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!
Stuff you need:
9V attachment clip
Cut some of the metallic tape to use on the clothes pin
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.
Wrap both ends of the clothes pin with the metallic tape.
When these touch, they will close the circuit of your alarm.
Place the round end of the wires on the clothespin as shown.
Duct tape the wires to the grip end of the clothespin.
Wrap the outside of the wires with metallic tape.
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.
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.
Tape up the wires.
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.
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.
Loop some fishing line around the notch as shown.
Wrap the line and plastic with duct tape to secure it as shown.
Here is what you should have so far.
Tighten it up.
You can probably do better, but this is basically all you'll need.
Here's a little video of this working.
Cheers you all!