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Smoke detector using telephone link

  • US 5,283,816 A
  • Filed: 01/15/1991
  • Issued: 02/01/1994
  • Est. Priority Date: 01/15/1991
  • Status: Expired due to Fees
First Claim
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1. An apparatus comprising:

  • sensor means for detecting an alarm condition;

    a telephone dialer circuit and means for facilitating coupling of said telephone dialer circuit to a telephone line, said telephone dialer circuit having a plurality of keypad matrix inputs;

    means coupled to said matrix inputs of said dialer circuit and responsive to detection of said alarm condition by said sensor means for simulating a manual key press at said matrix inputs to said dialer circuit, said dialer circuit including means responsive to said simulated manual key press for automatically dialing a telephone number;

    means for generating an alarm signal at an audible frequency in response to detection of said alarm condition by said sensor means; and

    sound generating means responsive to said alarm signal for producing an audible sound at said audible frequency;

    said telephone dialer circuit including means for applying to the telephone line said alarm signal at said audible frequency after said automatic dialing of said telephone number;

    wherein said telephone dialer circuit includes means responsive to said automatic dialing for thereafter waiting a predetermined period of time while said alarm signal is applied to said telephone line, for thereafter interrupting said coupling of said telephone dialer circuit to said telephone line, for thereafter waiting a further predetermined period of time, for thereafter causing said telephone dialer circuit to again effect said automatic dialing, and for thereafter applying to the telephone line said alarm signal at said audible frequency, said audible frequency being applied to said telephone line regardless of whether a remote end of said telephone line is answered; and

    wherein said telephone dialer circuit includes memory means for storing a first telephone number and includes manually settable switch means for specifying a second telephone number and for selecting one of said first and second telephone numbers, said telephone dialer circuit being responsive to said simulated manual key press for automatically dialing said selected one of said first and second telephone numbers.

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