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Wireless alarm system

  • US 4,232,308 A
  • Filed: 06/21/1979
  • Issued: 11/04/1980
  • Est. Priority Date: 06/21/1979
  • Status: Expired due to Term
First Claim
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1. A wireless alarm system comprising:

  • a transmitter for radiating a radio frequency signal in response to and during the application of electrical power to the transmitter;

    a battery for providing electrical power to the transmitter;

    transmitter timer circuitry for intermittently applying to the transmitter electrical power provided by the battery, the timer circuitry being electrically series-inserted between the transmitter and the battery;

    switching means responsive to a predetermined alarm condition detected at the general site of the transmitter, activation of the switching means initiating operation of the transmitter timer circuitry, the operating timer circuitry intermittently applying power to the transmitter at regular predetermined intervals while the switching means remains activated, the transmitter intermittently radiating the signal in response to the intermittent application of power to the transmitter; and

    a radio frequency receiver for reception of the radiated signal, the radio frequency receiver activating at least one alarm indicator in response to reception of the radiated signal, the duration of alarm indicator activation being substantially greater than the duration of the radio frequency signal radiated by the transmitter during the application of power to the transmitter by the timer circuitry.

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