1. Electric Motors CHAPTER 21 ELECTROMAGNETISM AND ELECTRICITY AT WORK Powerpoint hosted on www.worldofteaching.comwww.worldofteaching.com Please visit for 100’s more free powerpoints

2. What are Motors used in? Electric motors are used in many, if not most, modern machines. Electric motors are used in many, if not most, modern machines. Fans, turbines, drills, the wheels on electric cars, locomotives and conveyor belts. Fans, turbines, drills, the wheels on electric cars, locomotives and conveyor belts. Robotics - turn the wheels of vehicular robots, and servo motors are used to turn arms and legs in humanoid robots. Robotics - turn the wheels of vehicular robots, and servo motors are used to turn arms and legs in humanoid robots. In flying robots, helicopters, airplanes, and military equipmentIn flying robots, helicopters, airplanes, and military equipment Turn saws and blades in cutting and slicing processes, and to spin gears and mixers Turn saws and blades in cutting and slicing processes, and to spin gears and mixers Many kitchen appliances. Food processors and grinders spin blades to chop and break up foods. Blenders use electric motors to mix liquids, and microwave ovens use motors to turn the tray food sits on. Toaster ovens also use electric motors to turn a conveyor to move food over heating elements. Many kitchen appliances. Food processors and grinders spin blades to chop and break up foods. Blenders use electric motors to mix liquids, and microwave ovens use motors to turn the tray food sits on. Toaster ovens also use electric motors to turn a conveyor to move food over heating elements.

3. Electric Motor A motor consists of 2 magnets. 1 - An electromagnet that creates a magnetic field when electricity flows through it (INSIDE). 2 - Permanent magnets that interact with the electromagnet to create spinning or rotational motion (OUTSIDE).

4. Parts of the Motor ArmatureCommutatorBrushes Permanent Magnet DC power supply of some sort ARMATURE BRUSHES COMMUTATOR PERMANENTMAGNET

5. Armature The armature is an electromagnet made by coiling wire into loops. When you run electricity into the armature, it creates a magnetic field that attracts and repels the magnetic fields of the permanent magnets.

6. Commutator and Brushes Commutator is a device that reverses the flow of electric current. Commutator and brushes work together to let current flow to the electromagnet, and also to flip the direction that the electrons are flowing at just the right moment. This keeps the motor spinning in one direction without stopping. BRUSHES COMMUTATOR

7. The brushes are just two pieces of metal or carbon that make contact with each half of the commutator. 1 2 3 4

8. Spinning Armature