Today we will be showing you how to make your very own bag alarm! This alarm system can be integrated into purses, backpacks, suitcases, pretty much any kind of bag. It can then be used to protect your personal belongings from theft, misplacement, and even nosey siblings. This system will use photoresistors to tell when the bag is open then send power to a small speaker to deter the theif, and alert you and anyone around you that your bag is being opened. This will come in serious handy when you need to leave your bag around some untrustworthy classmates and or co-workers. By following the next simple steps you can secure your favorite personal belongings for a lifetime!

Step 1: Materials

1. Parrallax Breadboard
2. Wires of varying lengths
3. 1 220 ohm resistor
4. 20 gauge wires
5. 1 photo resistor
6. 7-14 volt speaker
7. 1 TIP120 transistor
8. Parrallax breadboard enclosure (optional)
9. 1 103 capacitor
10. Basic Stamp Editor v2.5.3.
11. Switch
Use a reed switch to activate and deactivate it. Also add a method of sensing vibration/movement so people can't just run with your stuff.
Yes, this was an issue we ran into when we came up with this design. But there are a couple easy fixes for this! You could run the switch on a longer wire and make a hole somewhere on the outside of the bag so you can flip it on and off without opening or disturbing the device inside. Or you could make an electronic remote switch and use that if you wanted to make it extremely convenient.Thanks for the feedback!
A less obvious way could be using a magnetic switch like are used on windows and a magnet to operate it. It would need to be the normally closed type switch and would open when the magnet was placed over it.
cool, it would be really neat if you made it so that there was a special trick to opening the bag w/o an alarm, so you can access your own bag with no problems.

About This Instructable


5 favorites


More by SatCenterEngDes: "Ur Choice" Tailgate Opener Keepin' It Cool
Add instructable to: