How To Build a Morse Code Buzzer

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How to Build a Morse Code Buzzer

Here are the instructions on how to build a simple Morse code buzzer. We also have plans for a slightly more full featured buzzer and telegraph. You can use either buzzer to learn Morse code or to use in the classroom.

Parts List

The buzzer is simple to build, all you need is a button, a buzzer, a battery and a battery holder. All of these parts are available from Radio Shack:

12 Volt Buzzer (Radio Shack part # 273-055, $2.59)
Momentary Button (Radio Shack part #275-609, two in a package for $2.79)
9V Battery Clip (Radio Shack part #270-325, five in a package for $1.39)
9V Battery (Radio Shack part #23-783 $1.29)
Optional Project Box (Radio Shack part #270-221, $2.29)

The total cost per buzzer is $7.85 ($5.56 if you don't use the box.) It costs a little more if you only build one buzzer because battery clips and buttons come with more than one per package.

Instead of a project box, you can hold the button in you hand or mount it on a board or piece of stiff cardboard. If you do not have a Radio Shack or other suitable electronics store near you, you can get these parts by mail order by calling 1 (800) 843-7422. (1 817 624 1196 for orders outside of the United States.) TerraX.org is not affiliated with Radio Shack in any way, this is just any easy way for everyone to use the same part numbers.

Instructions:

The buzzer is easy to build too:

First drill a 1/2 inch (1.3 cm) hole in one end of the box and insert the button. If you chose a different button, drill an appropriately sized hole. A shop teacher, maintenance person, or art teacher may have a drill and be able to help drill the hole.
Remove 2 cm (3/4 inch) of insulation from the ends of the 4 wires (2 on the buzzer, 2 on the battery clip.)
Insert the end of the red wire from the battery clip halfway through ONE of the holes in the metal contact on the bottom of the button. Tightly twist the wire back around itself to make a secure connection.
Connect the red wire from the buzzer to the other metal contact on the button in the same fashion.
Twist the two bare ends of the black wires together.
Clip the battery clip onto the battery, the buzzer should then buzz when you push the button.
Tape the wires to the buzzer to the box such that the buzzer is held firmly against the bottom of the box.
Attach the box lid.

The following steps are not necessary, but will make the project more durable:
A shop teacher, science teacher or maintenance person may have a soldering iron or electical tape.

It helps to solder each connection if you have a soldering iron available.
Tape each connection with electrical tape. (Masking tape will help if you don't have electrical tape.)
Tape, glue, or screw the battery holder and the buzzer to the box. You should drill another hole in the case over the buzzer so that the sound is more audible. Keep glue away from the holes in the top of the buzzer.

Optional Options

You can substitute a 12 Volt LED light for the buzzer, or in addition to the buzzer. We have additional plans for a telegraph that includes the LED light and a connector so that you can buzz people at the other end of a wire!

That's it, you're done!

Visit the Morse code page or the teacher's lesson plan. If you would like to expand your buzzer's capabilities, see the plans for the buzzer and telegraph.