How to Connect Two Phones at Home for an Intercom or for Children Amusement

I was inspired by two Instructables to create an intercom at home.

• Old Phone Intercom Device
• Build your own intercom or walkie talkie out of two old cordless phones

The only difference in mine was using a dead laptop power supply to power the telephones instead of batteries. Like it is appreciated in the picture I drilled a hole on a plastic electrical box and pushed the wire through. I made a knot to avoid someone yanking the wires of the phone jack by accident.

The 20 volt transformer came with just one white colored wire and another braided wire around this single wire. I assumed that the white wire was the "live" or negative charged wire and the braided uninsulated wire was the "neutral" or positive wire. I was pleased to discovered that I was correct.

With a crimper I connected all the wires.

• Live or negative (the red wire on the picture) to A jack green
• Neutral or positive (the black and red wire) to B jack red
• Connect a resistor between A red and B green

After I connected all the wires I enclosed the project. Soon my children were talking to each other using this "intercom".