How does an Electric Motor work? (DC Motor)

• Many devices in a house have electric motors, such as kids' toys, table fans, toothbrushes, hairdryers, and electric cutting knives
• How an electric motor works

  1. Turn it on

  2. It starts rotating
• Circuit


  A path for electricity to flow, consisting of a battery, wires, and a device that uses electricity
• Electricity flows through the circuit, but stops flowing if there is a break in the wire
• Conventional flow


  The direction electricity flows in a circuit
• Magnet


  • Has a north pole and a south pole
  • Opposite poles attract, same poles repel
• Permanent magnet


  A magnet that is always on, cannot be turned off
• Spinning magnet


  1. Place a magnet on something that allows it to spin

  2. Bring another magnet towards it

  3. The spinning magnet will line up with opposite poles next to each other

  4. Keep switching out the side magnet

  5. The spinning magnet will keep spinning
• Electromagnet


  • A magnet created by running current through a wire wrapped around a metal object
  • Can be turned on and off
• Flipping the battery


  Reverses the polarity of the electromagnet
• Spinning electromagnet


  1. Replace the spinning magnet with an electromagnet

  2. Connect the wires to turn on the electromagnet

  3. The electromagnet lines up with the side magnet

  4. Reverse the polarity of the electromagnet

  5. The same poles repel and opposite poles attract

  6. Keep switching the polarity

  7. The electromagnet will keep spinning
• Electric motor


  • Uses an electromagnet and a spinning armature
  • Commutator ring switches the polarity of the electromagnet as it spins to keep it spinning
  • Multiple loops on the armature provide a continuous spinning motion
• Torque


  The spinning force on the armature
• Improving motor torque


  • More wires on the electromagnets
  • More electricity
• Stator


  The stationary part of the motor, such as the permanent magnets
• Rotor


  The spinning part of the motor, the armature
• DC motor


  A type of electric motor powered by direct current
• Electric motors can be used to power various devices by converting the spinning motion to other types of movement