Clothespin Trip Wire Alarm

Here is a fun little project that you can make quite easily.

BACKGROUND - I recently went on a canoeing trip. I the middle of the night, some people happened upon my campsite and tried to steal my canoe. I caught them before they managed to make off with my only transportation. And now they have learned to respect the sanctity of a man's camping spot.

Still, the experience led me to think... and thusly build this tripwire to alert me of strangers.

You can use it for a lot of different situations where you would need an alarm....

Duct tape one end to a door and let the trigger pull out when the door is moved.

Tape one end to an object and if it is moved, then it will sound off.

The possibilities are quite endless.

If you make one, post a pic and share with the rest of us potatoeheads!

Cheers spuds!

~ Robonerd

Step 1:

Stuff you need:

Fishing Line
Duct Tape
Metallic Tape
Electric Tape

Buzzer Speaker
9V attachment clip
9V Battery
Wires
Clothes pin

Scissors
Wire Srtippers
Wire Snipper

Step 2:

Cut some of the metallic tape to use on the clothes pin

Step 3:

Strip the wire on both ends
Strip one end more than the other
Bend the long ends into a circle - this will be the conductive end that is placed on the clothes pin.

Step 4:

Wrap both ends of the clothes pin with the metallic tape.
When these touch, they will close the circuit of your alarm.

Step 5:

Place the round end of the wires on the clothespin as shown.

Duct tape the wires to the grip end of the clothespin.

Step 6:

Wrap the outside of the wires with metallic tape.

Step 7:

Secure one end of the wires to the positive on the battery clip.

Secure the other end of the wires to the positive on the buzzer speaker.

Step 8:

Secure the ground of the battery clip to the ground of the buzzer motor.

You can solder all these wires, but you don't really have to.

Step 9:

Tape up the wires.

Step 10:

Take some fishing line and run it through the center of the clothes pin as shown.

Later you will secure this to a solid object to form one end of your alarm.

Step 11:

Cut a piece of scrap plastic in a rectangle (cardboard will work too).

Cut a notch as shown.

This will be placed between the conductive ends of the clothespin.

Step 12:

Loop some fishing line around the notch as shown.

Step 13:

Wrap the line and plastic with duct tape to secure it as shown.

Step 14:

Here is what you should have so far.

Step 15:

Tighten it up.

You can probably do better, but this is basically all you'll need.

Step 16:

Here's a little video of this working.

Bzzzzzzzzzzzzzzzzzzzzzzzzz!

Cheers you all!

Comments

[Malkaris]

Made something like is in Shop class as a kids, we used thumb-tacks as the contact points and a little wedge of wood tied to a string for our "burglar alarm". Hmm, if I still had it It would make a great instruct-able, I ended up giving it away to a kid who had an interest in electronics.

[clownpunch]

I made a water leak detector from a fire alarm by tapping into the test switch, while not as portable, it could use this trigger and would be very loud.

[roknrolla]

fyi, this is also how many IEDs are initiated.

source: found ieds with this switch.

[robonerd]

Every cub scout knows this. I think I'll stick to door buzzers for now. Thanks for the heads up though squire.

[ValleyMaker]

hence the reason I cringed when I saw this Instructables main picture.

[rbusch]

cleverly simple.

[diy_bloke]

Did mine with two bolts. never realised I could use metaltape. Great tip

[jmissavage]

Brilliant. would also work with parts you can aquire from an old smoke detector! perfect for campers. survivalist bear perimeter. or just your good ole run of the mill poor man prepper...endless possibilities...gate/door alarms.
thank you so much for sharing!!!!
-Jeremy

[robonerd]

My pleasure, glad you found it useful! Thanks for the tip on the smoke detector siren. I had a friend that was asking where he could salvage one of the buzzers. And he will be glad to hear your tip. Cheers sir!