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Portable intrusion alarm

  • US 4,319,228 A
  • Filed: 05/28/1980
  • Issued: 03/09/1982
  • Est. Priority Date: 12/20/1978
  • Status: Expired due to Term
First Claim
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1. A portable intrusion alarm comprising:

  • an enclosure having an electrical bus contained therein for interconnecting various circuit components,a power line normally connected to the bus for supplying AC voltage to the bus in said enclosure,a DC storage battery,an inverter for producing AC from said battery,a power control relay for connecting said inverter to the electrical bus upon AC power line failure,means for initializing said power control relay to utilize power from the AC power line,motion detecting means connected to said bus and operating a first relay,magnetic door switch means connected to said bus and operating a second relay,a plurality of alarm devices located external to said enclosure but connected to one side of said bus,each of said first and second relays having a set of normally open contacts, said sets being connected in parallel with each other to the other side of said bus and, when energized, connecting the other side of the bus to said alarm devices,whereby any one of the first and second relays can energize the alarm devices by operation of its associated relay contacts.

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