How To Build a Laser Security System
- April 7, 2008
- 42,754 Views
Writer
Howcast
Music
Edison Music Corp
Voice Over Artist
Peter Coleman
Expert
Randy Sarafan
Got a mystery to solve? Somebody’s been making off with your stuff, and you don’t have a clue who it is, do you? Here’s your chance to catch them in the act.
You Will Need
- A laser pointer
- Some Duct tape
- A few small mirrors
- An L.M.741 microchip
- A 220-ohm resistor
- A photocell
- An inexpensive digital camera
- An extra small screwdriver
- A wire coat hanger
- Some thin, insulated wire
- A printed circuit board
- A 9 volt battery
- A 9 volt battery clip
- Soldering equipment
- A pair of wire cutters
- A soap caddy with drainage holes
- A voltage relay
Step 1: Build the circuit
Build the circuit. Center the microchip on the circuit board. Pop in the voltage regulator. Connect the battery clip leads to the regulator. Run 2 more leads out from the regulator. Pop in the resistor and the photo cell. Link the chip to the photo cell. Pop in the relay. Link the chip to it as well. Link the other side of the relay to “power.”
Step 2: Disassemble camera
Disassemble the digital camera so you can access the board connected to the camera’s trigger button.
You may have to remove the camera’s board to get a good solder point on the terminal.
Step 3: Solder wires to terminals
Look for the two tiny terminals that lead to the trigger button. Solder wires to each of these terminals and feed them through the trigger button hole.
Step 4: Reassemble the camera
Reassemble the camera. If you can’t get it back together easily, use duct tape to keep it closed. Just don’t tape over the lens.
Step 5: Position circuit inside soap caddy
Position the circuit inside the soap caddy so the photocell is exposed behind one of the holes.
Step 6: Connect battery to circuit
Connect the battery to the circuit, and use tape to secure the whole assemblage inside the box.
Step 7: Attach wires to voltage relay
Slip the two wires coming from the camera through another hole, and attach them to either side of the voltage relay.
Step 8: Cut & tape coat hangers
Cut the coat hanger into several pieces. Tape one piece to the laser pointer and the others to the back of the mirrors.
Step 9: Place camera
Place the camera in an inconspicuous location with the lens pointing at the object you want to protect and secure it in place.
Step 10: Position laser pointer
Position the laser pointer in another inconspicuous place and secure it too.
Step 11: Place mirrors
Place the mirrors to create a perimeter around the object you’re protecting, adjusting them until the laser hits the photocell.
Step 12: Test the system
Now break the beam to test the system…
And get ready to confront the perpetrator with your irrefutable evidence.
The term LASER is really an acronym for Light Amplification by Stimulated Emission of Radiation.
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Comments (13)
This was an awsome video
2 thumbs up :D
over 3 years ago by NolMcall
Where can i buy LM.741 microchip how much willl it cost $$$$$$$$$$$$$$$$$$$$$$$$$
over 3 years ago by mcmc
where can you find them
over 2 years ago by techdawg989
you can easily fint it in wallmart
about 1 year ago by leonardokrleza
the lm741 is an op-amp. a replacement part that will work is the lm358 found here: http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&;name=LM358ANFS-ND
over 2 years ago by bstack88
What is a LM.741 microchip
over 3 years ago by mcmc
which voltage relay is he using and also what does it mean :Link the other side of the relay to “power.”
about 1 year ago by timrocks55
i had laser surgery on my eye balls
over 2 years ago by zzzzzzzandaz
seriosly i have not been able to find one by searching on google. i really need one
over 2 years ago by techdawg989
if i make the except thing like thiss but i dont use a camera but a sirene. will it work then ??
over 2 years ago by shaqqy
Clear, Entertaining, intriguing
Intellectually stimulating!
Well-researched.
http://mcatprep.yolasite.com/
over 2 years ago by Wynne_Evans
I think this video is an altogether fail.
about 1 year ago by Aron
this is the excitin project ive ever seen.....
about 1 year ago by idtsraj
can you please tell me specifications on voltage relay and voltage regulator
about 1 year ago by leonardokrleza
too fking lot materials
over 3 years ago by eddieyou1018
I don't think this is very helpful Lm741 op amp is an integrated circuit, you have to be an electronic technician with an ecg master guide ic book list to know which pins to connect or else you destroy the ic itself if you connect the leads on the wrong pins.
over 2 years ago by Roy_Darvin
it takes two seconds to look it up on google. what im more concerned about is the values for the photoresistor, the relay and the voltage regulator. With most photoresistors the 220 ohm resistor wont work, and im also wondering why the non-inverting input to the op amp doesnt have to be connected to anything.
over 2 years ago by Dennis_Cushing
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