Home Made Laser Security System?, Made cheap

Hey guys, havent been on for a while. I was bored and now iam on a mission to create a cool laser security system for my room.
So far i bought a buzzer from radio shack for about $4.00 it says its a 12V buzzer
and i boght a small project box, laying around i found a laser level, works great, some mirrors, and about 5 night lights which all broke

this is what i did basicly i took apart a night light with the photocell exposed, and took the buld out, and the two copper looking things inside that connected to the light buld, i connected the buzzer directly to them, on the buzzer one wire is black and the other is red, but i dont think it mattered where you connect it to, so now i got a night light instead of a light buld i got a loud buzzer. Now heres the problem, when i plug the night light into the wall, i hear i quck buzz a snap, alittle but of smoke and silence when i took a look iside seams like this little black transistor poped in half, like it blew. can someone help me out please, cause this would be an awsome security system

by the way the night light says the buld runs on 4watt

This post has been edited by lbcitezen on April 27, 2008 01:33 am

You need a buzzer which runs on mains AC, which yours obviously did not. The RatShak buzzers are all meant to run on low voltage DC. The blown 'transistor' is likely a TRIAC & a new light is the cheapest way to go.

well that buzzer i got, maybe i can put a resistor before it so not so much electricity goes throw?

http://www.radioshack.com/product/index.js...rentPage=search
right here is what i got as the buzzer iam sorry it runs off of 12v

These should wake ya up (have a couple myself).

http://www.allelectronics.com/cgi-bin/item...AC_BUZZER_.html

hmm that might work, actually. Do they have them at radio shack, or maybe i can take something apart and take a buzzer out of that like an alarm clock?

Their online search only shows DC buzzers unless I overlooked something.

http://www.radioshack.com/search/index.jsp...gkw=buzzer&sr=1

Not sure about all alarm clocks, but I've never found a 120VAC buzzer in one.

maybe a smoke alarm what does that use?

Lol, a battery operated one? I'm guessing low voltage DC...

well i tried diffrent sicrets that i solder together, using 9V battery, a DC buzzer, transistor, a 5k variable resistor and a photocell i pulled of a nightlight, that did not work i dont know why, but all i heard is a little bit of screaching inside the buzzer. lol. will a night light work if instead of connecting it to the ac wall, maybe connect a 9v battery, or a ac dc adapter to it?

You should be able to use just the photocell and operate a transistor as an on/off switch. The nightlight has SCR switching that's designed for high voltage AC, and the photocell alone may not be able to carry much of a load.

Have you tested the photocell to see what it does in light and darkness? If it's a photoresistor, its resistance will change when checked with an ohmmeter.

I like this idea a lot

really that was brilliant idea

It is kind of scary that so many people need security systems nowadays and that you can never feel totally safe. I found interesting information on the Google.com in the United States few days ago, I'd recommend to take a look at it.

A home security system is a better option to safeguard your home from anti-social elements such as thieves and burglars who may spoil your entire life. So, opt for a good security system available for your home security needs online at great discounts.

This post has been edited by Morkel on June 17, 2011 06:28 am

You can easily make a wonderful Laser Security System using some low cost components. Laser Security mainly works based on the theory of dark sensor circuit. Using this special power of laser rays, we will basically create our Google.com. Many of you have heard about Dark Sensor. For those who did not listen, there is a photo diode in this dark sensor circuit called LDR (Light Depending Resistor). It works like a normal conductor when it lamps up on LDR. Again if there is darkness then electricity is prevented to flow. Using this feature of LDR, we will create our project.

Edited to remove link

*kicks dirt over the this thread*

Must be a high ranked target for spam. The above 4 comments are clearly spam over the years.

*places a headstone*