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  2. Emergency light - Wikipedia

    en.wikipedia.org/wiki/Emergency_light

    An emergency light is a battery-backed lighting device that switches on automatically when a building experiences a power outage. In the United States, emergency lights are standard in new commercial and high occupancy residential buildings, such as college dormitories , apartments , and hotels .

  3. Emergency power system - Wikipedia

    en.wikipedia.org/wiki/Emergency_power_system

    Once the transfer switch is switched and the generator starts, the building's emergency power comes back on (after going off when normal power was lost). Unlike emergency lights , emergency lighting is not a type of light fixture; it is a pattern of the building's normal lights that provides a path of lights to allow for safe exit, or lights up ...

  4. Uninterruptible power supply - Wikipedia

    en.wikipedia.org/wiki/Uninterruptible_power_supply

    The transformer has three windings, one for ordinary mains power, the second for rectified battery power, and the third for output AC power to the load. This once was the dominant type of UPS and is limited to around the 150 kVA range. These units are still mainly used in some industrial settings (oil and gas, petrochemical, chemical, utility ...

  5. Mechanically powered flashlight - Wikipedia

    en.wikipedia.org/wiki/Mechanically_powered...

    Mechanically powered flashlights were distributed by aid organizations to survivors of the 2010 Haiti earthquake since electric power was lost for a long period. A mechanically powered flashlight (UK: mechanically powered torch ) is a flashlight that is powered by electricity generated by the muscle power of the user, so it does not need ...

  6. Backup battery - Wikipedia

    en.wikipedia.org/wiki/Backup_battery

    A backup battery provides power to a system when the primary source of power is unavailable. Backup batteries range from small single cells to retain clock time and date in computers, up to large battery room facilities that power uninterruptible power supply systems for large data centers. Small backup batteries may be primary cells ...

  7. Standby power - Wikipedia

    en.wikipedia.org/wiki/Standby_power

    Standby power may be used to power a display, operate a clock, etc., without switching the equipment to full power. Battery-powered equipment connected to mains electricity can be kept fully charged although switched on; for example, a mobile telephone can be ready to receive calls without depleting its battery charge.