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Alarm system prior to firedoor drop

  • US 4,785,293 A
  • Filed: 12/05/1985
  • Issued: 11/15/1988
  • Est. Priority Date: 12/05/1985
  • Status: Expired due to Fees
First Claim
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1. A warning system, having a power supply, for generating a warning signal in response to either of two events, detection of smoke by a smoke detector or failure of external power supply to the system, comprisingcontrol means connected to an element to which power is supplied and being responsive to such element when power is not supplied thereto for generating a first control signal,a first timer means connected to said element and being responsive thereto for generating a second control signal at the end of a first delay interval,a second timer means connected to said first timer means and being responsive to said second control signal for generating a series of reoccurring control pulses, andsignal means connected to said second timer means and being responsive to said control pulses for generating a series of warning signals.

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