Welcome to this page on how to modify a old cell phone to work with your security system all you need is a cell phone with one touch dialing or speed dialing on it and a cheap relay to make it work.

On the flash video above you can see the modified mobile phone call my phone with the help of a simple circuit and power from my security system

The photo below is of a modified cell phone that I fixed to my Security System also the small electronic circuit is inside the Main box. Now Just below you can see my timer unit this is to charge the cell phone up so I always have a fully charged cell phone battery in case the alarm is activated.

The simple modification turns a simple alarm system into an advanced system for very little money with no monitoring fees you just have to put some credit on the phone just incase the security system is activated it needs credit to make the call that is it.

In the photo below you can see the little green circuit inside my main alarm unit. The holder for the cell phone is just a simple holder you would use in your car to hold the cell phone on the dash board.

Now if you want to see a bigger photo click on the one below.

How to build your own follow the information below.

Here is a photo of the finished unit above I have used a PP3 Battery clip to test the unit if it works like the video above then you have done it right .

1). I set this page up to help people on a low budget add a monitoring system to there security system. 

2). I will cover the items you will need to build a modified cell phone to work with your security system I will cover the monitoring system for homes or offices.

3). Things you will need one old cell phone I will use a Nokia 3310 for this any cell phone with one touch or speed dialing will work try ebay for a old Nokia 3310 cell phone as there seems to be a lot of them for sale cheap on ebay Click here

Nokia 3310 - SIM Free (various colours)

4). You will all so need a cell phone opening kit see photo below or you may get one on ebay cheap from time to time. The kit below Contains useful tools designed to assist in the opening and repair of mobile phones especially suited to Nokia and Ericsson and Motorola phones but equally useful when attempting repair on other models click here.


5). You will all so need solder and a soldering iron I used the Maplin Gas Torch Combination Kit see photo below. You can use any soldering iron just get a small tip this kit from Maplin click here or your local electronic shops or stores.

Below a very useful relay kit for this project.

7). If you want to make a professional looking unit then you can order a simple Relay Kit like the one above Click here.

8). Now you have the equipment you need to modify a cell phone you can move on to the next part of the set up Click here.