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How to Connect the Alarm to the Door as a Kid's Experiment

Every kid needs a little bit of privacy, but how do you make sure your little brother or sister doesn't get into your things? You can make a door alarm that buzzes to alert you that there is an intruder in your room. You'll make a simple electrical circuit powered by a safe battery. When the alarm is on and someone opens your door, you'll be alerted by the alarm.

Things You'll Need

(2) 1-foot lengths of insulated copper bell wire with ends stripped
(2) 1-foot lengths of bare copper bell wire
1.5 volt battery in a battery holder
5 feet of kite string
Scissors
Electrical tape
1.5-volt mini-buzzer
Wooden clothespin, spring-type
Wooden board or stiff cardboard, at least 4-by-12 inches
Piece of cardboard, approximately 1-by-1 inch
Super glue
Nail polish remover
Gauze square

Instructions

- 1
  Place a board or cardboard horizontally in front of you on the table. Place a battery holder horizontally in the upper-left corner of the board with the negative terminal to the left. Tape the battery holder to the board.
- 2
  Connect one of the insulated wires to the negative battery terminal. Connect the remaining insulated wire to the positive battery terminal.
- 3
  Place the buzzer vertically in the upper-right corner. One terminal will face the top edge of the board. Tape the buzzer to the board.
- 4
  Wrap each piece of bare wire three times around one of the closed ends of the spring clothespin. You will need to push the open ends of the clothespin together while you wrap the wire. When you let the clothespin close, the two wires should touch.
- 5
  Connect one of the bare wires from the clothespin to the free end of the wire connected to the negative battery terminal. Connect the other bare wire from the clothespin to the bottom terminal of the buzzer. If your buzzer came with wires attached, connect the clothespin wire to the buzzer wire.
- 6
  Connect the free wire on the positive battery terminal to the top terminal of the buzzer. If your buzzer came with wires attached, connect the battery terminal wire to the top terminal wire of the buzzer.
- 7
  Place the battery in the battery holder. The bare wires should touch and make the buzzer sound. If it doesn̵7;t, make sure your wiring is secure and correct.
- 8
  Place the small piece of cardboard between the closed ends of the clothespin to prevent the wires from touching and sounding the buzzer. Poke a hole in the center of the cardboard and thread the kite string through it. Tie the string securely.
- 9
  Put the nail polish remover and gauze square near your board. You will be using supper glue that dries quickly and is difficult to remove. If you get some on your fingers, remove it immediately with the nail polish remover.
- 10
  Glue the clothespin vertically to the board along the bottom edge between the middle of the board and the left side. Tie the free end of the kite string to your doorknob. Place the board against the wall near the door so when the door opens, it turns on the buzzer.

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