Transcript of Basics of Motor Theory
Basics of DC Motor Theory An Introduction What is an Electric Motor? An electric motor is a machine that converts electricity into mechanical energy or motion. What does a DC motor look like? How does a DC Motor work? A DC motor runs on the simple principle of repulsion and attraction using magnetism. Three factors need to be present for a motor to work; Magnetic lines of flux, current through a conductor and relative motion. What are the main parts of a DC motor? Armature-Contains many loops of wire Permanent Magnets are stationary Connection point for stationary power source and moving armature Power source Maintains correct direction of current flow How Does it Operate? 1. Power is applied to the armature through the brushes causing it to turn, by creating repulsion from one magnet and attraction to the other magnet. 2. As the armature rotates so does the commutator. Commutator and Armature 3. When the armature has made a half rotation the commutator causes polarity change and attraction back to the starting position. 4. This continues until the power source is removed. Commutator Armature Advantages of DC Motors? Excellent speed control Very high starting torque Quick starting, stopping and reversing Free from reactive power consumption Disadvantages of DC Motors Initial cost is high Increased maintenance cost due to commutator and brush repair Cannot use in explosive atmosphere due to sparking at commutator Follow up What are some advantages to a DC motor? What are some disadvantages? What does an electric motor do? Where Do We Use DC Motors? Wrist watches Locomotives Cranes Elevators Conveyor systems Motor Type Torque Comparisons What three things have to be present for a motor to work? Confused? Me too...... Let's simplify it! Don't worry....... If you don't understand we will have time for clarification in the following lessons as we revisit this theory and look into the individual parts and their operation. Motor Theory Follow Up Using the model as an example, assess why the wire is not spinning. 1.The magnets are in the correct location; however the wire is not spinning. List all the possibilities.Full transcript
2. The magnets are in the correct location; the battery is connected and has a full charge, however the wire is not spinning.
3. The magnets are in the correct location; the battery is connected,however the wire is spinning slowly.
4.The magnets are in the correct location; the battery has a full charge, however the wire is not spinning at all.