Welcome to this very simple Smoke Alarm modification that can act like a security deterrent.
Now if you would like to hear the sound it gives off as a fake security deterrent, Then see my You Tube page here.
1). I designed or modified this old smoke alarm that was passed its use by date of 2012, I was just going to bin it but then came up with the idea of seeing how low the voltage was when it started to bleep.
We all know most criminals like no security systems to be in place as it makes there job that much easer, This simple design gives off a bleep sound this acts like a real security warning system is in place. I know most criminals would find it better to move on and look for less secure area away from any type of security deterrent.
2). I connected my regulated power supply to the battery clips and went down low to see what the voltage was when it started to bleep, I found this out when the voltage hit 3.3 or 3 volts the smoke alarm started to bleep.
3). I felt this would make a very simple and cheap fake security deterrent with many uses from in side a motor vehicle, Garden Shed, Boat, home by a back window, or any where you may find a criminal may want to gain access.
4). Now as the design is very simple you don't need a back ground in electronics for this design as it is very simple to follow but if you do have a back ground in electronics then we will look at building a regulator for 3.3 volts.
5). Now the items you need to build this simple project is one old smoke alarm any store or look on ebay for the cheapest.
6). One 2 AA battery holder to hold two AA batteries in it with PP3 Clip see photo above order it from here or ebay.
7). 2 PP3 Battery Clips Heavy Duty PP3 Battery
Clip Click here.
8). Now in the above photo you can see how to connect the two PP3 battery clips together use some PVC Electrical tape and rap it around the two contacts.
9). When you have done this put your two AA batteries in the holders and the Smoke Alarm should start to bleep on and off depending on the smoke alarm some models may only bleep every 30 Seconds or so please keep that in mind.
10). Now if you have a back ground in Electronics and want to Build your self a regulator then my design below should work fine.
Now if you have any problems please do e-mail me at firstname.lastname@example.org