Smoke detector with delayed alarm after change to stand-by power
AssigneeGeneral Electric Company
InventorMorris J. Kornblit
Life of this patent
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Abstract
The smoke detector is powered by standard AC current and a stand-by power source consisting of rechargeable batteries. A detector is provided for detecting the loss or failure of AC power, and the shift to the stand-by power source. The power loss detector initiates a time delay after which the smoke detector signal alarm is energized to alert the user about the loss of AC power. If AC power is restored before the time delay interval, the signal is not energized since the user need not be alerted. If the alarm is energized to alert the user of a loss of AC power, a manual reset switch may be used to terminate the alarm. If the manual reset switch is not used, the alarm is terminated automatically upon the restoration of AC power.
Claims11
A smoke detector apparatus including:
- means for receiving energizing power from a first power source,
- a stand-by power source automatically operable to supply power to said apparatus upon failure of said first power source,
- a first switching means connected to said means for receiving energizing power and operable upon failure of the first power source,
- a time delay means connected to be triggered on by said first switching means upon failure of said first power source,
- a second switching means connected to be triggered on by said time delay means at the end of the time delay period,
- a signal means connected for energization by said second switching means at the end of the time delay period, and
- reset means connected to said means for receiving energizing power and operable upon reestablishment of power from the first power source prior to the timing out of said time delay means to reset said time delay means to prevent the energization of said signal means.
Dependencies are inferred from the claim text.