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Electronic alarm apparatus

  • US 4,792,796 A
  • Filed: 02/10/1987
  • Issued: 12/20/1988
  • Est. Priority Date: 11/20/1986
  • Status: Expired due to Fees
First Claim
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1. In apparatus for monitoring the presence or absence of a common coded radio frequency signal within a given area, monitoring means including electronic circuit means for receiving said coded radio frequency signal, and at least one transmitting means associated with said monitoring means including electronic circuit means for producing and transmitting said coded radio frequency signal periodically in predetermined spaced apart time intervals;

  • said monitoring means including;

    electronic circuit means for programming said transmitting means to produce and transmit said coded radio frequency signal in said predetermined spaced apart time intervals;

    electronic circuit means, including a logic timing circuit, for identifying said coded radio frequency signal received with said associated transmitting means; and

    electronic circuit means and alarm means for indicating failure of reception of said common coded radio frequency signal.

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