Modem interface device

An apparatus for selectively coupling a telecommunications device having a pair of communication lines and a telephone handset having a pair of handset microphone lines and a pair of handset speaker lines to a telephone base at corresponding pairs of base microphone and speaker lines, said apparatus comprising:

• mode switch means selectable between a voice position and a data position for, when in said voice position, electrically coupling said handset microphone and speaker lines with said respective base microphone and speaker lines;
• converter means coupled to said switch means for electrically interfacing said communications lines with said base microphone and speaker lines, said mode switch means for when in said data position electrically coupling said communications lines, said base microphone lines and said base speaker lines to said converter means, said converter means for inductively coupling a first signal on said communications lines to said base microphone lines and for directly coupling a second signal on said base speaker lines to said communications lines, said converter means further for electrically isolating said base microphone lines from said base speaker lines.

A circuit for coupling a telecommunications device having a pair of communication lines and a telephone handset having a pair of handset microphone lines and a pair of handset speaker lines to a telephone base at corresponding pairs of microphone and speaker lines, said circuit comprising:

• first inductive means for, coupling to said pair of communications lines and said pair of base speaker lines, receiving a first signal upon said pair of base speaker lines, amplifying said first signal, and transmitting said amplified first signal upon said pair of communications lines;
• second inductive means for coupling to said pair of base microphone lines, said second inductive means electromagnetically coupled to said first inductive means, said first and second inductive means electrically isolating said pair of base speaker lines from said pair of base microphone lines, said first inductive means further for receiving a second signal on said communications lines and for electromagnetically coupling said second signal to said second inductive means, and said second inductive means for receiving said electromagnetically coupled second signal from said first inductive means and for transmitting said received electromagnetically coupled second signal upon said base microphone lines.

A circuit for coupling a telecommunications device, having a pair of communication lines, to a two-wire telephone line via a telephone set having a telephone handset and a a telephone base coupled by a pair of microphone lines and a pair of speaker lines, said circuit comprising:

• first and second inductive means electromagnetically coupled to one another, said first inductive means for coupling to said pair of speaker lines, for receiving a first signal upon said pair of speaker lines, and for electromagnetically coupling said first signal to said second inductive means, said second inductive means for, coupling to said pair of communications lines and said pair of microphone lines, receiving said electromagnetically coupled first signal, amplifying said electromagnetically coupled first signal, and transmitting said amplified first signal upon said pair of communications lines, and said second inductive means further for receiving a second
• signal on pair of said communications lines and coupling said second signal upon said pair of base microphone lines.