How to Create a Buzzer

First you need to gather up all of the materials you will need. Below is a list of the following items needed to conduct this project:

• 9 feet of PVC covered wire (both ends stripped)
• 1 steel bolt
• Modeling clay
• 1 empty thread spool
• 1 steel nail file
• 1 rubber band
• Scissors
• Plastic tape
• Thick cardboard
• 1 soda can
• 1 switch
• 4.5 volt battery

Are you ready? Let’s get started. Leaving both ends of the wire loose wrap the wire around the steel bolt as tight as you can – approx. 200 times. Grab the clay and affix the steel bolt to the cardboard. Using the rubber band, attach the handle of the nail file to the empty thread spool (the spool needs to be on its side). Scrape away the paint from the bottom of the soda can using the scissors. Attach the empty thread spool with the nail file on it to the cardboard with the clay and then tape one end of the wire to the metal end of the nail file. Cut the two wires and attach one end to the battery and the scraped part of the soda can and the other to the battery and the switch. Using the clay, attach the can to the cardboard and touch the scraped part of the can to the metal part of nail file. Press the switch and the can emits a loud buzz. The nail file vibrates and strikes the can repeatedly. When you release the switch, the buzz will stop and the nail file will quit vibrating. So I bet you’re wondering how all of this works? Electricity is flowing from the battery through the soda can and then to the nail file. When the nail file strikes the can, electricity flows through it to the electromagnet formed by the steel bolt and wire. Then it proceeds through the switch and back to the battery. The electromagnet then pulls the nail file away from the soda can. Accordingly, the electricity will stop and the nail file will spring back striking the can again, thus repeating the cycle. The buzzing sound is created by the movement of the electromagnet.