Device for switching between IP phone and normal PSTN phone

The utility model discloses a device used for switching between an IP phone and a normal PSTN phone, which is characterized in that the device comprises an external line interface, a telephone interface, a switch/resume circuit, an isolating circuit, an audio interface, a power source circuit and a microprocessor. The external circuit interface, the telephone interface and the isolating circuit are respectively connected with the switch/resume circuit; the audio interface is connected with the isolating circuit; and the power source circuit is connected with the external line interface. The device overcomes the disadvantage of high cost of the two-module phone, realizes the switching between the IP phone and the normal PSTN phone and enables a user to make phone calls in the most economic and convenient way.