How to Create Your Own Home Intercom System How to Create Your Own Home Intercom System

What You'll Need
In-line coupler
9 volt battery connector
9 volt battery
Wire cutter
Wire stripper
Dremel tool
Soldering gun
300 OHM resistor
Electrical tape
2 telephones
2 CAT 1 cables (telephone cords)
Ring-tone generator

Shouting around the house to find a loved one can get tedious and frustrating but that can stop with a home intercom system. There are plenty of home intercom systems that you can purchase that can cost a lot of money. Everyone has extra telephones lying around (or you can purchase cheap ones from a department store) that can be used to build your own home intercom system. The article that follows will show you how to turn two old telephone units into a home intercom system. The process is rather simple and very inexpensive.

Step 1 - Exposing the In-line Coupler

Open the in-line couple by applying pressure to the center of the plastic casing. With enough pressure the couple will snap open to expose the internal components. If you are having trouble opening it then you may try using a screwdriver with a flat head or using the side of a table or desk. Once the couple is open there will be 4 colored wires: yellow, red, green and black. The only wires in the couple you want to worry about are the red and green wires. You can cut and remove the other two wires or leave them intact. They have no bearing on the home intercom system you are making.

Step 2 - Working with the Wires

The bread and butter of the home intercom system are the wires inside the in-line coupler. Snip the red wire as close to center as you can so you will essentially have two red wires. Strip both ends of the cut red wire. Solder one of the red wires to the resistor and the other end of the resistor to the 9 volt battery connector. Now, solder the remaining end of the 9 volt battery connector to the other red wire. Remove any excess wire as this should be fully contained inside the plastic casing.

Step 3 - Testing the Home Intercom System

With the soldering complete you can now test your new home intercom system. Plug a phone into each side of the coupler then install a 9 volt battery. Pick up the phones and start talking to test the system. You can use two cordless phones if you like but each phone will need to be fully charged in order to work. Once you are sure the home intercom system will work you can install the purchased ring-tone generator. Follow the instructions for the generators as they are more complicated.

Step 4 - Finishing Up

Wrap the exposed wires with a piece of electrical tape. Use the dremel to carve out a small notch on each side of the coupler where they snap together. Carefully close the coupler putting the wires for the 9 volt battery connector between the notches. You can use telephone cable as long as you need it to be in order for both telephones to be in separate areas.

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