Motor effect

  • current + magnetic field = motion

  • there is a magnetic field (due to permanent magnet)

  • current in wire causes magmetic field (two magnetic fields interact)

  • current is in opposiye direction in each side of coil

  • so forces act in opposite directions on either side of the coil (so it will rotate)

  • split ring commutator ensures that the force in the left/right side of the coil is always in the same direction

  • the current reverses each half rotation