Simple DC signalling can be achieved on a telecommunications line in a similar way to phantom powering of microphones. A switch connected to the transformer centre-tap at one end of the line can operate a similarly connected relay at the other end. The return path is through the ground connection. This arrangement can be used for remotely controlling equipment.
Simple DC signalling can be achieved on a telecommunications line in a similar way to phantom powering of microphones. A switch connected to! the transformer ce?ntre-tap at one end of the line can operate a similarly connected relay at the other end. The return path is through the ground conn.e,ction This arrangement can be used for remotely controlling !equipment.