Patent ID: RE43706

Claim:
A fallback telecommunications device comprising: a microprocessor utilized to perform a predetermined operation and processing of a predetermined input signal and then output a corresponding signal; at least one relay circuit having an amplifier circuit and a relay, an input terminal of said amplifier circuit being connected to said microprocessor and an output terminal of said amplifier circuit being connected to the signal input terminal of said relay; a terminal at a first side of said relay being connected to a telephone line tip/ring terminal and a terminal at a second side of said relay being connected to a Public Services Telephone Network (PSTN) tip and ring terminals of said microprocessor; wherein the telephone line tip and ring terminals is connected to the PSTN tip and ring terminals, wherein when the said relay is controlled into operation, the connection of the tip and ring terminals is switched to Voice Over Internet Protocol (VOIP) tip and ring terminals of said microprocessor; an off-hook detection circuit connected to said PSTN tip and ring terminals and a ring detection terminal of said microprocessor that is utilized to ascertain telephone off-hook status and send a signal to said ring detection terminal; and a dummy load circuit connected to the tip terminal and the ring terminal of said PSTN for generating a simulated off-hook signals to transmit to said PSTN when the VOIP tip and ring terminals are in use, wherein said dummy load circuit consists of a full-wave bridge rectifier circuit and a relay; one end of said full-wave bridge rectifier circuit is connected to the ring terminal of said PSTN and another end of said full-wave bridge rectifier circuit is connected to a shunt terminal at one side of said relay, a shunt terminal at another side of said relay is connected to the PSTN tip terminal and the signal input terminal of said relay is connected to said microprocessor which controls continuity between said ring and tip terminals.