A: Lumen is amount of light emitted from light source. According to Wikipedia, “If a light source emits one candela of luminous intensity into a solid angle of one steradian, the total luminous flux emitted into that solid angle is one lumen. Alternatively, an isotropic one-candela light source emits a total luminous flux of exactly [...]
EVERYONE! Architects and lighting designers are specifying entire lighting packages in their new designs. Contractors are using them in everything from custom kitchens to retail stores. Many homeowners are replacing their incandescents with LED bulbs. LED lighting can replace every instance of old lighting technology, as well create entirely new lighting applications due to its [...]
In the past, we have generally referred to the brightness of a bulb in terms of its wattage, or the amount of power that the bulb uses (or energy it consumes). Because of the disparity between incandescent and LED technologies, we have to change our language a bit in order to account for progress. When [...]
There are quite a few advantages to using LEDs. Generally they are heatless, use 90% less energy, and last ten years. They are also smaller and do not contain any dangerous chemicals like mercury. They can readily be put in places that have always been too small or out-of-the-way for many incandescent lights, as well [...]
Yes. The E26 is the standard 120 Volt American base. The E27 is the European variant and is rated at 220 Volts. E26 is 26 mm and the E27 is 27 mm diameter. However, an E26 bulb can fit in E27 base and an E27 bulb can fit in E26 base without problem. The sockets [...]
LED lighting has been around for many years and is just now really coming into its own. For years, the Light Emitting Diode was simply used as an indicator or display light in various small-scale applications. Think of those old Texas Instruments calculators, or your blinking VCR light. LED is a solid-state technology. This means [...]
Since high power LEDs are more and more used in general lighting there is an increasing demand for off-line power supplies to drive these. Due to the VI characteristic of LED such a power supply must have a constant current output. The following article describes a PSU based on a Fairchild Power Switch (FPS™) that [...]
The application field of Solid state lighting, in the form of light emitting diodes (LEDs) has changed from traditional indicator functions to illuminator applications. With traditional light sources such as incandescent lighting, much of the energy required to generate visible light is dissipated as heat in the radiant beam of light. LED light sources do [...]
The most common way for LEDs (and diode lasers) to fail is the gradual lowering of light output and loss of efficiency. However, sudden failures can occur as well.
The mechanism of degradation of the active region, where the radiative recombination occurs, involves nucleation and growth of dislocations; this requires a presence of an existing defect [...]
If the emitting layer material of an LED is an organic compound, it is known as an Organic Light Emitting Diode (OLED). To function as a semiconductor, the organic emitting material must have conjugated pi bonds. The emitting material can be a small organic molecule in a crystalline phase, or a polymer. Polymer materials can [...]