"Last Day" Magnetic Sonic Cube Landmine
Intro: "Last Day" Magnetic Sonic Cube Landmine
UPDATE: It worked! Apparently someone picked it up Monday morning. It went off, and apparently went off for a while. It sounds like they had to disassemble it to shut it up. I'm ridiculously happy with the results.
At my present job, I have been known as something of a crazy hacker. For reasons too complex to explain here I have decided to leave after ten years. This Friday is my last day. I decided to leave a small present behind for anyone trying to scavenge scraps from my old cube.
Several ideas presented themselves to me, but eventually I decided on creating a small alarm that would go off mysteriously when someone moved it. Despite the elaborate title, the design is simple, and not to hard to replicate.
The alarm I used is something I pulled off the scrap dock of the job. It was originally designed to provide an audible alarm for manufacturing machines. Mine is capable of about 80db on a 9v battery, but you could replicate this with a Radio Shack buzzer or other alarm circuit.
The basic idea is to have a box siting on my desk. When someone moves it, an alarm sounds, and won't shut off. This is because the box has a magnetic trigger inside, and when the box was moved from the desk, it was also moved away from the hard drive magnet I planted under the desk, thus triggering the alarm. It will shut off again if they put it back in the same place, but there will *intentionally* not be anything to mark it's position.
At my present job, I have been known as something of a crazy hacker. For reasons too complex to explain here I have decided to leave after ten years. This Friday is my last day. I decided to leave a small present behind for anyone trying to scavenge scraps from my old cube.
Several ideas presented themselves to me, but eventually I decided on creating a small alarm that would go off mysteriously when someone moved it. Despite the elaborate title, the design is simple, and not to hard to replicate.
The alarm I used is something I pulled off the scrap dock of the job. It was originally designed to provide an audible alarm for manufacturing machines. Mine is capable of about 80db on a 9v battery, but you could replicate this with a Radio Shack buzzer or other alarm circuit.
The basic idea is to have a box siting on my desk. When someone moves it, an alarm sounds, and won't shut off. This is because the box has a magnetic trigger inside, and when the box was moved from the desk, it was also moved away from the hard drive magnet I planted under the desk, thus triggering the alarm. It will shut off again if they put it back in the same place, but there will *intentionally* not be anything to mark it's position.
STEP 1: Parts
You will need:
Parts:
1 Alarm circuit, buzzer, or other device to make noise.
1 project box or enclosure. Preferably plastic. The alarm I had came in an enclosure already.
1 9v battery, or a power source appropriate for the circuit you are using.
Small momentary switch. I used one out of a mouse. It needs to have a light trigger.
Hard drive magnet, or any other form of rare earth magnet. needs to be strong.
Misc hardware and some ingenuity. A genuine distaste for your co-workers is also handy.
Tools:
Soldering gun and solder.
Wire stripper and/or wire cutter
Screwdrivers
Rotary tool
You could make life a lot simpler if you had a magnetically actuated switch laying around you could use, but I rarely have things work out the easy way. I was forced to do it the hard way and create a magnetic switch from a conventional mouse-button switch.
Parts:
1 Alarm circuit, buzzer, or other device to make noise.
1 project box or enclosure. Preferably plastic. The alarm I had came in an enclosure already.
1 9v battery, or a power source appropriate for the circuit you are using.
Small momentary switch. I used one out of a mouse. It needs to have a light trigger.
Hard drive magnet, or any other form of rare earth magnet. needs to be strong.
Misc hardware and some ingenuity. A genuine distaste for your co-workers is also handy.
Tools:
Soldering gun and solder.
Wire stripper and/or wire cutter
Screwdrivers
Rotary tool
You could make life a lot simpler if you had a magnetically actuated switch laying around you could use, but I rarely have things work out the easy way. I was forced to do it the hard way and create a magnetic switch from a conventional mouse-button switch.
STEP 2: The Switch
The only hard part of this was getting the trigger put together and dialed in. I had to mount the switch to the side of the box, then find a small metal bar to act as a lever. Then I attached a metal weight to the other end of the bar. When a magnet is below the box, it pulls the weight down, disconnecting the battery from the alarm. When the magnet is removed, or the box moved, the weight goes up, connecting the alarm to the battery. Check the notes on the pictures.
STEP 3: Final Setup
I don't have any fear of this causing much of a panic. It will, in fact, be exactly the sort of thing people expect of me.
The desk I use is your standard cube issue. It has areas underneath where there is only an 1/4 inch or so of metal and material thickness. the magnet sticks to it just fine, and you can feel the magnetic effect clearly through to the top.
A magnet or two will go underneath, and the box over the "sweet spot" on top. I'll plug in the battery and walk.
I'll prob expand on this one more later. Just thought I would throw this one up there for the hell of it for now.
The desk I use is your standard cube issue. It has areas underneath where there is only an 1/4 inch or so of metal and material thickness. the magnet sticks to it just fine, and you can feel the magnetic effect clearly through to the top.
A magnet or two will go underneath, and the box over the "sweet spot" on top. I'll plug in the battery and walk.
I'll prob expand on this one more later. Just thought I would throw this one up there for the hell of it for now.
115 Comments
codongolev 12 years ago
build a large robot with several proximity sensors, powerful wheels, and a big, thick steel body. (use an electric wheelchair or something like that.) give it lots of huge batteries to keep it running for a long time (or make it seek out and plug in to outlets, but that could prove difficult). fill it with concrete so that it's somewhere around 500 lbs, then just set it loose in the halls. make it just wander around without hitting anything, maybe make it get angry if it's moved, etc....
BrefelanDesigns 13 years ago
RGM La Paz 15 years ago
account3r2 13 years ago
golddigger1559 15 years ago
abadfart 14 years ago
sam1997 13 years ago
lol
Saturn V 13 years ago
photozz 15 years ago
Saturn V 13 years ago
bounty1012 14 years ago
neardood 16 years ago
TheMadTinker 16 years ago
neardood 16 years ago
Akoi Meexx 14 years ago
DavidRobertson 15 years ago
Insaneisfun 16 years ago
neardood 15 years ago
glsluvs2snobrd 16 years ago
Gamer917 15 years ago