How to Make a Room Security Alarm

Place the wood block horizontally on a work table or other flat surface. Place the alarm buzzer at about the center of the wood block. Screw the alarm buzzer into the wood block with wood screws using the Phillips screwdriver.

Place the battery pack on the left end of the wood block. Tape the sides of the battery pack to the wood block with strips of duct tape.

Heat up the soldering iron for five minutes. Cut a 6-inch length of electric wire off the wire spool with a utility knife. Strip a 1/2 inch of insulation from each end of the wire with wire strippers. Repeat this procedure with two other lengths of electric wire, but make these pieces each 2 feet long.

Solder an exposed end of the 6-inch wire to one of the two contacts on the battery pack. Let the solder cool for a minute. Solder the other exposed end of the wire to one of the two contacts on the alarm buzzer. Let the solder cool for a minute.

Solder the exposed end of one of the 2-foot wires to the other contact on the alarm buzzer and let the solder cool for a minute. Solder an exposed end of the final electric wire to the other contact on the battery pack and let the solder cool for a minute. Unplug the soldering iron and let it cool thoroughly before putting it away.

Grip the back of the clothespin and press down to open the jaws. Strip an additional 6 inches from the ends of the two free wires with the wire strippers. Wrap the exposed end of one of the wires around the top jaw of the open clothespin. Wrap the exposed end of the other wire around the bottom jaw of the clothespin. Release the clothespin to close the jaws. Confirm that the two wires touch each other when the clothespin is closed -- if not, open the clothespin and rewind the wires so that they do.

Open the window. Place the back end of the clothespin on the window sill at the right corner of the window frame. Close the window all the way down -- this will open the jaws of the clothespin slightly.

Insert batteries into the battery pack. Place the wood block on the floor next to the window. If the window is opened, the wires on the clothespin will touch each other and your room security alarm will sound off to alert you.