About LED Lighting
An LED lamp is a light-emitting diode (LED) product which is assembled into a lamp (or light bulb) for use in lighting fixtures.
LED lamps have a lifespan and electrical efficiency which are several times longer than incandescent lamps, and significantly more efficient than most fluorescent lamps, with some chips able to emit more than 300 lumens per watt (as claimed by Cree and some other LED manufacturers).
The LED lamp market is projected to grow by more than twelve-fold over the next decade, from $2 billion in the beginning of 2014 to $25 billion in 2023, a compound annual growth rate (CAGR) of 25%. As of 2016, LEDs use only about 10% of the energy an incandescent lamp requires.
Like incandescent lamps and unlike most fluorescent lamps (e.g. tubes and compact fluorescent lamps or CFLs), LEDs come to full brightness without need for a warm-up time; the life of fluorescent lighting is also reduced by frequent switching on and off.
The initial cost of LED is usually higher. Degradation of LED dye and packaging materials reduces light output to some extent over time.
Some LED lamps are made to be a directly compatible drop-in replacement for incandescent or fluorescent lamps.
An LED lamp packaging may show the lumen output, power consumption in watts, color temperature in kelvins or description (e.g. “warm white”), operating temperature range, and sometimes the equivalent wattage of an incandescent lamp of similar luminous output.
Most LEDs do not emit light in all directions, and their directional characteristics affect the design of lamps, although omni-directional lamps which radiate light over a 360° angle are becoming more common.
The light output of a single LED is less than that of incandescent and compact fluorescent lamps; in most applications multiple LEDs are used to form a lamp, although high-power versions are becoming available.
LED chips need controlled direct current (DC) electrical power; an appropriate circuit which is normally called as LED driver is required to convert alternating current from the supply to the regulated voltage direct current used by the LEDs.
LEDs are adversely affected by high temperature, so LED lamps typically include heat dissipation elements such as heat sinks and cooling fins.
LED drivers is the essential component of LED lamp or luminaire. Good LED drivers can guarantee a long life time of LED systems and provide additional features such as dimming and control.
The LED drivers can be put inside lamp or luminaire which is called built-in type or be put outside which is called independent type.
According to different applications, different types of LED drivers need to be applied, for example outdoor driver for street light, indoor point driver for down light, indoor linear driver for panel light.
In 2016, General Electric announced the phase out of CFL production. LED prices had dropped steadily, falling well below $5 for a basic bulb in 2015. As a result, customers had been migrating toward LEDs.
CFLs were also having difficulty qualifying for the Energy Star rating under newer regulations.
