摘要 |
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.
|