Presure Switch Alarm




About: I got a VEX robotics kit for christmass, even though it says "14" and older I practically mastered it and the programing kit I got for my birthday. I've always made alarms just for fun but they really work w...

An alarm to keep intruders out for practicly no money! Very effective and scares intruders. Extremly easy, maybe to easy.


Step 1: Gather Your Things.

Ok you will need:
One medium sized piece of cardboard-strong not flimsy.
An alarm or piezo or hor or somthing that makes loud noise.
One short piece of wire.
A battery OF THE CORRECT VOLTAGE I'm saying this because I used a nine volt and it blew out my alarm, make sure your alarm can handle your voltage.
Siccors and electricle tape or transparent tape will work fine.
And Alluminum foil.

Step 2: Folding the Cardboard

Thats it fold the cardboard in half.

Step 3: Cutting the Foil

Cut the foil to the width of your cardboard.

Step 4: Tapeing

Now tape the foil to the edge of the folded cardboard. And push the wire of the battery holder through the foil and tape it in place.

Step 5: Tapeing the Other Side

Now tape the other piece of foil to the other side of the cardboard. Then push the piece of wire through the foil and tape it in place.

Step 6: Attching the Alarm

Now attatch the two extra wires, making sure positive and negative are correct, to the alarms battery terminals with tape. Pluug the battery in and turn on the alarm.

Step 7: Hide

Now put it under a light rug and be sure to have cardboard that doesn't fold all the way when the rug is on it. Now when someone steps on it the circuit will be completed and the alarm will go off.

This is my first instructable and I hope you liked it.



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    23 Discussions


    12 years ago on Introduction

    The alarm he used is available at the dollar store BTW. Very loud, until you take it out of it's case. The plastic seems to amplify the sound.

    4 replies

    actually what happens is, the plastic has a very firm grip on the speaker (which helps piezoelectric speakers to work better) and since it has such a good grip, most of the sound is picked up by the plastic, cause the case itself to make sound.


    9 years ago on Introduction

    "Oh lookie here, who's battery is this? And oh, look i found another alarm. Back to looting" :D


    12 years ago on Introduction

    Just for your information, technically speaking, a pressure switch usually refers to air pressure (and is pretty much useless for most applications). These things are generally referred to as floor switches or something of the sort. I have an industrial grade version of these floor switches that came my way when they "fell off the back of a truck" a while back. Essentially they follow the same principle as the one you have just built. I like the idea of using the cardboard as a hinge and also think this would benefit from using a plastic straw or two as spacers. Nice work.

    2 replies

    11 years ago on Introduction

    This is a Great instructable!!! i am going to make this right now....hehe


    12 years ago on Introduction

    i made one of these a wile back because our dog was sneaking into the living room to sleep on the new leather furniture! so i made something very similar to this and put it under a cussion then put a wire though the roof to a cheap and nasty digital doorbell. so later that night ...... DINGDONG...DINGDONG...DINGDONG... (NOISE DAD RUSHING DOWNSTEARS)...WHAT THE "%$£! Y DOIN ON THE CHAIR! (NOISE OF DOG MAKING A RUN FOR IT!) LOL

    1 reply