Welcome to this page on how to wire your DTMF decoder to your lights in your home with the help of a Cable Tracer.


1). How the circuit works when the light switch on the wall is pushed down the light comes on as it is allowing current to flow into the light, but when the light is switched off this cuts the flow of current.

2) .This simple modification allows any DTMF Decoder to by pass the main on/off switch and turn the relay on making the same contact but allowing the current to flow with the help of the relay to the lamp.

3). If you send your DTMF Decoder a command to send power to the relay and the light is off the contacts on the relay will close this is making a short cut for the current to flow in to the lamp and will switch it on or off by Global remote control. 

4). Then if you what to turn your lights back on you must send the DTMF decoder the command to cut the power to the relay and the wall switch will work like normal.

5). Now if you are working with mains voltages then you must be very careful and switch all the switches on the fuse box or Circuit Breaker box to off and the main switch to off as well.

Now we will look at how to find the right cable for your light and switch using a cheap tool called a cable tracer.

MASTECH MS6812 Network Cable Tester Wire Line Tracker Phone Telephone Tracer UK

Buy a Cable tracer from sites like Ebay here

7). Now how to use the Cable Tracer first Unscrew the screws on the light wall socket If you have a single gang light switch then you will see 3 wires input earth output connect the red wire to the Com Terminal of the wires and connect the black clip to the earth/ground wire.

8).  Now as you go around touching the cables you will or may not hear a tone you are listening for the highest pitch tone this will be the right one as it is the strongest signal so the Signal injector will be connected to this wire.

9). The good thing about using a cable tracer is it speeds it all up and detects the right cable remember, No mains must be switched on when using the tracer.

10). Now if you know the location of the cable then touch the out side of the cable with the probe if no sound is detected then that is not the cable you need only when you detect the high pitch tone is then right cable.

 In the photo below you can see how I connected my own Cable Tracer to one of my wires in side the wall switch.

Now when you have connected your injector to one of the wires go in to your loft and touch the out side casing of the mains wires it is only when you hit the right cable you will get the high pitch tone.

This photo is showing me touching the out side cable to see if it is the right one or not.

Now if you would like to see me detecting the right cable with my Cable tracer then visit my You tube page here.




Please note if you have any problems then please do e-mail me and I will do what I can to help: Anthony@anthony-dacko.net

My Electronics Page here.