Simple DC Motor

• Diagram of a simple DC motor

  
• • As a current flows through the coil of wire in the magnetic field, a force will act in the coil causing it to move - using the split rings ensures that the force on one side of the coil is always up and the other side is always down.
• • As the coil turns, the split ring swaps contact with the brushes every half-turn (swapping the + / -) keeping the rotation in the same direction - carbon brushes ensure there’s a connection between the power supply and the split ring.
• • Can use Flemings left hand rule to predict the direction of the rotation.
• To make the motor spin faster, you can use…

  • a coil with more turns
  • a larger current
  • stronger magnet
  • a coil with a larger area (more turns)
• • To change the direction of the motor, you can change the direction of the current or reverse the field.
• Split rings - change direction of current in coil every half turn (swapping + / -) keeping same direction - force on one side always up and on other side always down.