[Brad] was asked by his Sister to design a motion-based alarm that would help her catch ... that is only active at night and can be battery-powered. What he came up with is a light-sensitive ...

That dip didn’t put anything out of commission, but clocks that ... that most wall-powered clocks are. In thinking about this I wondered how the clock could have a battery-backup if it is ...

The First Alert SM500V Interconnected Battery-Operated Smoke Alarm with Voice ... Items like the Lifetone HL Bedside Fire Alarm and Clock and the SafeAwake Smoke Alarm with Bed Shaker pick up ...