Kipkay
Here is an easy to make and powerful laser alarm system that can protect your entire home, indoors or out! My inspiration for this project came from Brad Graham & Kathy McGowan. Watch the video for details and the Test Results. You'll be impressed. I hope you enjoy this Instructable.
- 2 small project boxes
- 1 1000 uF 35 v Capacitor
- 1 5 K Variable Resistor
- Photocell
- IC Board
- 9 v battery and clip
- 1 N3904 Transistor
- Toggle switch
- Small mirrors
- HandiTak
- 12 v DC Piezo Siren - 102 dB
- Aixiz 650 nm 5 mw 12 X 30 mm laser
- Aixiz 3.2 v AC Adapter
Build the circuit based on the diagram. I cut my IC board with a dremel to make it smaller so there was enough room in the box along with the 9 V battery.
Install the circuit board and the 9 V battery in the hobby box. Line up the photocell at the hole and hot glue everything in place. Also, attach the siren and run the wiring inside the box. Finish your solder connections with the siren.
Cut 3 holes in your second hobby box. One for the switch, one for the laser housing and one small one for the wires from the AC Adapter. Run the wires from the AC adapter in the box. Install the swicth and hot glue the laser in place. Wire the positive end of the AC adapter to the red wire from the laser and wire the negative ends of the laser and adapter to the switch.
Turn on the laser and point it at the photocell box. You will have to adjust the resistor so the photocell is sensitive to the laser pointing at it during the day. At night, when the laserbeam is broken, the siren will sound.
Decide where you want your protection, across what doorways and then decide on where you want the laser to plug in and where you want the photocell box to pick up the laser. I used 1" square mirrors (from an arts and crafts store) and HandiTak to mount the mirrors. You could use a more permanent solution for the mirrors. The idea is to angle all the mirrors to the next wall across where you want protection and then have it end up pointing at the photocell.
Now when it gets dark and the laserbeam is broken, the LOUD 102 dB siren will wail! Hope you enjoy this Instructable.
