Hobbies And Interests
Things You'll Need
Instructions
Cut off a 20-foot piece of insulated wire. Use the wire stripper to strip about 1 inch of insulation off each end of the wire.
Wrap the wire around the bolt 200 times. This wire and bolt will form the electromagnet. When electricity travels through a coil, it produces a stronger magnetic field than if it just travels through a straight wire. The denser the coil, the more intense the field.
Fasten the nail file to the cork with a rubber band. When the circuit is complete, the nail file will move back and forth. The sound of the buzzer comes from the file hitting the can.
Fasten the electromagnet and the cork to your cardboard base with glue.
Fasten one wire from the electromagnet to the end of the nail file.
Fasten the other wire from the electromagnet around the metal shaft of a push pin. Call this Push Pin 1.
Push the push pin through the paper clip into the cardboard base. The wire wrapped around the shaft of Push Pin 1 must make contact with the paper clip. Leave enough room so you can move the paper clip.
Cut a 12-inch piece of insulated wire. Strip the ends as in Step 1.
Wrap one end of this wire around another push pin, Push Pin 2. Insert Push Pin 2 into the cardboard near enough that it can touch the paper clip connected to Push Pin 1.
Wrap two batteries together with electrical tape. Positioned side by side, one battery should have its positive end (with the small bump) pointing up and the other battery should have its negative end (flat) pointing up. Take a piece of wire and link it over the positive and negative terminals of the batteries and secure it in place with a piece of electrical tape. The batteries are now linked and work as a single unit.
Flip the battery unit over so that you now see another positive and negative terminal. Connect the other end of the wire from Step 9 to the positive terminal on the battery unit.
Prepare the metal can. Remove any paper wrappings. If the can has paint on it, scrape it off on opposite sides of the can. Position the can on the cardboard so that it is within reach of the nail file. If you want a different tone, use a bell instead of a can.
Cut off another 12-inch piece of wire. Tape one end of the wire to the free negative terminal of the battery pack. Tape the other end of this wire to the can. The circuit is now complete. You can open and close the circuit by bringing the paper clip in and out of contact with Push Pin 2.