Patent ID: 7929517

Claim:
A telephone detection and switching adapter, comprising: a switching circuit receiving a first control signal; a first telephone port adapted to couple to a wired communication channel; a second telephone port adapted to couple to a telephone, wherein the first and second telephone ports are coupled to the switching circuit and wherein the switching circuit is configured to connect the first and second telephone ports in response to the first control signal; a third port adapted as an Internet connection, wherein the second telephone port and the third port are coupled together to enable the telephone to make calls through the Internet connection; a VoIP protocol module coupled between the third port and the switching circuit, wherein the VoIP protocol module automatically outputs the first control signal if the Internet connection is down; and a voltage comparator coupled to the first telephone port that compares an external voltage with a reference voltage to determine whether sufficient power is available for making a VoIP call, wherein the voltage comparator and the switching circuit receives power from the wired communication channel through the first telephone port.