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Electromagnetic buzzer

There are many fun and useful applications of magnets. Here we look at how to create a simple electromagnetic buzzer. Make your own using basic items you can find around the home.

You will need:

  • wirestrippers
  • scissors
  • coated wire (one 2m piece, 2 10cm pieces)
  • screwdriver, paper clips
  • D battery
  • tape
  • card
  • steel bolt
  • nail file
  • steel can
  • cotton reel
  • paper fasteners
  • plasticine
  • rubber band
1

Make a switch by pushing two paper fasteners through the card, no more than a paperclip length apart.  Attach a steel paperclip to one of the fasteners.

 

2

Strip 2cm at both ends of the wire, and wrap firmly around the bolt about 200 times with about 10cm of spare at each end.

3

Fix horizontally to the card with plasticine..

4

Using the rubber band attach the nail file to the cotton reel.

5

Scrape the paint off two patches on opposite sides at the bottom of the can.

6

Tape one end of the wire to the metal part of the nail file.

7

Fix the flat end of the cotton reel to the card using plasticine.

8

Strip 1cm at both ends of the 10cm pieces of wire. Connect one piece from a battery terminal to the switch, and one from the other battery terminal to a scraped patch on the can.

9

Stick the can to the card, make sure that the nail file touches the other scraped section.

10

Make the final connection using the spare end of wire from the bolt to the switch.

11

Close the switch by bringing the paperclip into contact with the second paper fastener.