City Pedia Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Light-emitting diode physics - Wikipedia

    en.wikipedia.org/wiki/Light-emitting_diode_physics

    Light-emitting diodes (LEDs) produce light (or infrared radiation) by the recombination of electrons and electron holes in a semiconductor, a process called "electroluminescence". The wavelength of the light produced depends on the energy band gap of the semiconductors used. Since these materials have a high index of refraction, [ note 1 ...

  3. Light-emitting diode - Wikipedia

    en.wikipedia.org/wiki/Light-emitting_diode

    Efficiency: LEDs emit more lumens per watt than incandescent light bulbs. [169] The efficiency of LED lighting fixtures is not affected by shape and size, unlike fluorescent light bulbs or tubes. Size: LEDs can be very small (smaller than 2 mm 2 [170]) and are easily attached to printed circuit boards.

  4. 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. The voltage drop across a lit LED is ...

  5. Take 20% Off Raycon Earbuds, Headphones and Speakers ... - AOL

    www.aol.com/entertainment/20-off-raycon-earbuds...

    These Basic Earbuds. The Work Earbuds Classic. Raycon. For everyday wear that’s easy to take in and out, these buds are the perfect pick! See it! Get The Work Earbuds Classic (originally $120 ...

  6. Electromagnetic spectrum - Wikipedia

    en.wikipedia.org/wiki/Electromagnetic_spectrum

    The electromagnetic spectrum is the full range of electromagnetic radiation, organized by frequency or wavelength. The spectrum is divided into separate bands, with different names for the electromagnetic waves within each band. From low to high frequency these are: radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and ...

  7. Active noise control - Wikipedia

    en.wikipedia.org/wiki/Active_noise_control

    Noise control is an active or passive means of reducing sound emissions, often for personal comfort, environmental considerations, or legal compliance. Active noise control is sound reduction using a power source. Passive noise control is sound reduction by noise-isolating materials such as insulation, sound-absorbing tiles, or a muffler rather ...

  8. Phase-out of incandescent light bulbs - Wikipedia

    en.wikipedia.org/wiki/Phase-out_of_incandescent...

    60 W incandescent light bulb with energy efficiency class E Equivalent 42 W halogen incandescent light bulb with efficiency class C Compact fluorescent lamp LED lamp. Various governments have passed legislation to phase out manufacturing or importation of incandescent light bulbs for general lighting in favor of more energy-efficient alternatives.

  9. Foucault's measurements of the speed of light - Wikipedia

    en.wikipedia.org/wiki/Foucault's_measurements_of...

    In 1850, Léon Foucault measured the relative speeds of light in air and water. The experiment was proposed by Arago, who wrote, Two radiating points placed one near the other and on the same vertical, shine instantly in front of a rotating mirror. The rays from the upper point reach this mirror only by passing through a tube filled with water ...