Make a Buzzer
(Buzzer or Bell)
Buzzer or electric bell is an electromagnet that automatically connects and disconnects many times per minute. This will cause the vibration of the armature and creation of a buzzing sound. The sound of a buzzer in a commercial buzzer is amplified by a small hammer hitting a bell. Before you do this experiment, you must have successfully completed the telegraph sounder experiment.
|In the telegraph sounder you made before, the magnetized nail will attract the long arm or armature any time you push the key. We will now use the same armature as a secondary key in our circuit in a way that when the armature is pulled down, it disconnects the the circuit. This will make the nail to lose its magnetic strength so the armature pulls back up again. As the armature moves up, the circuit will close again and the cycle repeats.|
|Make a Flipper:|
To do this you must bend a bare copper wire as shown in this image. This is called a flipper because it automatically flips the circuit from off to on or wise versa. (This copper wire is only available in advanced kits. If you don’t have an advanced kit, use any bare copper wire). Use a screw to secure this wire on the board in a way that the other end of the wire touches the top of the armature.
|In your telegraph sounder, the red wire of the battery holder was connecting to the key. In this buzzer you connect the red wire of the battery holder to the screw of flipper. Then you also connect another wire from the screw of armature to the key.|
Now the electricity enters the flipper, passes through the armature and then enters the key/ switch.
|Test your buzzer:|
Push the key to connect the circuit. The buzzer must buzz. If it is not do some trouble shooting as described here: