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Data communication apparatus coupled to two telephone lines

  • US 5,056,133 A
  • Filed: 07/24/1989
  • Issued: 10/08/1991
  • Est. Priority Date: 08/05/1988
  • Status: Expired due to Term
First Claim
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1. A data communication apparatus which is coupled to two telephone lines, said data communication apparatus comprising:

  • a single telephone circuit coupled to the two telephone lines for making a telephone call;

    call detecting means coupled to the two telephone lines for independently detecting a call received from the two telephone lines and for outputting a call detection signal indicative of a telephone line which receives the call;

    modem means for transmitting and receiving data for making a data communications;

    switching means coupled to said telephone circuit and said modem means for coupling a selected one of said telephone circuit and said modem means to a selected one of the two telephone lines responsive to a switching signal;

    line protection means including a transformer means having primary and secondary slides wherein said primary side is coupled to said two telephone lines and wherein said secondary side is connected to said switching means and wherein said telephone circuit is provided on said secondary side of said line protection means and wherein said telephone circuit receives current from a predetermined current source means; and

    control means for controlling said switching means by generating the switching signal responsive to the called detection signal received from said call detecting means.

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