The supplies you need should all be available at your local hardware store or home center. If a 1.5 volt buzzer isn't available at your local hardware or home center, try looking at an electronics store. All things considered, these supplies should cost around $30 if you have to buy all of the following:  1.5 volt battery 1.5 volt mini buzzer Cardboard (like from a cereal box) Electrical tape Glue Insulated wire (3 strands, small gauge) Piece of plywood (4x12 in (10.2x30.5 cm) or larger) Tape measure (or measuring stick) Wall hangers (glue-based, removable) Wooden clothespin (with spring) 3 - 5 ft (.91 - 1.5 m) of string Wire snips (or sturdy scissors) Wire strippers Use removable wall hangers or tape to attach the wood on the wall. This will be the base of your door alarm. You may need to drill holes in the wood to hang it from the hangers.  Generally, you'll want to attach your piece of wood close to the top of the door, within a foot (30.5 cm) from the door frame. Alternatively, you can place the alarm flat on a desk, nightstand, or bookshelf positioned close to the door so you don't have to hang it. An alarm that's high up will be harder to reach and deactivate. Doing this, however, might require more string. Use a pair of sturdy scissors or wire snips to cut three stands of wire each one foot (30.5 cm) long. If using scissors, you may have to work these back and forth before the wire weakens and cuts.  Measure the wires with a tape measure or measuring stick and bend the wires where you will cut them. This will make it easier to cut accurately. If you find that your scissors don't cut the wire well, a sharp knife, like a utility knife, can work as a substitute. Each wire should be covered in an insulated coating. This can be stripped off with your wire strippers. Place two inches (5 cm) of wire into the slot on the strippers that is marked for the gauge of wire you are using. Close the strippers firmly and pull the wire through to remove the insulation. Do this for both ends of each strand.  Scissors or a utility knife can also be used to remove insulation. Cut the insulation until you hit the metal wire on the inside, then peel off the insulation. If the insulation doesn't come free easily, use a pair of pliers to grip the insulation firmly and pull it off.
اجمع الأدوات اللازمة لصناعة جرس الإنذار. الصق الخشب الرقائقي على الحائط بجانب الباب. اقطع ثلاثة فروع من الشريط العازل. أزل العازل من أطراف كل فرع من السلك.