechanical load (like a fan, or a robot wheel, etc.).

### Simple Version:
In simpler terms: When you pass electricity through the wires inside the motor, it creates a magnetic field around them. This magnetic field interacts with another magnetic field (from the stator), and that causes the armature to spin. The commutator helps make sure the armature keeps turning in the same direction.

That’s the basic working of a DC motor!