How to Make a Pressure Mat

A pressure mat slides under a rug or doormat.

A pressure mat alarm system is a type of mat that emits a sound when the mat is stepped on and the circuit is completed. This type of mat is often used by practical jokers and is often used during Halloween to scare children and other visitors. Making a homemade pressure mat is easy, and you can make one from household supplies.

Things You'll Need

• Clear tape
• Scissors
• 4.5 volt battery
• 3VDC buzzer
• Metal paperclips
• Aluminum foil
• Electric cable
• Drinking straws
• Door mat

Instructions

1. Fold the foil in half so it is a 6-inch by 8-inch rectangle.

2. Cut the plastic coating off the ends of the wire on the buzzer and the electrical cable. The electrical cable should be about 8 inches long.

3. Connect the electrical cable to the negative side of the battery. Wrap the wires around the battery so they will not fall off.

4. Tape the other end of the electrical wire to the aluminum foil. It doesn't matter where the wire connects, but it is easier to connect it to the edge of the foil.

5. Connect the black wire from the buzzer to a paperclip. Wrap the exposed wire end over the top of the paperclip. Connect 20 additional paperclips to the first one, making a long paperclip chain.

6. Wrap the red wire from the buzzer around the positive end of the battery. Touch the end of the paperclips to the foil. The buzzer should sound. If it does not, then make sure that all wires are touching the metal parts they are supposed to touch.

7. Stretch the line of paperclips straight across the floor where the mat will go. Place straws on either side of the paperclips to prevent the mat from touching the paperclips. Tape the straws in place to prevent them from rolling away or moving.

8. Place the foil on top of the straws. Hide the battery and the buzzer behind a plant or some other decorative object so they cannot be seen.

9. Place the mat over the foil. Test the mat by stepping onto it. The buzzer will sound if all metal pieces are touching. After several uses, you may have to replace the straws.

Tips & Warnings

• A 3VDC buzzer can be somewhat difficult to find. However, most hobby stores should have one in the crafts section. If you cannot find a local store that has the buzzer, do an Internet search for these small buzzers.

• This project uses an electrical current, therefore, it is important to take safety precautions when working with wires. Never touch a bare electrical wire while it is connected to a power source.

• Do not operate the pressure mat in wet conditions or near water of any kind. This can cause dangerous electrical shock to the person stepping on the mat.

References

• Meta Cafe: Pressure Mat Instructions
• TEP: Completing Alarm Circuts