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Coded acoustic alarm transmitter/receiver system

  • US 4,602,357 A
  • Filed: 04/11/1983
  • Issued: 07/22/1986
  • Est. Priority Date: 02/12/1982
  • Status: Expired due to Term
First Claim
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1. A personal acoustic alarm unit having means for providing an audible alarm signal in the audio range comprising a first transmitter means including a first signal generating means for simultaneously generating a plurality of individual sonic signals in the audio frequency range, each such audio range sonic signal having an audio frequency which differs from that of the remaining audio range sonic signals, first code generator means connected to receive at least one of said individual audio range sonic signals and operating to apply a unique code thereto, and means for transmitting said audio range sonic signals simultaneously as an audible alarm signal;

  • andmeans for providing a silent alarm signal outside of the audio range comprising a second transmitter means including a second signal generating means for simultaneously producing a plurality of individual sonic signals in the inaudible frequency range, each such inaudible range sonic signal having an audio frequency that differs from that of the remaining inaudible range sonic signals, second code generating means connected to receive at least one of said individual inaudible range sonic signals and operating to apply a unique code thereto, and second means for transmitting said inaudible range sonic signals simultaneously as a silent alarm signal; and

    actuating means for initiating operation of said first and second signal generating means.

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