1. IOT POLY ENGINEERING 3 6 Dec 2011 Speaker Project

2. IOT POLY ENGINEERING 3 Goals 1.To understand how speakers work and how the reverse process of turbines work to generate electricity 2.Apply the engineering design process 3.Communicate results

3. IOT POLY ENGINEERING 3 How Power Plants Work 1)Convert Potential Energy to Mechanical Energy 2)Convert Mechanical Energy to Electrical Energy

4. IOT POLY ENGINEERING 3 How Speakers Work 1)Convert Electrical Energy to Magnetic Energy 2)Convert Magnetic Energy to Mechanical Energy

5. IOT POLY ENGINEERING 3 How Speakers Work 1)Electrical Energy is inputted by Audio Device

6. IOT POLY ENGINEERING 3 How Speakers Work 2)Electricity passing through a wire creates a magnet - Increase the strength of the magnet by wrapping wire into coils.

7. IOT POLY ENGINEERING 3 How Speakers Work 3) Electromagnet attracts or repels permanent magnet.

8. IOT POLY ENGINEERING 3 How Speakers Work 4) One magnet is fixed and the other magnet is attached to a membrane. As electromagnet changes direction, membrane vibrates.

9. IOT POLY ENGINEERING 3 How Speakers Work 5) Vibrating membrane moves air molecules. Air molecules collide with our ear drums and we hear sound.

10. IOT POLY ENGINEERING 3 Supplies 1 square foot of cardboard 1 neodymium magnet 4 feet of magnet wire Paper plate 1 piece of construction paper scissors glue

11. IOT POLY ENGINEERING 3 Speaker Steps 1.Make electromagnet out of wire -Slightly wider than magnet -At least 6 inches of wire before and after coil -Tightly wound 2.Make suspension system Must support paper plate and allow it to vibrate 3. Connect coil to the center of the paper plate

12. IOT POLY ENGINEERING 3 Speaker Steps 4.Connect magnet to cardboard 5.Connect suspension system to paper plate 6.Connect suspension system to cardboard 7.Test the Speaker 8.Redesign if speaker doesn’t work

13. IOT POLY ENGINEERING 3 Assessment Work with one partner –Produce a working speaker that clearly plays music –Produce a write up that details every step needed to make the speaker. Should be written so that a 3 rd grader could make the speaker

14. IOT POLY ENGINEERING 3 Supplies Provided with 1 magnet, 4 ft wire, paper, and cardboard Extra Supplies –$1 per magnet –$0.20 for every foot of wire