PROJECT # 4
To use an electromagnet in the construction of a telegraph.
sheet metal piece (looks like the letter Z)
wood from project 1
2 battery holders
hookup wire (yellow wire that has plastic insulation)
Keep in mind that a telegraph consists of a sounder and key switch.
Before you start you will need to make another strong electromagnet with 300 turns like you did for the last electromagnet. Remember that you had to start and finish 1\4 from the straw because you had to remove the nail, this time make it in the way that you begin from the top don't forget to insert the straw and it does no matter if the wire touches the nail. Remember to make three layers starting from the top going your way down coming back up and then going down, and to beging from 2ft from the wire. When you finish take the two ends of the magnet wire and tie them together. Grab your wood and remove everything except the screws and the key switch. Take a hammer and insert the strong electromagnet in hole 8. After you insert the electromagnet, connect the sheet metal that looks like the letter Z in hole 5. Cut two pieces of masking tape and tape one piece in the edge of the sheet metal to reduce unwanted vibration of the strip when it bounces back from the sounder. The sounder is the connections you made with the electromegnet and the sheet metal because this part will be the part that will make noise. The other piece, tape it in the bottom of the sheet metal to for more help in trying to reduce unwanted vibration. If your sheet metal and the top of the nail are to apart you can adjust then by bending the sheet metal in a way that is 1\8'' from the top of the electromagnet, really close but not touching. Take one end of the electromagnet and connect it in hole 9. The other end of the electromagnet connect it in hole 1. Take your battery holder and connect the negative side to hole 9. The positive side of the battery connect it to the key switch. Now that you have finish in constructing your telegraph test it by pressing the key switch.
If the Sounder Doens't Function Check the following:
Bring a compass close to the electromagnet and then press the key. Did your compass move? If it didn't adjust the sheet metal and the top of the nail to be a little more closer.
You can also ckeck the connections from the battery to the key and the sounder. Make sure that the end of the wires are insulated to make a good electrical connection and that the screws are tight agains the wire ends.
Now that you have your telegraph working, you can send messages to yourself using the International Morse Code. The . dot is about 1\4 second long and the - dash is about three times longer. What if you want to send messages to someone else?If you want to send messages to someone else, you will need another wood. If there is a wood available, do the same connections you made to construct your telegraph. When you finish take the hookup wire and cut two pieced as much needed, but remember that they have to be away from each other. Take one end of a wire and connect it to one of the woods in hole 9. The other end of that same wire connect it to the other wood in the same place in hole 9. Take the other wire and connect one end to one wood in hole 1. The other end connect it to the other wood in the same place in hole 1. Now you can test your new telegraph.