Tech Support: Electric Motor



Helpful Tips

  • This experiment is a great application of the engineering design cycle. Students of all ages have been successful with this equipment module.
  • Do not store D-cells in the battery holders. If the leads get crossed during storage, the unit might heat up and cause damage, not to mention waste your D-cell energy. Always remove D-cells from the battery holder when not in use.
  • If you are concerned about losing the wonderful little ceramic magnets, make it a habit to have the students replace all 12 magnets in the rotor pockets at the end of class. Once quick visual check by the teacher will be sufficient to see that all of the magnets have been returned. If there is a magnet missing, don't automatically assume a student has deliberately taken one! These little magnets tend to become fastened to the metal on desks, to metal snaps on clothing, and have even been found sticking to the back of a student's chair and on a belt buckle.
  • Older students will enjoy using a digital multi-meter to make measurements as they optimize the performance of different motor configurations.
  • Purchase a cheap DC motor from Radio Shack (in the $1.50 range) and take it apart - let the students identify the parts of the motor as they relate to the CPO Science Electric Motor equipment module.


Q: I followed the directions for setting up the magnets, disk, and electromagnet, but nothing happens when I press the "Run" button.

A: Check the following: Be sure the 4 D-cells are placed correctly in the battery holder. Use your hand to roll them around in place a few times to insure good connections. Try giving the rotor a small push to get started. Try this in one direction, and then the other. Be sure that a black/clear division line on the plastic disk is aligned with a magnet on the rotor. Be sure that the rotor magnets are set up so that north and south poles alternate. Check the electromagnet, and be sure that it is firmly seated on the connection post, and is making good contact by tightening the thumb screw. You should see a green LED come on when you manually turn the rotor past the electromagnet.