Light Telegram for TDE 331

A Brief History: The telegraph is one of the oldest forms of electronic communication. Invented by Samuel Morse in the mid 1800s. The Telegraph uses electrical pulses along wires to transmit messages composed of a series of dots and dashes known as Morse Code. The Telegraph fell out of use with the invention of more modern forms of long distance communication in the early 21st century, but it is an important part of telecommunications history. Traditionally telegraphs use audible clicks to communicate messages, but we used an LED to visually show the electric impulses.

Materials

Copper strip

2 nails

9v battery and connector

1 LED

1 Resistor

Scrap Wood

2 bottle caps

3 insulated wires (or alligator clips)

On one end of your board place one of your bottle caps and the copper strip and secure them with the nail as shown in the picture. Next place the second bottle cap near where the end of the copper strip is and put the nail all the way in.

Attach the battery and connector, next attach a wire to the nail in you second bottle cap with the other end attached to one of the leads on your battery.

Attach the negative lead on your battery to a resistor with the other wire leading from the resistor to the negative end of the LED. Then attach the positive led to the copper plate with a wire.

Now you are ready to start telegraphing, but you will need to know Morse code to do so properly!