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Alarm system

  • US 4,195,288 A
  • Filed: 02/21/1978
  • Issued: 03/25/1980
  • Est. Priority Date: 02/21/1978
  • Status: Expired due to Term
First Claim
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1. An alarm device comprising:

  • a protective loop, said loop including a coded module and a pair of conductors joined to said coded module, said conductors connected to normally opened and normally closed sensing means, a multi-functional alarm control means connected to said conductors, said multi-functional alarm control means containing an analyzer circuit for discriminating between normally open or normally closed violations and having high voltage and radio frequency input protection, said coded module and said analyzer circuit cooperating to prevent defeat of said sensing means.

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