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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. Light-emitting diode physics - Wikipedia

    en.wikipedia.org/wiki/Light-emitting_diode_physics

    A LED is a long-lived light source, but certain mechanisms can cause slow loss of efficiency of the device or sudden failure. The wavelength of the light emitted is a function of the band gap of the semiconductor material used; materials such as gallium arsenide , and others , with various trace doping elements , are used to produce different ...

  4. Light-emitting diode - Wikipedia

    en.wikipedia.org/wiki/Light-emitting_diode

    Switch on time: LEDs light up extremely quickly. A typical red indicator LED achieves full brightness in under a microsecond. [69] LEDs used in communications devices can have even faster response times. Focus: The solid package of the LED can be designed to focus its light. Incandescent and fluorescent sources often require an external ...

  5. LED circuit - Wikipedia

    en.wikipedia.org/wiki/LED_circuit

    Simple LED (Light Emitting Diode) circuit diagram. In electronics, an LED circuit or LED driver is an electrical circuit used to power a light-emitting diode (LED). The circuit must provide sufficient current to light the LED at the required brightness, but must limit the current to prevent damaging the LED.

  6. Twilight switch - Wikipedia

    en.wikipedia.org/wiki/Twilight_switch

    A twilight switch is an electronic component that allows the automatic activation of a lighting circuit when natural light drops in a given environment. Among a large number of uses, the most common is to enable automatic lighting of streets, roads, highways, roads, gardens, courtyards, etc., when sunlight drops below a certain level (e.g.: a ...

  7. 40 of the very best gifts for new dads (that aren't for the baby)

    www.aol.com/lifestyle/best-gifts-for-new-dads...

    LED Neck Light. $18 at Amazon. The Milk Bar Sampler. ... It includes an LED screen and is water-resistant, too. $21 at Walmart. ... Use one dial to switch between Bluetooth, AM or FM, another to ...

  8. AOL Mail

    mail.aol.com

    Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!

  9. Flashlight - Wikipedia

    en.wikipedia.org/wiki/Flashlight

    A set of modern LED flashlights. A flashlight or electric torch (Commonwealth English), usually shortened to torch, is a portable hand-held electric lamp.Formerly, the light source typically was a miniature incandescent light bulb, but these have been displaced by light-emitting diodes (LEDs) since the early 2000s.